Hyperosmotic-induced changes in lymphoid cell gene expression

We have taken S49 Neo cells (an immature murine T-cell line) through repeated exposures of 500 mOsm Mannitol for 4 hours, killing over 90% of the cells, and then allowed them to recover. After 25 rounds of Mannitol exposure, we observed that these cells now have the ability to volume regulate upon an acute exposure to an osmotic stress, an ability not observed in the parental cell line. Interestingly, we found that these repeated Mannitol treated cells to be resistant to glucocorticoid-induced apoptosis, whereas the parental cell line is highly sensitive to glucocorticoid-induced cell death. The RNA was prepared from cultured cells (~1x106 cells/ml) of the parental cell line S49 Neo and the Mannitol Recovered cell line MR 4-25 using the Qiagen RNeasy mini-kit and including DNase treatment. Three replicates were used for each cell line.