scholarly journals HIF-dependent regulation of claudin-1 is central to intestinal epithelial tight junction integrity

2015 ◽  
Vol 26 (12) ◽  
pp. 2252-2262 ◽  
Author(s):  
Bejan J. Saeedi ◽  
Daniel J. Kao ◽  
David A. Kitzenberg ◽  
Evgenia Dobrinskikh ◽  
Kayla D. Schwisow ◽  
...  

Intestinal epithelial cells (IECs) are exposed to profound fluctuations in oxygen tension and have evolved adaptive transcriptional responses to a low-oxygen environment. These adaptations are mediated primarily through the hypoxia-inducible factor (HIF) complex. Given the central role of the IEC in barrier function, we sought to determine whether HIF influenced epithelial tight junction (TJ) structure and function. Initial studies revealed that short hairpin RNA–mediated depletion of the HIF1β in T84 cells resulted in profound defects in barrier and nonuniform, undulating TJ morphology. Global HIF1α chromatin immunoprecipitation (ChIP) analysis identified claudin-1 (CLDN1) as a prominent HIF target gene. Analysis of HIF1β-deficient IEC revealed significantly reduced levels of CLDN1. Overexpression of CLDN1 in HIF1β-deficient cells resulted in resolution of morphological abnormalities and restoration of barrier function. ChIP and site-directed mutagenesis revealed prominent hypoxia response elements in the CLDN1 promoter region. Subsequent in vivo analysis revealed the importance of HIF-mediated CLDN1 expression during experimental colitis. These results identify a critical link between HIF and specific tight junction function, providing important insight into mechanisms of HIF-regulated epithelial homeostasis.

2018 ◽  
Vol 66 ◽  
pp. 93-109 ◽  
Author(s):  
Yeojung Kim ◽  
Gail A. West ◽  
Greeshma Ray ◽  
Sean P. Kessler ◽  
Aaron C. Petrey ◽  
...  

2016 ◽  
Vol 120 (6) ◽  
pp. 692-701 ◽  
Author(s):  
Karol Dokladny ◽  
Micah N. Zuhl ◽  
Pope L. Moseley

A single layer of enterocytes and tight junctions (intercellular multiprotein complexes) form the intestinal epithelial barrier that controls transport of molecules through transcellular and paracellular pathways. A dysfunctional or “leaky” intestinal tight junction barrier allows augmented permeation of luminal antigens, endotoxins, and bacteria into the blood stream. Various substances and conditions have been shown to affect the maintenance of the intestinal epithelial tight junction barrier. The primary focus of the present review is to analyze the effects of exertional or nonexertional (passive hyperthermia) heat stress on tight junction barrier function in in vitro and in vivo (animals and humans) models. Our secondary focus is to review changes in tight junction proteins in response to exercise or hyperthermic conditions. Finally, we discuss some pharmacological or nutritional interventions that may affect the cellular mechanisms involved in maintaining homeostasis of the intestinal epithelial tight junction barrier during heat stress or exercise.


2011 ◽  
Vol 300 (6) ◽  
pp. G1054-G1064 ◽  
Author(s):  
Rana Al-Sadi ◽  
Khaldun Khatib ◽  
Shuhong Guo ◽  
Dongmei Ye ◽  
Moustafa Youssef ◽  
...  

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.


2012 ◽  
Vol 142 (5) ◽  
pp. S-808
Author(s):  
Rana Al-Sadi ◽  
Shuhong Guo ◽  
Karol Dokladny ◽  
Archana Kaza ◽  
Thomas Y. Ma

2020 ◽  
Vol 158 (6) ◽  
pp. S-510
Author(s):  
Ashwlnkumar Subramenium Ganapathy ◽  
Eric Suchanec ◽  
Kushal Saha ◽  
Meghali Nighot ◽  
Thomas Y. Ma ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document