Helicobacter pylori upregulates prion protein expression in gastric mucosa: A possible link to prion disease

AIM: Pathological prion protein (PrP(sc)) is responsible for the development of transmissible spongiform encephalopathies (TSE). While PrPc enters the organism via the oral route, less data is available to know about its uptake and the role of gastrointestinal inflammation on the expression of prion precursor PrPc, which is constitutively expressed in the gastric mucosa. METHODS: We studied PrPc expression in the gastric mucosa of 10 Helicobacter pylori-positive patients before and after successful H pylori eradication compared to non-infected controls using RT-PCR and Western blotting. The effect of central mediators of gastric inflammation, i.e., gastrin, prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-alpha) and interleukin 1 beta (IL-1 beta) on PrPc expression was analyzed in gastric cell lines. RESULTS: PrPc expression was increased in H pylori infection compared with non-infected controls and decreased to normal after successful eradication. Gastrin, PGE2, and IL-1 beta dose-dependently upregulated PrPc in gastric cells, while TNF-alpha had no effect. CONCLUSION: H pylori infection leads to the upregulation of gastric PrPc expression. This can be linked to H pylori induced hypergastrinemia and increased mucosal PGE2 and IL-1 beta synthesis. H pylori creates a milieu for enhanced propagation of prions in the gastrointestinal tract. (C) 2005 The WJG Press and Elsevier Inc. All rights reserved.