Induction of pyroptosis by light-induced activation of optoCaspase-1, optoCaspase-4, or optoCaspase-5. Time-lapse fluorescence confocal microscopy of GSDMD-transgenic HEK293T cells transiently transfected with indicated constructs and stimulated with blue light (5 mW/cm2) for 30 min. Composite of DIC, mCherry (marking optoCaspase or Cry2olig used as a control, red), CellTox (membrane permeabilization marker, green), and Annexin V (PS exposure marker, blue) is shown. Pyroptotic cells display characteristic morphological features, such as early membrane blebbing, swelling, and ballooning, as well as nuclear rounding and condensation and acquisition of CellTox and Annexin staining. Cry2olig-expressing cells remain morphologically unchanged over the course of experiment. Scale bar, 20 µm.
