• Title/Summary/Keyword: Biology of aging

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A Colorimetric Glucose Assay via Concentration Gradient Paper Chip (종이기반 농도 구배 형성 칩을 통한 포도당 발색 반응 검사)

  • Kim, Taehoon H.;Shin, Hyun Young;Lee, Yun-Il;Tae, Ki-Sik;Kim, Minseok S.
    • Journal of Biomedical Engineering Research
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    • v.38 no.6
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    • pp.302-307
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    • 2017
  • This paper presents a paper-based concentration gradient chip to analyze colorimetric glucose assay. The paper-based concentration gradient chip was fabricated through a wax patterning technique that can design the fluidic channel by selectively printing hydrophobic and hydrophilic areas. Afterwards, glucose and dilution solutions were loaded into the inlet of a concentration gradient chip and each solution was then mixed sequentially at mixing channel. Finally, concentration gradient was formed at each outlet of the chip. To measure the glucose concentration of the solution in outlets, we conducted colorimetric glucose assay with fixed concentration of glucose solution (0, 5, 10, 15 and 20 mM) and obtained normalized intensity. Subsequently, glucose concentrations of the outlets were calculated by substituting the normalized intensity to linear regression function based on the normalized intensity of fixed glucose concentration. Finally, the concentration gradient of glucose was formed on the chip with the result of colorimetric assay. The concentration gradient paper chip has the potential to accurately analyze unknown glucose concentration.

Role of the insulin-like growth factor system in gonad sexual maturation in Pacific oyster Crassostrea gigas

  • Moon, Ji-Sung;Choi, Youn Hee
    • Fisheries and Aquatic Sciences
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    • v.23 no.2
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    • pp.3.1-3.8
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    • 2020
  • Background: The IGF system plays important roles in controlling growth, development, reproduction, and aging of organisms. Methods: To estimate maturation of the Pacific oyster Crassostrea gigas, we investigated the expression of insulin-like growth factor (IGF) system components and sex-specific genes. To determine the role of the IGF system in the growth and spawning period of female and male oysters, we examined mRNA expression levels of the C. gigas insulin receptor-related receptor (CIR), IGF binding protein complex acid labile subunit (IGFBP_ALS), and molluscan insulin-related peptide (MIP), as well as those of vitellogenin (Vg) and receptor-type guanylate cyclase (Gyc76C) in gonads of C. gigas collected between April and October, when sex can be determined visually in this species. Results: We found that MIP, IGFBP_ALS, and CIR mRNA expression levels were dependent on sex and month and were greater in males than in females. CIR and Vg mRNA expression levels were very similar among females, whereas IGF system components and Gyc76C were very similarly expressed among males. The highest expression values were observed in May, when oysters are mature; CIR and Vg mRNA expression levels were highest in females, and those of MIP, IGFBP_ALS, CIR, and Gyc76C were highest in males. Interestingly, we observed a 1:1 proportion of females to males during this period. Conclusion: Our results suggest that IGF system components, as well as Vg and Gyc76C, are associated with sexual maturation in C. gigas.

Human collagen alpha-2 type I stimulates collagen synthesis, wound healing, and elastin production in normal human dermal fibroblasts (HDFs)

  • Hwang, Su Jin;Ha, Geun-Hyoung;Seo, Woo-Young;Kim, Chung Kwon;Kim, KyeongJin;Lee, Sang Bae
    • BMB Reports
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    • v.53 no.10
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    • pp.539-544
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    • 2020
  • Skin aging appears to be the result of overlapping intrinsic (including genetic and hormonal factors) and extrinsic (external environment including chronic light exposure, chemicals, and toxins) processes. These factors cause decreases in the synthesis of collagen type I and elastin in fibroblasts and increases in the melanin in melanocytes. Collagen Type I is the most abundant type of collagen and is a major structural protein in human body tissues. In previous studies, many products containing collagen derived from land and marine animals as well as other sources have been used for a wide range of purposes in cosmetics and food. However, to our knowledge, the effects of human collagen-derived peptides on improvements in skin condition have not been investigated. Here we isolate and identify the domain of a human COL1A2-derived protein which promotes fibroblast cell proliferation and collagen type I synthesis. This human COL 1A2-derived peptide enhances wound healing and elastin production. Finally, the human collagen alpha-2 type I-derived peptide (SMM) ameliorates collagen type I synthesis, cell proliferation, cell migration, and elastin synthesis, supporting a significant anti-wrinkle effect. Collectively, these results demonstrate that human collagen alpha-2 type I-derived peptides is practically accessible in both cosmetics and food, with the goal of improving skin condition.

