• Title/Summary/Keyword: Biology of aging

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STUDIES ON THE VIRUSES OF RADISH MOSAIC

  • KIM, Woon-Soo
    • Journal of Plant Biology
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    • v.6 no.2
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    • pp.9-21
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    • 1963
  • A mosaic diseased radish collected from the suburb of Seoul, in November, 1961 was used for studing the host range, physical properteis, purificaitiion, insect transmission, and electron microscopy. A Japanese strain of radish mosaic(RPV) was also used with Korean strain of radish mosaic (KRMV) for a comparative study. The two viruses, KRMA and RPV, were identified by the difference in host range, insect transmission and electron microscopy. The KRMA was severely infective on tobacco and Nicotiana glutinosa, while on Gomphrena globsa was immune to the virus. RPV produces necrotic local lesions on Gomphrena globosa but did not infect tobacco and N. glutinosa. Among varieties of radish, Seoul, Akamaroo, Akanagea, Koong-Joong showed more severe symptoms than Simoo, Minong, Paek-soo, which appeared to be fainly resistant. In a number of tests, it was found that the virus KRMA retained its infectivity until to a dilution of 1:2,000, heating at $58^{\circ}$ for 10 minutes, adn aging in vitro for 7 days at room temperature. The RPV was not inactivated until it was diluted to 1:2,000, heated to $56^{\circ}$, and aged for 6 days. The KRMV was readily transmitted by the aphid(Myzus persicae Sulz). The virus RPV was not transmitted by the aphid in a number of tests. Partialy purified viruses using ammonium acetate buffer, salting-out by ammonium sulfate and centrifugation of high and low speed were highly infective. Electron micrographs showed that the KRMV paticles are of spherical particles whereas the RPV particles are rod-shaped.

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STUDIES ON THE VIRUSES OF RADISH MOSAIC

  • Kim, Woon Soo
    • Journal of Plant Biology
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    • v.6 no.2
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    • pp.7-7
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    • 1963
  • A mosaic diseased radish collected from the suburb of Seoul, in November, 1961 was used for studing the host range, physical properteis, purificaitiion, insect transmission, and electron microscopy. A Japanese strain of radish mosaic(RPV) was also used with Korean strain of radish mosaic (KRMV) for a comparative study. The two viruses, KRMA and RPV, were identified by the difference in host range, insect transmission and electron microscopy. The KRMA was severely infective on tobacco and Nicotiana glutinosa, while on Gomphrena globsa was immune to the virus. RPV produces necrotic local lesions on Gomphrena globosa but did not infect tobacco and N. glutinosa. Among varieties of radish, Seoul, Akamaroo, Akanagea, Koong-Joong showed more severe symptoms than Simoo, Minong, Paek-soo, which appeared to be fainly resistant. In a number of tests, it was found that the virus KRMA retained its infectivity until to a dilution of 1:2,000, heating at $58^{\circ}$ for 10 minutes, adn aging in vitro for 7 days at room temperature. The RPV was not inactivated until it was diluted to 1:2,000, heated to $56^{\circ}$, and aged for 6 days. The KRMV was readily transmitted by the aphid(Myzus persicae Sulz). The virus RPV was not transmitted by the aphid in a number of tests. Partialy purified viruses using ammonium acetate buffer, salting-out by ammonium sulfate and centrifugation of high and low speed were highly infective. Electron micrographs showed that the KRMV paticles are of spherical particles whereas the RPV particles are rod-shaped.

Poly (ADP-ribose) in the pathogenesis of Parkinson's disease

  • Lee, Yunjong;Kang, Ho Chul;Lee, Byoung Dae;Lee, Yun-Il;Kim, Young Pil;Shin, Joo-Ho
    • BMB Reports
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    • v.47 no.8
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    • pp.424-432
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    • 2014
  • The defining feature of Parkinson's disease is a progressive and selective demise of dopaminergic neurons. A recent report on Parkinson's disease animal model demonstrates that poly (ADP-ribose) (PAR) dependent cell death, also named parthanatos, is accountable for selective dopaminergic neuronal loss. Parthanatos is a programmed necrotic cell death, characterized by PARP1 activation, apoptosis inducing factor (AIF) nuclear translocation, and large scale DNA fragmentation. Besides cell death regulation via interaction with AIF, PAR molecule mediates diverse cellular processes including genomic stability, cell division, transcription, epigenetic regulation, and stress granule formation. In this review, we will discuss the roles of PARP1 activation and PAR molecules in the pathological processes of Parkinson's disease. Potential interaction between PAR molecule and Parkinson's disease protein interactome are briefly introduced. Finally, we suggest promising points of therapeutic intervention in the pathological PAR signaling cascade to halt progression in Parkinson's disease.

