Cell Death Processes Are Reversible
In 2007, Ho Man “Holly” Tang took a break from her undergraduate biology studies at Iowa State University to join her older brother, Ho Lam “Hogan” Tang, then a doctoral student at the Chinese University of Hong Kong, to work on a project together. In Ming-Chiu Fung’s immunology lab, Hogan had been investigating how disturbances in the cytoskeletons of cells might contribute to the fragmentation of mitochondria during apoptosis, the most familiar form of cell suicide. But the siblings had a more fundamental question: Can cells recover from the cellular chaos that ensues once apoptosis is initiated?
There are many different triggers of apoptosis, but they all ultimately activate executioners called caspases. Cleaving hundreds of different kinds of proteins within a cell, these enzymes wreak havoc on the genome, attack structural proteins composing the cell’s organelles, and dismantle the cytoskeleton, leading cells to shrink, bleb, fragment, and seemingly die. “At that time, and even now, the general dogma was that apoptosis is irreversible,” Hogan (hereafter, Tang) recalls. “Holly and I were very curious and asked, ‘Is this really true?’”