Loss of NHE8 expression impairs intestinal mucosal integrity.
The newest member of the Na(+)/H(+) exchanger (NHE) family, NHE8, is abundantly expressed at the apical membrane of the intestinal epithelia. We previously reported that mucin 2 expression was significantly decreased in the colon in NHE8(-/-) mice, suggesting that NHE8 is involved in intestinal mucosal protection. In this study, we further evaluated the role of NHE8 in intestinal epithelial protection after dextran sodium sulfate (DSS) challenge. Compared with wild-type mice, NHE8(-/-) mice have increased bacterial adhesion and inflammation, especially in the distal colon. NHE8(-/-) mice are also susceptible to DSS treatment. Real-time PCR detected a remarkable increase in the expression of IL-1β, IL-6, TNF-α, and IL-4 in DSS-treated NHE8(-/-) mice compared with DSS-treated wild-type littermates. Immunohistochemistry showed a disorganized epithelial layer in the colon of NHE8(-/-) mice. Periodic acid-Schiff staining showed a reduction in the number of mature goblet cells and the area of the goblet cell theca in NHE8(-/-) mice. Phyloxine/tartrazine staining revealed a decrease in functional Paneth cell population in the NHE8(-/-) small intestinal crypt. The expression of enteric defensins was also decreased in NHE8(-/-) mice. The reduced mucin production in goblet cells and antimicrobial peptides production in Paneth cells lead to disruption of the intestinal mucosa protection. Therefore, NHE8 may be involved in the establishment of intestinal mucosal integrity by regulating the functions of goblet and Paneth cells.
Department of Pediatrics, Steele Children's Research Center, University of Arizona, Tucson, Arizona; Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, College of Preventive Medicine, Third Military Medical University, Chongqing, China; and.
Aiping
A
Wang
Department of Pediatrics, Steele Children's Research Center, University of Arizona, Tucson, Arizona;
Jing
J
Li
Department of Pediatrics, Steele Children's Research Center, University of Arizona, Tucson, Arizona;
Yang
Y
Zhao
Department of Medical Biochemistry, University of Gothenburg, Gothenburg, Sweden.
Malin E V
ME
Johansson
Department of Pediatrics, Steele Children's Research Center, University of Arizona, Tucson, Arizona;
Hua
H
Xu
Department of Pediatrics, Steele Children's Research Center, University of Arizona, Tucson, Arizona; fghishan@peds.arizona.edu.
Fayez K
FK
Ghishan
D000818:Animals; D001422:Bacterial Adhesion; D018988:Bacterial Translocation; D003092:Colitis / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D003106:Colon / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D023082:Defensins / Q000378:metabolism; D016264:Dextran Sulfate; D004195:Disease Models, Animal; D005786:Gene Expression Regulation; D020397:Goblet Cells / Q000378:metabolism / Q000473:pathology; D018836:Inflammation Mediators / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D008297:Male; D018345:Mice, Knockout; D009077:Mucins / Q000378:metabolism; D019879:Paneth Cells / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors
D016207:Cytokines; D023082:Defensins; D018836:Inflammation Mediators; D009077:Mucins; D012333:RNA, Messenger; C471945:Slc9a8 protein, mouse; D017923:Sodium-Hydrogen Exchangers; D016264:Dextran Sulfate
Paneth cell; goblet cell; sodium/hydrogen exchanger 8