Extracellular cadherin repeat domains EC1 and EC5 of T-cadherin are essential for its ability to stimulate angiogenic behavior of endothelial cells

• Published in: The FASEB journal 2009-11, Vol.23 (11), p.4011-4021
• Main Authors: Joshi, Manjunath B, Kyriakakis, Emmanouil, Pfaff, Dennis, Rupp, Katharina, Philippova, Maria, Erne, Paul, Resink, Thérèse J
• Format: Article
• Language: English
• Subjects: adhesion; Angiogenesis Inducing Agents; Cadherins - chemistry; Cadherins - genetics; Cadherins - physiology; Cell Adhesion - drug effects; Cell Proliferation - drug effects; deletion mutant; Endothelial Cells - physiology; Endothelium, Vascular - growth & development; Glycogen Synthase Kinase 3 - physiology; Glycogen Synthase Kinase 3 beta; Humans; lentivirus vector; migration; Neovascularization, Physiologic - physiology; proliferation; Protein Structure, Tertiary; signaling; Wound Healing - physiology
• ISSN: 0892-6638; 1530-6860
• DOI: 10.1096/fj.09-133611

T-cadherin (T-cad) promotes survival, proliferation, and migration of endothelial cells and induces angiogenesis. We aimed to identify domains of T-cad functionally relevant to its effects on endothelial cell behavior. To specifically target the functional properties of the 5 cadherin repeat domains (EC1-EC5) of T-cad, endothelial cells were transduced with lentivectors containing specific T-cad-domain-deletion mutant constructs (ΔI, ΔII, ΔIII, ΔIV, ΔV). Empty (E) lentivector-transduced cells served as control. Similarly to overexpression of native T-cad, cells expressing ΔII, ΔIII, or ΔIV displayed elevated levels of p-Akt and p-GSK3β and increased proliferation rates (for ΔII, ΔIII) vs. E. ΔI- and ΔV-transduced cells exhibited reduced levels of p-Akt and p-GSK3β and retarded growth rates vs. E. Stimulatory effects of native T-cad overexpression on Akt and GSK3β phosphorylation were dose dependently inhibited by coexpression of ΔI or ΔV. Subsequent functional analyses compared only ΔI-, ΔII-, and ΔV-mutant constructs with E as a negative control. Unlike ΔII cells, ΔI and ΔV cells failed to exhibit homophilic ligation and deadhesion responses on a substratum of T-cad protein. In the wound assay, migration was increased for ΔII cells but impaired for ΔI and ΔV cells. In endothelial cell-spheroid assay, angiogenic sprouting was augmented for ΔII cells but inhibited for ΔI and ΔV cells. We conclude that EC1 and EC5 domains of T-cad are essential for its proangiogenic effects. ΔI and ΔV constructs may serve as dominant-negative mutants and as potential tools targeting excessive angiogenesis.--Joshi, M. B., Kyriakakis, E., Pfaff, D., Rupp, K., Philippova, M., Erne, P., Resink, T. J. Extracellular cadherin repeat domains EC1 and EC5 of T-cadherin are essential for its ability to stimulate angiogenic behavior of endothelial cells.