Korean Red Ginseng Water Extract Restores Impaired Endothelial Function by Inhibiting Arginase Activity in Aged Mice

  • Choi, Kwanhoon;Yoon, Jeongyeon;Lim, Hyun Kyo;Ryoo, Sungwoo
    • The Korean Journal of Physiology and Pharmacology
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    • v.18 no.2
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    • pp.95-101
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    • 2014
  • Cardiovascular disease is the prime cause of morbidity and mortality and the population ages that may contribute to increase in the occurrence of cardiovascular disease. Arginase upregulation is associated with impaired endothelial function in aged vascular system and thus may contribute to cardiovascular disease. According to recent research, Korean Red Ginseng water extract (KRGE) may reduce cardiovascular disease risk by improving vascular system health. The purpose of this study was to examine mechanisms contributing to age-related vascular endothelial dysfunction and to determine whether KRGE improves these functions in aged mice. Young ($10{\pm}3$ weeks) and aged ($55{\pm}5$ weeks) male mice (C57BL/6J) were orally administered 0, 10, or 20 mg/mouse/day of KRGE for 4 weeks. Animals were sacrificed and the aortas were removed. Endothelial arginase activity, nitric oxide (NO) generation and reactive oxygen species (ROS) production, endothelial nitric oxide synthase (eNOS) coupling, vascular tension, and plasma peroxynitrite production were measured. KRGE attenuated arginase activity, restored nitric oxide (NO) generation, reduced ROS production, and enhanced eNOS coupling in aged mice. KRGE also improved vascular tension in aged vessels, as indicated by increased acetylcholine-induced vasorelaxation and improved phenylephrine-stimulated vasoconstriction. Furthermore, KRGE prevented plasma peroxynitrite formation in aged mice, indicating reduced lipid peroxidation. These results suggest KRGE exerts vasoprotective effects by inhibiting arginase activity and augmenting NO signaling and may be a useful treatment for age-dependent vascular diseases.

Effects of Citrus sunki Peel Extract on Matrix Metalloproteinase-1 Expression (진귤 과피 추출물의 MMP-1 발현조절 효과)

  • Han, Gu-Seul;Lee, Sun-Ryung
    • Journal of Life Science
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    • v.23 no.12
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    • pp.1553-1556
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    • 2013
  • Flavonoids are one of the major components found in the peels of citrus fruits. Present evidence has suggested that polymethoxyflavonoids, including nobiletin and tangeretin isolated from Citrus sunki, have many biological properties, such as anti-inflammatory, anti-oxidant, and anti-obesity capabilities. Here, we investigated the effect of Citrus sunki peel extract and its possible mechanisms on oxidative stress-induced MMP-1 expression, a major marker of skin photoaging. $H_2O_2$ induced MMP-1 expression in a dose- and time-dependent manner. Extract of Citrus sunki peel (1-25 ${\mu}g/ml$) dose-dependently decreased MMP-1 mRNA levels. When $H_2O_2$ was combined with Citrus sunki peel extract, the phosphorylation of ERK was further decreased compared to a single treatment with $H_2O_2$ alone. Moreover, U0216, an MEK inhibitor, markedly prevented the production of MMP-1. These data suggest that Citrus sunki peel extract has demonstrated protective activity against oxidative damage on MMP-1 expression, and ERK MAP kinase may be involved.

