ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of simulated microgravity on erythroid differentiation of K562 cells and explore the possible mechanism.</p><p><b>METHODS</b>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, β-Tubulin and vimentin mRNA expressions. The changes of cytoskeleton were observed by fluorescence microscopy, and Western blotting was employed to assay F-actin, β-tubulin and vimentin protein expression levels.</p><p><b>RESULTS</b>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, β-tubulin and vimentin mRNA expressions and up-regulated mRNA expressions of GATA-2 and Ets-1, and reduced F-actin, β-tubulin and vimentin protein expressions. Exposure to simulated microgravity caused decreased fluorescence intensities of cytoskeletal filament F-actin, β-tubulin and vimentin in the cells.</p><p><b>CONCLUSION</b>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.</p>
Subject(s)
Humans , Actins , Metabolism , Cell Differentiation , Down-Regulation , GATA1 Transcription Factor , Metabolism , GATA2 Transcription Factor , Metabolism , Hemin , Pharmacology , K562 Cells , Proto-Oncogene Protein c-ets-1 , Metabolism , Tubulin , Metabolism , Up-Regulation , Vimentin , Metabolism , Weightlessness SimulationABSTRACT
We report two cases of rituximab (RTX)-induced interstitial pneumonia in two lymphoma patients receiving RTX treatment. Interstitial pneumonia was successfully managed in these two cases after a one-week-long intervention with corresponding treatments without affecting further treatment of the primary disease. RTX-induced interstitial pneumonia is characterized by a latent onset with an unclear pathological mechanism and absence of typical symptoms. High-resolution CT scan can provide valuable evidence for early diagnosis of RTX-induced interstitial pneumonia, which might be attributed partially to an increased susceptibility to P. jirovecii and fungal infection due to prolonged RTX treatment.