Researchers in the United States and Japan have discovered a new mechanism that links age-related cartilage tissue stiffening with the repression of a key protein associated with longevity. These findings enhance the understanding of mechanisms that lead to the deterioration of joints that causes osteoarthritis, according to the authors of a new study, published Jan. 10 in Nature Communications.
In the study, researchers showed that increased stiffening of the extracellular matrix — a network of proteins and other molecules that surround and support tissues in the body — led to a decrease in a so-called longevity protein called Klotho (α-Klotho) in knee cartilage, brought about by epigenetic changes, or how DNA is organized and regulated. This Klotho decrease then damaged cells in healthy cartilage called chondrocytes. Conversely, exposing aged chondrocytes to a softer extracellular matrix restored the knee cartilage to a more youthful state.