TGFβ1 single-nucleotide polymorphism C-509T alters mucosal cell function in pediatric eosinophilic esophagitis.

Eosinophilic esophagitis (EoE) is a chronic Th2 antigen-driven disorder associated with tissue remodeling. Inflammation and remodeling lead to esophageal rigidity, strictures, and dysphagia. TGFβ1 drives esophageal remodeling including epithelial barrier dysfunction and subepithelial fibrosis. A functional SNP in the TGFβ1 gene that increases its transcription (C-509T) is associated with elevated numbers of esophageal TGFβ1-expressing cells. We utilized esophageal biopsies and fibroblasts from TT-genotype EoE children to understand if TGFβ1 influenced fibroblast and epithelial cell function in vivo. Genotype TT EoE esophageal fibroblasts had higher baseline TGFβ1, collagen1α1, periostin, and MMP2 (p < 0.05) gene expression and distinct contractile properties compared with CC genotype (n = 6 subjects per genotype). In vitro TGFβ1 exposure caused greater induction of target gene expression in genotype CC fibroblasts (p < 0.05). Esophageal biopsies from TT-genotype subjects had significantly less epithelial membrane-bound E-cadherin (p < 0.01) and wider cluster distribution at nanometer resolution. TGFβ1 treatment of stratified primary human esophageal epithelial cells and spheroids disrupted transepithelial resistance (p < 0.001) and E-cadherin localization (p < 0.0001). A TGFβ1-receptor-I inhibitor improved TGFβ1-mediated E-cadherin mislocalization. These data suggest that EoE severity can depend on genotypic differences that increase in vivo exposure to TGFβ1. TGFβ1 inhibition may be a useful therapy in subsets of EoE patients

Wide Distribution of O157-Antigen Biosynthesis Gene Clusters in Escherichia coli

Most Escherichia coli O157-serogroup strains are classified as enterohemorrhagic E. coli (EHEC), which is known as an important food-borne pathogen for humans. They usually produce Shiga toxin (Stx) 1 and/or Stx2, and express H7-flagella antigen (or nonmotile). However, O157 strains that do not produce Stxs and express H antigens different from H7 are sometimes isolated from clinical and other sources. Multilocus sequence analysis revealed that these 21 O157:non-H7 strains tested in this study belong to multiple evolutionary lineages different from that of EHEC O157:H7 strains, suggesting a wide distribution of the gene set encoding the O157-antigen biosynthesis in multiple lineages. To gain insight into the gene organization and the sequence similarity of the O157-antigen biosynthesis gene clusters, we conducted genomic comparisons of the chromosomal regions (about 59 kb in each strain) covering the O-antigen gene cluster and its flanking regions between six O157:H7/non-H7 strains. Gene organization of the O157-antigen gene cluster was identical among O157:H7/non-H7 strains, but was divided into two distinct types at the nucleotide sequence level. Interestingly, distribution of the two types did not clearly follow the evolutionary lineages of the strains, suggesting that horizontal gene transfer of both types of O157-antigen gene clusters has occurred independently among E. coli strains. Additionally, detailed sequence comparison revealed that some positions of the repetitive extragenic palindromic (REP) sequences in the regions flanking the O-antigen gene clusters were coincident with possible recombination points. From these results, we conclude that the horizontal transfer of the O157-antigen gene clusters induced the emergence of multiple O157 lineages within E. coli and speculate that REP sequences may involve one of the driving forces for exchange and evolution of O-antigen loci

MMPs-2 and-14 are elevated in eosinophilic esophagitis and reduced following topical corticosteroid therapy

Objectives: Eosinophilic esophagitis (EoE) is a chronic, antigen-mediated disease in children and adults associated with substantial esophageal remodeling and fibrosis. The expression of the remodeling-associated matrix metalloproteinases (MMPs) has not been previously detailed in EoE. Methods: MMP-2 and-14 expression and cellular localization were assessed using real-time quantitative polymerase chain reaction and immunohistochemistry/immunofluorescence in EoE fibroblasts, active and inactive pediatric EoE biopsies, and nondiseased control biopsies. The effect of transforming growth factor (TGF)-b1 treatment on MMP-2 expression in cultured esophageal epithelial (HET1A) cells was analyzed. Results: MMP-2 and-14 mRNA were expressed in EoE fibroblasts and biopsies. Proliferating epithelial cells produced MMP-14 more abundantly in EoE than in controls (P<0.001) and the degree of epithelial MMP-14 expression correlated positively with basal zone hyperplasia (r=0.65, P=0.002). EoE lamina propria had higher numbers of MMP-2-and-14-positive cells (906±167 and 701±93 cells/mm2) as compared with controls (258±93 cells/mm2, P<0.01 and 232±54 cells/mm2, P<0.01), and MMP-14 expression correlated with the severity of fibrosis. Following therapy with topical corticosteroids, MMP-14 and-2 were significantly diminished (P<0.01). TGF-b1 increased the expression and secretion of MMP-2 from esophageal epithelial HET1A cells. Conclusions: MMP-2 and-14 are elevated in pediatric patients with EoE and significantly decrease following topical corticosteroid therapy. TGF-b1 increases MMP-2 in esophageal epithelial cells. This alludes to previously unappreciated role for MMPs in EoE-associated esophageal remodeling and a potential positive feedback loop via TGF-b1

MMPs-2 and-14 are elevated in eosinophilic esophagitis and reduced following topical corticosteroid therapy

Objectives: Eosinophilic esophagitis (EoE) is a chronic, antigen-mediated disease in children and adults associated with substantial esophageal remodeling and fibrosis. The expression of the remodeling-associated matrix metalloproteinases (MMPs) has not been previously detailed in EoE. Methods: MMP-2 and-14 expression and cellular localization were assessed using real-time quantitative polymerase chain reaction and immunohistochemistry/immunofluorescence in EoE fibroblasts, active and inactive pediatric EoE biopsies, and nondiseased control biopsies. The effect of transforming growth factor (TGF)-b1 treatment on MMP-2 expression in cultured esophageal epithelial (HET1A) cells was analyzed. Results: MMP-2 and-14 mRNA were expressed in EoE fibroblasts and biopsies. Proliferating epithelial cells produced MMP-14 more abundantly in EoE than in controls (P<0.001) and the degree of epithelial MMP-14 expression correlated positively with basal zone hyperplasia (r=0.65, P=0.002). EoE lamina propria had higher numbers of MMP-2-and-14-positive cells (906±167 and 701±93 cells/mm2) as compared with controls (258±93 cells/mm2, P<0.01 and 232±54 cells/mm2, P<0.01), and MMP-14 expression correlated with the severity of fibrosis. Following therapy with topical corticosteroids, MMP-14 and-2 were significantly diminished (P<0.01). TGF-b1 increased the expression and secretion of MMP-2 from esophageal epithelial HET1A cells. Conclusions: MMP-2 and-14 are elevated in pediatric patients with EoE and significantly decrease following topical corticosteroid therapy. TGF-b1 increases MMP-2 in esophageal epithelial cells. This alludes to previously unappreciated role for MMPs in EoE-associated esophageal remodeling and a potential positive feedback loop via TGF-b1