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This Article Full Text Full Text (PDF) Supplemental Material All Versions of this Article: 29/2/161    most recent 00134.2006v1 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 ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Bossé, Y. Articles by Hudson, T. J. Search for Related Content PubMed PubMed Citation Articles by Bossé, Y. Articles by Hudson, T. J.

1,25-Dihydroxy-vitamin D₃ stimulation of bronchial smooth muscle cells induces autocrine, contractility, and remodeling processes

¹ McGill University and Génome Québec Innovation Centre, Montréal, Québec, Canada
² University of Montréal, Sacré-Coeur Hospital, Research Centre, Montréal, Québec, Canada

Genetic variants in the vitamin D receptor (VDR) gene were recently associated with asthma. The biological mechanisms explaining this association are unknown but are likely to involve many cell types given the pleiotropic effect of its ligand, 1,25-dihydroxy-vitamin D₃ [1,25(OH)₂D₃]. Considering the prominent role of bronchial smooth muscle cells (BSMCs) in the pathogenesis of asthma, experiments were conducted to explore the gene regulatory effects of 1,25(OH)₂D₃ in these cells. Using RT-PCR and Western blot, we showed that VDR is present both at the mRNA transcript and protein levels in human BSMCs. The functionality of the receptor was then demonstrated by showing a >200-fold change in the expression of the 24-hydroxylase (CYP24A1) gene following 1,25(OH)₂D₃ stimulation. Microarray experiments were then performed to identify differentially regulated genes and pathways in BMSCs treated or not with 1,25(OH)₂D₃. A total of 729 probe sets on the U133 plus 2.0 Affymetrix GeneChip showed fold-change differences above the 1.5 threshold using the Robust Multichip Average intensities. This corresponds to 231 unique genes that were upregulated and 215 unique genes that were down-regulated following 1,25(OH)₂D₃ stimulation. A high similarity between microarray and real-time PCR results was observed for 13 random genes, with a concordance correlation coefficient of 0.91. Real-time PCR was also performed to confirm the regulation of asthma candidate genes. To identify the biological relevance of this regulation, biological pathways analyses were performed. The most significant network of upregulated genes included genes involved in morphogenesis, cell growth, and survival as well as genes encoding structural proteins, which are potentially involved in airway remodeling.

microarray; real-time PCR; pathways analyses; candidate genes