Figure 2

Over-expression of wild-type MMP28 confers a cell-survival advantage during serum-deprivation conditions. An equal number of A549 neg, wtMMP28 and muMMP28 cells (1-2 clones each, performed in duplicate) were plated onto collagen I-coated chamber slides in the absence of serum. (A) After 6 days in culture, the above images were obtained demonstrated floating cellular debris in the A549 neg and mutant clones (left 3 columns) and many viable cells in the wild-type clones (right 2 columns). Notably, initial adherence and spreading of the cells on collagen were similar, but survival after six-days of serum-deprivation was enhanced in clones expressing active MMP28. (B) Assessment of nuclear condensation and fragmentation (associated with apoptosis) using DAPI staining of serum-deprived cells at 24 h, revealed increased condensed (arrows) and fragmented (arrowhead) nuclei in only the A549 neg, muMMP28 cells and not wtMMP28.