Methionyl-tRNA Synthetase Regulates Lifespan in Drosophila

  • Suh, Yoon Seok;Yeom, Eunbyul;Nam, Jong-Woo;Min, Kyung-Jin;Lee, Jeongsoo;Yu, Kweon
    • Molecules and Cells
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    • v.43 no.3
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    • pp.304-311
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    • 2020
  • Methionyl-tRNA synthetase (MRS) is essential for translation. MRS mutants reduce global translation, which usually increases lifespan in various genetic models. However, we found that MRS inhibited Drosophila reduced lifespan despite of the reduced protein synthesis. Microarray analysis with MRS inhibited Drosophila revealed significant changes in inflammatory and immune response genes. Especially, the expression of anti-microbial peptides (AMPs) genes was reduced. When we measured the expression levels of AMP genes during aging, those were getting increased in the control flies but reduced in MRS inhibition flies age-dependently. Interestingly, in the germ-free condition, the maximum lifespan was increased in MRS inhibition flies compared with that of the conventional condition. These findings suggest that the lifespan of MRS inhibition flies is reduced due to the down-regulated AMPs expression in Drosophila.

The role of Purkinje cell-derived VEGF in cerebellar astrogliosis in Niemann-Pick type C mice

  • Park, Min Hee;Lee, Ju Youn;Jeong, Min Seock;Jang, Hyung Sup;Endo, Shogo;Bae, Jae-sung;Jin, Hee Kyung
    • BMB Reports
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    • v.51 no.2
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    • pp.79-84
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    • 2018
  • Niemann-Pick type C disease (NP-C) is a fatal neurodegenerative disorder caused by a deficiency of NPC1 gene function, which leads to severe neuroinflammation such as astrogliosis. While reports demonstrating neuroinflammation are prevalent in NP-C, information about the onset and progression of cerebellar astrogliosis in this disorder is lacking. Using gene targeting, we generated vascular endothelial growth factor (VEGF) conditional null mutant mice. Deletion of VEGF in cerebellar Purkinje neurons (PNs) led to a significant increase of astrogliosis in the brain of NP-C mice in addition to the loss of PNs, suggesting PN-derived VEGF as an important factor in NP-C pathology. Moreover, replenishment of VEGF in neurons improved brain pathology in NP-C mice. Overall, our data provide a new pathological perspective on cerebellar astrogliosis in NP-C and suggest the importance of VEGF as a therapeutic target for this disease.

Identificaiton of the dITP- and XTP-Hydrolyzing Protein from Escherichia coli

  • Chung, Ji-Hyung;Park, Hyun-Young;Lee, Jong-Ho;Jang, Yang-Soo
    • BMB Reports
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    • v.35 no.4
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    • pp.403-408
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    • 2002
  • A hypothetical 21.0 kDa protein (ORF O197) from Escherichia coli K-12 was cloned, purified, and characterized. The protein sequence of ORF O197(termed EcO197) shares a 33.5% identity with that of a novel NTPase from Methanococcus jannaschii. The EcO197 protein was purified using Ni-NTA affinity chromatography, protease digestion, and gel filtration column. It hydrolyzed nucleoside triphosphates with an O6 atom-containing purine base to nucleoside monophosphate and pyrophosphate. The EcO197 protein had a strong preference for deoxyinosine triphosphate (dITP) and xanthosine triphosphate (XTP), while it had little activity in the standard nucleoside triphosphates (dATP, dCTP, dGTP, and dTTP). These aberrant nucleotides can be produced by oxidative deamination from purine nucleotides in cells; they are potentially mutagenic. The mutation protection mechanisms are caused by the incorporation into DNA of unwelcome nucleotides that are formed spontaneously. The EcO197 protein may function to eliminate specifically damaged purine nucleotide that contains the 6-keto group. This protein appears to be the first eubacterial dITP-and XTP-hydrolyzing enzyme that has been identified.

Nicotinamide Exerts Antioxidative Effects on Senescent Cells

  • Kwak, Ju Yeon;Ham, Hyun Joo;Kim, Cheol Min;Hwang, Eun Seong
    • Molecules and Cells
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    • v.38 no.3
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    • pp.229-235
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    • 2015
  • Nicotinamide (NAM) has been shown to suppress reactive oxygen species (ROS) production in primary human fibroblasts, thereby extending their replicative lifespan when added to the medium during long-term cultivation. Based on this finding, NAM is hypothesized to affect cellular senescence progression by keeping ROS accumulation low. In the current study, we asked whether NAM is indeed able to reduce ROS levels and senescence phenotypes in cells undergoing senescence progression and those already in senescence. We employed two different cellular models: MCF-7 cells undergoing senescence progression and human fibroblasts in a state of replicative senescence. In both models, NAM treatment substantially decreased ROS levels. In addition, NAM attenuated the expression of the assessed senescence phenotypes, excluding irreversible growth arrest. N-acetyl cysteine, a potent ROS scavenger, did not have comparable effects in the tested cell types. These data show that NAM has potent antioxidative as well as anti-senescent effects. Moreover, these findings suggest that NAM can reduce cellular deterioration caused by oxidative damage in postmitotic cells in vivo.

