The present invention relates to hepatic fibrosis-suppressing agents that are suitable for treating or preventing fibrotic liver diseases such as cirrhosis, which comprise as an active ingredient a substance that inhibits the production or accumulation of chondroitin sulfate proteoglycans including chondroitinase ABC and ADAMTS-4; and methods of screening for the agents.
The present inventors discovered for the first time that hepatic fibrosis could be efficiently suppressed by suppressing the production or accumulation of chondroitin sulfate proteoglycans. Specifically, fibrosis of liver tissues can be suppressed by administering chondroitinase ABC, a chondroitin sulfate proteoglycan-degrading enzyme, or by using siRNA to suppress the expression of C4ST-1, C6ST-1, or C6ST-2, a sulfotransferase for chondroitin sulfate proteoglycans. Compounds such as nucleic acids that are used as siRNA can be used as effective agents for suppressing hepatic fibrosis. Furthermore, hepatic fibrosis-suppressing agents can be found by screening for compounds that suppress the production or accumulation of chondroitin sulfate proteoglycans.