TY - JOUR

T1 - Circulating ouabain modulates expression of claudins in rat intestine and cerebral blood vessels

AU - Markov, Alexander G.

AU - Fedorova, Arina A.

AU - Kravtsova, Violetta V.

AU - Bikmurzina, Anastasia E.

AU - Okorokova, Larisa S.

AU - Matchkov, Vladimir V.

AU - Cornelius, Valeria

AU - Amasheh, Salah

AU - Krivoi, Igor I.

PY - 2020/7/2

Y1 - 2020/7/2

N2 - The ability of exogenous low ouabain concentrations to affect claudin expression and therefore epithelial barrier properties was demonstrated previously in cultured cell studies. We hypothesized that chronic elevation of circulating ouabain in vivo can affect the expression of claudins and tight junction permeability in different tissues. We tested this hypothesis in rats intraperitoneally injected with ouabain (1 μg/kg) for 4 days. Rat jejunum, colon and brain frontal lobes, which are variable in the expressed claudins and tight junction permeability, were examined. Moreover, the porcine jejunum cell line IPEC-J2 was studied. In IPEC-J2-cells, ouabain (10 nM, 19 days of incubation) stimulated epithelial barrier formation, increased transepithelial resistance and the level of cSrc-kinase activation by phosphorylation, accompanied with an increased expression of claudin-1,-5 and down-regulation of claudin-12; the expression of claudin-3,-4,-8 and tricellulin was not changed. In the jejunum, chronic ouabain increased the expression of claudin-1,-3 and-5 without an effect on claudin-2 and-4 expression. In the colon, only down-regulation of claudin-3 was observed. Chronic ouabain protected the intestine transepithelial resistance against functional injury induced by lipopolysaccharide treatment or by modeled acute microgravity; this regulation was most pronounced in the jejunum. Сlaudin-1 was also up-regulated in cerebral blood vessels. This was associated with reduction of claudin-3 expression while the expression of claudin-5 and occludin was not affected. Altogether, our results confirm that circulating ouabain can functionally and tissue-specifically affect barrier properties of epithelial and endothelial tissues via Na,K-ATPase-mediated modulation of claudins expression.

AB - The ability of exogenous low ouabain concentrations to affect claudin expression and therefore epithelial barrier properties was demonstrated previously in cultured cell studies. We hypothesized that chronic elevation of circulating ouabain in vivo can affect the expression of claudins and tight junction permeability in different tissues. We tested this hypothesis in rats intraperitoneally injected with ouabain (1 μg/kg) for 4 days. Rat jejunum, colon and brain frontal lobes, which are variable in the expressed claudins and tight junction permeability, were examined. Moreover, the porcine jejunum cell line IPEC-J2 was studied. In IPEC-J2-cells, ouabain (10 nM, 19 days of incubation) stimulated epithelial barrier formation, increased transepithelial resistance and the level of cSrc-kinase activation by phosphorylation, accompanied with an increased expression of claudin-1,-5 and down-regulation of claudin-12; the expression of claudin-3,-4,-8 and tricellulin was not changed. In the jejunum, chronic ouabain increased the expression of claudin-1,-3 and-5 without an effect on claudin-2 and-4 expression. In the colon, only down-regulation of claudin-3 was observed. Chronic ouabain protected the intestine transepithelial resistance against functional injury induced by lipopolysaccharide treatment or by modeled acute microgravity; this regulation was most pronounced in the jejunum. Сlaudin-1 was also up-regulated in cerebral blood vessels. This was associated with reduction of claudin-3 expression while the expression of claudin-5 and occludin was not affected. Altogether, our results confirm that circulating ouabain can functionally and tissue-specifically affect barrier properties of epithelial and endothelial tissues via Na,K-ATPase-mediated modulation of claudins expression.

KW - Brain blood vessels

KW - Circulating ouabain

KW - Claudins

KW - Intestine

KW - IPEC-J2 cells

KW - Na,K-ATPase

KW - EPITHELIAL BARRIER

KW - intestine

KW - PERMEABILITY

KW - CARDIOTONIC STEROIDS

KW - TIGHT JUNCTION

KW - circulating ouabain

KW - NA-K-ATPASE

KW - brain blood vessels

KW - PROTECTS

KW - Na

KW - K-ATPase

KW - CELL MONOLAYERS

KW - INHIBITORS

KW - claudins

KW - PROTEINS

KW - BRAIN

UR - http://www.scopus.com/inward/record.url?scp=85088680701&partnerID=8YFLogxK

U2 - 10.3390/ijms21145067

DO - 10.3390/ijms21145067

M3 - Article

C2 - 32709081

AN - SCOPUS:85088680701

VL - 21

SP - 1

EP - 16

JO - International Journal of Molecular Sciences

JF - International Journal of Molecular Sciences

SN - 1422-0067

IS - 14

M1 - 5067

ER -