FIGURE 12.

Individual knockdown of particular CerS isoforms inhibits UV-C-induced ceramide accumulation but fails to significantly inhibit UV-C-induced plasma membrane permeabilization. A, cells were transfected with siCerS1, siCerS5, siCerS6, or siControl for 48 h, the media were changed, and cells were treated (UV) or not treated (NT) with 10 mJ/cm² UV-C. The cells were then incubated for 24 h, and ceramide levels were measured by HPLC/MS. Total ceramide levels are reported (A), and a heat map displays the log₂ -fold change of ceramide compared with untreated siControl (B). Statistical significance was determined by two-way ANOVA and Bonferroni post hoc tests. Data are mean and error bars represent S.E. of four independent experiments. C, cells were treated as in A, and LDH release was assessed and reported as a percentage of total LDH released from siRNA-transfected cells lysed with Triton X-100. Statistical significance was determined by two-way ANOVA and Bonferroni post hoc tests. Data are mean and error bars represent S.E. for five independent experiments.*, p < 0.05; **, p < 0.01; ***, p < 0.001 versus siRNA-matched untreated cells. #, p < 0.05 versus treatment-matched siControl-transfected cells.