FIGURE 1.

Genetic ablation of ceramide kinase increases the levels of TNFα. A, genetic ablation of ceramide kinase increases the levels of TNFα in immortalized MEFs. MEFs (2 × 10⁵ cells) derived from either wild-type mice or CERK^−/− mice were seeded overnight in 35-mm plates. The following day, cells were transfected with either control adenovirus (adCMV) (20 multiplicities of infection) or CERK adenovirus (adCERK) (20 multiplicities of infection). After 48 h, cells were then washed and placed in complete media supplemented with 2% FBS. After 4 h, the media were collected and analyzed for TNFα content by ELISA. Data presented is the mean of n = 7 ± S.E. repeated on three separate occasions. Student's t test was used to assess statistical significance (statistical significance = p < 0.01). B, genetic ablation of ceramide kinase increases the levels of TNFα in response to LPS. BMDMs (2 × 10⁵ cells) derived from either wild-type mice or CERK^−/− mice were seeded overnight in 35-mm plates. Cells were treated for 0, 4, 8, 24, and 48 h with LPS (0.5 ng/ml). The media were then collected at the appropriate time points and analyzed for TNFα content by ELISA. The data presented are representative of the means ± S.E. of an n = 7 repeated on three separate occasions (asterisk indicates a statistical significance of p < 0.01).