HNF4A regulation of transcription profiles in the mouse ileal and colonic epithelial cells

Purpose: HNF4A is a highly conserved nuclear receptor that has been associated with inflammatory bowel diseases. The goal of this study is to determine and compare transcriptional regulation by HNF4A in the small intestine and large intestine in mice. Methods: Intestinal epithelial cells (IECs) were flow sorted from the ileum and colon of WT and HNF4A IEC-specific KO mice at 21~22 days old and sequenced for transcriptome. Differentially expressed genes in the illeum and colon respectively comparing the WT and HNF4A IEC-KO were determined. Results: HNF4A regulates expression of hundreds of genes in both ileal and colonic IECs. However, many of the DE genes and the magnitude of changes are location specific. In general, a more significant dependancy on HNF4A is found in the colon. HNF4A is particularly required for the expression of a set of immune signaling molecules that are critical for the IEC-intrapithelial lymphocyte crosstalk. Those molecules include members of the butyrophilin-like molecules (Btnl1, Btnl2, Btnl4, and Btnl6) and MHC-I like molecule H2-T3 etc. Expression of the immune signaling molecules was validated by qPCR. Further comparison with HNF4A ChIP-seq datasets and validation with ChIP-qPCR confirmed that those genes are also direct HNF4A targets. mRNA profiling of ileal and colonic IECs from cohoused littermate controlled 3-week-old WT (Hnf4a fl/fl) and IEC-specific HNF4A KO (Hnf4a fl/fl Villin-Cre) mice. 4 biological replicates for each group.