New research may lead to an innovative approach for cartilage repair. Scientists at ZymoGenetics have developed the protein Zfgf5 as a cellular growth factor to help repair cartilage tissue damaged by osteoarthritis and rheumatoid arthritis. Preclinical results reported in the April issue of Osteoarthritis and Cartilage provide new evidence suggesting Zfgf5 may have therapeutic benefits for these diseases.
Production of chondrocytes (mature cartilage cells) have long been known to be critical to connective tissue healing. In preclinical studies, researchers found that Zfgf5 had potent effects on chondrocytes. Local administration of Zfgf5 in a rodent model, for example, caused a significant increase in the number of cartilage cells and a corresponding increase in the deposit of type II collagen, a protein important in the maintenance and repair of cartilage tissue. Zfgf5 treatment similarly stimulated the growth of human chondrocytes grown in cell culture. Additionally, analysis of human tissue samples further demonstrated that Zfgf5 is naturally found in human cartilage.
“While these findings are preliminary, they suggest a potential role for Zfgf5 in the repair of damaged cartilage tissue,” stated Jeff Ellsworth, Ph.D., Senior Scientist at ZymoGenetics. “As our human population ages, the need for therapeutics that can stimulate cartilage repair will grow. We anticipate an increase in the number of osteoarthritis cases requiring therapeutic intervention, as well as a rise in the number of surgeries to repair damaged cartilage due to sports injuries. With few agents available that promote this critical repair process, Zfgf5 may represent a valuable therapeutic opportunity.”
Additional findings presented at the Orthopaedic Research Society meeting held in February 2002 reported that Zfgf5 stimulated healing of cartilage and subchondral bone defects in a large animal model of cartilage repair. The healing response was accompanied by an increase in matrix proteins and the deposition of structural collagen within the defective tissue site. Both of these responses are required for the regeneration of functional cartilage tissue.