By Xiang Teng1,2, Lei Qin2, Roland Le Borgne3,4, Yusuke Toyama5,2,6
Development. November 2016. 144(1). 95-105. doi: 10.1242/dev.139865.
Apoptosis is a mechanism of eliminating damaged or unnecessary cells during development and tissue homeostasis. During apoptosis within a tissue, the adhesions between dying and neighboring non-dying cells need to be remodeled so that the apoptotic cell is expelled. In parallel, contraction of actomyosin cables formed in apoptotic and neighboring cells drives cell extrusion. To date, the coordination between the dynamics of cell adhesion and the progressive changes in tissue tension around an apoptotic cell is not fully understood. Live imaging of histoblast expansion, which is a coordinated tissue replacement process during Drosophila metamorphosis, shows remodeling of adherens junctions (AJs) between apoptotic and non-dying cells, with a reduction in the levels of AJ components, including E-cadherin. Concurrently, surrounding tissue tension is transiently released. Contraction of a supra-cellular actomyosin cable, which forms in neighboring cells, brings neighboring cells together and further reshapes tissue tension toward the completion of extrusion. We propose a model in which modulation of tissue tension represents a mechanism of apoptotic cell extrusion.
1Department of Biological Sciences, National University of Singapore, Singapore.
2Mechanobiology Institute, National University of Singapore, Singapore.
3CNRS, UMR 6290, Institute of Genetics and Development of Rennes, F-35043 Rennes, France.
4Université Rennes 1, Faculté de Médecine, F35043 Rennes, France.
5Department of Biological Sciences, National University of Singapore, Singapore.
6Temasek Life Sciences Laboratory, Singapore.