TY - JOUR
T1 - Enterohemorrhagic E. Coli (EHEC)—Secreted serine protease EspP stimulates electrogenic ion transport in human colonoid monolayers
AU - Tse, C. Ming
AU - In, Julie G.
AU - Yin, Jianyi
AU - Donowitz, Mark
AU - Doucet, Michele
AU - Foulke-Abel, Jennifer
AU - Ruiz-Perez, Fernando
AU - Nataro, James P.
AU - Zachos, Nicholas C.
AU - Kaper, James B.
AU - Kovbasnjuk, Olga
N1 - Funding Information:
Funding: This research was funded by NIH grants P01 AI-125181, P30 DK-089502, and K01 DK-106323.
Publisher Copyright:
© 2018 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2018/9
Y1 - 2018/9
N2 - One of the characteristic manifestations of Shiga-toxin-producing Escherichia coli (E. coli) infection in humans, including EHEC and Enteroaggregative E. coli O104:H4, is watery diarrhea. However, neither Shiga toxin nor numerous components of the type-3 secretion system have been found to independently elicit fluid secretion. We used the adult stem-cell-derived human colonoid monolayers (HCM) to test whether EHEC-secreted extracellular serine protease P (EspP), a member of the serine protease family broadly expressed by diarrheagenic E. coli can act as an enterotoxin. We applied the Ussing chamber/voltage clamp technique to determine whether EspP stimulates electrogenic ion transport indicated by a change in short-circuit current (Isc). EspP stimulates Isc in HCM. The EspP-stimulated Isc does not require protease activity, is not cystic fibrosis transmembrane conductance regulator (CFTR)-mediated, but is partially Ca2+-dependent. EspP neutralization with a specific antibody reduces its potency in stimulating Isc. Serine Protease A, secreted by Enteroaggregative E. coli, also stimulates Isc in HCM, but this current is CFTR-dependent. In conclusion, EspP stimulates colonic CFTR-independent active ion transport and may be involved in the pathophysiology of EHEC diarrhea. Serine protease toxins from E. coli pathogens appear to serve as enterotoxins, potentially significantly contributing to watery diarrhea.
AB - One of the characteristic manifestations of Shiga-toxin-producing Escherichia coli (E. coli) infection in humans, including EHEC and Enteroaggregative E. coli O104:H4, is watery diarrhea. However, neither Shiga toxin nor numerous components of the type-3 secretion system have been found to independently elicit fluid secretion. We used the adult stem-cell-derived human colonoid monolayers (HCM) to test whether EHEC-secreted extracellular serine protease P (EspP), a member of the serine protease family broadly expressed by diarrheagenic E. coli can act as an enterotoxin. We applied the Ussing chamber/voltage clamp technique to determine whether EspP stimulates electrogenic ion transport indicated by a change in short-circuit current (Isc). EspP stimulates Isc in HCM. The EspP-stimulated Isc does not require protease activity, is not cystic fibrosis transmembrane conductance regulator (CFTR)-mediated, but is partially Ca2+-dependent. EspP neutralization with a specific antibody reduces its potency in stimulating Isc. Serine Protease A, secreted by Enteroaggregative E. coli, also stimulates Isc in HCM, but this current is CFTR-dependent. In conclusion, EspP stimulates colonic CFTR-independent active ion transport and may be involved in the pathophysiology of EHEC diarrhea. Serine protease toxins from E. coli pathogens appear to serve as enterotoxins, potentially significantly contributing to watery diarrhea.
KW - CFTR
KW - Diarrhea
KW - EHEC
KW - Human colonoid monolayers
KW - Intracellular Ca2+
KW - SPATEs
KW - Serine protease EspP
KW - Short circuit current
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U2 - 10.3390/toxins10090351
DO - 10.3390/toxins10090351
M3 - Article
C2 - 30200426
AN - SCOPUS:85053057234
VL - 10
JO - Toxins
JF - Toxins
SN - 2072-6651
IS - 9
M1 - 351
ER -