• 제목/요약/키워드: biological aging

검색결과 462건 처리시간 0.03초

Akt: Versatile Mediator of Cell Survival and Beyond

  • Kim, Do-Hoon;Chung, Jong-Kyeong
    • BMB Reports
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    • 제35권1호
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    • pp.106-115
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    • 2002
  • The serine/threonine kinase Akt has been intensely studied for its role in growth factor-mediated cell survival for the past 5 years. On the other hand, the ongoing research effort has recently uncovered novel regulatory mechanisms and downstream effectors of Akt that demonstrate the involvement of Akt in other cellular functions such as cell cycle progression, angiogenesis, and cancer cell invasion/metastasis. Furthermore, recent studies using whole model organisms suggest additional roles for Akt in important diseases such as aging and diabetes. The following review addresses these recent advances in the understanding of Akt function.

Histone tail cleavage as a novel epigenetic regulatory mechanism for gene expression

  • Yi, Sun-Ju;Kim, Kyunghwan
    • BMB Reports
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    • 제51권5호
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    • pp.211-218
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    • 2018
  • Chromatin is an intelligent building block that can express either external or internal needs through structural changes. To date, three methods to change chromatin structure and regulate gene expression have been well-documented: histone modification, histone exchange, and ATP-dependent chromatin remodeling. Recently, a growing body of literature has suggested that histone tail cleavage is related to various cellular processes including stem cell differentiation, osteoclast differentiation, granulocyte differentiation, mammary gland differentiation, viral infection, aging, and yeast sporulation. Although the underlying mechanisms suggesting how histone cleavage affects gene expression in view of chromatin structure are only beginning to be understood, it is clear that this process is a novel transcriptional epigenetic mechanism involving chromatin dynamics. In this review, we describe the functional properties of the known histone tail cleavage with its proteolytic enzymes, discuss how histone cleavage impacts gene expression, and present future directions for this area of study.

Thermally Induced Mesophase Development in Ethanesilica Films via Macromolecular Templating Approach

  • Cho, Whirang;Char, Kook-Heon;Kwon, Su-Yong
    • Macromolecular Research
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    • 제17권9호
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    • pp.697-702
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    • 2009
  • Mesoporous ethanesilica thin film was prepared using PEO-PLGA-PEO triblock copolymers as structure-directing agents and (1,2-bis(triethoxysilyl) ethane BTESE; bridged organosilicates) as inorganic precursors via one-step sol-gel condensation of ethanesilica precursors. The mesostructure of ethanesilica films is critically dependent on the processing experimental parameters after the hydrolyzed silica sol mixture was spin-cast. This study examined the effects of the block copolymer template/organosilica precursor ratio in the casting solution and aging period before calcination of the mesostructure. It was further demonstrated that mesoscopic ordering of organosilicate thin films is induced by the rearrangement of block copolymer template/organosilica hybrid during thermal decomposition of the PEO-PLGA-PEO triblock copolymer. The mesoporous structure and morphology were characterized by SAXS, TEM and solid-state NMR measurement.

Biological activity of peptides purified from fish skin hydrolysates

  • Abuine, Racheal;Rathnayake, Anuruddhika Udayangani;Byun, Hee-Guk
    • Fisheries and Aquatic Sciences
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    • 제22권5호
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    • pp.10.1-10.14
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    • 2019
  • Fish skin waste accounts for part of the solid waste generated from seafood processing. Utilization of fish skin by bioconversion into high-grade products would potentially reduce pollution and economic cost associated with treating fish processing waste. Fish skin is an abundant supply of gelatin and collagen which can be hydrolyzed to produce bioactive peptides of 2-20 amino acid sequences. Bioactivity of peptides purified from fish skin includes a range of activities such as antihypertensive, anti-oxidative, antimicrobial, neuroprotection, antihyperglycemic, and anti-aging. Fish skin acts as a physical barrier and chemical barrier through antimicrobial peptide innate immune action and other functional peptides. Small peptides have been demonstrated to possess biological activities which are based on their amino acid composition and sequence. Fish skin-derived peptides contain a high content of hydrophobic amino acids which contribute to the antioxidant and angiotensin-converting enzyme inhibitory activity. The peptide-specific composition and sequence discussed in this review can be potentially utilized in the development of pharmaceutical and nutraceutical products.

