Fetal liver hematopoietic stem cell niches associate with portal vessels.
United States. In Science, Feb 2016
After closure of the umbilical inlet at birth, portal vessels undergo a transition from Neuropilin-1(+)Ephrin-B2(+) artery to EphB4(+) vein phenotype, associated with a loss of periportal Nestin(+)NG2(+) cells and emigration of HSCs away from portal vessels.
Shear stress, arterial identity and atherosclerosis.
Montréal, Canada. In Thromb Haemost, Jan 2016
Notch1/4, Notch ligand delta-like 4 (Dll4), and Notch downstream effectors are typically expressed in arterial cells along with EphrinB2, whereas chicken ovalbumin upstream promoter transcription factor II (COUP-TFII) and EphB4 characterise vein endothelial cells.
Talking among ourselves: paracrine control of bone formation within the osteoblast lineage.
Australia. In Calcif Tissue Int, 2014
We provide four snapshots of communication pathways that exist within the osteoblast lineage between different stages of their differentiation, as follows: (1) PTHrP, a factor produced by early osteoblasts that stimulates the activity of more mature bone-forming cells and the most mature osteoblast embedded within the bone matrix, the osteocyte; (2) sclerostin, a secreted factor, released by osteocytes into their extensive communication network to restrict the activity of younger osteoblasts on the bone surface; (3) oncostatin M, a member of the IL-6/gp130 family of cytokines, expressed throughout osteoblast differentiation and acting to stimulate osteoblast activity that works on a different receptor in the mature osteocyte compared to the preosteoblast; and (4) Eph/ephrins, cell-contact-dependent kinases, and the osteoblast-lineage-specific interaction of EphB4 and ephrinB2, which provides a checkpoint for entry to the late stages of osteoblast differentiation and restricts RANKL expression.
Boning up on ephrin signaling.
Nashville, United States. In Cell, 2006
Zhao et al. (2006) now demonstrate bidirectional signaling between these two cell populations via the transmembrane ligand ephrinB2 expressed by osteoclasts and its receptor EphB4 expressed by osteoblasts.