Gelatinase B (MMP-9) Modulates Joint Inflammation and Cartilage Degradation After Overload Injury

Osteoarthritis is the leading cause for disability in the U.S. Primary osteoarthritis occurs progressively with age due to a variety of factors, while secondary osteoarthritis is usually the result of a sports or accident-related joint injury. Several recent studies found that degraded matrix in synovial fluid was surged within days after initial injury along with the elevation of matrix degradative enzymes, including matrix metalloproteinases (MMPs) and aggrecanases [1]. The elevation of degraded matrix could last for up to a decade, although it is not clear whether these degradative events are related to joint inflammation, the chronic presence of which is the hallmark of rheumatoid arthritis and often leads to joint degeneration.