• Title/Summary/Keyword: Cell biology

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도룡뇽 (Hynobius leechi) 피부선의 미세구조: I. 점액선

  • Kim, Han-Hwa;Noh, Yong-Tai;Chung, Young-Wha;Chi, Young-Duk
    • The Korean Journal of Zoology
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    • v.23 no.2
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    • pp.77-88
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    • 1980
  • The ultrastructures of the mucous glands in the Asiatic land salamander (Hynobius leechi) skin were observed by means of electron microscope. The results were as follows; 1. The mucous gland of the Asiatic land salamander skin consisted of a body of gland and a duct. The body of gland consisted of the glandular epithelial and the myoepithelial cells. 2. The light, the dark, the mitochondria-rich, the endoplasmic reticulum-developed, the secretory granule-containing and the vesiculated cells were observed in the mucous glandular epithelium. 3. It is supposed that the light, the dark and the mitochondria-rich cells are undifferentiated cells, the endoplasmic reticulum-developed cell is pre-secretory cell, the secretory granule-containing cell is mature cell and the vesiculated cell is evacuated cell.

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Paired Ig-Like Type 2 Receptor-Derived Agonist Ligands Ameliorate Inflammatory Reactions by Downregulating β1 Integrin Activity

  • Lee, Kyoung-Jin;Lim, Dongyoung;Yoo, Yeon Ho;Park, Eun-Ji;Lee, Sun-Hee;Yadav, Birendra Kumar;Lee, Yong-Ki;Park, Jeong Hyun;Kim, Daejoong;Park, Kyeong Han;Hahn, Jang-Hee
    • Molecules and Cells
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    • v.39 no.7
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    • pp.557-565
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    • 2016
  • The paired immunoglobulin-like type 2 receptor (PILR) family consists of two functionally opposite members, inhibitory $PILR{\alpha}$ and activating $PILR{\beta}$ receptors. PILRs are widely expressed in various immune cells and interact with their ligands, especially CD99 expressed on activated T cells, to participate in immune responses. Here we investigated whether PILR-derived agonists inhibit ${\beta}1$ integrin activity as ligands for CD99. PILR-derived peptides as well as PILR-Fc fusion proteins prevented cell adhesion to fibronectin through the regulation of ${\beta}1$ integrin activity. Especially, PILRpep3, a representative 3-mer peptide covering the conserved motifs of the PILR extracellular domain, prevented the clustering and activation of ${\beta}1$ integrin by dephosphorylating FAK and vinculin, which are major components of focal adhesion. In addition, PILRpep3 inhibited transendothelial migration of monocytes as well as endothelial cell tube formation. Furthermore, upon intraperitoneal injection of PILRpep3 into mice with collagen-induced arthritis, the inflammatory response of rheumatoid arthritis was strongly suppressed. Taken together, these results suggest that PILR-derived agonist ligands may prevent the inflammatory reactions of rheumatoid arthritis by activating CD99.

Homogeneity of XEN Cells Is Critical for Generation of Chemically Induced Pluripotent Stem Cells

  • Dahee Jeong;Yukyeong Lee;Seung-Won Lee;Seokbeom Ham;Minseong Lee;Na Young Choi;Guangming Wu;Hans R. Scholer;Kinarm Ko
    • Molecules and Cells
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    • v.46 no.4
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    • pp.209-218
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    • 2023
  • In induced pluripotent stem cells (iPSCs), pluripotency is induced artificially by introducing the transcription factors Oct4, Sox2, Klf4, and c-Myc. When a transgene is introduced using a viral vector, the transgene may be integrated into the host genome and cause a mutation and cancer. No integration occurs when an episomal vector is used, but this method has a limitation in that remnants of the virus or vector remain in the cell, which limits the use of such iPSCs in therapeutic applications. Chemical reprogramming, which relies on treatment with small-molecule compounds to induce pluripotency, can overcome this problem. In this method, reprogramming is induced according to the gene expression pattern of extra-embryonic endoderm (XEN) cells, which are used as an intermediate stage in pluripotency induction. Therefore, iPSCs can be induced only from established XEN cells. We induced XEN cells using small molecules that modulate a signaling pathway and affect epigenetic modifications, and devised a culture method which can produce homogeneous XEN cells. At least 4 passages were required to establish morphologically homogeneous chemically induced XEN (CiXEN) cells, whose properties were similar to those of XEN cells, as revealed through cellular and molecular characterization. Chemically iPSCs derived from CiXEN cells showed characteristics similar to those of mouse embryonic stem cells. Our results show that the homogeneity of CiXEN cells is critical for the efficient induction of pluripotency by chemicals.

INHALATION TOXICITY STUDY ON H MENTHOL(NICOTINE FREE-TOBACCO FREE) HERBAL CIGARETTES

  • Jung, Ji-Won;Cho, Sung-Dae;Ahn, Nam-Shik;Park, Joon-Suk;Tiep, Nguyen-Ba;Lee, Yong-Soon;Kang, Kyung-Sun
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2002.05a
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    • pp.135-135
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    • 2002
  • Nowadays a huge variety of products that aim to assist to quit smoking or reduce addictive symptoms are developed and manufactured with safety evaluation, but the safety of the most recent products of interest which do not contain tobacco and nicotine, and shape cigarettes is not evaluated and guaranteed relatively.(omitted)

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Influence of Tyrosol on Cell Growth Inhibition of KB Human Oral Cancer Cells

  • Lee, Ue-Kyung;Kim, Su-Gwan;Go, Dae-San;Yu, Sun-Kyoung;Kim, Chun Sung;Kim, Jeongsun;Kim, Do Kyung
    • International Journal of Oral Biology
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    • v.41 no.4
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    • pp.175-181
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    • 2016
  • Tyrosol, a phenylethanoid and a derivative of phenethyl alcohol, possesses various biological properties, such as anti-oxidative and cardioprotective activity. Olive oil is the principal source of tyrosol in the human diet. However, so far the anti-cancer activity of tyrosol has not yet been well defined. This study therefore undertakes to examine the cytotoxic activity and the mechanism of cell death exhibited by tyrosol in KB human oral cancer cells. Treatment of KB cells with tyrosol induced the cell growth inhibition in a concentration- and a time-dependent manner. Furthermore, the treatment of tyrosol induced nuclear condensation and fragmentation of KB cells. Tyrosol also promoted proteolytic cleavage of procaspase-3, -7, -8 and -9, increasing the amounts of cleaved caspase-3, -7, -8 and -9. In addition, tyrosol increased the levels of cleaved PARP in KB cells. These results suggest that tyrosol induces the suppression of cell growth and cell apoptosis in KB human oral cancer cells, and is therefore a potential candidate for anti-cancer drug discovery.