Glutamine Enhances Tight Junction Protein Expression and Modulates Corticotropin-Releasing Factor Signaling in the Jejunum of Weanling Piglets. Issue 1 (19th November 2014)

• Record Type: Journal Article
• Authors: Wang, Hao; Zhang, Chen; Wu, Guoyao; Sun, Yuli; Wang, Bin; He, Beibei; Dai, Zhaolai; Wu, Zhenlong
• Is Part Of: Journal of nutrition. Volume 145:Issue 1(2015)
• Page Start: 25
• Page End: 31
• Publication Date: 2014-11-19
• Subjects: glutamine -- tight junction -- corticotropin-releasing factor -- pigs -- small intestine -- weaning stress; Nutrition -- Periodicals; Diet -- Periodicals; 613.205
• DOI: 10.3945/jn.114.202515
• Languages: English
• ISSNs: 0022-3166

Abstract

Abstract: Background: Dysfunction of tight junction integrity is associated with decreased nutrient absorption and numerous gastrointestinal diseases in humans and piglets. Although L-glutamine has been reported to enhance intestinal-mucosal mass and barrier function under stressful conditions, in vivo data to support a functional role for L-glutamine on intestinal tight junction protein (TJP) expression in weanling mammals are limited. Objective: This study tested the hypothesis that glutamine regulates expression of TJPs and stress-related corticotropin-releasing factor (CRF) signaling in the jejunum of weanling piglets. Methods: Piglets were reared by sows or weaned at 21 d of age to a corn and soybean meal–based diet that was or was not supplemented with 1% L-glutamine for 7 d. Growth performance, intestinal permeability, TJP abundance, and CRF expression were examined. Results: Weaning caused increases ( P < 0.05) in intestinal permeability by 40% and in CRF concentrations by 4.7 times in association with villus atrophy ( P < 0.05). Western blot analysis showed reductions ( P < 0.05) in jejunal expression of occludin, claudin-1, zonula occludens (ZO) 2, and ZO-3, but no changes in the abundance of claudin-3, claudin-4, or ZO-1 in weanling piglets compared with age-matched suckling controls. Glutamine supplementation improved ( P < 0.05) intestinal permeability and villus height, while reducing ( P < 0.05) jejunal mRNA and protein levels for CRF and attenuating ( P < 0.05) weanling-induced decreases in occludin, claudin-1, ZO-2, and ZO-3 protein abundances. Conclusion: Collectively, our results support an important role for L-glutamine in regulating expression of TJPs and CRF in the jejunum of weanling piglets.