New Functional Properties of Passion Fruit Extract on Skin (패션 프룻 추출물이 피부에 미치는 새로운 기능적 효과)

  • Jeong, Mi Suk;Kim, Soon-Rae;Han, Chang Woo;Kim, Hyeon Jin;Jang, Se Bok
    • Journal of Life Science
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    • v.32 no.2
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    • pp.101-107
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    • 2022
  • In this research, the anti-inflammatory, antioxidant, antiaging, and skin whitening properties of pulp and seed extracts of passion fruit were studied. The result of the primary skin irritation test using a skin-attached patch determined the skin irritation index to be 0.00 for the passion fruit extract. In addition, RAW 264.7 macrophages produce NO by stimulation of lipopolysaccharides, and the application of extracts to this resulted in significantly lower NOs, confirming the excellent anti-inflammatory properties of passion fruit extracts. The 2,2-diphenyl-1-picrylhydrazyl test further confirmed that the passion fruit extract exhibits a good 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate radical scavenging ability of 5.11% and strong antioxidant properties. The presence of collagen type I in the skin is a measure of aging and various skin diseases. The results obtained from the analysis of the activity of human procollagen I alpha 1 confirmed that the passion fruit extract reduces the synthesis of procollagen. In addition, the skin whitening property of the passion fruit extract was confirmed by the melanin inhibition test, and a sample was obtained that contained more than 2% of arbutin, a whitening agent approved by the Ministry of Food and Drug Safety, which is generally present in the form of a white powder and is used as a functional ingredient. This confirms that the whitening efficacy of the passion fruit extract obtained from nature contributes to the development of functional raw materials for cosmetics and food.

The Induction of ROS-dependent Autophagy by Particulate Matter 2.5 and Hydrogen Peroxide in Human Lung Epithelial A549 Cells (미세먼지와 산화적 스트레스에 의한 인간 폐 상피 A549 세포에의 ROS 의존적 자가포식 유도)

  • Park, Beom Su;Kim, Da Hye;Hwangbo, Hyun;Lee, Hyesook;Hong, Su Hyun;Cheong, Jaehun;Choi, Yung Hyun
    • Journal of Life Science
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    • v.32 no.4
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    • pp.310-317
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    • 2022
  • Recently, interest in the harmful factors of particulate matter (PM), a major component of air pollution, has been increasing. In particular, PM2.5 with a diameter of less than 2.5 ㎛ is well known to induce oxidative stress accompanied by autophagy in human lung epithelial cells. However, studies on whether PM2.5 increases autophagy under oxidative stress and whether this process is reactive oxygen species (ROS)-dependent are insufficient. Therefore, in this study, we investigated whether PM2.5 promotes autophagy through the generation of ROS in human alveolar epithelial A594 cells. According to our results, cells co-treated with PM2.5 and hydrogen peroxide (H2O2) showed a lower cell viability than cells treated with each alone, which was associated with increased total and mitochondrial ROS production. The co-treatment of PM2.5 and H2O2 also increased autophagy induction, which was confirmed through Cyto-ID staining, and the expression of autophagy biomarker proteins increased. However, when ROS generation was artificially blocked by N-acetyl-L-cysteine pretreatment, the reduction in cell viability and induction of autophagy by PM2.5 and H2O2 co-treatment were markedly attenuated. Therefore, the present results suggest that PM2.5-induced ROS generation may play a critical role in autophagy induction in A549 cells.

