A pore-forming toxin produced by Aeromonas sobria activates cAMP-dependent Cl- secretory pathways to cause diarrhea.
Aeromonas sobria hemolysin (ASH) is one of the major virulence factors produced by A. sobria, a human pathogen that causes diarrhea. We investigated the effects of ASH on Cl(-) transport in human colonic epithelial cells. ASH increased short-circuit currents (Isc) and (125)I efflux from Caco-2 cells, indicating ASH activate Cl(-) secretion. Additions of inhibitors of cyclic AMP dependent Cl(-) channels, glybenclamide and NPPB suppressed the Isc and (125)I efflux increases induced by ASH. And ASH increased the intracellular cyclic AMP concentration. Moreover, ASH stimulated fluid accumulation in the iliac loop test, and glybenclamide and NPPB suppressed this fluid accumulation. Thus, cAMP-dependent Cl(-) secretory pathway could be related with diarrhea induced by A. sobria.
Tanoue
Naomi
N
Department of Nutrition, School of Medicine, Tokushima University, 3-18-5 Kuramoto-cho, Tokushima City, Tokushima 770-8503, Japan.
Takahashi
Akira
A
Okamoto
Keinosuke
K
Fujii
Yoshio
Y
Taketani
Yutaka
Y
Harada
Nagakatsu
N
Nakano
Masayuki
M
Nakaya
Yutaka
Y
D000333:Aeromonas / Q000737:chemistry*; D000818:Animals; D001427:Bacterial Toxins / Q000633:toxicity*; D018938:Caco-2 Cells; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D018118:Chloride Channels / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism*; D003967:Diarrhea / Q000378:metabolism / Q000382:microbiology*; D006460:Hemolysin Proteins / Q000633:toxicity*; D006801:Humans; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000378:metabolism; D051379:Mice
D001427:Bacterial Toxins; D018118:Chloride Channels; D002712:Chlorides; D006460:Hemolysin Proteins; D000242:Cyclic AMP