First published online November 26, 2007
Development 134, 2403e (2007)
© The Company of Biologists Limited
Ang-ling for apoptosis clean up
Macrophages recognize and remove dead cells throughout the body but they
also sometimes actively induce apoptosis. Richard Lang and co-workers have
been investigating this phenomenon during programmed vascular regression of
the hyaloid vessels in the developing mouse eye. They now report that in this
system macrophages play an obligatory role in a cell death switch mediated by
angiopoietin 2 (Ang2; see p.
4449). Using genetic experiments and the intra-ocular injection of
various factors, the researchers show that during hyaloid vessel regression,
Ang2 (probably produced by the pericytes that coat small blood vessels) has
two effects: it suppresses Akt-mediated cell survival signalling in the
vascular endothelial cells (VECs) and it stimulates the production of Wnt7b by
macrophages. Wnt7b, the researchers report, stimulates VECs to enter the cell
cycle where they die in G1 phase because of the absence of survival signals.
This mechanism, the researchers suggest, ensures that macrophages are on hand
to sweep up the debris when cell death occurs.
Related articles in Development:
- Obligatory participation of macrophages in an angiopoietin 2-mediated cell death switch
- Sujata Rao, Ivan B. Lobov, Jefferson E. Vallance, Kaoru Tsujikawa, Ichiro Shiojima, Shailaja Akunuru, Kenneth Walsh, Laura E. Benjamin, and Richard A. Lang
Development 2007 134: 4449-4458.
[Abstract]
[Full Text]