Examination of the Presence and Differential Expression of Connexin Isoforms in the Urinary Bladder of the Male Rat During Postnatal Period

  • Lee, Ki-Ho
    • Journal of Animal Science and Technology
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    • v.54 no.6
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    • pp.419-425
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    • 2012
  • The coordinated action of the detrusor muscle cells in the urinary bladder is governed by cell-cell communication through gap junction, consisted of connexin (Cx) molecules. Even though a number of researches have been mostly focused on expressional changes of a few Cx isoforms in clinically dysfunctional condition of the bladder, less attention has been paid for investigation of Cx isoforms present in the bladder. Using real-time PCR analysis, the present study examined Cx isoforms expressing in the male rat bladder during postnatal period. Also, expressional patterns of Cx isoforms were evaluated in the bladder at different postnatal ages. Of a total of 13 Cx isoforms tested in the present study, we were able to detect mRNAs of 6 Cx isoforms in the rat urinary bladder, including Cxs 31, 31.1, 32, 37, 40, and 45. The transcript levels of Cxs 31, 31.1, 37, 40, and 45 were gradually increased from 1 week of age until 25 days of age, followed by transient decreases at 45 days of age. However, abundance of Cx32 transcript was drastically increased at 15 days of age, followed by a sharp drop at 45 days of age. These results indicate that differential expression of Cx isoforms in the bladder during postnatal development would be necessary for maintaining proper function of the bladder. A question remains to be answered if significant decreases of transcript levels of some Cx isoforms at the elderly are associated with age-dependent dysfunction of the bladder.

Effect of MLN8237, a Novel Aurora A Kinase Inhibitor, on the Spontaneous Fragmentation of Ovulated Mouse Oocytes

  • Park, Ji-Hun;Choi, Tae-Saeng
    • Reproductive and Developmental Biology
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    • v.35 no.4
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    • pp.499-502
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    • 2011
  • Aurora A kinase is a mitotic serine/threonine kinase whose proposed functions include the maturation of centrosomes, G2/M transition, alignment of chromosomes at metaphase, and cytokinesis. In this study, we investigated the effect of MLN8237, an aurora A kinase inhibitor, on the postovulatory aging of oocytes based on the frequency of oocyte fragmentation, cdk1 kinase activity, and cyclin B degradation. The fragmentation of ovulated oocytes during prolonged culture was inhibited by treatment with MLN8237 in a concentration-dependent manner. The frequency of fragmented oocytes was significantly lower in oocytes treated with 2 ${\mu}M$ MLN8237 (13%) than in control oocytes (64%) after two days of culture. Most of the control (non-fragmented) oocytes (91%) were activated after two days of culture. In comparison, only 22% of the MLN8237-treated oocytes were activated; the rest of the oocytes (78%) were still in metaphase with an abnormal spindle and dispersed chromosomes. Next, cdk1 activity and the level of cyclin B were examined. The level of cyclin B and cdk1 activity in MLN8237-treated oocytes were nearly equal to those in control oocytes. Our results indicate that MLN8237 inhibited the fragmentation of ovulated oocytes during prolonged culture, although it blocked the spontaneous decrease in activity of cdk1 and degradation of cyclin B. This mechanism of inhibition is different from that in oocytes treated with nocodazole, which have high levels of cdk1 activity and cyclin B.

Screening of Plants with Inhibitory Activity on Cellular Senescence

  • Lee, Seung-Eun;Kim, Jae-Ryong;Noh, Hyung-Jun;Kim, Geum-Sook;Lee, Jeong-Hoon;Choi, Jehun;Lee, Dae-Young;Kim, Seung-Yu
    • Korean Journal of Plant Resources
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    • v.27 no.6
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    • pp.601-609
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    • 2014
  • In this study, the effect of plant extract on the senescence action and cell survival rate in two types of cells, in which aging was derived by adriamycin, was analyzed to find the materials for suppressing cell senescence from natural resources. The results are as follows. For human umbilical vein endothelial cells (HUVECs), the fruit of Physalis angulata L. and the aerial part of Synurus deltoides (Aiton) Nakai showed excellent cell-senescence inhibition activities in a treatment concentration-dependent manner, demonstrating the high possibility for utilization as a material for prevention and treatment for vascular diseases. The water extract from the root of Polygonatum odoratum var. pluriflorum for variegatum Y. N. Lee showed potent cell-senescence inhibitory effect for human dermal fibroblasts (HDFs). Thus it is considered that the additional study on the plant needs for elucidating the possible utilization as material for skin health improvement.