Featured
-
-
Letter |
A mechanically stabilized receptor–ligand flex-bond important in the vasculature
Here, a new type of behaviour of receptor–ligand bonds has been identified, by using a new method that links receptor and ligand in a single molecule to measure binding and unbinding. The binding of von Willebrand factor to the glycoprotein Ib α subunit on the surface of platelets is important for coagulation. This receptor–ligand bond is now shown to have two distinct states, one seen at low force and a second that has greater force resistance. This has implications for how increased blood flow activates platelet plug formation.
- Jongseong Kim
- , Cheng-Zhong Zhang
- & Timothy A. Springer
-
Article |
Mesenchymal and haematopoietic stem cells form a unique bone marrow niche
The identity of the cells that form the haematopoietic stem cell (HSC) niche in bone marrow has been unclear. These authors identify nestin-expressing mesenchymal stem cells as niche-forming cells. These nestin-expressing cells show a close physical association with HSCs and express high levels of genes involved in HSC maintenance, and their depletion reduces bone marrow homing of haematopoietic progenitors.
- Simón Méndez-Ferrer
- , Tatyana V. Michurina
- & Paul S. Frenette
-
Letter |
Blood stem cells emerge from aortic endothelium by a novel type of cell transition
One of two papers showing the generation of haematopoietic stem cells (HSCs) from the ventral wall of the dorsal aorta in live zebrafish embryos. Here, using imaging of live zebrafish, HSCs are shown to emerge directly from the aorta floor. This process does not involve cell division but movement of single endothelial cells out of the aorta ventral wall into the sub aortic space, where they transform into haematopoietic cells.
- Karima Kissa
- & Philippe Herbomel
-
Article |
Systemic signals regulate ageing and rejuvenation of blood stem cell niches
Age-associated changes in stem cell supportive niche cells are shown to deregulate normal haematopoiesis by causing haematopoietic stem cell dysfunction. Age-dependent defects in niche cells are systemically regulated and can be reversed by exposure to a young circulation or by neutralization of the conserved longevity regulator, insulin-like growth factor-1, in the marrow microenvironment.
- Shane R. Mayack
- , Jennifer L. Shadrach
- & Amy J. Wagers
A novel tumour-suppressor function for the Notch pathway in myeloid leukaemia