title: Enterocolitis causes profound lymphoid depletion in endothelin receptor B- and endothelin 3-null mouse models of Hirschsprung-associated enterocolitis.
abstract: Potentially life-threatening enterocolitis is the most frequent complication in children with colonic aganglionosis (Hirschsprung disease, HSCR), and little is known about the mechanisms leading to enterocolitis. Splenic lymphopenia has been reported in the Endothelin Receptor B (Ednrb)-null mouse model of HSCR that develops enterocolitis. In this study, we sought to identify molecular mechanisms underlying this immune phenotype. We employed the Ednrb(-/-) mouse, and the knockout of its ligand, Edn3 (Edn3(-/-)). The major finding is that enterocolitis in the Ednrb(-/-) and Edn3(-/-) mice lead to thymic involution, splenic lymphopenia, and suppression of B lymphopoiesis as a consequence of colonic aganglionosis, not an intrinsic Edn3-Ednrb signaling defect directly affecting the lymphoid organs. We showed that adoptive transfer of Ednrb(-/-) marrow repopulated the RAG2-null mice marrow, thymus and spleen without development of enterocolitis. We identified the glucocorticoid corticosterone, as a potential mediator of the immune phenotype. This previously unrecognized pattern of immune abnormalities in mouse is nearly identical to lymphoid depletion in neonatal sepsis during severe physiological stress, suggesting that the mouse model used here could be also used for sepsis studies.
authors.affiliation: Division of Pediatric Surgery and The Pediatric Surgery Laboratory, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Philip K
authors.initials: PK
authors.lastname: Frykman
authors.forename: Zhi
authors.initials: Z
authors.lastname: Cheng
authors.forename: Xiao
authors.initials: X
authors.lastname: Wang
authors.forename: Deepti
authors.initials: D
authors.lastname: Dhall
mesh_terms: D000818:Animals; D003106:Colon / Q000276:immunology / Q000473:pathology; D003345:Corticosterone / Q000235:genetics / Q000276:immunology; D004195:Disease Models, Animal; D019334:Endothelin-3 / Q000235:genetics / Q000276:immunology*; D004760:Enterocolitis / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D006627:Hirschsprung Disease / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout; D044023:Receptor, Endothelin B / Q000235:genetics / Q000276:immunology*; D013154:Spleen / Q000276:immunology / Q000473:pathology; D013950:Thymus Gland / Q000276:immunology / Q000473:pathology
chemical_list: D019334:Endothelin-3; D044023:Receptor, Endothelin B; D003345:Corticosterone
keywords: Corticosterone; Endothelins; Enterocolitis; Glucocorticoids; HAEC; Hirschsprung disease; Lymphoid depletion