The apically located inter-cellular tight junctions (TJ) within the intestinal epithelium act as a paracellular barrier and prevent permeation of noxious luminal antigens. Loss of TJ barrier function is a key pathologic factor in intestinal disorders an inflammatory bowel diseases. Emerging evidence shows that intracellular vesicular membrane transport including caveolar transport is a key process in the formation of tight junction domains. Our preliminary studies indicated that the intestinal barrier recovery in the event of epithelial injury is impaired in the absence of ClC-2 chloride channel protein. Our preliminary studies also suggested that ClC-2 plays a vital role in the intestinal barrier recovery by modulation of intracellular trafficking of key tight junction protein occludin via its interaction with caveolae. Based on preliminary studies, we hypothesize that ClC-2 plays an integral role in the intestinal mucosal repair process by promoting recruitment of tight junction protein occludin via caveolin-1 dependent process.
In specific aim 1, we plan to elucidate the role of ClC-2 in caveolar trafficking of occludin, and in aim 2, we intend to define the mechanisms of ClC-2 mediated enhancement of intestinal epithelial TJ barrier.
Specific aim 3 is dedicated to testing our hypothesis in-vivo and defining the role of ClC-2 in intestinal barrier recovery. Clinically, repai of mucosal barrier in intestine is imperative for preventing further intestinal mucosal damage, and for therapeutic success. This study will provide a novel insight into the crucial role ClC-2 plays n intestinal barrier recovery. The proposed studies will provide us with mechanistic and potentially therapeutic information on how chloride channel ClC-2 enhances the gut barrier function.

Public Health Relevance

Defective intestinal barrier allows penetration of harmful luminal antigens in the gut which in turn leads to intestinal inflammation. Recent studies have shown an integral role of ion transporters in intestinal tight junction regulation. The purpose of this grant application is to elucidate the mechanisms involved in chloride channel ClC-2-mediated enhancement of the intestinal epithelial tight junction barrier recovery. Clinically, repar of mucosal barrier in intestine is imperative for preventing further intestinal mucosal damage, and for therapeutic success. This study will provide a novel insight into the crucial role ClC-2 plays in intestinal barrier recovery.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Scientist Development Award - Research & Training (K01)
Project #
7K01DK100562-06
Application #
9755739
Study Section
Kidney, Urologic and Hematologic Diseases D Subcommittee (DDK)
Program Officer
Saslowsky, David E
Project Start
2014-04-01
Project End
2019-03-31
Budget Start
2018-12-11
Budget End
2019-03-31
Support Year
6
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Pennsylvania State University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
129348186
City
Hershey
State
PA
Country
United States
Zip Code
17033
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Nighot, Prashant K; Leung, Lana; Ma, Thomas Y (2017) Chloride channel ClC- 2 enhances intestinal epithelial tight junction barrier function via regulation of caveolin-1 and caveolar trafficking of occludin. Exp Cell Res 352:113-122
Nighot, Meghali; Al-Sadi, Rana; Guo, Shuhong et al. (2017) Lipopolysaccharide-Induced Increase in Intestinal Epithelial Tight Permeability Is Mediated by Toll-Like Receptor 4/Myeloid Differentiation Primary Response 88 (MyD88) Activation of Myosin Light Chain Kinase Expression. Am J Pathol 187:2698-2710
Nighot, Prashant; Ma, Thomas (2016) Role of autophagy in the regulation of epithelial cell junctions. Tissue Barriers 4:e1171284
Moore, Sarah A; Nighot, Prashant; Reyes, Cynthia et al. (2016) Intestinal barrier dysfunction in human necrotizing enterocolitis. J Pediatr Surg 51:1907-1913
Nighot, Prashant; Al-Sadi, Rana; Rawat, Manmeet et al. (2015) Matrix metalloproteinase 9-induced increase in intestinal epithelial tight junction permeability contributes to the severity of experimental DSS colitis. Am J Physiol Gastrointest Liver Physiol 309:G988-97
Nighot, Prashant K; Hu, Chien-An Andy; Ma, Thomas Y (2015) Autophagy enhances intestinal epithelial tight junction barrier function by targeting claudin-2 protein degradation. J Biol Chem 290:7234-46
Nighot, Prashant; Young, Karen; Nighot, Meghali et al. (2013) Chloride channel ClC-2 is a key factor in the development of DSS-induced murine colitis. Inflamm Bowel Dis 19:2867-77