Researchers send experiments into space (9/14/2007)

When a Foton spacecraft launches from Kazakhstan on Sept. 14, two U of T professors will be bidding farewell to its passengers. Not to astronauts - the ship is unmanned - but to their experiments.

Professors Reginald Gorczynski and Rene Harrison are two of only three Canadian researchers involved in the eOSTEO Experiments - a joint venture between the Canadian Space Agency and the European Space Agency that is the first to study bone loss in living bone cells in vitro from space without on-site supervision by astronauts.

Bone loss is accelerated in the zero gravity conditions of space, making it an ideal lab. Astronauts lose a significant amount of bone in microgravity (the state where gravity is reduced to negligible levels) - an estimated two per cent per month, which is approximately 10 times faster than in severe osteoporosis. Even after five years back on Earth, studies have shown that they do not fully recover this bone loss.

Gorczynski of surgery and immunology will be examining the impact of microgravity on CD200, a molecule he discovered that regulates bone loss. In the microgravity conditions of space, Gorczynski found that bone cells produce too much CD200, which causes increased bone cell turnover and, he believes, contributes to the loss of bone mass in astronauts. He will be testing this hypothesis by sending mouse cell samples aboard the Foton shuttle.

"If we can manipulate bone loss and bone growth by targeting these molecules in microgravity, which is really an accelerated form of osteoporosis, we think we may be onto something particularly relevant, not only just for astronauts but for osteoporosis on the ground," Gorczynski said.

In 2003 Gorczynski's team sent experiments including studies of CD200 into space on the shuttle Columbia. Tragically, the craft was destroyed on re-entry, killing seven astronauts and destroying nearly 100 experiments. Gorczynski's team was one of four U of T research teams to lose its research.

Harrison, a professor of biological sciences at U of T Scarborough, aims to shed light on the processes around bone loss. Since microgravity fosters bone loss, she hopes to learn more about disuse osteoporosis, a form of osteoporosis in which patients are bedridden or paralyzed because their bones aren't able to bear weight. The focus of Harrison's research will be on the interplay between osteoblasts - bone making cells - and osteoclasts - bone degrading cells. The specimens, about one million bone cells from lab mice, occupy less space than an average pencil case.

"When you are healthy, these two types of cells work in equal balance but when osteoporosis sets in there is a shift in that balance that leads to bone loss and we don't know exactly how it happens," said Harrison.

She and technician Arian Khandani and PhD student Noushin Nabavi will monitor the 12-day flight from the European Space Agency's microgravity space lab in the Netherlands.

Note: This story has been adapted from a news release issued by the University of Toronto

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