Proteotoxic Stress and Cell Lifespan Control

  • Cenci, Simone;Pengo, Niccolo;Sitia, Roberto
    • Molecules and Cells
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    • v.26 no.4
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    • pp.323-328
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    • 2008
  • Eukaryotic cells continuously integrate intrinsic and extrinsic signals to adapt to the environment. When exposed to stressful conditions, cells activate compartment-specific adaptive responses. If these are insufficient, apoptosis ensues as an organismal defense line. The mechanisms that sense stress and set the transition from adaptive to maladaptive responses, activating apoptotic programs, are the subject of intense studies, also for their potential impact in cancer and degenerative disorders. In the former case, one would aim at lowering the threshold, in the latter instead to increase it. Protein synthesis, consuming energy for anabolic processes as well as for byproducts disposal, can be a significant source of stress, particularly when difficult-to-fold proteins are produced. Recent work from our and other laboratories on the differentiation of antibody secreting cells, revealed a regulatory circuit that integrates protein synthesis, secretion and degradation (proteostasis), into cell lifespan determination. The apoptotic elimination - after an industrious, yet short lifetime - of terminal immune effectors is crucial to maintain immune homeostasis. Linking proteostasis to cell death, this paradigm might prove useful for biotechnological purposes, and the design of novel anti-cancer therapies.

In vitro Effect of Ecklonia stolonifera Okamura Extract on the Cell Growth in CCD-986sk Human Fibroblast and Melanin Formation Inhibition in Clone M-3 Mouse Melanocyte Cell Line (청정해역 곰피추출물의 세포생리활성 연구)

  • Whang, Eun-Kyoung;Cho, Myung-Hwan;Park, Chan-Sun;Kim, Myung-Hee;Park, Kap-Joo
    • Korean Journal of Environmental Biology
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    • v.26 no.1
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    • pp.30-35
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    • 2008
  • In order to investigate whether or not CCD-986sk cell line can be affected by Korean Ecklonia stolonifera Okamura, we examined the MTT assay when we treated Korean Ecklonia stolonifera Okamura extract in CCD-986sk human fibroblast cell line. The sample were tested for cell proliferation activity by means of a modification of the MTT assay. Ecklonia stolonifera Okamura extract showed significantly strong cell proliferation activity at the range of from 6.25 mg $mL^{-1}$ to 1.56 mg $mL^{-1}$ compared with control group. And in order to search for inhibition agents of skin melanin formation, we tested for inhibition effect of melanin pigmentation of Korean Ecklonia stolonifera Okamura using Clone M-3 mouse melanocyte cell lines. when we treated the extracts of Ecklonia stolonifera Okamura to the mouse melanocyte cell lines, the sample showed a significantly little formation of melanin pigments compared with control group at the only range of 200 mg $mL^{-1}$. These results suggest that extract of Korean Ecklonia stolonifera Okamura may represents an excellent candidate for inhibition of melanin pigmentation and for protection of human skin aging at in vitro level.

Determination of Microbial Community as an Indicator of Kimchi Fermentation (김치발효의 지표로서 미생물군집의 측정)

  • Han, Hong-Ui;Lim, Chong-Rak;Park, Hyun-Kun
    • Korean Journal of Food Science and Technology
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    • v.22 no.1
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    • pp.26-32
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    • 1990
  • Attempts were made to define the characteristics of microbial community as an indicator of Kimchi fermentation. Determination of communities was carried out by simple Gram-stain, followed by direct microcopic counts. In room-temperature $(15^{\circ}C)$ fermentation, microbial succession was occurred in the order of communities of Gram-positive bacteria, yeasts and Gram-negative bacteria. It was characteristic that Gram-positive bacterial community was developed during the production of lactic acid, yeasts community was developed to cause rancidity, and Gram-negative bacterial community was relevant to maceration (or softening) as well as rancidity. The fluctuation of apparent Gram-negative reaction group might be used as a criterion of death or aging of Gram-positive bacterial populations. In low-temperature fermentation $(5^{\circ}C)$, however, it was found that yeasts and Gram-negative bacterial communities did not developed but only Gram-positive bacterial community did. It follows from these results mentioned above that maturity of Kimchi depends on the development of Cram-positive bacterial community. Thus, the size and occurrence of microbial community are avaiable for an indicator of Kimchi fermentation, and also determination of community could be a useful method to predict the maturity.

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