Role of Ca(2+) on TNF-alpha and IL-6 secretion from RBL-2H3 mast cells.
Ca2+ acts as an important second messenger in mast cells. However, the mechanisms involved in the secretion of inflammatory cytokines from activated mast cells are unknown. In this study, we examined the signaling pathway involved in calcium-related cytokine secretion in a mast cell line, RBL-2H3 cells. We report that treatment with 1,2-bis (2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA-AM), a chelator of intracellular calcium, can inhibit IgE-stimulated TNF-alpha and IL-6 secretion in a concentration-dependent manner with IC50 values of 0.41 and 0.014 microM, respectively. Maximal inhibition of TNFalpha- and IL-6 secretion was 58.5 +/- 3% and 87 +/- 8% in BAPTA-AM, respectively. BAPTA-AM also completely inhibited the IgE-induced TNF-alpha and IL-6 mRNA levels. In activated RBL-2H3 cells, the expression level of NF-kappaB/Rel A protein increased in the nucleus. However, the level of NF-kappaB/Rel A in nucleus was decreased by treatment of BAPTA-AM. In addition, BAPTA-AM completely inhibited the IgE-induced IkappaB kinase beta (IKKbeta) activation and IkappaBalpha phosphorylation. These observations demonstrate that the intracellular Ca2+ may play an important role in IgE-induced TNF-alpha and IL-6 secretion from mast cells via IKKbeta activation.
Jeong
Hyun-Ja
HJ
Department of Oriental Pharmacy, College of Pharmacy, and Korea Institute of Oriental Pharmacy, Wonkwang University, Iksan, 570-749, Chonbuk, South Korea.
Hong
Seung-Heon
SH
Lee
Dong-Jin
DJ
Park
Jae-Hwang
JH
Kim
Kyung-Suk
KS
Kim
Hyung-Min
HM
D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D002614:Chelating Agents / Q000494:pharmacology; D004533:Egtazic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D051550:I-kappa B Kinase; D007073:Immunoglobulin E / Q000276:immunology; D015850:Interleukin-6 / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008407:Mast Cells / Q000276:immunology*; D016328:NF-kappa B / Q000378:metabolism; D010739:Phospholipase D / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D051996:Transcription Factor RelA; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*
D002614:Chelating Agents; D015850:Interleukin-6; D016328:NF-kappa B; D012333:RNA, Messenger; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; D007073:Immunoglobulin E; D004533:Egtazic Acid; D017346:Protein Serine-Threonine Kinases; D051550:I-kappa B Kinase; D010739:Phospholipase D; D002118:Calcium