Luminal Extracellular Vesicles (EVs) in Inflammatory Bowel Disease (IBD) Exhibit Proinflammatory Effects on Epithelial Cells and Macrophages

Inflamm Bowel Dis. 2016 Jul;22(7):1587-95. doi: 10.1097/MIB.0000000000000840.

Abstract

Background: Extracellular vesicles (EVs) are membrane-enclosed particles released by cells as a means of intercellular communication. They are potential novel biomarkers, as they are readily isolated from body fluids, and their composition reflects disease pathways. Whether these particles are released from sites of intestinal inflammation in inflammatory bowel disease (IBD) has not previously been determined.

Methods: EVs were isolated by ultracentrifugation of colonic luminal fluid aspirates and characterized according to surface proteins, and constituent mRNA and proteins. The effects of EVs on colonic epithelial cells and macrophages in culture were assessed at the transcriptional, translational, and functional levels.

Results: Intestinal luminal aspirates contained abundant EVs, at a mean concentration of 4.3 × 10 particles/mL and with a mean diameter of 146 nm. EVs from patients with IBD with a high endoscopic score (≥1) contained significantly higher mRNA and protein levels of interleukin 6 (IL-6), IL-8, IL-10, and tumor necrosis factor α than EVs from healthy controls. EVs were absorbed by cultured colonic epithelial cells, leading to an increased translation of IL-8 protein by recipient cells when treated with EVs from patients with IBD. EVs and EV-treated epithelial cells induced migration of a significantly greater number of macrophages than epithelial cells alone.

Conclusions: EVs shed from sites of intestinal inflammation in patients with IBD have a distinct mRNA and protein profile from those of healthy individuals. These EVs have proinflammatory effects on the colonic epithelium, in vitro. Their stability in luminal samples and their mRNA and protein content identify them as a potential fecal biomarker that reflects mucosal inflammatory pathways.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, CD / metabolism
  • Calgranulin B / genetics
  • Cell Adhesion Molecules / metabolism
  • Cell Line
  • Cell Movement
  • Colon
  • Epithelial Cells / metabolism*
  • Epithelial Cells / physiology
  • Extracellular Vesicles / metabolism*
  • Extracellular Vesicles / ultrastructure
  • Flow Cytometry
  • GPI-Linked Proteins / metabolism
  • Humans
  • Inflammatory Bowel Diseases / genetics*
  • Inflammatory Bowel Diseases / metabolism*
  • Interleukin-8 / genetics
  • Interleukin-8 / metabolism
  • Interleukins / genetics
  • Interleukins / metabolism*
  • Leukocyte Common Antigens / metabolism
  • Lipopolysaccharide Receptors / metabolism
  • Macrophages / physiology
  • Mice
  • Microscopy, Electron, Transmission
  • Mucin-1 / metabolism
  • Mucin-2 / genetics
  • Particle Size
  • RNA, Messenger / metabolism*
  • Transforming Growth Factor beta / genetics
  • Tumor Necrosis Factor-alpha / metabolism
  • alpha-Defensins / genetics

Substances

  • Antigens, CD
  • CEACAM8 protein, human
  • Calgranulin B
  • Cell Adhesion Molecules
  • GPI-Linked Proteins
  • Interleukin-8
  • Interleukins
  • Lipopolysaccharide Receptors
  • MUC1 protein, human
  • MUC2 protein, human
  • Mucin-1
  • Mucin-2
  • RNA, Messenger
  • Transforming Growth Factor beta
  • Tumor Necrosis Factor-alpha
  • alpha-Defensins
  • human neutrophil peptide 3
  • Leukocyte Common Antigens
  • PTPRC protein, human