Effect of exercise interventions on sarcopenic obesity in middle-aged and older adults: a comprehensive review

  • Hye-Ryoung Kim
    • Journal of Korean Biological Nursing Science
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    • 제25권4호
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    • pp.256-265
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    • 2023
  • Purpose: This study examined the definitions, diagnostic criteria, and measurements of sarcopenic obesity and identified effective exercise interventions that improve cardiometabolic outcomes in middle-aged and older adults, in whom the prevalence of sarcopenic obesity is increasing. Methods: This comprehensive review followed the principles of literature search, data extraction, and review, as described in the PRISMA 2009 guidelines. Results: The 11 articles included in this study presented different concepts of sarcopenic obesity. Exercise interventions for sarcopenic obesity varied in their effects. Resistance exercise improved muscle mass and physical function, while aerobic exercise primarily impacted obesity and cardiometabolic indicators. Combined exercise had mixed results across indicators. Conclusion: This study addressed a pressing public health concern in the context of an aging population, acknowledged the unique challenges of sarcopenic obesity, and attempted to clarify definitions and assessment methods, while identifying effective exercise interventions to reduce cardiometabolic risk. Sarcopenic obesity is a multifaceted condition with varying definitions and diagnostic criteria. Its association with cardiometabolic risk underscores the need for comprehensive assessments considering both muscle and obesity indicators. While exercise interventions hold promise for managing sarcopenic obesity, further research is required to establish effective strategies.

Variations in endopolyploidy level during the short period of the early growing stage in the roots and leaves of maize (Zea mays) seedlings

  • Ogawa, Atsushi;Taguchi, Nanako;Miyoshi, Kazumitsu
    • Plant Biotechnology Reports
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    • 제4권2호
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    • pp.117-123
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    • 2010
  • We used a flow cytometer to investigate the variations in endopolyploidy (the frequencies of nuclei with DNA contents equivalent to 4C through 16C) during the short period of the early growing stage in vigorously growing young tissues of maize seedlings. We examined different portions of the root and leaves that had been growing for 7 (day 7) and 13 (day 13) days after germination. Endoreplication showed two opposing phenomena without aging. In one case, the endopolyploidy of the first leaf was higher on day 13 than on day 7. In the latter case, endopolyploidy decreased, as clearly revealed by a comparison of the endopolyploidy of the second leaves and the 160-170 mm portion of the seminal root on days 7 and 13. Endopolyploidy was also lower in the top of the leaf. In roots, endopolyploidy was increased by the exogenous application of abscisic acid for only 1 day. The levels of endopolyploidy increased without an increase in cell size in the roots. These results showed that endoreplication occurs in actively growing and young tissue and that the variation can be induced in the short period examined.

Production of GABA (gamma amino butyric acid) by Lactic Acid Bacteria

  • Kook, Moo-Chang;Cho, Seok-Cheol
    • 한국축산식품학회지
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    • 제33권3호
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    • pp.377-389
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    • 2013
  • Gamma-amino butyric acid (GABA) is a kind of pharmacological and biological component and its application is wide and useful in Korea specially, becoming aging society in the near feature. GABA is request special dose for the purposed biological effect but the production of concentrated GABA is very difficult due to low concentration of glutamic acid existed in the fermentation broth. To increase GABA concentrate using fermentation technology, high content of glutamic acid is required. For this reason, various strains which have the glutamic acid decarboxylase (GAD) and can convert glutamic acid to GABA, were isolated from various fermented foods. Most of GABA producing strains are lactic acid bacteria isolated from kimchi, especially added monosodium glutamate (MSG) as a taste enhancer. Optimizing the formulation of culture media and the culture condition, GABA conversion yield and amounts were increased. Finally GABA concentration of fermentation broth in batch or fed batch fermentation reached 660 mM or 1000 mM, respectively. Furthermore formulation of culture media for GABA production developed commercially. Many studies about GABA-rich product have been continued, so GABA-rich kimchi, cheese, yogurt, black raspberry juice and tomato juices has been also developed. In Korea many biological effects of GABA are evaluated recently and GABA will be expected to be used in multipurpose.

