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Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death
09:18

Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death

Published on: December 27, 2016

Obligatory participation of macrophages in an angiopoietin 2-mediated cell death switch

Sujata Rao1, Ivan B Lobov, Jefferson E Vallance

  • 1Division of Pediatric Ophthalmology, Children's Hospital Research Foundation, University of Cincinnati, Cincinnati, OH 45229, USA.

Development (Cambridge, England)
|November 28, 2007
PubMed

Insights

Resident macrophages orchestrate programmed cell death in vascular regression. Angiopoietin 2 triggers Wnt signaling, causing vascular endothelial cells (VECs) to die, ensuring macrophages are present for clearance.

Area of Science:

  • Cell Biology
  • Immunology
  • Developmental Biology

Background:

  • Macrophages are key in clearing dead cells.
  • Macrophages can also induce cell death.
  • Vascular regression involves programmed cell death.

Purpose of the Study:

  • To investigate the role of macrophages in developmentally scheduled vascular regression.
  • To elucidate the signaling mechanisms by which macrophages influence vascular endothelial cell (VEC) survival or death.

Main Methods:

  • Studied signaling pathways during vascular regression.
  • Investigated the effects of angiopoietin 2 and Wnt ligands on VECs and macrophages.

Main Results:

  • Macrophages are essential for a signaling switch favoring cell death during vascular regression.
  • Angiopoietin 2 suppresses VEC survival signals and stimulates macrophage Wnt ligand production.
  • Wnt signaling induces VEC cell cycle entry, leading to death in the absence of survival signals.

Conclusions:

  • Macrophages actively participate in programmed cell death during vascular regression.
  • A novel mechanism involving angiopoietin 2 and Wnt signaling regulates VEC fate.
  • This ensures macrophage presence for efficient clearance of dying cells.

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