Search

Your search keyword '"Lee, Hong Kum"' showing total 33 results
Start Over Author "Lee, Hong Kum" Publication Year Range Last 10 years
33 results on '"Lee, Hong Kum"'

20. Anti-Inflammatory Activity of Lobaric Acid via Suppressing NF- κ B/MAPK Pathways or NLRP3 Inflammasome Activation.

Author

Lee, Hee-Weon, Kim, JinWook, Yim, Joung-Han, Lee, Hong-Kum, and Pyo, Suhkneung

Subjects
INFLAMMATION prevention, ANIMAL experimentation, CELLULAR signal transduction, GENE expression, INFLAMMATORY mediators, INTERLEUKIN-1, INTERLEUKINS, MACROPHAGES, MEDICINAL plants, MOLECULAR structure, NITRIC oxide, OXIDOREDUCTASES, PROSTAGLANDINS E, PROTEIN kinases, TUMOR necrosis factors, DNA-binding proteins, PLANT extracts, LIPOPOLYSACCHARIDES, CASPASES, SIGNAL peptides, PHARMACODYNAMICS
Abstract

Lobaric acid (LA) is a constituent of the lichen Stereocaulon alpinum. LA has multiple biological activities, including antibacterial and antioxidant ones. The purpose of this study was to investigate the effect of LA and its mechanism on lipopolysaccharide (LPS)-induced inflammatory responses in macrophages. Macrophages were pretreated with different concentrations of LA (0.2 – 20 µM), followed by LPS stimulation. LA treatment of LPS stimulated macrophages decreased their nitric oxide production and the expression of cyclooxygenase-2 and prostaglandin E2. LA also significantly reduced the production of tumor necrosis factor- α and interleukin (IL)-6 by inhibiting the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF- κ B). Additionally, LA inhibited the production of IL-1 β and IL-18, as well as caspase-1 maturation, by inhibition of NLRP3 inflammasome activation in LPS/ATP-stimulated cells. These results strongly suggest that LA could inhibit inflammation by downregulating NF- κ B/MAPK pathways and NLRP3 inflammasome activation in activated macrophages. These results reveal a new therapeutic approach to modulate inflammatory diseases linked to deregulated inflammasome activities. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

31. Ramalin Isolated from Ramalina Terebrata Attenuates Atopic Dermatitis-like Skin Lesions in Balb/c Mice and Cutaneous Immune Responses in Keratinocytes and Mast Cells.

Author

Park, Hye ‐ Jin, Jang, Yeon Jeong, Yim, Joung ‐ Han, Lee, Hong ‐ Kum, and Pyo, Suhkneung

Abstract

Atopic dermatitis (AD) is a chronic inflammatory skin disease that involves eczematous skin lesions with pruritic erythematous papules. In this study, we investigated the mitigating effects of ramalin, a component of the Antarctic lichen Ramalina terebrata against AD in vivo and in vitro. Oral administration of ramalin lessened scratching behaviors and significantly reduced both serum immunoglobulin E and IL-4 levels, and mRNA levels of IL-4 and IL-10 in AD-induced Balb/c mice. In vitro, treatment with ramalin produced significantly less inflammatory chemokines and cytokines, including TARC, MCP-1, RANTES, and IL-8 in TNF-α-stimulated HaCaT cells. In addition, ramalin inhibited the activation of nuclear factor-kappa B as well as the phosphorylation of mitogen-activated protein kinases (MAPK). Furthermore, ramalin treatment resulted in decreased production of β-hexosaminidase and proinflammatory cytokines IL-4, IL-6, and TNF-α in 2,4 dinitrophenyl-human serum albumin-stimulated RBL-2H3 cells through blocking MAPK signaling pathways. The results suggest that ramalin modulates the production of immune mediators by inhibiting the nuclear factor-kappa B and MAPK signaling pathways. Taken together, ramalin effectively attenuated the development of AD and promoted the mitigating effects on Th2 cell-mediated immune responses and the production of inflammatory mediators in mast cells and keratinocytes. Thus, ramalin may be a potential therapeutic agent for AD. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Published
2016
Full Text
View/download PDF

