Thrombospondin-1 Antibody #14778

The adhesive glycoprotein thrombospondin-1 (THBS1, TSP1) localizes to the extracellular matrix (ECM) and mediates interactions between cells and the ECM and among cells. Thrombospondin-1 is a multi-domain, glycosylated protein that interacts with a wide variety of extracellular targets, including matrix metalloproteinases (MMPs), collagens, cell receptors, growth factors, and cytokines (1). The protein structure of THBS1 includes an amino-terminal laminin G-like domain, a von Willebrand factor-binding domain, and multiple thrombospondin (TSP) repeated sequences designated as type I, type II, or type III repeats. Each thrombospondin domain interacts with a distinct type of cell surface ligands or protein targets. The amino-terminal domain interacts with aggrecan, heparin, and integrin proteins. Type I TSP repeats interact with MMPs and CD36, while carboxy-terminal repeats bind the thrombospondin receptor CD47 (1). Through these interactions, THBS1 exerts diverse effects on different signaling pathways, such as VEGF receptor/NO signaling, TGFβ signaling, and the NF-κB pathway (2-5). Thrombospondin-1 is an important regulator of many biological processes, including cell adhesion/migration, apoptosis, angiogenesis, inflammation, vascular function, and cancer development (2-5). The activity of thrombospondin-1 is mainly regulated by extracellular proteases. The metalloproteinase ADAMTS1 cleaves thrombospondin, resulting in the release of peptides with anti-angiogenic properties. Elastase and plasmin proteases degrade the THBS1 protein and down regulate its activity (6). As THBS1 is an important protein inhibitor of angiogenesis, the development of thrombospondin-based compounds and their use in therapeutic studies may provide a beneficial approach to the treatment of cancer (7,8).