Microgravity-induced programmed cell death in astrocytes

摘要

Cultured astrocytes were submitted to simulated microgravity using a Fokker clinostat under continuous rotation (60 rpm) for 15', 30', 1h, 20h and 32h. Samples processing included (ⅰ) nuclear stainings using Propidium Iodide and 4,6-diamidino-2-phenilindole, dihydro chloride, (ⅱ) immunohistochemical identification of Caspase-7, (ⅲ) identification of DNA fragmentation using the terminal dUTP nick end labelling and (ⅳ) Scanning Electron Microscope analysis. After 30' at simulated microgravity the glial cells showed morphological evidence of apoptosis: cell shrinkage, chromatin condensation, nuclear blebs and fragmentation. The enzyme caspase-7 was present and DNA fragmentation was evident. After 32h the density of the cell population was much lower than that observed in controls.