Figure 4
The effects of hGX are reproduced by other PC-hydrolyzing sPLA 2 s. (A) Quiescent MDA-MB-231 cells were treated with the indicated concentrations of recombinant hGIIA, hGV and AtxA(V31W) in combination with varespladib (Var; 50 μM) in serum-free medium for 96 h. Cellular neutral lipid content was then determined by Nile red staining (A) and the percentage of apoptotic cells within the population was measured in parallel samples by the TMRM/YO-PRO-1 assay (B). The hGV and AtxA(V31W) sPLA2s, similar to hGX in their ability to hydrolyze PC-rich membranes[13, 46], induced LD formation and prolonged cell survival in an enzymatic activity-dependent manner, while hGIIA did not induce LD formation or prolong survival. Values on the graphs are means ± SD of three experiments performed in duplicate. Results that are statistically significant over control samples are indicated (**, P < 0.01; ***, P < 0.001; one-way ANOVA with Bonferroni adjustment).