HUMAN STEM CELLS GROW DIFFERENTLY IN SPACE
Cells grown in microgravity generate problematic proteins (absent in normal stem cells) that play a role in bone deterioration.
Human stem cells grown in a rotating vessel to simulate microgravity are vastly different from those allowed to develop under normal conditions, a new study shows. The research raises questions about the viability of humans traveling in space without gravity for long periods of time. Australian scientists used a NASA-developed bioreactor to grow cells from a human embryonic stem cell line. These types of cells can develop into any of the body's three primary layers -- ectoderm, endoderm and mesoderm, which in turn form more than the 220 types of cells found in humans. The team discovered that 64 percent of the proteins found in the stem cells grown in simulated microgravity were not in control samples. In particular, the bioreactor cells contained several proteins involved in the breakdown of bone and in the regulation of calcium, neither type of which were found in stem cells grown in regular, Earth gravity. "To the best of our knowledge, this is the first study conducted that has investigated the effect of (simulated microgravity conditions) on an embryonic stem cell line and demonstrated a significant alteration in human cell function as a result of growth in microgravity conditions," lead scientist Elizabeth Blaber, with the Australian Center for Astrobiology, wrote in a paper presented at a key astrobiology conference in Houston last month.
