Features: Volume 111, Number 5

• Book ID: 102304654
• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 129 KB
• Volume: 111
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.22988

✦ Synopsis

The National Aeronautics and Space Administration's (NASA) space exploration mission is challenged by microgravity (Xg) (weightlessness) conditions. Astronauts can lose 1-2% of entire bone mass per month in space. Studies have indicated that Xg affects normal bone homoeostasis through suppression of the bone forming ability of osteoblast cells and increased osteoclast bone resorption activity. However, the mechanism underlying Xg-induced osteoclast formation/bone resorption is unclear. Sambandam et al utilized the NASA-developed ground-based Rotating Wall Vessel Bioreactor (RWV), and the Rotary Cell Culture System (RCCS) model to simulate Xg conditions and performed large-scale microarray analysis to assess the gene expression patterns during osteoclast differentiation. The study revealed 11.4% of the genes were differentially regulated; of these 54% were upregulated and 45% were down regulated. Results identifi ed increased expression of cytokines/growth factors, bone matrix degrading proteases, adhesion molecules and transcription factors, which play important roles in osteoclast differentiation and bone resorption activity. Further, Xg signifi cantly down regulated negative regulators of osteoclastogenesis. Thus, modeled Xg regulated gene expression profi ling during osteoclast differentiation provides new insights into molecular mechanisms and therapeutic targets of osteoclast differentiation/activity to prevent bone loss and fracture risk in astronauts during space fl ight missions.