Matrix metalloproteinase gene expression in chronic gastric ulcer: a potential role of eosinophils in perforation.

Gene expression of matrix degrading enzymes was investigated in surgical specimens of perforated gastric ulcers. In these ulcers, the inflammatory cells infiltrating into the granulation tissue were granulocytes, particularly eosinophils. The extracellular matrix of the stomach wall consists mainly of collagen types I and III, which are selectively degraded by matrix metalloproteinase-1 (MMP-1). MMP-1 mRNA was detected in the cytoplasm of infiltrating cells, suggesting that eosinophils play an important role in ulcer recurrence and in perforation of the stomach wall. The degree of eosinophil infiltration into an ulcer base may be a useful marker for the risk of perforation. Patients showing this marker may benefit from a prophylactic therapy for preventing severe complications. The control of MMP gene expression represents a potential strategy for the treatment of recurrent gastric ulcer.