ZBP-89 Regulates Expression of Tryptophan Hydroxylase I and Mucosal Defense Against Salmonella Typhimurium in Mice

• Published in: Gastroenterology (New York, N.Y. 1943) Vol. 144; no. 7; pp. 1466 - 1477.e9
• Main Authors: Essien, Bryan E, Grasberger, Helmut, Romain, Rachael D, Law, David J, Veniaminova, Natalia A, Saqui–Salces, Milena, El–Zaatari, Mohamad, Tessier, Arthur, Hayes, Michael M, Yang, Alexander C, Merchant, Juanita L
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2013
• Subjects: 5HT; Animals; Butyrate; Butyrates - immunology; Colitis - immunology; Defensin; DNA-Binding Proteins - genetics; DNA-Binding Proteins - physiology; Enterochromaffin Cells - immunology; Gastroenterology and Hepatology; Intestinal Mucosa - immunology; Mice; Mice, Transgenic; Promoter Regions, Genetic; RNA, Messenger - analysis; Salmonella Infections - immunology; Salmonella typhimurium; Serotonin - biosynthesis; Serotonin - immunology; Transcription Factors - genetics; Transcription Factors - physiology; Tryptophan Hydroxylase - physiology; ΔhilA; 5HT; Tph1; 5-hydroxytryptamine; tryptophan hydroxylase 1; SPI-1; mRNA; Butyrate; messenger RNA; MDP; TLR; WT; EC; Toll-like receptor; ChgA; muramyl dipeptide; enterochromaffin; SCFA; short chain fatty acid; ΔhilA; 5HTP; chromogranin A; Defensin; Salmonella pathogenicity island 1; wild-type; 5-hydroxytryptophan
• ISSN: 0016-5085; 1528-0012
• DOI: 10.1053/j.gastro.2013.01.057

Background & Aims ZBP-89 (also ZNF148 or Zfp148) is a butyrate-inducible zinc finger transcription factor that binds to GC-rich DNA elements. Deletion of the N-terminal domain is sufficient to increase mucosal susceptibility to chemical injury and inflammation. We investigated whether conditional deletion of ZBP-89 from the intestinal and colonic epithelium of mice increases their susceptibility to pathogens such as Salmonella typhimurium. Methods We generated mice with a conditional null allele of Zfp148 (ZBP-89FL/FL ) using homologous recombination to flank Zfp148 with LoxP sites (ZBP-89FL/FL ), and then bred the resulting mice with those that express VillinCre. We used microarray analysis to compare gene expression patterns in colonic mucosa between ZBP-89ΔInt and C57BL/6 wild-type mice (controls). Mice were gavaged with 2 isogenic strains of S typhimurium after administration of streptomycin. Results Microarray analysis revealed that the colonic mucosa of ZBP-89ΔInt mice had reduced levels of tryptophan hydroxylase 1 (Tph1) messenger RNA, encoding the rate-limiting enzyme in enterochromaffin cell serotonin (5-hydroxytryptamine [5HT]) biosynthesis. DNA affinity precipitation demonstrated direct binding of ZBP-89 to the mouse Tph1 promoter, which was required for its basal and butyrate-inducible expression. ZBP-89ΔInt mice did not increase mucosal levels of 5HT in response to S typhimurium infection, and succumbed to the infection 2 days before control mice. The ΔhilA isogenic mutant of S typhimurium lacks this butyrate-regulated locus and stimulated, rather than suppressed, expression of Tph1 approximately 50-fold in control, but not ZBP-89ΔInt , mice, correlating with fecal levels of butyrate. Conclusions ZBP-89 is required for butyrate-induced expression of the Tph1 gene and subsequent production of 5HT in response to bacterial infection in mice. Reductions in epithelial ZBP-89 increase susceptibility to colitis and sepsis after infection with S typhimurium , partly because of reduced induction of 5HT production in response to butyrate and decreased secretion of antimicrobial peptides.