Site-specific changes in transforming growth factor-α and -β1 expression in colonic mucosa of adolescents with inflammatory bowel disease

Abstract

<h4>Background</h4>Transforming growth factors (TGF-alpha and -beta1) play important roles in intestinal growth and repair. To further understand their roles in the pathophysiology of inflammatory bowel disease (IBD), this study examined changes in their expression in colonic mucosa of adolescents with IBD.<h4>Methods</h4>TGF-alpha and -beta1 expression was examined by immunohistochemistry and in situ hybridization.<h4>Results</h4>TGF-gamma immunostaining and mRNA labelling appeared unchanged in the epithelium of specimens with active IBD. Similarly, expression of epithelial TGF-beta1 remained unaltered in IBD. However, the numbers of TGF-beta1-positive cells, including T cells, neutrophils, and monocytes/macrophages, in the lamina propria increased during disease activity.<h4>Conclusions</h4>Adolescent IBD is characterized by a normal expression of TGF-alpha and -beta1 peptide and mRNA in the colonic epithelium but by an increased density of TGF-beta1-positive immune cells in the lamina propria during disease activity, suggesting a role in inflammatory modulation in IBD.