Bacteroides fragilis toxin 2 damages human colonic mucosa in vitro

Citation
M. Riegler et al., Bacteroides fragilis toxin 2 damages human colonic mucosa in vitro, GUT, 44(4), 1999, pp. 504-510
Citations number
35
Categorie Soggetti
Gastroenerology and Hepatology","da verificare
Journal title
GUT
ISSN journal
00175749 → ACNP
Volume
44
Issue
4
Year of publication
1999
Pages
504 - 510
Database
ISI
SICI code
0017-5749(199904)44:4<504:BFT2DH>2.0.ZU;2-#
Abstract
Background-Strains of Bacteroides fragilis producing a 20 kDa protein toxin (B fragilis toxin (BFT) or fragilysin) are associated with diarrhoea in an imals and humans. Although in vitro results indicate that EFT damages intes tinal epithelial cells in culture, the effects of BFT on native human colon are not known. Aims-To examine the electrophysiological and morphological effects of purif ied BFT-2 on human colonic mucosa in vitro. Methods-For resistance (EP) measurements, colonic mucosa mounted in Ussing chambers was exposed to luminal or serosal BFT-2 (1.25-10 nM) and after fou r hours morphological damage was measured on haematoxylin and eosin stained sections using morphometry. F actin distribution was assessed using confoc al microscopy. Results-Serosal BFT-2 for four hours was four-, two;, seven-, and threefold more potent than luminal BFT-2 in decreasing resistance, increasing epithe lial H-3-mannitol permeability, and damaging crypt and surface colonocytes, respectively. (p<0.05). Confocal: microscopy showed reduced colonocyte F a ctin staining intensity after exposure to BFT-2. Conclusions-BFT-2 increases human colonic permeability and damages human co lonic epithelial cells in vitro. These effects may be important in the deve lopment of diarrhoea and intestinal inflammation caused by B fragilis in vi vo.