Pathological angiogenesis, or new blood vessel formation, is involved in many pathologies, including cancer and serious eye diseases. While traditional anti-angiogenic therapies target vascular endothelial growth factor receptors to reduce or inhibit new vessel formation, this approach has several downsides, including unpleasant side effects and low efficacy over time. Therefore, identifying new targets to treat pathological angiogenesis is still needed. CMG2, one of the two identified anthrax toxin receptors, has been proposed as an alternative target to treat pathological angiogenesis. CMG2’s role as a cell surface receptor that mediates anthrax toxin internalization is very well documented. One physiological function for CMG2, not related to anthrax intoxication, is suggested by the observation that loss-of-function mutations in CMG2 cause hyaline fibromatosis syndrome (HFS), a genetic disease that results in accumulations of extra-cellular matrix (ECM) protein in different parts of the body. While the complete molecular mechanism for CMG2’s role in regulating angiogenesis has not been determined, this dissertation addresses multiple ways CMG2 regulates pathological angiogenesis. We have discovered that CMG2 plays a role in mediating ECM homeostasis via endocytosis of ECM proteins and protein fragments as a way to generate angiogenic signals from the cell. We have also demonstrated that a fragment from Col IV, S16, is endocytosed into the cells by interacting with CMG2, and S16 treatment to endothelial cells leads to a significant reduction in cell migration. Also, an endothelial cell migration assay with CMG2 knockout cells results in abolished directional migration, indicating that CMG2 is required for endothelial cell chemotaxis. Notably, we have identified that bFGF, VEGF, and PDGF are involved in CMG2 mediated chemotaxis but not insulin and sphingosine-1-phosphate (S1P). While recent literature reports show that CMG2 works closely with RhoA GTPase, which is commonly known to regulate cell migration, we have also observed that inhibition of RhoA also reduced cell chemotaxis towards VEGF but not S1P. These results could be leveraged to develop new classes of therapeutic molecules to treat pathological angiogenesis induced by multiple various growth factors via targeting CMG2.
College and Department
Physical and Mathematical Sciences; Chemistry and Biochemistry
BYU ScholarsArchive Citation
Tsang, Tsz Ming Jeremy, "Capillary Morphogenesis Gene Protein 2 (CMG2) Mediates Matrix Protein Uptake and is Required for Endothelial Cell Chemotaxis in Response to Multiple Vascular Growth Factors" (2020). Theses and Dissertations. 8410.
capillary morphogenesis gene 2 (CMG2), pathological angiogenesis, extracellular matrix, growth factors, chemotaxis, RhoA GTPase