title: Bacteria regulate intestinal epithelial cell differentiation factors both in vitro and in vivo.
abstract: BACKGROUND
  The human colon harbours a plethora of bacteria known to broadly impact on mucosal metabolism and function and thought to be involved in inflammatory bowel disease pathogenesis and colon cancer development. In this report, we investigated the effect of colonic bacteria on epithelial cell differentiation factors in vitro and in vivo. As key transcription factors we focused on Hes1, known to direct towards an absorptive cell fate, Hath1 and KLF4, which govern goblet cell.
  
  
  METHODS
  Expression of the transcription factors Hes1, Hath1 and KLF4, the mucins Muc1 and Muc2 and the defensin HBD2 were measured by real-time PCR in LS174T cells following incubation with several heat-inactivated E. coli strains, including the probiotic E. coli Nissle 1917+/- flagellin, Lactobacilli and Bifidobacteria. For protein detection Western blot experiments and chamber-slide immunostaining were performed. Finally, mRNA and protein expression of these factors was evaluated in the colon of germfree vs. specific pathogen free vs. conventionalized mice and colonic goblet cells were counted.
  
  
  RESULTS
  Expression of Hes1 and Hath1, and to a minor degree also of KLF4, was reduced by E. coli K-12 and E. coli Nissle 1917. In contrast, Muc1 and HBD2 expression were significantly enhanced, independent of the Notch signalling pathway. Probiotic E. coli Nissle 1917 regulated Hes1, Hath1, Muc1 and HBD2 through flagellin. In vivo experiments confirmed the observed in vitro effects of bacteria by a diminished colonic expression of Hath1 and KLF4 in specific pathogen free and conventionalized mice as compared to germ free mice whereas the number of goblet cells was unchanged in these mice.
  
  
  CONCLUSIONS
  Intestinal bacteria influence the intestinal epithelial differentiation factors Hes1, Hath1 and KLF4, as well as Muc1 and HBD2, in vitro and in vivo. The induction of Muc1 and HBD2 seems to be triggered directly by bacteria and not by Notch.
authors: Dr. Margarete Fischer-Bosch Institute for Clinical Pharmacology, Stuttgart, Germany.
authors: Svetlana
authors: S
authors: Becker
authors: Tobias A
authors: TA
authors: Oelschlaeger
authors: Andy
authors: A
authors: Wullaert
authors: Katerina
authors: K
authors: Vlantis
authors: Manolis
authors: M
authors: Pasparakis
authors: Jan
authors: J
authors: Wehkamp
authors: Eduard F
authors: EF
authors: Stange
authors: Michael
authors: M
authors: Gersemann
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D001644:Bifidobacterium; D002454:Cell Differentiation / Q000502:physiology*; D045744:Cell Line, Tumor; D003106:Colon / Q000166:cytology / Q000378:metabolism / Q000382:microbiology*; D004926:Escherichia coli; D020397:Goblet Cells / Q000166:cytology / Q000378:metabolism / Q000382:microbiology*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism*; D007778:Lactobacillus; D051379:Mice; D008810:Mice, Inbred C57BL; D018396:Mucin-1 / Q000235:genetics / Q000378:metabolism; D055262:Mucin-2 / Q000235:genetics / Q000378:metabolism; D000072056:Transcription Factor HES-1; D023083:beta-Defensins / Q000235:genetics / Q000378:metabolism
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D018398:Homeodomain Proteins; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; D018396:Mucin-1; D055262:Mucin-2; D000072056:Transcription Factor HES-1; D023083:beta-Defensins; C500942:ATOH1 protein, human; C106641:DEFB4A protein, human; C000715467:KLF4 protein, human; C000715468:Klf4 protein, mouse; C060192:MUC1 protein, human; C524625:MUC2 protein, human; C078493:HES1 protein, human