Cells bumping against one another use electricity to identify which of their neighbors has the least energy to expel them. The King's College London study in partnership with the Francis Crick Institute provides insight into diseases including cancer and stroke, where cellular energy levels can be disrupted, preventing the maintenance of healthy cell numbers.

Epithelial cells, which line all organs in the body, turnover rapidly to maintain a tightly packed protective layer. They undergo a process called extrusion to eliminate excess or damaged cells, essential for balancing cell division and cell death.
Extrusion is a fundamental process, common in living organisms from sea sponge to humans, that drives most epithelial cell death. When it goes wrong and the balance of healthy cells is disrupted, it can lead to disease.

Earlier work by the group led by Professor Jody Rosenblatt at King's College London discovered that extrusion is mechanical—when too many epithelial cells accumulate, crowding triggers some to be physically squeezed out, causing them to die.

The scientists were unsure if the crowded cells selected to extrude were randomly selected, or some were specifically targeted. This latest discovery, published in Nature, reveals that crowding selectively targets the weakest, energy-poor cells for death.

Epithelial cells spend a remarkable amount of energy establishing and maintaining an electrically charged surface or membrane. While this electrical potential is well known in nerve cells, its role in other cell types has been largely overlooked.