Deletion of Hyaluronan-Binding Protein Involved in Hyaluronan Depolymerization (HYBID) Results in Attenuation of Osteoarthritis in Mice.

Hyaluronan (HA)-binding protein involved in HA depolymerization (HYBID) is involved in cartilage destruction via HA depolymerization in human knee osteoarthritis. However, roles of HYBID in the progression of osteoarthritis remain elusive. This study sought to examine whether genetic depletion of Hybid could suppress surgically induced osteoarthritis of mouse knee joints. In osteoarthritis induced by medial collateral ligament transection with meniscus removal, articular cartilage destruction and osteophyte formation at the medial femoral-tibial joint were significantly inhibited in Hybid-deficient (Hybid-/-) mouse group compared to wild-type group. Hybid was highly produced by synovial cells and articular chondrocytes in wild-type mouse osteoarthritis joint. Interleukin-1β, interleukin-6 and tumor necrosis factor-α were up-regulated in the osteoarthritis joint tissues of both wild-type and Hybid-/- mice. Vascular density at the synovial and periosteal junction was significantly reduced in Hybid-/- mice compared to wild-type mice. High-molecular-weight HA was accumulated in osteoarthritis joint tissues of Hybid-/- mice. Injections of high-molecular-weight HA to knee joints attenuated the cartilage destruction and osteophyte formation in wild-type mouse osteoarthritis group. Inhibition of cartilage destruction and osteophyte formation in Hybid-/- mice was also observed in destabilization of the medial meniscus model. These data are the first to demonstrate that cartilage destruction and osteophyte formation are suppressed in Hybid-/- mice and suggest that Hybid-mediated HA depolymerization is implicated for the progression of mechanically induced knee osteoarthritis.