Table 2.
Targets for endothelial drug delivery.
| Endothelial target |
MM | Functions | Vascular expression, EC density, internalization |
|---|---|---|---|
| PECAM-1 | 130 kDa | Component of intercellular junctions, interaction with cytoskeleton, ITIM-mediated inhibitory function, mechanoreceptor |
Constitutively expressed by EC of all blood and lymphatic vessels at high density. Internalizable upon clustering. |
| ICAM-1 | 85-110 kDa |
Leukocyte adhesion to endothelium | Ubiquitously expressed in vasculature, upregulated in activated EC. Internalizable upon clustering. |
| VCAM-1 | 110 kDa | Monocyte adhesion to endothelium | Expressed at a low level, upregulated on sites of inflammation |
| E-selectin | 150 kDa | Leukocyte rolling and adhesion | Expressed at a low level, upregulated on sites of inflammation |
| P-selectin | 146-160 kDa |
Leukocyte rolling and adhesion | Constitutively expressed by EC, localized in Weibel-Palade bodies, released upon cell activation |
| ACE | 150-180 kDa |
Peptidase, converts AngI into AngII, cleaves bradykinin |
Constitutively expressed. Enriched in lung endothelium |
| APP-2 | Trimer of 75 kDa |
Membrane-bound metalloprotease, plays a role in inflammation, metabolizes bradykinin |
Enriched in lung endothelium. Transcytosed along with caveolae. |
| TfR | 180 kDa | Cellular uptake of iron occurs via receptor-mediated endocytosis of ligand-occupied transferrin receptor into specialized endosomes |
Ubiquitously distributed. Internalized by receptor-mediated endocytosis. |
| TM | 105 kDa | EC receptor, forms a complex with thrombin, which activate protein C producing anticoagulant APC |
Constitutively expressed. Enriched in lung endothelium |
ACE, angiotensin-converting enzyme; APP-2, aminopeptidase 2; EC, endothelial cell; ICAM, intercellular adhesion molecule; MM, molecular mass; PECAM, platelet-endothelial cell adhesion molecule; TfR, transferrin receptor; TM, thrombomodulin; VCAM, vascular cell adhesion molecule.