title: (S)-armepavine inhibits human peripheral blood mononuclear cell activation by regulating Itk and PLCgamma activation in a PI-3K-dependent manner.
abstract: Chinese herbs are useful edible and medicinal plants for their immune modulatory functions. We have proven that (S)-armepavine (C19H23O3N; MW313) from Nelumbo nucifera inhibits the proliferation of human PBMCs activated with PHA and improves autoimmune diseases in MRL/MpJ-lpr/lpr mice. In the present study, the pharmacological activities of (S)-armepavine were evaluated in PHA-activated PBMCs. The results showed that (S)-armepavine suppressed PHA-induced PBMC proliferation and genes expression of IL-2 and IFN-gamma without direct cytotoxicity. Inhibition of NF-AT and NF-kappaB activation suggested phospholipase Cgamma (PLCgamma)-mediated Ca2+ mobilization and protein kinase C activation were blocked by (S)-armepavine. Phosphorylation of PLCgamma is regulated by lymphocyte-specific kinase (Lck), ZAP-70, and IL-2-inducible T cell kinase (Itk). We found (S)-armepavine inhibited PHA-induced phosphorylation of Itk and PLCgamma efficiently but did not influence Lck or ZAP-70 phosphorylation. In addition, ZAP-70-mediated pathways, such as the association of linker for activation of T cells with PLCgamma and activation of ERK, were also intact in the presence of (S)-armepavine. Finally, reduction of phosphoinositide 3,4,5-trisphosphate formation and Akt phosphorylation suggested that (S)-armepavine inhibited Itk, and PLCgamma phosphorylation might be a result of the influence of PI-3K activation. Addition of exogenous IL-2 or PMA/A23187 rescued PBMC proliferation in the presence of (S)-armepavine. Therefore, we concluded that (S)-armepavine inhibited PHA-induced cell proliferation and cytokine production in a major way by blocking membrane-proximal effectors such as Itk and PLCgamma in a PI-3K-dependent manner.
authors.affiliation: Institute of Pharmacology, National Yang-Ming University, Laboratory of Biochemistry, National Research Institute of Chinese Medicine, No. 155-1, Sec. 2, Li-Nung St., Shih-Pai, 112, Taipei, Taiwan, ROC.
authors.forename: Chih-Peng
authors.initials: CP
authors.lastname: Liu
authors.forename: Yuh-Chi
authors.initials: YC
authors.lastname: Kuo
authors.forename: Chien-Chang
authors.initials: CC
authors.lastname: Shen
authors.forename: Ming-Hsi
authors.initials: MH
authors.lastname: Wu
authors.forename: Jyh-Fei
authors.initials: JF
authors.lastname: Liao
authors.forename: Yun-Lian
authors.initials: YL
authors.lastname: Lin
authors.forename: Chieh-Fu
authors.initials: CF
authors.lastname: Chen
authors.forename: Wei-Jern
authors.initials: WJ
authors.lastname: Tsai
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D044182:Benzylisoquinolines / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000037:antagonists & inhibitors / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007371:Interferon-gamma / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D007376:Interleukin-2 / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000276:immunology; D008968:Molecular Conformation; D008970:Molecular Weight; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism; D050778:NFATC Transcription Factors / Q000037:antagonists & inhibitors / Q000378:metabolism; D031653:Nelumbo / Q000737:chemistry; D019869:Phosphatidylinositol 3-Kinases / Q000096:biosynthesis / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051966:Phospholipase C gamma / Q000187:drug effects* / Q000378:metabolism; D010766:Phosphorylation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000187:drug effects* / Q000378:metabolism; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D012639:Seeds / Q000737:chemistry; D013329:Structure-Activity Relationship; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D000470:Alkaloids; D044182:Benzylisoquinolines; D000001:Calcimycin; D002118:Calcium; D007371:Interferon-gamma; D007376:Interleukin-2; D016328:NF-kappa B; D050778:NFATC Transcription Factors; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051966:Phospholipase C gamma; D011493:Protein Kinase C; D011505:Protein-Tyrosine Kinases; D012333:RNA, Messenger; D013755:Tetradecanoylphorbol Acetate; C080813:emt protein-tyrosine kinase; C064689:armepavine