Cryptdins are a form of defensin released into the intestinal crypt lumen by specialized epithelial cells such as Paneth cells. These molecules exhibit antimicrobial activity and thus likely participate in defense of the crypt epithelial surface and perhaps in defense of the intestinal epithelial surface in general. We have generated pilot data indicating that these molecules can, by interacting with crypt apical membranes, alter the electrophysiological properties of crypt epithelial monolayers. Specifically purified cryptdin induces net electrogenic transport of ions across this epithelium associated with the introduction of an apical channel. These data are of particular interest since it is known that other species of defensin molecules can produce anion selective pores in artificial membranes. The data in hand are most consistent with cryptdin induction of electrogenic C1 transport- an event which protects mucosal surfaces by """"""""flushing"""""""" them with isotonic solution. In this project we will first characterize the nature of the transport event stimulated by cryptdins. Secondly, we will then use crypt epithelial monolayers with permeabilized basolateral membranes to better characterize the nature of the pore induced by cryptdins. Thirdly, we will examine fractions derived from purified cryptdin species in order to identify the specific molecule(s) in the crytdin fraction responsible for the effects on crypt epithelia. Lastly, we will use synthetic peptides to verify the peptide(s) species responsible for these effects on epithelial transport and then synthesize mutant peptide species to perform structure-function analyses. Such data should provide insights into cross-talk between Paneth cells and other crypt cells and yield information concerning how these cell type interact in defense to the crypt unit.

Project Start
1998-04-01
Project End
2000-03-31
Budget Start
1997-10-01
Budget End
1998-09-30
Support Year
15
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Massachusetts General Hospital
Department
Type
DUNS #
City
Boston
State
MA
Country
United States
Zip Code
02199
Senger, Stefania; Ingano, Laura; Freire, Rachel et al. (2018) Human Fetal-Derived Enterospheres Provide Insights on Intestinal Development and a Novel Model to Study Necrotizing Enterocolitis (NEC). Cell Mol Gastroenterol Hepatol 5:549-568
Henström, Maria; Diekmann, Lena; Bonfiglio, Ferdinando et al. (2018) Functional variants in the sucrase-isomaltase gene associate with increased risk of irritable bowel syndrome. Gut 67:263-270
Guo, Shuangshuang; Gillingham, Tyler; Guo, Yuming et al. (2017) Secretions of Bifidobacterium infantis and Lactobacillus acidophilus Protect Intestinal Epithelial Barrier Function. J Pediatr Gastroenterol Nutr 64:404-412
Walker, W Allan (2017) The importance of appropriate initial bacterial colonization of the intestine in newborn, child, and adult health. Pediatr Res 82:387-395
Mercado-Lubo, Regino; Zhang, Yuanwei; Zhao, Liang et al. (2016) A Salmonella nanoparticle mimic overcomes multidrug resistance in tumours. Nat Commun 7:12225
Saslowsky, David E; Thiagarajah, Jay R; McCormick, Beth A et al. (2016) Microbial sphingomyelinase induces RhoA-mediated reorganization of the apical brush border membrane and is protective against invasion. Mol Biol Cell 27:1120-30
Rautava, Samuli; Walker, W Allan; Lu, Lei (2016) Hydrocortisone-induced anti-inflammatory effects in immature human enterocytes depend on the timing of exposure. Am J Physiol Gastrointest Liver Physiol 310:G920-9
Giannogonas, Panagiotis; Apostolou, Athanasia; Manousopoulou, Antigoni et al. (2016) Identification of a novel interaction between corticotropin releasing hormone (Crh) and macroautophagy. Sci Rep 6:23342
Hoffman, Jill M; Baritaki, Stavroula; Ruiz, Jonathan J et al. (2016) Corticotropin-Releasing Hormone Receptor 2 Signaling Promotes Mucosal Repair Responses after Colitis. Am J Pathol 186:134-44
Meng, Di; Zhu, Weishu; Ganguli, Kriston et al. (2016) Anti-inflammatory effects of Bifidobacterium longum subsp infantis secretions on fetal human enterocytes are mediated by TLR-4 receptors. Am J Physiol Gastrointest Liver Physiol 311:G744-G753

Showing the most recent 10 out of 271 publications