scholarly journals Manipulation of Actin Cytoskeleton and Tight Junction Protein Knockdown Differentially Interact to Modulate Basal and H 2 O 2 ‐Induced Paracellular Permeability of Renal Epithelial Cells

2018 ◽  
Vol 32 (S1) ◽  
Author(s):  
Sahar Bilal ◽  
Rhea Sharma ◽  
Angelina Voronina ◽  
Josephine Axis ◽  
Kurt Amsler
Keyword(s):  
Epithelial Cells ◽  
Tight Junction ◽  
Actin Cytoskeleton ◽  
Paracellular Permeability ◽  
Tight Junction Protein ◽  
Renal Epithelial Cells ◽  
Junction Protein

Nuclear Localization of the Tight Junction Protein ZO-2 in Epithelial Cells

2002 ◽  
Vol 274 (1) ◽  
pp. 138-148 ◽  
Author(s):  
Socorro Islas ◽  
Jesús Vega ◽  
Lissette Ponce ◽  
Lorenza González-Mariscal
Keyword(s):  
Epithelial Cells ◽  
Tight Junction ◽  
Nuclear Localization ◽  
Tight Junction Protein ◽  
Junction Protein

scholarly journals Correlation of occludin protein mobility with paracellular leak pathway permeability in renal epithelia

2018 ◽  
Author(s):  
Josephine Axis ◽  
Alexander L. Kolb ◽  
Robert L. Bacallao ◽  
Kurt Amsler
Keyword(s):  
Tight Junction ◽  
Ischemia Reperfusion Injury ◽  
Mdck Cells ◽  
Ischemia Reperfusion ◽  
Paracellular Permeability ◽  
Tight Junction Protein ◽  
Protein Mobility ◽  
Junction Protein ◽  
Leak Pathway

ABSTRACTStudies have demonstrated regulation of the epithelial paracellular permeability barrier, the tight junction, by a variety of stimuli. Recent studies have reported a correlation between changes in paracellular permeability, particularly paracellular permeability to large solutes (leak pathway), and mobility of the tight junction protein, occludin, in the plane of the plasma membrane. This had led to the hypothesis that changes in occludin protein mobility are causative for changes in paracellular permeability. Using a renal epithelial cell model system, MDCK, we examined the effect of various manipulations on both leak pathway permeability, monitored as the paracellular movement of a fluorescent molecule (calcein), and occludin protein mobility, monitored through fluorescence recovery after photobleaching. Our results indicate that knockdown of the associated tight junction protein, ZO-1, increases baseline leak pathway permeability, whereas, knockdown of the related tight junction protein, ZO-2, does not alter baseline leak pathway permeability. Knockdown of either ZO-1 or ZO-2 decreases the rate of movement of occludin protein but only knockdown of ZO-2 protein alters the percent of occludin protein that is mobile. Further, treatment with hydrogen peroxide increases leak pathway permeability in wild type MDCK cells and in ZO-2 knockdown MDCK cells but not in ZO-1 knockdown MDCK cells. This treatment decreases the rate of occludin movement in all three cell lines but only alters the mobile fraction of occludin protein in ZO-1 knockdown MDCK cells. Finally, we examined the effect of renal ischemia/reperfusion injury on occludin protein mobility in vivo.Ischemia/reperfusion injury both increased the rate of occludin mobility and increased the fraction of occludin protein that is mobile. These results indicate that, at least in our cell culture and in vivo model systems, there is no consistent correlation between paracellular leak pathway permeability and occludin protein mobility.

Characterization of the tight junction protein ZO-2 localized at the nucleus of epithelial cells

2004 ◽  
Vol 297 (1) ◽  
pp. 247-258 ◽  
Author(s):  
Blanca Estela Jaramillo ◽  
Arturo Ponce ◽  
Jacqueline Moreno ◽  
Abigail Betanzos ◽  
Miriam Huerta ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Tight Junction ◽  
Tight Junction Protein ◽  
Junction Protein

scholarly journals Occludin S408 phosphorylation regulates tight junction protein interactions and barrier function