대두피를 이용한 발효사료의 개발 연구 (Improvement of Nutritive Value of Soybean bran by Fermentation)

  • 이양희;김숙희;조명죽
    • Journal of Nutrition and Health
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    • 제5권1호
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    • pp.33-42
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    • 1972
  • This study was designed to investigate the nutritional value of fermented soybean bran as animal feed. Natural soybean bran has low protein quality and high cellulase contents. The soybean bran was supplemented by urea and ammoniumsulfate as N-source for incubation of Aspergillus niger. After incubation of soybean bran with Aspergillus niger, the nutritional quality of protein and riboflavin contents were increased in general and more in aging process than in fermentation. In order to elucidate the biological efficiency of prepared soybean bran, 120 male weanling rats were divided into 22 groups, five rats each, and were fed by standard casein diet mixed with soybean bran in the proportion of 1/10, 1/15, 1/20 respectively. The animals were kept under the experimental diet for nine weeks. In the result of this study, food efficiency ratio showed higher in the groups of urea and ammonium-sulfate-add group than row soybean bran group but the former group is lower than the later in the body weight gains. Protein efficiency ratio was also same trend. It was noteworthy that the nitrogen retention rate in total body on the basis of urinary nitrogen excretion and dietary intake nitrogen and in big organ such as liver and spleen were higher in fermented group than raw soybean bran fed group. It was worth while to treat the soybean bran in first place fermentation and further aging process to elevate the biological efficiency and effect of nutritional values specifically of protein and of riboflavin.

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Rhamnose-rich and fucose-rich oligo- and polysaccharides (RROP-s and FROPs), agonists and antagonists of cell-membrane receptors as new active principles against skin aging.

  • Robert, L.;Robert, A.M.;Gesztes, J.L.;Luppi, E.
    • 대한화장품학회:학술대회논문집
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    • 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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    • pp.352-373
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    • 2003
  • Rhamnose-rich (RROP-s) and fucose-rich (FROP-s) oligo-and polysaccharides were prepared and extensively characterised by physical and chemical procedures [1,2] and compared to L-fucose. Their biological properties were then studied on human skin fibroblast cell cultures, human skin explant cultures and on hairless rat skin, using a variety of cell-biological, biochemical and computerised morphometrical procedures. Among the most important properties we could establish, the following are of particular interest for the tretment and prevention of age-dependent modifications of human skin (loss of skin-tissue, cells and matrix, wrinkle formation and others) : stimulation of cell proliferation (by $^3$[H]-thymidine incorporation and the MTT test), scavenging of reactive oxygen species (ROS) using several different procedures, and protease (MMP-2 and MMP-9) down-regulation. A topical preparation, using RROP-s and FROP-s, and/or L-fucose, was shown to increase cell proliferation, dermal matrix synthesis, efficient scavenging of ROS-s and to increase also the thickness of dermal tissue when applied for 4 weeks on hairless rat skin, accompanied by the densification of collagen bundles as well as by an increase of elastin synthesis. Using fluorescent labeled FROPs, it could be shown that these oligosaccharides react with cell-membrane receptors and especially with the elastin-laminin-receptor and the fucose-mannose receptor, but they penetrate also in the cell nucleus, suggesting the possibility of a direct action on the regulation of gene expression. When applied to the human skin of a team of voluntary women encompassing all age-groups, the efficiency of FROP-containing preparation could be confirmed using indentometry and computerised evaluation of skin micro-relief, as well as evaluation of periorbital wrinkles. It appears therefore that these preparations correspond to all the requirements of active anti-aging principles.

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식물세포배양기술을 이용한 순무 캘러스 추출물의 생리활성 (Biological activities of Brassica rapa (Turnip) callus extracts by plant cell culture technology)

  • 신수영;모상현;황유진
    • Journal of Plant Biotechnology
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    • 제43권2호
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    • pp.248-254
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    • 2016
  • 본 연구에서는 인천광역시 강화군의 특화작물을 이용한 기능성 소재를 개발하기 위해 순무 캘러스를 배양하고 열수, 초음파 그리고 에탄올 추출하여 생리활성을 평가하였다. 순무 캘러스의 열수, 초음파 그리고 에탄올 추출물에서 DPPH radical소거활성이 대조군에 비해 농도 의존적으로 증가하였다. 순무 캘러스 에탄올 추출물의 수렴효과는 열수 및 초음파 추출물보다 높게 나타났다. 콜라겐 생합성량을 측정한 결과 순무 캘러스 에탄올 추출물의 5 ppm과 10 ppm 농도에서 59%와 78%의 주름개선 효과를 확인하였다. 이러한 결과들은 순무 캘러스의 열수, 초음파 그리고 에탄올 추출물이 천연 항산화 소재로의 활용이 가능할 것으로 사료되며 특히, 에탄올 추출물은 수렴효과와 주름개선 효과가 뛰어나 기능성 화장품 천연소재로서의 활용이 가능할 것으로 기대된다.