An extrahepatic human neutrophil collagenase complementary DNA (matrix metalloprotease-8) cloned in an adenovirus vector was used as a therapeutic agent in cirrhosis.

A high titer of clinical-grade AdMMP8 was obtained.

HeLa cells transduced with AdMMP8 expressed recombinant matrix metalloprotease-8 messenger RNA and matrix metalloprotease-8 protein. Matrix metalloprotease-8 in culture sups showed enzymatic activity against native collagen type I, which was inhibited by ethylenediaminetetraacetic acid, 1,10-phenanthroline, and tissue inhibitor of metalloprotease-1. In vivo transduction showed matrix metalloprotease-8 activity, and studies to establish the efficacy of this characterized vector were performed in CCl₄ and bile duct-ligated cirrhotic rats. Transduction with 3 × 10¹¹ viral particles per kilogram resulted in hepatic detection of both messenger RNA and protein matrix metalloprotease-8. A consistent response in fibrosis reversal was observed in CCl₄ rats. Liver fibrosis in bile duct-ligated cirrhotic animals was decreased in 45%, along with diminished hydroxyproline content, after AdMMP8 treatment. The expression of matrix metalloprotease-2 and matrix metalloprotease-3 was up-regulated in AdMMP8 rats. Free tissue inhibitor of metalloprotease-1, as an indirect measurement of active uncomplexed matrix metalloproteases, was also increased in the AdMMP8 groups. Transforming growth factor-β messenger RNA was diminished, and matrix metalloprotease-9 and hepatocyte growth factor increased. Treatment in both models correlated with improvements in ascites, functional hepatic tests, and gastric varices, indicating diminished intrahepatic blood pressure in animals injected with AdMMP8.

Therefore, therapy with the matrix metalloprotease-8 gene is promising for use in a clinical setting.