scholarly journals Circulating Ouabain Modulates Expression of Claudins in Rat Intestine and Cerebral Blood Vessels

2020 ◽  
Vol 21 (14) ◽  
pp. 5067
Author(s):  
Alexander G. Markov ◽  
Arina A. Fedorova ◽  
Violetta V. Kravtsova ◽  
Anastasia E. Bikmurzina ◽  
Larisa S. Okorokova ◽  
...  
Keyword(s):  
Tight Junction ◽  
Blood Vessels ◽  
Barrier Properties ◽  
Transepithelial Resistance ◽  
Epithelial Barrier ◽  
Cerebral Blood Vessels ◽  
Down Regulation ◽  
Barrier Formation ◽  
Tight Junction Permeability

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. Claudin-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.

scholarly journals In VitroPrevention ofSalmonellaLipopolysaccharide-Induced Damages in Epithelial Barrier Function by VariousLactobacillusStrains

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Chun-Yan Yeung ◽  
Jen-Shiu Chiang Chiau ◽  
Wai-Tao Chan ◽  
Chun-Bin Jiang ◽  
Mei-Lien Cheng ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Tight Junction ◽  
Mononuclear Cells ◽  
Intestinal Epithelial Cells ◽  
Barrier Properties ◽  
Bacterial Invasion ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Peripheral Blood Mononuclear

Background.Lactobacillusshows beneficial anti-inflammatory effects onSalmonellainfection. The maintenance of the tight junction (TJ) integrity plays an importance role in avoiding bacterial invasion. WhetherLactobacilluscould be used to regulate the TJ protein expression and distribution in inflamed intestinal epithelial cells was determined.Methods. Using the transwell coculture model,Salmonellalipopolysaccharide (LPS) was apically added to polarized Caco-2 cells cocultured with peripheral blood mononuclear cells in the basolateral compartment. LPS-stimulated Caco-2 cells were incubated with variousLactobacillusstrains. TJ integrity was determined by measuring transepithelial electrical resistance across Caco-2 monolayer. Expression and localization of TJ proteins (zonula-occludens- (ZO-) 1) were determined by Western blot and immunofluorescence microscopy.Results. Various strains ofLactobacilluswere responsible for the different modulations of cell layer integrity. LPS was specifically able to disrupt epithelial barrier and change the location of ZO-1. Our data demonstrate thatLactobacilluscould attenuate the barrier disruption of intestinal epithelial cells caused bySalmonellaLPS administration. We showed thatLactobacillusstrains are associated with the maintenance of the tight junction integrity and appearance.Conclusion. In this study we provide insight that live probiotics could improve epithelial barrier properties and this may explain the potential mechanism behind their beneficial effectin vivo.

Multiple forms of estrogen receptor-α in cerebral blood vessels: regulation by estrogen

2003 ◽  
Vol 284 (1) ◽  
pp. E184-E192 ◽  
Author(s):  
Chris Stirone ◽  
Sue P. Duckles ◽  
Diana N. Krause
Keyword(s):  
Estrogen Receptor ◽  
Blood Vessels ◽  
Estrogen Receptor Α ◽  
26S Proteasome ◽  
Target Tissue ◽  
Female Rat ◽  
Cerebral Vasculature ◽  
Cerebral Blood Vessels ◽  
Multiple Forms

The cerebral vasculature is an important target tissue for estrogen, as evidenced by significant effects of estrogen on vascular reactivity and protein levels of endothelial nitric oxide synthase and prostacyclin synthase. However, the presence, localization, and regulation of estrogen receptors in the cerebral vasculature have not been investigated. In this study, we identified the presence of estrogen receptor-α (ER-α) in female rat cerebral blood vessels and localized this receptor to both smooth muscle and endothelial cells by use of immunohistochemistry and confocal microscopy. With immunoblot analysis, multiple forms of ER-α were detected at 110, 93, 82, 50, and 45 kDa in addition to a relatively weak band corresponding to the 66-kDa putative unmodified receptor. The 82-kDa band was identified as Ser118-phosphorylated ER-α, whereas the 50-kDa band lacks the normal NH2 terminus, suggestive of an ER-α splice variant. Lower molecular mass bands persisted after in vivo inhibition of 26S proteasome activity with lactacystin, whereas the 110- and 93-kDa bands increased. All forms of ER-α in cerebral vessels were decreased after ovariectomy but significantly increased after chronic estrogen exposure in vivo.

scholarly journals Amylin: Localization, Effects on Cerebral Arteries and on Local Cerebral Blood Flow in the Cat

2001 ◽  
Vol 1 ◽  
pp. 168-180 ◽  
Author(s):  
Lars Edvinsson ◽  
Peter J. Goadsby ◽  
Rolf Uddman
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Blood Vessels ◽  
Cerebral Arteries ◽  
In Vivo Studies ◽  
Cerebral Blood Vessels ◽  
Local Cerebral Blood Flow ◽  
Doppler Flowmetry

