Osteoarthritis (OA) is a degenerative condition that involves the breakdown of joint cartilage that affects over 70 percent of individuals between the ages of 55 and 70 in the United States. If untreated, it can eventually lead to severe disability. Currently, the available options for individuals suffering from OA are medication to relieve pain and eventual surgical invention often involving joint replacement.
The disease process is complex and multi-faceted. It involves:
- degradation of the integrity of the extracellular matrix
- lack of sufficient replacement and repair of this matrix
- abnormal cell death
- accelerated differentiation of cartilage cells.
Dr. Kristen Johnson and colleagues from the Genomics Institute of the Novartis Research Foundation in San Diego California are developing an approach to the treatment of OA using mesenchymal stem cells (MSCs). Stem cells are cells found in the body that are so-called pluripotent cells in that they have the capacity, under the appropriate conditions, to differentiate into a variety of tissue cells. MSCs are normally found in the bone marrow and are capable of differentiating into a variety of cell types including chondrocytes – the cells responsible for making new cartilage.
In their research, Johnson's group discovered a small molecule called kartogenin that they have shown can stimulate the differentiation of MSCs into chondrocytes and therefore lead to the enhanced production and repair of cartilage – a process known as chondrogenesis.
These results are significant in that they suggest a non-invasive stem cell- based procedure as a therapy for OA in place of the current surgical option.