(445d) Stretching and Gallic Acid Promote Extracellular Matrix Production in Human Articular Chondrocytes

Articular Cartilage (AC) is an avascular protective soft tissue that covers bones in articulating joints. The avascular nature of AC makes its access to oxygen and nutrients limited and reduces its ability to regenerate after trauma. AC degenerates gradually after injury leading to osteoarthritis (OA), the most common form of arthritis worldwide. Although OA was categorized as “non-inflammatory” for a long time in contrast to rheumatoid arthritis, recent studies reconsidered the definition after observing immune responses and apparent symptoms of inflammation, e.g., swelling, in the joints of OA patients. Another critical symptom of inflammation is the upregulation of catabolic genes that destroy the extracellular matrix (ECM) proteins of cartilage, making cartilage mechanically weaker. In this work, we studied the use of of biochemical and mechanical factors for reducing the inflammation of human articular cartilage cells, chondrocytes (hAChs). To do that, human chondrocytes were pooled, taken from four different OA study participant tissues removed after total knee arthroplasty. hACHs were cultured within two separate groups, a static group and a group mechanically stimulated by stretching. Group samples were either treated with standard culture medium as a negative control or aa nutraceutical supplemented medium as the experimental group. Nutraceuticals were used because of their potential for downregulating catabolism. Then, we monitored hACh production of healthy cartilage extracellular matrix proteins, total collagen (COL), and total glycosaminoglycan (GAG), as indicators of inflammation reduction. Our results show that simultaneous stretching and nutraceutical supplementation increased COL and GAG content by more than 11- and 21-fold, respectively.