Assessing the Global Metabolic Response of Encapsulated Chondrocytes to Simulated Microgravity
Space sojourns are crucial for understanding aeronautics, physics, the solar system, and evaluating the possibility of interplanetary travel. However, there are many potential health risks associated with space travel such as prominent detrimental effects on both the cardiovascular and musculoskeletal systems. In space, astronauts experience a micro-gravitational force of 10-6 G. The musculoskeletal system has been of particular focus for the risks of microgravity because of the mechanosensitive nature of the tissues. Due to the reduced joint loading in space, there is high concern for mobility issues during and after spaceflight. Osteoarthritis (OA) is one of the chief concerns for space travel. OA can be debilitating to patients, and is the most common degenerative joint disease, but there are no current interventions to restore or prevent OA due to the poor understanding of the underlying disease mechanism. OA is thought to be caused by abnormal loading of the joint, and a microgravity environment causes altered loading of joints that may be similar to conditions of OA generation. To investigate the effects of microgravity on chondrocyte metabolism, and implications for OA, human chondrocytes were encapsulated in a three-dimensional agarose gel construct to mimic the microenvironment of cartilage. Gel constructs were then introduced to a simulated microgravity (SM) environment using a rotating cell culture system (RCCS). Global metabolomics, a method that analyzes thousands of small, intermediate molecules within a sample, was used to analyze the effects of microgravity on chondrocyte metabolism.