ASGSB 1999 Annual Meeting Abstracts

cDNA MICROARRAY ANALYSIS OF GENES EXPRESSED IN HUMAN LYMPHOCYTES (JURKAT) IN MICROGRAVITY. M.L. Lewis¹, L.A. Cubano¹, B. Zhao², H. Dinh², J. Pabalan2, E.H. Piepmeier², and P.D. Bowman². ¹Dept. Biology, Univ. Alabama in Huntsville, ²College of Pharmacy, University of Texas at Austin.

We previously reported that human T lymphoblastoid cells (Jurkat) flown on the Space Shuttle (STS-76) manifested growth failure, increased glucose metabolism, increased apoptosis, disorganized microtubule and microtubule organizing centers, and released the cell death factor Fas/APO-1 in a time- and microgravity-dependent manner (Lewis, et al., FASEB J. 1998).  To probe for mechanisms underlying these space flight responses, we applied gene expression profiling analysis to evaluate expression of more than 4000 known human genes in space flown Jurkat cells (STS-95).  The cells, filtered from culture medium after 24 and 48 hours in microgravity, were lysed with a solution containing guanidinium isothiocyanate followed by freezing at -80 C for the duration of the mission.  Total RNA was extracted post-flight and 33P labeled cDNA was prepared and hybridized to GeneFiltersTM (Research Genetics).  Analysis of the phosphosimages of the GeneFiltersTM showed significant differences between space flown and ground controls in expression of genes regulating cell cycle, apoptosis, heat shock response, intracellular signaling, metabolism, and cancer, as well as genes for structural proteins, mitochondrial proteins, and a number of transcription factors and DNA binding proteins. Up-regulation of plectin, gelsolin precursor, dynactin, c-nap 1, and tropomodulin genes are of particular interest since all are mediators of cytoskeletal organization.  This new knowledge of gene expression during spaceflight significantly facilitates future investigation of basic regulatory mechanisms and signaling pathways in space flown cells.

This research was supported in part by NASA Grant: NAG2-985

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