Dataset Information

Enhanced Ca2+ entry due to Orai1 plasma membrane insertion increases IL-8 secretion by cystic fibrosis airways.

ABSTRACT: Cystic fibrosis (CF) is caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR). The most common mutation, ?F508, causes retention of CFTR in the endoplasmic reticulum (ER). Some CF abnormalities can be explained by altered Ca(2+) homeostasis, although it remains unknown how CFTR influences calcium signaling. This study examined the novel hypothesis that store-operated calcium entry (SOCE) through Orai1 is abnormal in CF. The significance of Orai1-mediated SOCE for increased interleukin-8 (IL-8) expression in CF was also investigated. CF and non-CF human airway epithelial cell line and primary cells (obtained at lung transplantation) were used in Ca(2+) imaging, electrophysiology, and fluorescence imaging experiments to explore differences in Orai1 function in CF vs. non-CF cells. Protein expression and localization was assessed by Western blots, cell surface biotinylation, ELISA, and image correlation spectroscopy (ICS). We show here that store-operated Ca(2+) entry (SOCE) is elevated in CF human airway epithelial cells (hAECs; ? 1.8- and ? 2.5-fold for total Ca(2+)(i) increase and Ca(2+) influx rate, respectively, and ? 2-fold increase in the I(CRAC) current) and is caused by increased exocytotic insertion (? 2-fold) of Orai1 channels into the plasma membrane, which is normalized by rescue of ?F508-CFTR trafficking to the cell surface. Augmented SOCE in CF cells is a major factor leading to increased IL-8 secretion (? 2-fold). CFTR normally down-regulates the Orai1/stromal interaction molecule 1 (STIM1) complex, and loss of this inhibition due to the absence of CFTR at the plasma membrane helps to explain the potentiated inflammatory response in CF cells.

SUBMITTER: Balghi H

PROVIDER: S-EPMC3236623 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Enhanced Ca2+ entry due to Orai1 plasma membrane insertion increases IL-8 secretion by cystic fibrosis airways.

Balghi Haouaria H Robert Renaud R Rappaz Benjamin B Zhang Xuexin X Wohlhuter-Haddad Adeline A Evagelidis Alexandra A Luo Yishan Y Goepp Julie J Ferraro Pasquale P Roméo Philippe P Trebak Mohamed M Wiseman Paul W PW Thomas David Y DY Hanrahan John W JW

FASEB journal : official publication of the Federation of American Societies for Experimental Biology 20110826 12

Cystic fibrosis (CF) is caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR). The most common mutation, ΔF508, causes retention of CFTR in the endoplasmic reticulum (ER). Some CF abnormalities can be explained by altered Ca(2+) homeostasis, although it remains unknown how CFTR influences calcium signaling. This study examined the novel hypothesis that store-operated calcium entry (SOCE) through Orai1 is abnormal in CF. The significance of Orai1-mediated SOCE ...[more]

PMID: 21873556

Similar Datasets

Project description:BACKGROUND:Store-operated Ca2+ entry (SOCE) through Ca2+ release-activated Ca2+ channels is an essential signaling pathway in many cell types. Ca2+ release-activated Ca2+ channels are formed by ORAI1, ORAI2, and ORAI3 proteins and activated by stromal interaction molecule (STIM) 1 and STIM2. Mutations in the ORAI1 and STIM1 genes that abolish SOCE cause a combined immunodeficiency (CID) syndrome that is accompanied by autoimmunity and nonimmunologic symptoms. OBJECTIVE:We performed molecular and immunologic analysis of patients with CID, anhidrosis, and ectodermal dysplasia of unknown etiology. METHODS:We performed DNA sequencing of the ORAI1 gene, modeling of mutations on ORAI1 crystal structure, analysis of ORAI1 mRNA and protein expression, SOCE measurements, immunologic analysis of peripheral blood lymphocyte populations by using flow cytometry, and histologic and ultrastructural analysis of patient tissues. RESULTS:We identified 3 novel autosomal recessive mutations in ORAI1 in unrelated kindreds with CID, autoimmunity, ectodermal dysplasia with anhidrosis, and muscular dysplasia. The patients were homozygous for p.V181SfsX8, p.L194P, and p.G98R mutations in the ORAI1 gene that suppressed ORAI1 protein expression and SOCE in the patients' lymphocytes and fibroblasts. In addition to impaired T-cell cytokine production, ORAI1 mutations were associated with strongly reduced numbers of invariant natural killer T and regulatory T (Treg) cells and altered composition of γδ T-cell and natural killer cell subsets. CONCLUSION:ORAI1 null mutations are associated with reduced numbers of invariant natural killer T and Treg cells that likely contribute to the patients' immunodeficiency and autoimmunity. ORAI1-deficient patients have dental enamel defects and anhidrosis, representing a new form of anhidrotic ectodermal dysplasia with immunodeficiency that is distinct from previously reported patients with anhidrotic ectodermal dysplasia with immunodeficiency caused by mutations in the nuclear factor κB signaling pathway (IKBKG and NFKBIA).

Dataset Information

Enhanced Ca2+ entry due to Orai1 plasma membrane insertion increases IL-8 secretion by cystic fibrosis airways.

Publications

Enhanced Ca2+ entry due to Orai1 plasma membrane insertion increases IL-8 secretion by cystic fibrosis airways.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets