Related Experiment Video
Updated: Jul 15, 2026

Implantation of Fibrin Gel on Mouse Lung to Study Lung-specific Angiogenesis
Published on: December 21, 2014
Interaction of alpha9beta1 integrin with thrombospondin-1 promotes angiogenesis
Izabela Staniszewska1, Shachi Zaveri, Luis Del Valle
1Department of Neuroscience, Center for Neurovirology, Temple University, School of Medicine, Philadelphia, PA 19122, USA.
Abstract:
Thrombospondin-1 is a multifunctional protein interacting with several cell surface receptors including integrins. We found that it is a ligand for alpha9beta1 integrin, and has an integrin binding site within its N-terminal domain (NoC1). Interaction of thrombospondin-1 and its recombinant NoC1 domain with alpha9beta1 integrin was confirmed in ELISA and cell adhesion assays. Binding of NoC1 to cells expressing alpha9beta1 integrin activated signaling proteins such as Erk1/2 and paxillin. Blocking of this integrin by monoclonal antibody and the met-leu-asp-disintegrin inhibited dermal human microvascular endothelial cell proliferation and NoC1-induced migration of these cells. Immunohistochemical studies revealed that alpha9beta1 is expressed on microvascular endothelium in several organs including skin, lung, heart and brain. NoC1 induced neovascularization in an experimental quail chorioallantoic membrane system and Matrigel plug formation assay in mice. This proangiogenic activity of NoC1 in vivo was inhibited by alpha9beta1 inhibitors. In summary, our results revealed that alpha9beta1 integrin expressed on microvascular endothelial cells interacts with thrombospondin-1, and this interaction is involved in modulation of angiogenesis.
Related Concept Videos
Intracellular Signaling Affects Focal Adhesions
Some...
Regulation of Angiogenesis and Blood Supply
Mechanism of Angiogenesis
Activation of Integrins
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus.
TGF - β Signaling Pathway
Clot Retraction and Fibrinolysis