2011 ◽  
Vol 193 (3) ◽  
pp. 565-582 ◽  
Author(s):  
David R. Raleigh ◽  
Devin M. Boe ◽  
Dan Yu ◽  
Christopher R. Weber ◽  
Amanda M. Marchiando ◽  
...  
Keyword(s):  
Tight Junction ◽  
Dynamic Behavior ◽  
Protein Interactions ◽  
Protein Complex ◽  
Barrier Function ◽  
Therapeutic Potential ◽  
Paracellular Permeability ◽  
Tight Junction Protein ◽  
Barrier Dysfunction ◽  
Junction Protein

Although the C-terminal cytoplasmic tail of the tight junction protein occludin is heavily phosphorylated, the functional impact of most individual sites is undefined. Here, we show that inhibition of CK2-mediated occludin S408 phosphorylation elevates transepithelial resistance by reducing paracellular cation flux. This regulation requires occludin, claudin-1, claudin-2, and ZO-1. S408 dephosphorylation reduces occludin exchange, but increases exchange of ZO-1, claudin-1, and claudin-2, thereby causing the mobile fractions of these proteins to converge. Claudin-4 exchange is not affected. ZO-1 domains that mediate interactions with occludin and claudins are required for increases in claudin-2 exchange, suggesting assembly of a phosphorylation-sensitive protein complex. Consistent with this, binding of claudin-1 and claudin-2, but not claudin-4, to S408A occludin tail is increased relative to S408D. Finally, CK2 inhibition reversed IL-13–induced, claudin-2–dependent barrier loss. Thus, occludin S408 dephosphorylation regulates paracellular permeability by remodeling tight junction protein dynamic behavior and intermolecular interactions between occludin, ZO-1, and select claudins, and may have therapeutic potential in inflammation-associated barrier dysfunction.

scholarly journals PSIII-36 The endocytic pathway plays a major role in the regulation of tight junction remodeling during nutrient starvation in jejunal IPEC-J2 cells

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 366-366
Author(s):  
Enkai Li ◽  
Kola Ajuwon
Keyword(s):  
Epithelial Cells ◽  
Tight Junction ◽  
Intestinal Epithelial Cells ◽  
Endocytic Pathway ◽  
Tight Junction Protein ◽  
Protein Abundance ◽  
Intestinal Epithelial ◽  
Bafilomycin A1 ◽  
Prolonged Starvation ◽  
Junction Protein

Abstract Postweaning pigs are subjected to nutrient deprivation during which intestinal epithelial cells undergo increased turnover. To preserve intestinal function, intestinal epithelial cells must activate adaptive mechanisms that allow them to cope with starvation-induced stress; most importantly, the preservation of intestinal barrier function. The objective of this study was to investigate the underlying mechanisms involved in starvation-induced alteration of tight junction protein abundance and function in IPEC-J2 cells. Cells were subjected to total nutrient starvation in Krebs-Ringer bicarbonate (KRB) buffer for 0, 3, 6, 12 and 24 h. Abundance of tight junction proteins was determined by RT-PCR, western blotting and immunofluorescence. Compared with control group (0 h), the protein expression of claudin 1, claudin 3 and claudin 4 protein was downregulated up to 6 h of starvation and then increased thereafter (P < 0.01). However, there was no change in the protein level of occludin and ZO-1. To determine the contribution of the lysosome and the ubiquitin proteasome pathways to regulation of tight junction protein abundance, the lysosome (Bafilomycin A1) and the proteasome (MG132) inhibitors were used in nutrient starved cells. Results showed the degradation of claudin 1, 3 and 4 up to 6 h of starvation was through the lysosomal pathway. Surprisingly, re-synthesis of claudins 4 and claudin 3 after prolonged starvation (12 and 24 h) was prevented when cells were treated with bafilomycin A1 and MG132, respectively. The autophagy-lysosome pathway inhibitors (Wortmannin and MHY1485) and endosome-lysosome pathway inhibitors (Dynasore and Pitstop 2) were further used to determine the specific roles of these pathways. In summary, the degradation of claudin 3 and claudin 4 during short-term starvation (up to 6 h) was through the dynamin-dependent endocytic pathway. However, re-synthesis of these proteins after prolonged starvation relies on both the lysosome and proteasome pathways.

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