NFATc1 regulation of TRAIL expression in human intestinal cells

• Published in: PloS one 2011-05, Vol.6 (5), p.e19882-e19882
• Main Authors: Wang, Qingding, Zhou, Yuning, Weiss, Heidi L, Chow, Chi-Wing, Evers, B Mark
• Format: Article
• Language: English
• Subjects: Acetic acid; Activation; Apoptosis; Binding sites; Biology; Calcimycin; Calcineurin; Calcium; Cell differentiation; Cells, Cultured; Clonal deletion; Cyclosporins; Differentiation (biology); Gene deletion; Gene expression; Gene Expression Regulation; Humans; Inhibition; Intestine; Intestines - cytology; Intestines - metabolism; Kinases; Lymphocytes; Medicine; NF-AT protein; NFATC Transcription Factors - genetics; NFATC Transcription Factors - physiology; Phorbol 12-myristate 13-acetate; Promoter Regions, Genetic; Protein Binding; Ribonucleic acid; RNA; RNA, Messenger - biosynthesis; RNA-mediated interference; Signaling; Sp1 protein; Sp1 Transcription Factor - genetics; T cell receptors; T cells; TNF-Related Apoptosis-Inducing Ligand - biosynthesis; TNF-Related Apoptosis-Inducing Ligand - genetics; TRAIL protein; Transcription factors; Tumor necrosis factor; Tumor necrosis factor-TNF
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0019882

TNF-related apoptosis-inducing ligand (TRAIL; Apo2) has been shown to promote intestinal cell differentiation. Nuclear factor of activated T cells (NFAT) participates in the regulation of a variety of cellular processes, including differentiation. Here, we examined the role of NFAT in the regulation of TRAIL in human intestinal cells. Treatment with a combination of phorbol 12-myristate 13-acetate (PMA) plus the calcium ionophore A23187 (Io) increased NFAT activation and TRAIL expression; pretreatment with the calcineurin inhibitor cyclosporine A (CsA), an antagonist of NFAT signaling, diminished NFAT activation and TRAIL induction. In addition, knockdown of NFATc1, NFATc2, NFATc3, and NFATc4 blocked PMA/Io increased TRAIL protein expression. Expression of NFATc1 activated TRAIL promoter activity and increased TRAIL mRNA and protein expression. Deletion of NFAT binding sites from the TRAIL promoter did not significantly abrogate NFATc1-increased TRAIL promoter activity, suggesting an indirect regulation of TRAIL expression by NFAT activation. Knockdown of NFATc1 increased Sp1 transcription factor binding to the TRAIL promoter and, importantly, inhibition of Sp1, by chemical inhibition or RNA interference, increased TRAIL expression. These studies identify a novel mechanism for TRAIL regulation by which activation of NFATc1 increases TRAIL expression through negative regulation of Sp1 binding to the TRAIL promoter.