T-cadherin

2V37101212554ENSG00000140945ENSMUSG00000031841P55290Q9WTR5NM_001257NM_019707NP_001248NP_062681T-cadherin also known as cadherin 13, H-cadherin (heart) (CDH13) is a unique member of cadherin superfamily because it lacks the transmembrane and cytoplasmic domains and is anchored to the cells membrane through the GPI anchor. Classical cadherins are necessary for cell–cell contacts, dynamic regulation of morphogenetic processes in embryos and tissue integrity in adult organism. Cadherins function as membrane receptors mediating outside-in signals, activating small GTPases and beta-catenin/Wnt pathway, and resulting in dynamic cytoskeleton reorganization and changes in the phenotype. T-cadherin also known as cadherin 13, H-cadherin (heart) (CDH13) is a unique member of cadherin superfamily because it lacks the transmembrane and cytoplasmic domains and is anchored to the cells membrane through the GPI anchor. Classical cadherins are necessary for cell–cell contacts, dynamic regulation of morphogenetic processes in embryos and tissue integrity in adult organism. Cadherins function as membrane receptors mediating outside-in signals, activating small GTPases and beta-catenin/Wnt pathway, and resulting in dynamic cytoskeleton reorganization and changes in the phenotype. T-cadherin is a GPI-anchored member of cadherin superfamily, which lacks a direct contact with cytoskeleton and therefore is not involved in cell–cell adhesion. It is involved in low density lipoproteins (LDL) hormone-like effects on Ca2+-mobilization and increased cell migration as well as phenotype changes. Exact signaling partners and adapter proteins for T-cadherin remain to be elucidated. Though T-cadherin can mediate weak adhesion in aggregation assays in vitro, the lack of intracellular domain suggests that T-cadherin is not involved in stable cell-cell adhesion. In vivo T-cadherin was detected on the apical cell surface of the chick interstinal epithelium. In cultures of transfected MDCS cells, T-cadherin was also expressed apically, whereas N-cadherin located basolaterally corresponded to the zone of cell contacts. The apical cell surface distribution of T-cadherin was proposed to possibly endow T-cadherin with recognition functions. In confluent cultures of vascular cells, T-cadherin was distributed equally over the entire cell surface, in contrast to VE-cadherin, which was restricted to the cell junctions. In migrating vascular cells, T-cadherin was located at the leading edge as revealed by confocal microscopy. The distribution of T-cadherin on the cell membrane is restricted to lipid rafts where it co-localizes with signal-transducing molecules. These data strongly implicates T-cadherin in intracellular signaling rather than adhesion. Studying signaling effects of low density lipoproteins (LDL) in vascular smooth muscles (VSMCs), T-cadherin was isolated and identified as new LDL receptor using human aortic media and the ligand-blotting method. The properties of T-cadherin as an LDL receptor were markedly different from the presently known types of LDL receptors. LDL binding to T-cadherin leads to the activation of Erk 1/2 tyrosine kinase and the nuclear translocation of NF-kappaB. T-cadherin overexpression in ECs facilitates spontaneous cell migration, formation of stress fibers and change of the phenotype from quiescent to promigratory. T-cadherin expression results in LDL-induced migration of T-cadherin expressing cells compared to control. It is likely that T-cadherin regulates cell migration and phenotype via activation of small G-proteins with subsequent actin reorganization. RhoA/ROCK activation is necessary for cell contraction, stress fiber assembly and inhibition of spreading, while Rac is required for the formation of membrane protrusions and actin-rich lamellopodia at the leading edge of migrating cells. The function of T-cadherin in situ, in normal conditions, and in pathology is still largely unknown. T-cadherin is highly expressed in the heart, aortic wall, neurons of the brain cortex and spinal cord and also in the small blood vessels in spleen and other organs. Expression of T-cadherin is upregulated in atherosclerotic lesions and post-angioplasty restenosis —conditions associated with pathological angiogenesis. T-cadherin expression is upregulated in ECs, pericytes and VSMC of atherosclerotic lesions. T-cadherin expression in arterial wall after balloon angioplasty correlates with late stages of neointima formation and coincidentally with the peak in proliferation and differentiation of vascular cells. It is highly expressed in adventitial vasa vasorum of injured arteries suggesting the involvement of T-cadherin in the processes of angiogenesis after vessel injury. These data implicate T-cadherin to be involved in regulation of vascular functioning and remodeling; however, the exact role of T-cadherin in neointima formation and atherosclerosis development is poorly understood.