Genetic deletion of Klf4 in the mouse intestinal epithelium ameliorates dextran sodium sulfate-induced colitis by modulating the NF-κB pathway inflammatory response

Background: Krüppel-like factor 4 (KLF4) is a zinc finger transcription factor expressed in the differentiated epithelial cells lining of the intestine. Under physiological conditions, KLF4 inhibits cell proliferation. Conversely, KLF4 mediates proinflammatory signaling in macrophages and its overexpression in the esophageal epithelium activates cytokines, leading to inflammation-mediated esophageal squamous cell cancer formation in mice. Here, we tested whether KLF4 has a proinflammatory activity in experimental colitis in mice. Methods: Villin-Cre;Klf4^fl/fl mice with intestine-specific Klf4 deletion (Klf4^ΔIS) and control mice with floxed Klf4 gene (Klf4^fl/fl) were treated or not with 3% dextran sodium sulfate (DSS) for 7 days to induce colitis. Additionally, WT mice were administered or not, nanoparticles loaded with scrambled or Klf4-siRNA, and concomitantly given DSS. Results: Compared with DSS-treated Klf4^fl/fl mice, DSS-treated Klf4^ΔIS mice were significantly less sensitive to DSS-induced colitis. DSS treatment of Klf4^fl/fl mice induced Klf4 expression in the crypt zone of the colonic epithelium. DSS-treated Klf4^ΔIS mice had increased proliferation relative to DSStreated control mice. DSS treatment induced NF-κB signaling pathway in Klf4^fl/fl mice colon but not Klf4^ΔIS mice. Additionally, WT mice given DSS and nanoparticle/Klf4-siRNA were less sensitive to colitis and had reduced Klf4 expression and while maintaining the proliferative response in the colonic epithelium. Conclusions: Our results indicate that Klf4 is an important mediator of DSS-induced colonic inflammation by modulating NF-κB signaling pathway and could be involved in the pathogenesis and/or propagation of inflammatory bowel disease. Thus, Klf4 may represent a novel therapeutic target in inflammatory bowel disease.