32. CspB of an arctic bacterium, Polaribacter irgensiiKOPRI 22228, confers extraordinary freeze-tolerance

Author

Jung, Youn Hong, Lee, Yoo Kyung, Lee, Hong Kum, Lee, Kyunghee, and Im, Hana

Abstract

Freezing temperatures are a major challenge for life at the poles. Decreased membrane fluidity, uninvited secondary structure formation in nucleic acids, and protein cold-denaturation all occur at cold temperatures. Organisms adapted to polar regions possess distinct mechanisms that enable them to survive in extremely cold environments. Among the cold-induced proteins, cold shock protein (Csp) family proteins are the most prominent. A gene coding for a Csp-family protein, cspB, was cloned from an arctic bacterium, Polaribacter irgensiiKOPRI 22228, and overexpression of cspBgreatly increased the freeze-survival rates of Escherichia colihosts, to a greater level than any previously reported Csp. It also suppressed the cold-sensitivity of an E. coli csp-quadruple deletion strain, BX04. Sequence analysis showed that this protein consists of a unique domain at its N-terminal end and a well conserved cold shock domain at its C-terminal end. The most common mechanism of Csp function in cold adaption is melting of the secondary structures in RNA and DNA molecules, thus facilitating transcription and translation at low temperatures. P. irgensiiCspB bound to oligo(dT)-cellulose resins, suggesting single-stranded nucleic acid-binding activity. The unprecedented level of freeze-tolerance conferred by P. irgensiiCspB suggests a crucial role for this protein in survival in polar environments.

Published
2018
Full Text
View/download PDF

33. Anti-Inflammatory Activity of Lobaric Acid via Suppressing NF-κB/MAPK Pathways or NLRP3 Inflammasome Activation.

Author

Lee HW, Kim J, Yim JH, Lee HK, and Pyo S

Subjects
Animals, Blotting, Western, Cyclooxygenase 2 metabolism, Depsides pharmacology, Dinoprostone metabolism, Macrophages drug effects, Macrophages metabolism, Male, Mice, Mice, Inbred C57BL, Nitric Oxide metabolism, Signal Transduction drug effects, Anti-Inflammatory Agents pharmacology, Inflammasomes drug effects, Lactones pharmacology, MAP Kinase Signaling System drug effects, NF-kappa B metabolism, NLR Family, Pyrin Domain-Containing 3 Protein metabolism, Salicylates pharmacology
Abstract

Lobaric acid (LA) is a constituent of the lichen Stereocaulon alpinum . LA has multiple biological activities, including antibacterial and antioxidant ones. The purpose of this study was to investigate the effect of LA and its mechanism on lipopolysaccharide (LPS)-induced inflammatory responses in macrophages. Macrophages were pretreated with different concentrations of LA (0.2 - 20 µM), followed by LPS stimulation. LA treatment of LPS stimulated macrophages decreased their nitric oxide production and the expression of cyclooxygenase-2 and prostaglandin E2. LA also significantly reduced the production of tumor necrosis factor- α and interleukin (IL)-6 by inhibiting the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF- κ B). Additionally, LA inhibited the production of IL-1 β and IL-18, as well as caspase-1 maturation, by inhibition of NLRP3 inflammasome activation in LPS/ATP-stimulated cells. These results strongly suggest that LA could inhibit inflammation by downregulating NF- κ B/MAPK pathways and NLRP3 inflammasome activation in activated macrophages. These results reveal a new therapeutic approach to modulate inflammatory diseases linked to deregulated inflammasome activities., Competing Interests: The authors declare that they have no conflict of interest., (Georg Thieme Verlag KG Stuttgart · New York.)

Published
2019
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results