E-cadherin-mediated cell coupling is required for apoptotic cell extrusion.

Apoptotic extrusion is a multicellular process utilized by live cells to remove neighboring apoptotic cells. In epithelial tissues, this process has been shown to be critical for the preservation of tissue integrity and barrier function. Here we demonstrate that extrusion is driven by the retraction of the apoptotic cell, which, in turn, triggers a transient and coordinated elongation of the neighboring cells. The coordination of cell elongation requires E-cadherin-mediated cell-cell adhesion. Accordingly, cells that express low levels of E-cadherin are compromised in elongation and apoptotic extrusion, and furthermore, display loss of barrier function in response to apoptotic stimuli. These findings indicate that the maintenance of adhesive forces during apoptotic cell turnover might play an essential role in controlling tissue homeostasis.