GSE123345
Tristetraprolin targets Nos2 expression in the colonic epithelium
Tristetraprolin (TTP), encoded by the Zfp36 gene, is a zinc-finger protein that regulates RNA stability primarily through association with 3' untranslated regions (3'UTRs) of target mRNAs. While TTP is expressed abundantly in the intestines, its function in intestinal epithelial cells (IECs) is unknown. Here we used a cre-lox system to remove Zfp36 in the mouse epithelium to uncover a role for TTP in IECs and to identify target genes in these cells. While TTP was largely dispensable for establishment and maintenance of the colonic epithelium, we found an expansion of the proliferative zone and an increase in goblet cell numbers in the colon crypts of Zfp36?IEC mice. Furthermore, through RNA-sequencing of transcripts isolated from the colons of Zfp36fl/fl and Zfp36?IEC mice, we found that expression of inducible nitric oxide synthase (iNos or Nos2) was elevated in TTP-knockout IECs. We demonstrate that TTP interacts with AU-rich elements in the Nos2 3'UTR and suppresses Nos2 expression. In comparison to control Zfp36fl/fl mice, Zfp36?IEC mice were less susceptible to dextran sodium sulfate (DSS)-induced acute colitis. Together, these results demonstrate that TTP targets Nos2 expression in IECs and aggravates acute colitis. Overall design: Colonic mRNA profiles of 6- to 8- week old Zfp36fl/fl and Zfp36?IEC mice were generated by deep sequencing, in triplicate.