Transcription Factor Binding Site Enrichment Analysis In Co-Expression Modules In Celiac Disease

The aim of this study was to construct celiac co-expression patterns at a whole genome level and to identify transcription factors (TFs) that could drive the gliadin-related changes in coordination of gene expression observed in celiac disease (CD). Differential co-expression modules were identified in the acute and chronic responses to gliadin using expression data from a previous microarray study in duodenal biopsies. Transcription factor binding site (TFBS) and Gene Ontology (GO) annotation enrichment analyses were performed in differentially co-expressed genes (DCGs) and selection of candidate regulators was performed. Expression of candidates was measured in clinical samples and the activation of the TFs was further characterized in C2BBe1 cells upon gliadin challenge. Enrichment analyses of the DCGs identified 10 TFs and five were selected for further investigation. Expression changes related to active CD were detected in four TFs, as well as in several of their in silico predicted targets. The activation of TFs was further characterized in C2BBe1 cells upon gliadin challenge, and an increase in nuclear translocation of CAMP Responsive Element Binding Protein 1 (CREB1) and IFN regulatory factor-1 (IRF1) in response to gliadin was observed. Using transcriptome-wide co-expression analyses we are able to propose novel genes involved in CD pathogenesis that respond upon gliadin stimulation, also in non-celiac models.The authors thank the technical and human support provided by SGIker of the UPV/EHU. The work was funded by ISCIII Research Project Grants PI13/01201 and PI16/00258, cofunded by the European Union ERDF/ESF "A way to make Europe" and by Basque Department of Health project 2011/111034 to JRB and Basque Department of Health project 2015/111068 to I.S., N.F.-J. was supported by an IARC Postodctoral Fellowship (FP7 Marie Curie Actions-People-COFUND) and a Postdoctoral Fellowship from the Basque Department of Education. I.R.-G. and A.J.-M. are supported by predoctoral fellowship grants from the UPV/EHU and the Basque Department of Education, respectively