HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 286/5/C1100    most recent 00494.2003v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (62) Citing Articles via Google Scholar Google Scholar Articles by Kahlenberg, J. M. Articles by Dubyak, G. R. Search for Related Content PubMed PubMed Citation Articles by Kahlenberg, J. M. Articles by Dubyak, G. R.

RECEPTORS AND SIGNAL TRANSDUCTION

Mechanisms of caspase-1 activation by P2X₇ receptor-mediated K⁺ release

Departments of ¹Pathology and ²Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106

Submitted 10 November 2003 ; accepted in final form 12 December 2003

The mechanisms underlying caspase-1 activation and IL-1 processing during inflammatory activation of monocytes and macrophages are not well defined. Here, we describe an in vitro proteolytic processing assay that allows for comparison of caspase-1 regulatory components in a cell-free system separately from the confounding issue of IL-1 secretion. Analysis of in vitro IL-1 and caspase-1 processing in lysates from unstimulated Bac1 murine macrophages indicated a slow rate of basal caspase-1 activation and proteolytic maturation of IL-1. In contrast, brief (5 min) treatment of intact macrophages with extracellular ATP (as an activator of the P2X₇ receptor) or nigericin before cell lysis markedly accelerated the in vitro processing of caspase-1 and IL-1. This acceleration of in vitro processing was strictly dependent on loss of intracellular K⁺ from the intact cells. The induction of in vitro caspase-1 activation by lysis per se or by K⁺ loss before lysis was sensitive to pretreatment of intact macrophages with the tyrphostin AG-126 or bromoenol lactone, an inhibitor of Ca²⁺-independent phospholipase A₂. Caspase-1 activation and IL-1 processing in lysates from unstimulated macrophages were also accelerated by addition of recombinant ASC, a previously identified adapter protein that directly associates with caspase-1. These data indicate that increased K⁺ efflux via P2X₇ nucleotide receptor stimulation activates AG-126- and bromoenol lactone-sensitive signaling pathways in murine macrophages that result in stably maintained signals for caspase-1 regulation in cell-free assays.

AG-126; ASC; bromoenol lactone; IL-1; inflammation

This article has been cited by other articles:

				Z. L. Newman, S. H. Leppla, and M. Moayeri CA-074Me Protection against Anthrax Lethal Toxin Infect. Immun., October 1, 2009; 77(10): 4327 - 4336. [Abstract] [Full Text] [PDF]

				T. Kurenuma, I. Kawamura, H. Hara, R. Uchiyama, S. Daim, S. R. Dewamitta, S. Sakai, K. Tsuchiya, T. Nomura, and M. Mitsuyama The RD1 Locus in the Mycobacterium tuberculosis Genome Contributes to Activation of Caspase-1 via Induction of Potassium Ion Efflux in Infected Macrophages Infect. Immun., September 1, 2009; 77(9): 3992 - 4001. [Abstract] [Full Text] [PDF]

				W. R. Silverman, J. P. de Rivero Vaccari, S. Locovei, F. Qiu, S. K. Carlsson, E. Scemes, R. W. Keane, and G. Dahl The Pannexin 1 Channel Activates the Inflammasome in Neurons and Astrocytes J. Biol. Chem., July 3, 2009; 284(27): 18143 - 18151. [Abstract] [Full Text] [PDF]

				D. Donnelly-Roberts, S. McGaraughty, C.-C. Shieh, P. Honore, and M. F. Jarvis Painful Purinergic Receptors J. Pharmacol. Exp. Ther., February 1, 2008; 324(2): 409 - 415. [Abstract] [Full Text] [PDF]

				C. M. Turner, F. W. K. Tam, P.-C. Lai, R. M. Tarzi, G. Burnstock, C. D. Pusey, H. T. Cook, and R. J. Unwin Increased expression of the pro-apoptotic ATP-sensitive P2X7 receptor in experimental and human glomerulonephritis Nephrol. Dial. Transplant., February 1, 2007; 22(2): 386 - 395. [Abstract] [Full Text] [PDF]

				P. Honore, D. Donnelly-Roberts, M. T. Namovic, G. Hsieh, C. Z. Zhu, J. P. Mikusa, G. Hernandez, C. Zhong, D. M. Gauvin, P. Chandran, et al. A-740003 [N-(1-{[(Cyanoimino)(5-quinolinylamino) methyl]amino}-2,2-dimethylpropyl)-2-(3,4-dimethoxyphenyl)acetamide], a Novel and Selective P2X7 Receptor Antagonist, Dose-Dependently Reduces Neuropathic Pain in the Rat J. Pharmacol. Exp. Ther., December 1, 2006; 319(3): 1376 - 1385. [Abstract] [Full Text] [PDF]

				M. Garcia-Marcos, E. Perez-Andres, S. Tandel, U. Fontanils, A. Kumps, E. Kabre, A. Gomez-Munoz, A. Marino, J.-P. Dehaye, and S. Pochet Coupling of two pools of P2X7 receptors to distinct intracellular signaling pathways in rat submandibular gland J. Lipid Res., April 1, 2006; 47(4): 705 - 714. [Abstract] [Full Text] [PDF]

				C. A. Dinarello Blocking IL-1 in systemic inflammation J. Exp. Med., May 2, 2005; 201(9): 1355 - 1359. [Abstract] [Full Text] [PDF]

				M. Yamamoto, K. Yaginuma, H. Tsutsui, J. Sagara, X. Guan, E. Seki, K. Yasuda, M. Yamamoto, S. Akira, K. Nakanishi, et al. ASC is essential for LPS-induced activation of procaspase-1 independently of TLR-associated signal adaptor molecules Genes Cells, November 1, 2004; 9(11): 1055 - 1067. [Abstract] [Full Text] [PDF]

				P. A. Verhoef, S. B. Kertesy, M. Estacion, W. P. Schilling, and G. R. Dubyak Maitotoxin Induces Biphasic Interleukin-1{beta} Secretion and Membrane Blebbing in Murine Macrophages Mol. Pharmacol., October 1, 2004; 66(4): 909 - 920. [Abstract] [Full Text] [PDF]