CRACM/Orai ion channel expression and function in human lung mast cells.
J Allergy Clin Immunol
; 129(6): 1628-35.e2, 2012 Jun.
Article
de En
| MEDLINE
| ID: mdl-22409987
ABSTRACT
BACKGROUND:
Influx of extracellular Ca(2+) into human lung mast cells (HLMCs) is essential for the FcεRI-dependent release of preformed granule-derived mediators and newly synthesized autacoids and cytokines. However, the identity of the ion channels underlying this Ca(2+) influx is unknown. The recently discovered members of the CRACM/Orai ion channel family that carries the Ca(2+) release-activated Ca(2+) current are candidates.OBJECTIVES:
To investigate the expression and function of CRACM channels in HLMCs.METHODS:
CRACM mRNA, protein, and functional expression were examined in purified HLMCs and isolated human bronchus.RESULTS:
CRACM1, -2, and -3 mRNA transcripts and CRACM1 and -2 proteins were detectable in HLMCs. A CRACM-like current was detected following FcεRI-dependent HLMC activation and also in HLMCs dialyzed with 30 µM inositol triphosphate. The Ca(2+)-selective current obtained under both conditions was blocked by 10 µM La(3+) and Gd(3+), known blockers of CRACM channels, and 2 distinct and specific CRACM-channel blockers-GSK-7975A and Synta-66. Both blockers reduced FcεRI-dependent Ca(2+) influx, and 3 µM GSK-7975A and Synta-66 reduced the release of histamine, leukotriene C(4), and cytokines (IL-5/-8/-13 and TNFα) by up to 50%. Synta-66 also inhibited allergen-dependent bronchial smooth muscle contraction in ex vivo tissue.CONCLUSIONS:
The presence of CRACM channels, a CRACM-like current, and functional inhibition of HLMC Ca(2+) influx, mediator release, and allergen-induced bronchial smooth muscle contraction by CRACM-channel blockers supports a role for CRACM channels in FcεRI-dependent HLMC secretion. CRACM channels are therefore a potential therapeutic target in the treatment of asthma and related allergic diseases.
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Canaux calciques
/
Poumon
/
Mastocytes
Limites:
Humans
Langue:
En
Journal:
J Allergy Clin Immunol
Année:
2012
Type de document:
Article
Pays d'affiliation:
Royaume-Uni