Interaction between hepatic membrane type 1 matrix metalloproteinase and acireductone dioxygenase 1 regulates hepatitis C virus infection.

Membrane type 1 matrix metalloproteinase (MT1-MMP) binds to and regulates the function of tetraspanin-enriched microdomains. It also physically interacts with claudin-1 and acireductone dioxygenase 1 (ADI1), both associated with hepatitis C virus (HCV) cell entry. Here, we examined hepatic expression of MT1-MMP, ADI1 and claudin-1 as well as their physical interaction in relation to serum or intrahepatic HCV-RNA levels. A total of 104 liver biopsies obtained from chronic hepatitis C patients and 84 liver tissues obtained from noncancerous parts of surgically removed HCV-related hepatocellular carcinoma were analysed. Positive cytoplasmic ADI1 in liver biopsies was associated with higher serum HCV-RNA levels (P = 0.009). Positive MT1-MMP and ADI1 interaction assessed by co-immunoprecipitation was associated with lower tissue HCV-RNA levels (P = 0.009). Hepatic HCV-RNA levels were positively associated with ADI1 levels in the MT1-MMP and ADI1 co-immunoprecipitates (P = 0.030). Overexpression of MT1-MMP in Huh7.5 cells suppressed cell entry of HCV pseudoparticles as well as HCVcc infection. The suppression effect could be reversed by co-expression of ADI1 in a dose-dependent manner. In summary, clinical and cell-based experiments suggested that physical interaction between MT1-MMP and ADI1 led to suppression of HCV infection. This inhibitory effect could be reversed by ADI1 overexpression.