[Effect of simulated microgravity on erythroid differentiation of K562 cells and the mechanism].

ABSTRACT

OBJECTIVE: To investigate the effect of simulated microgravity on erythroid differentiation of K562 cells and explore the possible mechanism. METHODS: The fourth generation rotating cell culture system was used to generate the simulated microgravity environment. Benzidine staining was used to evaluate the cell inhibition rate, and real-time quantitative PCR (qRT-PCR) was used to detect GATA-1, GATA-2, Ets-1, F-actin, ß-Tubulin and vimentin mRNA expressions. The changes of cytoskeleton were observed by fluorescence microscopy, and Western blotting was employed to assay F-actin, ß-tubulin and vimentin protein expression levels. RESULTS: Benzidine staining showed that simulated microgravity inhibited erythroid differentiation of K562 cells. K562 cells treated with Hemin presented with increased mRNA expression of GATA-1 and reduced GATA-2 and Ets-1 mRNA expressions. Simulated microgravity treatment of the cells resulted in down-regulated GATA-1, F-actin, ß-tubulin and vimentin mRNA expressions and up-regulated mRNA expressions of GATA-2 and Ets-1, and reduced F-actin, ß-tubulin and vimentin protein expressions. Exposure to simulated microgravity caused decreased fluorescence intensities of cytoskeletal filament F-actin, ß-tubulin and vimentin in the cells. CONCLUSION: Simulated microgravity inhibits erythroid differentiation of K562 cells possibly by causing cytoskeleton damages to result in down-regulation of GATA-1 and up-regulation of GATA-2 and Ets-1 expressions.