Expressions of MMPs and TIMP-1 in gastric ulcers may differentiate H. pylori-infected from NSAID-related ulcers.

Background: Two major causes of gastric ulcers are Helicobacter pylori (H. pylori) infection and nonsteroidal anti-inflammatory drug (NSAID) use.
Aims: This study aimed to determine if there were different expressions of matrix metalloproteinases (MMPs) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) between H. pylori-infected and NSAID-related ulcers.
Methods: The 126 gastric ulcer patients (H. pylori infected n = 46; NSAID related n = 30; combined with two factors n = 50) provided ulcer and nonulcer tissues for assessment of MMP-3, -7, and -9 and TIMP-1 expression by immunohistochemical staining.
Results: Gastric ulcer tissues had significantly higher MMP-3, -7, and -9 and TIMP-1 expressions than nonulcer tissues (P < 0.05). H. pylori-infected gastric ulcers had even higher MMP-7, MMP-9, and TIMP-1 expressions in epithelial cells than NSAID-related gastric ulcers (P < 0.05). In patients with the two combined factors, gastric ulcers expressed similar proportions of antral ulcers and MMP-7 and MMP-9 intensities to NSAID-related gastric ulcers, but lower MMP-9 and TIMP-1 than H. pylori-infected gastric ulcers (P < 0.05).
Conclusions: H. pylori-infected gastric ulcers express higher MMP-7, MMP-9, and TIMP-1 than NSAID-related ulcers. In patients with the two combined factors, ulcer location and MMP-7 and MMP-9 intensities are similar to NSAID use.