PUBLICATION

Cooperative epithelial phagocytosis enables error correction in the early embryo

Authors
Hoijman, E., Häkkinen, H.M., Tolosa-Ramon, Q., Jiménez-Delgado, S., Wyatt, C., Miret-Cuesta, M., Irimia, M., Callan-Jones, A., Wieser, S., Ruprecht, V.
ID
ZDB-PUB-210212-2
Date
2021
Source
Nature   590(7847): 618-623 (Journal)
Registered Authors
Keywords
none
Datasets
GEO:GSE143734
MeSH Terms
  • Actin-Related Protein 2-3 Complex/metabolism
  • Actins/metabolism
  • Animals
  • Apoptosis
  • Cell Movement
  • Cell Shape
  • Cell Surface Extensions
  • Embryo, Mammalian/cytology*
  • Embryo, Mammalian/embryology*
  • Embryonic Development*
  • Epithelial Cells/cytology*
  • Immunity, Innate
  • Mice
  • Phagocytes/cytology*
  • Phagocytosis*
  • Phosphatidylserines/metabolism
  • Zebrafish/embryology*
  • rac1 GTP-Binding Protein/metabolism
PubMed
33568811 Full text @ Nature
Abstract
Errors in early embryogenesis are a cause of sporadic cell death and developmental failure1,2. Phagocytic activity has a central role in scavenging apoptotic cells in differentiated tissues3-6. However, how apoptotic cells are cleared in the blastula embryo in the absence of specialized immune cells remains unknown. Here we show that the surface epithelium of zebrafish and mouse embryos, which is the first tissue formed during vertebrate development, performs efficient phagocytic clearance of apoptotic cells through phosphatidylserine-mediated target recognition. Quantitative four-dimensional in vivo imaging analyses reveal a collective epithelial clearance mechanism that is based on mechanical cooperation by two types of Rac1-dependent basal epithelial protrusions. The first type of protrusion, phagocytic cups, mediates apoptotic target uptake. The second, a previously undescribed type of fast and extended actin-based protrusion that we call 'epithelial arms', promotes the rapid dispersal of apoptotic targets through Arp2/3-dependent mechanical pushing. On the basis of experimental data and modelling, we show that mechanical load-sharing enables the long-range cooperative uptake of apoptotic cells by multiple epithelial cells. This optimizes the efficiency of tissue clearance by extending the limited spatial exploration range and local uptake capacity of non-motile epithelial cells. Our findings show that epithelial tissue clearance facilitates error correction that is relevant to the developmental robustness and survival of the embryo, revealing the presence of an innate immune function in the earliest stages of embryonic development.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping