Can induce tyrosine phosphorylation of TIE2. Binds to TIE2
receptor and counteracts blood vessel
maturation/stability mediated by angiopoietin-1. Its function may
be context-dependent. In the absence of angiogenic
inducers, such as VEGF, ANG2-mediated loosening of cell-matrix
contacts may induce endothelial cell apoptosis with
consequent vascular regression. In concert with VEGF, it may
facilitate endothelial cell migration and proliferation,
thus serving as a permissive angiogenic signal
Tissue factor and PAR1 promote microbiota-induced
intestinal vascular remodelling
The gut microbiota is a complex ecosystem that has coevolved with host
physiology. Colonization of germ-free (GF) mice with a microbiota
promotes increased vessel density in the small intestine, ,
but little is known about the mechanisms involved. Tissue factor (TF)
is the membrane receptor that initiates the extrinsic coagulation
pathway,
and it promotes developmental and tumour angiogenesis.
Here we show that the gut microbiota promotes TF glycosylation
associated with localization of TF on the cell surface, the activation
of coagulation proteases, and phosphorylation of the TF cytoplasmic
domain in the small intestine. Anti-TF treatment of colonized GF mice
decreased microbiota-induced vascular remodelling and expression of
the proangiogenic factor angiopoietin-1 (Ang-1) in the small
intestine. Mice with a genetic deletion of the TF cytoplasmic domain
or with hypomorphic TF
alleles had a decreased intestinal vessel density. Coagulation
proteases downstream of TF activate protease-activated receptor (PAR)
signalling implicated in angiogenesis.
Vessel density and phosphorylation of the cytoplasmic domain of TF
were decreased in small intestine from PAR1-deficient
but not PAR2-deficient mice, and inhibition of thrombin showed that thrombin–PAR1 signalling
was upstream of TF phosphorylation. Thus, the microbiota-induced
extravascular TF–PAR1 signalling loop is a novel pathway that may be
modulated to influence vascular remodelling in the small intestine.
Reinhardt C., et al. Nature, 483, 627-631, 29 March 2012, doi:
10.1038/nature10893
Human
Angiopoietin 1 (ANGPT1) ELISA
Code No.: SK00631-01
Size: 96 T
Price: $360.00 USD
Standard Range:156-10000 pg/ml
Sensitivity:50 pg/ml
Sample Type: cell culture, serum, EDTA plasma
Sample requres: 100uL per well
IntraCV: 4-6%
InterCV: 8-10%
Protocol: PDF