title: Leustroducsin B activates nuclear factor-kappaB via the acidic sphingomyelinase pathway in human bone marrow-derived stromal cell line KM-102.
abstract: The novel colony-stimulating factor (CSF) inducer leustroducsin B (LSN-B), which was isolated from Streptomyces platensis, has been shown to have potent cytokine-inducing activities in clonal human bone marrow-derived stromal cell line KM-102 and in primary human bone marrow-derived stromal cells. In this study, we investigated the signal transduction pathway of LSN-B using luciferase expression plasmids linked to the 5'-flanking region of interleukin-8 (IL-8) and that of the IL-11 gene. In KM-102 cells, LSN-B induced luciferase activity both in the wild-type and in the activated protein 1 (AP-1) site point-mutated IL-8 promoter. The mutation in the nuclear factor-kappaB (NF-kappaB) site abrogated LSN-B-stimulated induction of the reporter gene. LSN-B-inducing activity was inhibited by (1) N-acetyl-L-cysteine, a well-characterized antioxidant, (2) cationic amphiphilic drugs, inhibitors of acidic sphingomyelinase (A-SMase), and (3) D609, an inhibitor of phosphatidylcholine-specific phospholipase C (PC-PLC). These observations suggest that LSN-B potentiates the A-SMase-mediated signaling pathway to stimulate NF-kappaB. In contrast, LSN-B did not induce IL-11 promoter-driven luciferase activity. The observed increase in IL-11 mRNA stability by LSN-B indicates that the inducible production of IL-11 by LSN-B is regulated at the posttranscriptional level. In addition, inhibition of LSN-B-mediated induction of IL-11 production by cationic amphiphilic drugs and D609 in KM-102 cells demonstrates that increased IL-11 mRNA stability by LSN-B might be mediated via NF-kappaB activation. From these results, we suggest that LSN-B induces cytokine production through at least two separate mechanisms, at the transcriptional level and at the posttranscriptional level via NF-kappaB activation.
authors.affiliation: Biomedical Research Laboratories, Sankyo Co., Ltd., Tokyo, Japan. koishi@shina.sankyo.co.jp
authors.forename: Ryuta
authors.initials: R
authors.lastname: Koishi
authors.forename: Chigusa
authors.initials: C
authors.lastname: Yoshimura
authors.forename: Takafumi
authors.initials: T
authors.lastname: Kohama
authors.forename: Nobufusa
authors.initials: N
authors.lastname: Serizawa
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism*; D001952:Bridged-Ring Compounds / Q000494:pharmacology; D002460:Cell Line; D002999:Clone Cells; D003891:Desipramine / Q000494:pharmacology; D017930:Genes, Reporter; D006801:Humans; D017370:Interleukin-11 / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D016209:Interleukin-8 / Q000032:analysis / Q000235:genetics; D007783:Lactones / Q000494:pharmacology*; D016297:Mutagenesis, Site-Directed; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D009636:Norbornanes; D009943:Organophosphorus Compounds / Q000494:pharmacology*; D010480:Perhexiline / Q000031:analogs & derivatives* / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D017354:Point Mutation; D011401:Promoter Regions, Genetic; D011499:Protein Processing, Post-Translational; D011753:Pyrones; D015398:Signal Transduction; D013108:Sphingomyelin Phosphodiesterase / Q000378:metabolism*; D017154:Stromal Cells / Q000166:cytology / Q000378:metabolism*; D013859:Thiocarbamates; D013871:Thiones / Q000494:pharmacology; D015533:Transcriptional Activation / Q000187:drug effects
chemical_list: D000975:Antioxidants; D001952:Bridged-Ring Compounds; D017370:Interleukin-11; D016209:Interleukin-8; D007783:Lactones; D016328:NF-kappa B; D009636:Norbornanes; D009943:Organophosphorus Compounds; D010726:Phosphodiesterase Inhibitors; D011753:Pyrones; D013859:Thiocarbamates; D013871:Thiones; C084414:leustroducsin B; C046498:tricyclodecane-9-yl-xanthogenate; D013108:Sphingomyelin Phosphodiesterase; C023470:perhexiline maleate; D010480:Perhexiline; D003891:Desipramine; D000111:Acetylcysteine