Tie1 (tyrosine kinase with immunoglobulin and epidermal growth factor-like domains 1) was first reported in 1992 along with its related receptor Tie2 (Qu and Baldwin 2013). These Tie receptors are co-expressed in the endothelium, the innermost layer of cells lining blood and lymphatic vasculature, as well as all the chambers of the heart. Tie1 and Tie2 appear to be mutually expressed in all endothelia, as no study to date has identified a subpopulation of endothelial cells that exclusively expresses just one Tie receptor. However, their expression and activity are differentially regulated, as is evident in the lymphatic endothelium where Tie1 expression predominates and Tie2 expression is relatively diminished (Shen et al. 2014). Null mutations of Tie1 result in vascular defects and embryonic demise, and conditional...
- Savant S, La Porta S, Budnik A, Busch K, Hu J, Tisch N, Korn C, Valls AF, Benest AV, Terhardt D, et al. The orphan receptor tie1 controls angiogenesis and vascular remodeling by differentially regulating tie2 in tip and stalk cells. Cell Rep. 2015;12(11):1761–73.PubMedPubMedCentralCrossRefGoogle Scholar