Fig. 1. Mechanical stretch induces keratin fragmentation in DM-EBS keratinocytes. Wild-type cells, NEB-1 (A,C,E) and DM-EBS cells, KEB-7 (B,D,F) were subjected to mechanical stress using an oscillating stretch with frequency of 4 Hz and amplitude of 12% for varying times. Cells were stained for keratin 14 using monoclonal antibody LL001. (A,B) Before stretch; (C,D) after 30 minutes stretch; (E,F) after 120 minutes stretch. All cells show concentric compaction and wrinkling of keratin filaments but only the EBS cells show accumulation of peripheral aggregates of keratin after stretch. By 120 minutes of stretch, the EBS cells show severely disrupted keratin networks with any remaining filaments concentrated around the nucleus. Bars, 10 µm.