BACKGROUND & AIMS: Experimental necrotizing enterocolitis (NEC) is characterized by circulating endotoxin (lipopolysaccharide [LPS]) and impaired enterocyte migration. We hypothesized that LPS increases integrin function and cell-matrix adhesion, leading to impaired enterocyte migration in the pathogenesis of NEC. METHODS: NEC-like intestinal injury was induced in newborn rats by hypoxia/gavage feedings, and restitution was determined by assessing bromodeoxyuridine-labeled enterocytes along the crypt-villus axis. Newborn mice were injected with 5 mg/kg LPS. IEC-6 cells were treated with LPS +/- LY294002 or wortmannin, and beta 1- and alpha 3-integrins were assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunofluorescence. Beta 1-integrin function was determined by adherence of fibronectin beads to IEC-6 monolayers. Migration of IEC-6 cells into a scraped wound was measured by time-lapse microscopy. RESULTS: Newborn intestinal injury was associated with decreased intestinal restitution and increased alpha 3- and beta 1-integrin expression in the ileal mucosa, which also was observed after LPS injection. In IEC-6 cells, LPS caused an increase in the expression of alpha 3- and beta 1-integrins, a shift of beta 1-integrins from the cytoplasm to the plasma membrane and an increase in fibronectin bead adhesion during which beta 1-integrins accumulated underneath attached beads. These effects could be reversed with LY294002 or wortmannin, suggesting phosphatidylinositol-3-phosphate kinase (PI3K) dependence. The increased integrin-matrix adhesion by LPS led to an inhibition of enterocyte migration, which could be reversed by anti-beta 1-antibodies. CONCLUSIONS: Enterocyte migration is inhibited by LPS through increased expression and function of alpha 3- and beta 1-integrins. Modulation of enterocyte migration via integrins may provide novel insights into the pathogenesis of NEC, in which intestinal restitution is impaired.
BACKGROUND & AIMS: Experimental necrotizing enterocolitis (NEC) is characterized by circulating endotoxin (lipopolysaccharide [LPS]) and impaired enterocyte migration. We hypothesized that LPS increases integrin function and cell-matrix adhesion, leading to impaired enterocyte migration in the pathogenesis of NEC. METHODS: NEC-like intestinal injury was induced in newborn rats by hypoxia/gavage feedings, and restitution was determined by assessing bromodeoxyuridine-labeled enterocytes along the crypt-villus axis. Newborn mice were injected with 5 mg/kg LPS. IEC-6 cells were treated with LPS +/- LY294002 or wortmannin, and beta 1- and alpha 3-integrins were assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunofluorescence. Beta 1-integrin function was determined by adherence of fibronectin beads to IEC-6 monolayers. Migration of IEC-6 cells into a scraped wound was measured by time-lapse microscopy. RESULTS:Newborn intestinal injury was associated with decreased intestinal restitution and increased alpha 3- and beta 1-integrin expression in the ileal mucosa, which also was observed after LPS injection. In IEC-6 cells, LPS caused an increase in the expression of alpha 3- and beta 1-integrins, a shift of beta 1-integrins from the cytoplasm to the plasma membrane and an increase in fibronectin bead adhesion during which beta 1-integrins accumulated underneath attached beads. These effects could be reversed with LY294002 or wortmannin, suggesting phosphatidylinositol-3-phosphate kinase (PI3K) dependence. The increased integrin-matrix adhesion by LPS led to an inhibition of enterocyte migration, which could be reversed by anti-beta 1-antibodies. CONCLUSIONS: Enterocyte migration is inhibited by LPS through increased expression and function of alpha 3- and beta 1-integrins. Modulation of enterocyte migration via integrins may provide novel insights into the pathogenesis of NEC, in which intestinal restitution is impaired.
Authors: Ward M Richardson; Chhinder P Sodhi; Anthony Russo; Richard H Siggers; Amin Afrazi; Steven C Gribar; Matthew D Neal; Shipan Dai; Thomas Prindle; Maria Branca; Congrong Ma; John Ozolek; David J Hackam Journal: Gastroenterology Date: 2010-05-24 Impact factor: 22.682
Authors: Juli M Richter; Brandon L Schanbacher; Hong Huang; Jianjing Xue; John A Bauer; Peter J Giannone Journal: J Pediatr Gastroenterol Nutr Date: 2012-05 Impact factor: 2.839
Authors: Chhinder P Sodhi; Xia-Hua Shi; Ward M Richardson; Zachary S Grant; Richard A Shapiro; Thomas Prindle; Maria Branca; Anthony Russo; Steven C Gribar; Congrong Ma; David J Hackam Journal: Gastroenterology Date: 2009-09-26 Impact factor: 22.682
Authors: Matthew D Neal; Chhinder P Sodhi; Hongpeng Jia; Mitchell Dyer; Charlotte E Egan; Ibrahim Yazji; Misty Good; Amin Afrazi; Ryan Marino; Dennis Slagle; Congrong Ma; Maria F Branca; Thomas Prindle; Zachary Grant; John Ozolek; David J Hackam Journal: J Biol Chem Date: 2012-09-06 Impact factor: 5.157
Authors: Shipan Dai; Chhinder Sodhi; Selma Cetin; Ward Richardson; Maria Branca; Matthew D Neal; Thomas Prindle; Congrong Ma; Richard A Shapiro; Bin Li; James H-C Wang; David J Hackam Journal: J Biol Chem Date: 2009-12-11 Impact factor: 5.157
Authors: Matthew D Neal; Chhinder P Sodhi; Mitchell Dyer; Brian T Craig; Misty Good; Hongpeng Jia; Ibrahim Yazji; Amin Afrazi; Ward M Richardson; Donna Beer-Stolz; Congrong Ma; Thomas Prindle; Zachary Grant; Maria F Branca; John Ozolek; David J Hackam Journal: J Immunol Date: 2013-03-01 Impact factor: 5.422