Differing roles for short chain fatty acids and GPR43 agonism in the regulation of intestinal barrier function and immune responses

PLoS One. 2017 Jul 20;12(7):e0180190. doi: 10.1371/journal.pone.0180190. eCollection 2017.

Abstract

Inflammatory bowel disease (IBD) is associated with a loss of intestinal barrier function and dysregulated immune responses. It has been shown that short chain fatty acids (SCFAs) are protective in IBD and that GPR43 mediates the protective effects of SCFAs. In this study, we investigated the effects of SCFAs in comparison to highly specific GPR43 agonists on human intestinal epithelial and immune cells. Our results confirm that SCFAs are enhancers of barrier function in intestinal epithelial cells. Additionally, SCFAs also displayed potent immunoregulatory properties based upon the ability to inhibit LPS-induced cytokine production in PBMC, and human T cell proliferation and cytokine production. Unexpectedly, and in contrast to the current belief, specific GPR43 agonists failed to exhibit similar barrier enhancing and anti-inflammatory properties. These findings demonstrate that SCFA possess broad protective functions in IBD and agonizing GPR43 alone is unlikely to be beneficial in patients.

MeSH terms

  • Animals
  • Caco-2 Cells
  • Cell Line
  • Cell Proliferation / drug effects
  • Cytokines / metabolism
  • Epithelial Cells / drug effects*
  • Epithelial Cells / immunology
  • Epithelial Cells / metabolism
  • Fatty Acids, Volatile
  • Humans
  • Intestinal Mucosa / drug effects*
  • Intestinal Mucosa / immunology
  • Intestinal Mucosa / metabolism
  • Leukocytes, Mononuclear / drug effects
  • Leukocytes, Mononuclear / immunology
  • Leukocytes, Mononuclear / metabolism
  • Mice
  • Receptors, Cell Surface / agonists*

Substances

  • Cytokines
  • FFA2R protein, human
  • Fatty Acids, Volatile
  • Receptors, Cell Surface

Grants and funding

Amgen provided support in the form of salaries for all authors, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.