ASGSB 2003 Annual Meeting Abstracts


[78]

Microgravity affects CLUSTER FORMATION, differentiation, and cytoskeletal organization of rauscher murine erythro-leukemia cells   K. Xu*, K. V. Holubec, J. Love, T. J. Goodwin and A.J. Sytkowski*.   *Laboratory for Cell and Molecular Biology, Division of Hematology and Oncology, Beth Israel Deaconess Medical Center, Department of Medicine, Harvard Medical School, Boston, MA, Wyle Laboratories, Houston, TX and Cellular Biotechnology Program, Johnson Space Center, Houston, TX.

   Humans and experimental animals subjected to microgravity, such as experienced during space flight, exhibit alterations in erythropoiesis, including changes in red blood cell morphology, survival and reduction in red blood cell mass. Human bone marrow cells grown on orbit showed a profound reduction in numbers of erythroid cells. We now report results of a study carried out on orbit  (ISS UF-1) in which an erythroid cell line was induced to differentiate. Rauscher murine erythroleukemia cells, a continuous cell line that can undergo erythropoietin (Epo)- or chemical-induced differentiation similar to normal erythropoiesis, were cultured for 6 days either in microgravity or on earth and then for 3 days in the absence or presence of 50 U Epo/ml or 0.7% dimethyl sulfoxide (DMSO). The cells were then fixed, stored on orbit and returned to earth for study. Compared to ground-based controls, cells cultured in microgravity exhibited a significantly higher percentage of cluster formation (p<0.05) and a greater degree of differentiation (hemoglobinization) (p<0.01). Actin content appeared reduced in microgravity, and following Epo or DMSO treatment, there was a more profound loss of actin stress fibers in microgravity. These results are consistent with the hypothesis that erythropoiesis is affected by gravitational forces at the cellular level.

(Supported by NASA: NAG9-1368 and NAG2-1592)

 

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