Journal
AMERICAN JOURNAL OF PATHOLOGY
Volume 186, Issue 5, Pages 1151-1165Publisher
ELSEVIER SCIENCE INC
DOI: 10.1016/j.ajpath.2015.12.016
Keywords
-
Categories
Funding
- National Institute of Diabetes and Digestive and Kidney Diseases [RO 1-DK-64165, RO 1-DK-81429]
- Veterans Affairs (VA) Merit Review grant from VA Research Service
Ask authors/readers for more resources
Tumor necrosis factor (TNF)-alpha, a key mediator of intestinal inflammation, causes an increase in intestinal epithelial tight junction (TJ) permeability by activating myosin light chain kinase (MLCK; official name MYLK3) gene. However, the precise signaling cascades that mediate the INF-alpha-induced activation of MLCK gene and increase in TJ permeability remain unclear. Our aims were to delineate the upstream signaling mechanisms that regulate the TNF-alpha modulation of intestinal TJ barrier function with the use of in vitro and in vivo intestinal epithelial model systems. TNF-alpha caused a rapid activation of both canonical and noncanonical NF-kappa B pathway. NF-kappa B-inducing kinase (NIK) and mitogen-activated protein kinase kinase-1 (MEKK-1) were activated in response to TNF-alpha. NIK mediated the TNF-alpha activation of inhibitory kappa B kinase (IKK)-alpha, and MEKK1 mediated the activation of IKK complex, including IKK-beta. NIK/IKK-alpha axis regulated the activation of both NF-kappa B p50/p65 and RelB/p52 pathways. Surprisingly, the siRNA induced knockdown of NIK, but not MEKK-1, prevented the TNF-alpha activation of both NF-kappa B p50/p65 and RelB/p52 and the increase in intestinal TJ permeability. Moreover, NIK/IKK-alpha/NF-kappa B p50/p65 axis mediated the TNF-alpha induced MLCK gene activation and the subsequent MLCK increase in intestinal TJ permeability. In conclusion, our data show that NIK/IKK-alpha/regulates the activation of NF-kappa B p50/p65 and plays an integral role in the TNF-alpha induced activation of MLCK gene and increase in intestinal TJ permeability.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available