Differential expression of laminin isoform (a2), integrins (a3B1 and a6B4) and cytokeratin 20 in H. pylori gastritis

Abstract

The expression of laminin-l chains (131 and yl), laminin-2 (merosin), integrin receptors to laminin (a3131 and a6134) and cytokeratin (CK20) were studied by immunohistochemical methods in gastric biopsies from antrum of 25 patients. H. pylori gastritis was found in 19 cases and intestinal metaplasia (IM) in four from these 19. Another 13 biopsies, all with IM were immunostained to laminin-2. Laminin-l chains in normal and gastritis areas without 1M were expressed as a strong, linear and continuous deposit in the basement membranes of the superficial and glandular epithelium. In metaplastic glands the reactivity to laminin-l chains was decreased. Merosin was discontinuous when a moderate to accentuated H. pylori glandular colonization was present. Samples with IM were negative to laminin- 2. The a3131 and a6134 integrins were negative only in IM gastric biopsies. The CK20 immunoreactivity was strong and homogeneous in the cells at the tip and the upper portion of foveolae in normal areas and in gastritis with IM the reactivity to CK 20 was heterogeneous. A differential expression of laminin isoforms is related to inflammation and subsequent IM caused by H, pylori. The alterations of a3131 and a6D4 parallel both modifications in merosin and CK20 expression in H. py10r.i chronic gastritis.