Amylin and adrenomedullin are two peptides structurally related to calcitonin gene-related peptide (CGRP). We studied the occurrence of amylin in trigeminal ganglia and cerebral blood vessels of the cat with immunocytochemistry and evaluated the role of amylin and adrenomedullin in the cerebral circulation by in vitro and in vivo pharmacology. Immunocytochemistry revealed that numerous nerve cell bodies in the trigeminal ganglion contained CGRP immunoreactivity (-ir); some of these also expressed amylin-ir but none adrenomedullin-ir. There were numerous nerve fibres surrounding cerebral blood vessels that contained CGRP-ir. Occasional fibres contained amylin-ir while we observed no adrenomedullin-ir in the vessel walls. With RT-PCR and Real-Time�PCR we revealed the presence of mRNA for calcitonin receptor-like receptor (CLRL) and receptor-activity-modifying proteins (RAMPs) in cat cerebral arteries. In vitro studies revealed that amylin, adrenomedullin, and CGRP relaxed ring segments of the cat middle cerebral artery. CGRP and amylin caused concentration-dependent relaxations at low concentrations of PGF2a-precontracted segment (with or without endothelium) whereas only at high concentration did adrenomedullin cause relaxation. CGRP8-37 blocked the CGRP and amylin induced relaxations in a parallel fashion. In vivo studies of amylin, adrenomedullin, and CGRP showed a brisk reproducible increase in local cerebral blood flow as examined using laser Doppler flowmetry applied to the cerebral cortex of the a-chloralose�anesthetized cat. The responses to amylin and CGRP were blocked by CGRP8-37. The studies suggest that there is a functional sub-set of amylin-containing trigeminal neurons which probably act via CGRP receptors.

Transepithelial resistance can be regulated by the intestinal brush-border Na+/H+ exchanger NHE3

2000 ◽  
Vol 279 (6) ◽  
pp. C1918-C1924 ◽  
Author(s):  
Jerrold R. Turner ◽  
Eric D. Black ◽  
Jeff Ward ◽  
Chung-Ming Tse ◽  
Frederick A. Uchwat ◽  
...  
Keyword(s):  
Tight Junction ◽  
Myosin Ii ◽  
Transepithelial Resistance ◽  
Cell Swelling ◽  
Intestinal Brush Border ◽  
Tight Junction Regulation ◽  
Cytoplasmic Acidification ◽  
Tight Junction Permeability ◽  
Dimethyl Amiloride ◽  
Mlc Phosphorylation

Initiation of intestinal Na+-glucose cotransport results in transient cell swelling and sustained increases in tight junction permeability. Since Na+/H+ exchange has been implicated in volume regulation after physiological cell swelling, we hypothesized that Na+/H+ exchange might also be required for Na+-glucose cotransport-dependent tight junction regulation. In Caco-2 monolayers with active Na+-glucose cotransport, inhibition of Na+/H+ exchange with 200 μM 5-( N, N-dimethyl)- amiloride induced 36 ± 2% increases in transepithelial resistance (TER). Evaluation using multiple Na+/H+ exchange inhibitors showed that inhibition of the Na+/H+ exchanger 3 (NHE3) isoform was most closely related to TER increases. TER increases due to NHE3 inhibition were related to cytoplasmic acidification because cytoplasmic alkalinization with 5 mM NH4Cl prevented both cytoplasmic acidification and TER increases. However, NHE3 inhibition did not affect TER when Na+-glucose cotransport was inhibited. Myosin II regulatory light chain (MLC) phosphorylation decreased up to 43 ± 5% after inhibition of Na+/H+ exchange, similar to previous studies that associate decreased MLC phosphorylation with increased TER after inhibition of Na+-glucose cotransport. However, NHE3 inhibitors did not diminish Na+-glucose cotransport. These data demonstrate that inhibition of NHE3 results in decreased MLC phosphorylation and increased TER and suggest that NHE3 may participate in the signaling pathway of Na+-glucose cotransport-dependent tight junction regulation.

Ca2+ regulation of tight-junction permeability and structure in Necturus gallbladder

1983 ◽  
Vol 245 (3) ◽  
pp. C203-C212 ◽  
Author(s):  
C. E. Palant ◽  
M. E. Duffey ◽  
B. K. Mookerjee ◽  
S. Ho ◽  
C. J. Bentzel
Keyword(s):  
Cell Membrane ◽  
Tight Junction ◽  
Morphological Changes ◽  
Freeze Fracture ◽  
Transepithelial Resistance ◽  
Mucosal Cell ◽  
Base Line ◽  
Ionophore A23187 ◽  
Necturus Gallbladder ◽  
Tight Junction Permeability

