TY - JOUR

T1 - Cholera toxin perturbs the paracellular barrier in the small intestinal epithelium of rats by affecting claudin-2 and tricellulin

AU - Markov, Alexander G.

AU - Vishnevskaya, Olga N.

AU - Okorokova, Larisa S.

AU - Fedorova, Arina A.

AU - Kruglova, Natalia M.

AU - Rybalchenko, Oksana V.

AU - Aschenbach, Jorg R.

AU - Amasheh, Salah

N1 - Funding Information: Authors’ contribution Performed research: AGM, ONV, LSO, AAF, NMK, OVR Analyzed data: AGM, JRA, SA Contributed new methods or models: AGM, JRA, SA Wrote the paper: AGM, JRA, SA Funding information This research was sponsored by a grant from the Russian Research Foundation (No. 18-15-00043), a grant from the Saint Petersburg State University (No. 0.37.218.2016), a grant from the Deutsche Forschungsgemeinschaft (AM 141/11-1), and the Partnership Program Freie Universität Berlin-Saint Petersburg State University. Publisher Copyright: © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.

PY - 2019/9/1

Y1 - 2019/9/1

N2 - Cholera toxin is commonly known to induce chloride secretion of the intestine. In recent years, effects on epithelial barrier function have been reported, indicating synergistic co-regulation of transporters and tight junction proteins. Our current study focused on the analysis of cholera toxin effects on transepithelial resistance and on tight junction proteins, the latter known as structural correlates of barrier function. Ligated segments of the rat jejunum were injected with buffered solution containing cholera toxin (1 mu g/ml) and incubated for 4 h. Subsequently, selfsame tissue specimens were mounted in Ussing chambers, and cholera toxin (1 mu g/ml) was added on the apical side. Transepithelial resistance and permeability of sodium fluorescein (376 Da) were analyzed. Subsequently, tissues were removed, expression and localization of claudins were analyzed, and morphological studies were performed employing transmission electron microscopy and confocal laser scanning microscopy. Cholera toxin induced a marked decrease in transepithelial resistance in the rat jejunal epithelium and an increase in paracellular permeability for sodium fluorescein. Immunoblotting of tight junction proteins revealed an increase in claudin-2 signals, which was verified by confocal laser scanning immunofluorescence microscopy, and a decrease in tricellulin, whereas other tight junction proteins remained unchanged. Transmission electron microscopy showed a reduction in the number of microvilli after incubation with cholera toxin. Moreover, cholera toxin led to a widening of the intercellular space between enterocytes. In accordance with the commonly known prosecretory effect of cholera toxin, our study revealed a complementary effect on small intestinal barrier function and integrity, which might constitute a pathomechanism with high relevance for prevention and therapeutic approaches.

AB - Cholera toxin is commonly known to induce chloride secretion of the intestine. In recent years, effects on epithelial barrier function have been reported, indicating synergistic co-regulation of transporters and tight junction proteins. Our current study focused on the analysis of cholera toxin effects on transepithelial resistance and on tight junction proteins, the latter known as structural correlates of barrier function. Ligated segments of the rat jejunum were injected with buffered solution containing cholera toxin (1 mu g/ml) and incubated for 4 h. Subsequently, selfsame tissue specimens were mounted in Ussing chambers, and cholera toxin (1 mu g/ml) was added on the apical side. Transepithelial resistance and permeability of sodium fluorescein (376 Da) were analyzed. Subsequently, tissues were removed, expression and localization of claudins were analyzed, and morphological studies were performed employing transmission electron microscopy and confocal laser scanning microscopy. Cholera toxin induced a marked decrease in transepithelial resistance in the rat jejunal epithelium and an increase in paracellular permeability for sodium fluorescein. Immunoblotting of tight junction proteins revealed an increase in claudin-2 signals, which was verified by confocal laser scanning immunofluorescence microscopy, and a decrease in tricellulin, whereas other tight junction proteins remained unchanged. Transmission electron microscopy showed a reduction in the number of microvilli after incubation with cholera toxin. Moreover, cholera toxin led to a widening of the intercellular space between enterocytes. In accordance with the commonly known prosecretory effect of cholera toxin, our study revealed a complementary effect on small intestinal barrier function and integrity, which might constitute a pathomechanism with high relevance for prevention and therapeutic approaches.

KW - Barrier function

KW - Jejunum

KW - Permeability

KW - Tight junctions

KW - Ussing chamber

UR - http://www.scopus.com/inward/record.url?scp=85068188088&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/cholera-toxin-perturbs-paracellular-barrier-small-intestinal-epithelium-rats-affecting-claudin2-tric

U2 - 10.1007/s00424-019-02294-z

DO - 10.1007/s00424-019-02294-z

M3 - статья

VL - 471

SP - 1183

EP - 1189

JO - Pflugers Archiv European Journal of Physiology

JF - Pflugers Archiv European Journal of Physiology

SN - 0031-6768

IS - 9

ER -