title: Ascofuranone inhibits lipopolysaccharide-induced inflammatory response via NF-kappaB and AP-1, p-ERK, TNF-α, IL-6 and IL-1β in RAW 264.7 macrophages.
abstract: The natural fungal compound ascofuranone (5-chloro-3-[(2E,6E)-7-[(2S)-5,5-dimethyl-4-oxo-tetrahydrofuran-2-yl]-3-methyl-octa-2,6-dienyl]-2,4-dihydroxy-6-methyl-benzaldehyde, MW 420.93) (AF) isolated from Ascochyta viciae has been known to promote cell cycle arrest and inhibit invasion of tumor cells. We have previously studied a structurally similar compound ascochlorin (ASC; MW 404.93) with regard to its anti-inflammatory activity in LPS- stimulated RAW 264.7 macrophages. In order to examine the relationship between the anti-inflammatory activities and the molecular differences between AF and ASC, the activity of AF is herein studied, because ASC has a unique trimethyl oxocyclohexyl structure, while AF has a unique dimethyl-oxo-tetrahydrofuran structure. AF dose-dependently inhibited the production of NO and iNOS and the COX-2 mRNA and protein levels in RAW 264.7 cells. In addition, AF suppressed mRNA expression levels of inflammatory cytokines such as TNF-α, IL-6, and IL-1β, as assessed by RT-PCR. AF (30-50 μg/ml) treatment clearly inhibited the nuclear translocation of NF-κB, AP-1 (p-c-Jun) from the cytosolic space. Phosphorylation of IκB, which functions to maintain the activity of NF-κB, was decreased by AF treatment. Moreover, AF suppressed the binding of NF-κB (p65). Inhibition of IkBa phosphorylation and degradation inhibits nuclear translocation of p65. Immunofluorescence confocal microscopy analysis also revealed that translocation of NF-κB and AP-1 (p-c-Jun) was decreased upon AF treatment. AF specifically decreased the expression level of p-ERK, but not the expression level of p-p38 or p-JNK. Given these results, we suggest that AF suppresses the inflammatory response by targeting p-ERK. This indicates that AF is a negative regulator of LPS-stimulated nuclear translocation of NF-κB and AP-1 (p-c-Jun) in RAW 264.7 macrophages, and specifically it targets p-ERK. Therefore, AF and ASC exert their effects in different ways, most probably because their structural differences allow for specific recognition and inhibition of their target MAPKs. Our results further suggest that AF could be a natural bioactive compound useful for treating inflammation-mediated pathological diseases.
authors.affiliation: Molecular and Cellular Glycobiology Unit, Department of Biological Sciences, SungKyunKwan University, Seoburo 2066, Jangan-Gu, Suwon, Gyunggi-Do, Korea.
authors.forename: Jun-Young
authors.initials: JY
authors.lastname: Park
authors.affiliation: School of Korean Medicine and Healthy Aging Korean Medicine Research Center, Pusan National University, Yangsan City, Gyeongsangnam-Do, Republic of Korea.
authors.forename: Tae-Wook
authors.initials: TW
authors.lastname: Chung
authors.affiliation: Research Institute of Biomedical Engineering and Department of Medicine, Catholic University of Daegu School of Medicine, Daegu, Republic of Korea.
authors.forename: Yun-Jeong
authors.initials: YJ
authors.lastname: Jeong
authors.affiliation: Molecular and Cellular Glycobiology Unit, Department of Biological Sciences, SungKyunKwan University, Seoburo 2066, Jangan-Gu, Suwon, Gyunggi-Do, Korea.
authors.forename: Choong-Hwan
authors.initials: CH
authors.lastname: Kwak
authors.affiliation: Molecular and Cellular Glycobiology Unit, Department of Biological Sciences, SungKyunKwan University, Seoburo 2066, Jangan-Gu, Suwon, Gyunggi-Do, Korea.
authors.forename: Sun-Hyung
authors.initials: SH
authors.lastname: Ha
authors.affiliation: Molecular and Cellular Glycobiology Unit, Department of Biological Sciences, SungKyunKwan University, Seoburo 2066, Jangan-Gu, Suwon, Gyunggi-Do, Korea.
authors.forename: Kyung-Min
authors.initials: KM
authors.lastname: Kwon
authors.affiliation: Molecular and Cellular Glycobiology Unit, Department of Biological Sciences, SungKyunKwan University, Seoburo 2066, Jangan-Gu, Suwon, Gyunggi-Do, Korea.
authors.forename: Fukushi
authors.initials: F
authors.lastname: Abekura
authors.affiliation: Division of Enteric Diseases, Center for Infectious Diseases Research, Korea National Institute of Health, Heungdeok-gu, Cheongju, Korea.
authors.forename: Seung-Hak
authors.initials: SH
authors.lastname: Cho
authors.affiliation: Faculty of Medicinal Biotechnology, Dong-A University, Busan, Republic of Korea.
authors.forename: Young-Choon
authors.initials: YC
authors.lastname: Lee
authors.affiliation: School of Korean Medicine and Healthy Aging Korean Medicine Research Center, Pusan National University, Yangsan City, Gyeongsangnam-Do, Republic of Korea.
authors.forename: Ki-Tae
authors.initials: KT
authors.lastname: Ha
authors.affiliation: Magae Bioscience Institute, 49-4 Fujimidai, Tsukuba, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Magae
authors.affiliation: Research Institute of Biomedical Engineering and Department of Medicine, Catholic University of Daegu School of Medicine, Daegu, Republic of Korea.
authors.forename: Young-Chae
authors.initials: YC
authors.lastname: Chang
authors.affiliation: Molecular and Cellular Glycobiology Unit, Department of Biological Sciences, SungKyunKwan University, Seoburo 2066, Jangan-Gu, Suwon, Gyunggi-Do, Korea.|Samsung Advanced Institute for Health Sciences & Technology (SAIHST), Sungkyunkwan University, Seoul, South Korea.
authors.forename: Cheorl-Ho
authors.initials: CH
authors.lastname: Kim
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D002478:Cells, Cultured; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D007249:Inflammation / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism; D018836:Inflammation Mediators / Q000378:metabolism*; D053583:Interleukin-1beta / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000633:toxicity; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D012717:Sesquiterpenes / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D015850:Interleukin-6; D008070:Lipopolysaccharides; D016328:NF-kappa B; D012717:Sesquiterpenes; D018808:Transcription Factor AP-1; D014409:Tumor Necrosis Factor-alpha; D048049:Extracellular Signal-Regulated MAP Kinases; C006640:ascofuranone