ASGSB 2003 Annual Meeting Abstracts


THE HEMATOPOIETIC STEM CELL THERAPY FOR MUSCLE LOSS DURING EXPLORATION OF SPACE. S. Ramsahai1, B.C. Kim1, A.N. Roach1, D. Riley2, and S. Ohi1. 1Howard University & Hospital, Washington D.C., and 2Medical College of Wisconsin, Milwaukee, W.I.

   The prolonged exposure to space environments results in severe/invasive disorders in astronauts such as muscle and bone losses. Hematopoietic stem cells exhibit extraordinary plasticity because they can differentiate to all types of blood cells, as well as transdifferentiate into various tissues such as muscle and bone. We have hypothesized that the hematopoietic stem cell therapy (HSCT) could alleviate space-caused muscle loss so as to maintain astronautsí homeostasis in space. To investigate HSCT for muscle loss, donor HSCs were genetically marked either by transfecting with b-galactosidase-containing plasmid, pCMV.SPORT-b-gal or by preparing from b-galactosidase transgenic mouse (LacZ mouse) and cultured in a liquid suspension culture system. When the marked HSCs were stained by X-gal, 60% of the transfected HSCs stained blue and 100% of the LacZ-HSCs stained blue. The LacZ-HSCs were transplanted to a hindlimb suspended mouse (strain 129S) and differentiation of HSCs to muscles were investigated by X-gal staining procedure. Although the HSCs were injected to thigh and gastrocnemius muscles of the right leg only, both right and left legs were stained bluish. The weight of combined legs was 14% heavier than that of the control suspended mouse. Histochemical analysis indicated the structural contribution of HSCs to muscle. We are now analyzing transitions of myosin heavy chain isoforms in unloaded muscles during hindlimb suspension using SDS-PAGE system. This experiment will lead to determining the interval and frequency of HSCT during the hindlimb unloading. In the future, HSCT for muscle loss may be applied to long-term bed-rest patients.

(Supported by NIAC/USRA grants)


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