• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.1
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• pp.95-101
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• 2018

The epidermis which is stratified by epithelial tissue renewal based on keratinocyte differentiation protects the organism from various environmental insults by forming a physical barrier. Autophagy is a mechanism which mediates lysosomal delivery and degradation of protein aggregates, damaged organelles and intracellular microorganisms. Recent reports have shown that autophagy has critical roles for proper terminal differentiation to stratum corneum via removing metabolic organelles and nuclei. However, whether increasing autophagy can activate epidermal differentiation is unknown. Here, we screened a library of natural single compounds and discovered that betaine specifically increased the LC3 positive cytosolic punctate vesicles and LC3-I to LC3-II conversion in HaCaT human keratinocyte cell line, indicating increased autophagy flux. mTOR pathway, which negatively regulates autophagy, was not affected by betaine treatment, suggesting betaine-induced autophagy through an mTOR-independent pathway. Betaine-induced autophagy was also observed in primary human keratinocyte and skin equivalent. Furthermore, epidermal thickness was increased in skin equivalent under betaine treatment. Overall, our finding suggests that betaine as a novel regulator of autophagy may induce epidermal turnover and improve the skin barrier abnormality of the aged epidermis.

• Analytical Science and Technology
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• v.31 no.5
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• pp.208-218
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• 2018

Autophagy is a cellular process whereby cytosolic materials or organelles are taken up in a double-membrane vesicle structure known as an autophagosome and transported into a lysosome for degradation. Although autophagy has been studied at the genetic, cellular, or biochemical level, systematic ultrastructural quantitative analysis of autophagosomes during the autophagy process by using transmission electron microscopy (TEM) has not yet been reported. In this study, we performed ultrastructural analysis of autophagosomes in wild-type (WT) mouse embryonic fibroblasts (MEFs) and autophagy essential gene (atg5) knockout (KO) MEFs. First, we performed ultrastructural analysis of autophagosomes in WT MEFs compared to atg5 KO MEFs in basal autophagy or starvation-induced autophagy. Although we observed phagopore, early, late autophagosomes, or autolysosomes in WT MEFs, atg5 KO MEFs had immature autophagosomes that showed incomplete closure. Upon starvation, late autophagosomes accumulated in WT MEFs while the number of immature autophagosomes significantly increased in atg5 KO MEF indicating that atg5 plays an important role in the maturation of autophagosomes. Next, we examined autophagosomes in the cell model expressing polyQ-expanded N-terminal fragment of huntingtin. Our TEM analysis indicates that the number of late autophagosomes was significantly increased in the cells expressing the mutant huntingtin, indicating that improving the fusion of autophagosome with lysosome may be effective to enhance autophagy for the treatment of Huntington's disease. Taken together, the results of our study indicate that ultrastructural and quantitative analysis of autophagosomes using TEM can be applied to various human cellular disease models, and that they will provide an important insight for cellular pathogenesis of human diseases associated with autophagy.

• Korean Journal of Plant Resources
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• v.36 no.4
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• pp.257-263
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• 2023

Autophagy contributes to enhancing the immune system (innate and adaptive immune system) against foreign pathogens. Autophagy of macrophages is used as a major indicator for developing vaccine adjuvants to increase the adaptive immune response. In this study, water extracts from Rosa acicularis leaves (RAL) increased the production of immunostimulatory mediators and phagocytic activity in RAW264.7 cells. RAL increased p62/SQSTM1 expression. Inhibition of TLR4, JNK, and PI3K/AKT blocked RAL-mediated increase of p62/SQSTM1. RAL activated JNK and PI3K/AKT signaling. RAL-mediated activations of JNK and PI3K/AKT signaling were reversed by TLR4 inhibition. Taken together, it is believed that RAL-mediated autophagy may be dependent on activating via TLR4-dependent activation of JNK and PI3K/AKT signaling in macrophages.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.222-227
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• 2018

Mycobacterium tuberculosis (MTB)-originated lipid antigen is presented on the antigen-presenting cell surface with CD1b. When monocyte-derived dendritic cells phagocytosed MTB H37Rv (Multiplicity of infection 10, infectivity: 46.89%), the CD1b expression level decreased slowly. Since this was just a live MTB-mediated phenomenon, it was not detected from heat-killed MTB or mycolic acid, which is a unique antigen of MTB. We confirmed that the phosphorylation of CD1b molecules using 2D electrophoresis with staining could phosphorylate and induce the presentation of the lipid antigen using the phagocytosis assay.

• Journal of the Korea Society for Simulation
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• v.22 no.3
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• pp.1-6
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• 2013

The ecosystem is the complex system consisting of various biotic and abiotic factors and the factors interact with each other in the hierarchical predator-prey relationship. Since the competitive relation spatiotemporally occurs, the initial state of population density and species distribution are likely to play an important role in the stability of the ecosystem. In the present study, we constructed a lattice model to simulate the three-trophic ecosystem (predatorprey- plant) and using the model, explored how the ecosystem stability is affected by the initial density. The size of lattice space was $L{\times}L$, (L=100) with periodic boundary condition. The initial density of the plant was arbitrarily set as the value of 0.2. The simulation result showed that predator and prey coexist when the density of predator is less than or equal to 0.4 and the density of prey is less than or equal to 0.5. On the other hand, when the predator density is more than or equal to 0.5 and the density of prey is more than or equal to 0.6, both of predator and prey were extinct. In addition, we found that the strong nonlinearity in the interaction between species was observed in the border area between the coexistence and extinction in the species density space.

• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.191-202
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• 2006

In addition to the removal of dying or dead lutein cells by phagocytosis in many species, macrophages exert both luteotropic effect during maturation period and luteolytic effect during degenerative period via mediating autocrine/paracrine actions of self-producing cytokines in the corpus luteum. In this experiment, immunohistochemical and transmission electron microscopic (TEM) studies were performed to observe the morphologic changes of luteal macrophages during luteolysis. A small number of macrophages and low immunoreactivity were present at the mature stage. The number of macrophages and immunoreactivity gradually increased along the advance of luteolysis. Two subtypes of macrophages could be observed through TEM observation. One type of macrophage located between the large lutein cells contained no lipid droplets in their cytoplasm at mature stage. The other type of macrophage located near the blood vessels contained many lipid droplets in their cytoplasm during luteolysis. Particularly, no phagocytic macrophages were observed, which suggested the macrophages in the porcine corpus luteum did not involve in the phagocytotic elimination of dying lutein cells.

• Applied Microscopy
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• v.30 no.2
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• pp.173-183
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• 2000

This study was designed to observe the ultrastructural localization of synoviocytes, which are concerned with the function of phagocytic synovial cells (type A synoviocytes, macrophage-like synoviocytes), in the knee joint of the human for CD14 and CD105 by cryo-immune-electron microscopic technique. The synovium were dissected and fixed for two hours (in 4% paraformaldehyde and 0.1% glutaraldehyde mixture), and were immerged in 2.3 M sucrose and 20% PVP solution. Finally, they were cut with the cryoultramicrotome and labelled with primary antibodies (monoclonal mouse anti-human CD14, monoclonal mouse anti-human CD105 (endoglin) and secondary (donkey anti-mouse IgG) tagged with 6 nm colloidal gold particles. The tissues were observed under transmission electron microscope. This study was resulted as follows. 1. In the synovium of the human knee joint, CD14+ cells were identified. These cells showed phagocytic synovial cell's features. In the phagocytic synoviocyte, the distributions of CD14 were marked in the cytoplasm, around vacuoles, and in cytoplasmic process, but not detected inside of vacuoles. 2. In the synovium of the human knee joint, CD105+ cells were identified. These cells were recognized endothelial cells and phagocytic synovial cells. In the phagocytic synovial cells, the distributions of CD105 (endoglin) were marked in cytoplasic process, around vacuoles, and in cell membrane, but not detected inside of vacuoles. On the basis of above findings, it is obvious that phagocytic synovial cells were marked at CD 14 and CD 105, and might be play the role of activated macrophages or phagocytes in the synovial membrane.

• Journal for History of Mathematics
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• v.25 no.1
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• pp.45-56
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• 2012

Mathematical biology has been recognized its importance recently and widely studied in the fields of mathematics, biology, medical sciences, and immunology. Mathematical ecology is an academic field that studies how populations of biological species change as times flows at specific locations in their habitats. It was the earliest form of the research field of mathematical biology and has been providing its basis. This article deals with various form of interactions between two biological species in a common habitat. Mathematical models of predator-prey type, competitive type, and simbiotic type are investigated.

• Journal for History of Mathematics
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• v.26 no.2_3
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• pp.197-210
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• 2013

The late 18C Malthus studied population growth for the first time, Verhulst the logistic model in 19C and, after that, the study of the predation competition between two species resulted in the appearance of Lotka-Volterra model and modified model supported by Gause's experiment with bacteria. Instable coexistence equilibrium being found, Solomon and Holling proposed functional and numerical response considering limited abilities of predator on prey, which applied to Lotka Volterra model. Nicholson and Baily, considering the predation between host and parasitoid in discrete time, made a model. In 20C there were developed various models of disease dynamics with the help of mathematics and real data and named SIS, SIR or SEIR on the basis of dynamical phenomena.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.437-442
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• 2015

This study, examined Chilocorus kuwanae for biological control of Saissetia coffeae. We measured basic developmental characteristics of C. kuwanae and its capability to prey on the second-instar larvae of S. coffeae by indoor breeding under the following conditions: $25^{\circ}C{\pm}2^{\circ}C$, humidity $70%{\pm}5%$, and day length 16L : 8D. The average daily consumption of the second-instar larvae of S. coffeae by C. kuwanae adults was approximately 77.5 larvae/day, which was significantly 2.8 and 2.9 times higher than consumption by Chrysoperla carnea and Cryptolaemus montrouzieri, respectively. During the nymphal period, C. kuwanae consumed a total of 659.0 second-instar larvae of S. coffeae. The interaction between C. kuwanae and the second-instar larvae of S. coffeae varied according to their densities, with the increase in C. kuwanae consumption rate noted to decelerate and gradually level off at the maximum, rsembling Holling's Type II functional response. Duration of egg to adult development varied from 21.1 days to nearly 27.9 days at temperatures of $25^{\circ}C{\pm}2^{\circ}C$. Hatchability, pupation rate, and adult emergence were greater than 72.3%, 77.8% and 83.3%, respectively.