To explore the role of Ca2+ in tight-junction permeability, the Necturus gallbladder was exposed to varying Ca2+ concentrations and to the Ca2+ ionophore A23187 added to the mucosal side (1.9 X 10(-6) to 6.8 X 10(-5) M). Electrophysiological parameters measured in an Ussing-type chamber were correlated with tight-junction morphology revealed by freeze-fracture electron microscopy. In Ca2+-free bathing media, transepithelial resistance decreases and tight-junctional ultrastructure is fragmented. In 1.8 mM Ca2+ media, A23187 induces an initial drop in transepithelial resistance, followed by an increase in transepithelial resistance to a value 20% above base line. At peak response to A23187, NaCl diffusion potentials decrease. Freeze-fracture replicas reveal that the number of junctional strands increase pari passu with junctional depth. Both physiological and morphological changes were partially reversible. The initial decrease in transepithelial resistance coincided with a persistent hyperpolarization of the mucosal cell membrane potential difference and a decrease in the mucosal-to-serosal cell membrane resistance ratio. Thus A23187 alters both the transcellular and paracellular pathway, resulting in opposing effects on transepithelial resistance.

scholarly journals Occludin regulates macromolecule flux across the intestinal epithelial tight junction barrier

2011 ◽  
Vol 300 (6) ◽  
pp. G1054-G1064 ◽  
Author(s):  
Rana Al-Sadi ◽  
Khaldun Khatib ◽  
Shuhong Guo ◽  
Dongmei Ye ◽  
Moustafa Youssef ◽  
...  
Keyword(s):  
Tight Junction ◽  
Intestinal Permeability ◽  
Transepithelial Resistance ◽  
Intestinal Epithelial ◽  
Knock Down ◽  
Large Channel ◽  
Epithelial Tight Junction ◽  
Mouse Intestine

Defective intestinal epithelial tight junction (TJ) barrier has been shown to be an important pathogenic factor contributing to the development of intestinal inflammation. The expression of occludin is markedly decreased in intestinal permeability disorders, including in Crohn's disease, ulcerative colitis, and celiac disease, suggesting that the decrease in occludin expression may play a role in the increase in intestinal permeability. The purpose of this study was to delineate the involvement of occludin in intestinal epithelial TJ barrier by selective knock down of occludin in in vitro (filter-grown Caco-2 monolayers) and in vivo (recycling perfusion of mouse intestine) intestinal epithelial models. Our results indicated that occludin small-interfering RNA (siRNA) transfection causes an increase in transepithelial flux of various-sized probes, including urea, mannitol, inulin, and dextran, across the Caco-2 monolayers, without affecting the transepithelial resistance. The increase in relative flux rate was progressively greater for larger-sized probes, indicating that occludin depletion has the greatest effect on the flux of large macromolecules. siRNA-induced knock down of occludin in mouse intestine in vivo also caused an increase in intestinal permeability to dextran but did not affect intestinal tissue transepithelial resistance. In conclusion, these results show for the first time that occludin depletion in intestinal epithelial cells in vitro and in vivo leads to a selective or preferential increase in macromolecule flux, suggesting that occludin plays a crucial role in the maintenance of TJ barrier through the large-channel TJ pathway, the pathway responsible for the macromolecule flux.

Abstract 166: Matrix Metalloproteinase-9 Mediates Post-hypoxic Vascular Pruning Of Cerebral Blood Vessels By Degrading Laminin And Claudin-5

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Amin Boroujerdi ◽  
Jennifer V Welser-Alves ◽  
Richard Milner
Keyword(s):  
Matrix Metalloproteinase ◽  
Tight Junction ◽  
Blood Vessels ◽  
Matrix Metalloproteinase 9 ◽  
Vascular Density ◽  
Cerebral Blood Vessels ◽  
Wild Type ◽  
Junction Protein ◽  
Metalloproteinase 9

Objective: Vascular remodeling involves a highly coordinated break-down and build-up of the vascular basal lamina and inter-endothelial tight junction proteins. The goal of this study was to examine the role of matrix metalloproteinase-9 (MMP-9) in remodeling of cerebral blood vessels, both in hypoxia-induced angiogenesis and in the vascular pruning that accompanies the switch from hypoxia back to normoxia. Approach and Results: In a chronic mild hypoxia model of cerebrovascular remodeling, gel zymography revealed that MMP-9 levels were increased, both in the hypoxic angiogenic response and in the post-hypoxic pruning response. Compared to wild-type mice, MMP-9 KO mice showed no alteration in hypoxic-induced angiogenesis, but did show marked delay in post-hypoxic vascular pruning. In wild-type mice, vascular pruning was associated with fragmentation of vascular laminin and the tight junction protein claudin-5, while this process was markedly attenuated in MMP-9 KO mice. In vitro experiments showed that hypoxia stimulated MMP-9 expression in brain endothelial cells (BECs) but not pericytes. While immunofluorescent and flow cytometry analyses showed that hypoxia led to reduced expression of laminin and claudin-5 in wild-type BECs, this decrease was absent in MMP-9 KO BECs. Conclusions: These results show that while MMP-9 is not essential for hypoxic-induced cerebral angiogenesis, it plays an important role in post-hypoxic vascular pruning by degrading laminin and claudin-5. Our data support the concept that MMP-9 inhibition might provide therapeutic benefit in the treatment of ischemic stroke, by preventing post-hypoxic vascular pruning, thereby optimizing vascular density and integrity.

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