Starvation improves epithelial fitness by selectively extruding DNA-damaged cells (bioRxiv preprint, King’s College London / Crick Institute)
- Glucose or glutamine starvation triggers a rapid wave of cell extrusion (STICE, starvation-induced cell extrusion).
- It selectively removes cells carrying DNA damage markers, unlike normal crowding-induced extrusion, which doesn’t specifically target damaged cells.
- Mechanism: p53-dependent and Piezo1-independent. p53-activated cells use LC3 to drive lysosomal exocytosis, which promotes extrusion. Other cells recycle their contents via autophagy.
- Eliminating defective and transformed cells makes the remaining tissue more resistant to damage and apoptotic stimuli.
- Big picture: STICE is a “tissue-level autophagy”. Instead of repairing and recycling inside individual cells, the tissue improves by removing substandard ones.
Caveat: this is a preprint (not peer-reviewed), and the evidence is from cell monolayers in culture. It doesn’t show that fasting or dieting does this in humans.