RWJ-56110 dihydrochloride is a potent, selective, peptide-mimetic inhibitor of PAR-1 activation and internalization (binding IC50=0.44 uM) and shows no effect on PAR-2, PAR-3, or PAR-4. RWJ-56110 dihydrochloride inhibits the aggregation of human platelets induced by both SFLLRN-NH2 (IC50=0.16 μM) and thrombin (IC50=0.34 μM), quite selective relative to U46619 . RWJ-56110 dihydrochloride blocks angiogenesis and blocks the formation of new vessels in vivo. RWJ-56110 dihydrochloride induces cell apoptosis[1][2].
Proteinase-activated receptors (PARs) are a family of G protein-coupled receptors activated by the proteolytic cleavage of their N-terminal extracellular domain, exposing a new amino terminal sequence that functions as a tethered ligand to activate the receptors.RWJ56110 inhibits the aggregation of human platelets induced by both SFLLRN-NH2 (IC50=0.16 μM) and thrombin (IC50=0.34 μM) while being quite selective relative to collagen and the thromboxane mimetic U46619 [1].RWJ-56110 dihydrochloride is fully inhibits thrombin-induced RASMC proliferation with an IC50 value of 3.5 μM. RWJ-56110 dihydrochloride shows blockade of thrombin's action with RASMC calcium mobilization (IC50=0.12 μM), as well as with HMVEC (IC50=0.13 μM) and HASMC calcium mobilization (IC50=0.17 μM)[1].RWJ56110 (0.1-10 μM; 24-96 hours) inhibits endothelial cell growth dose-dependently, with half-maximal inhibitory concentration of RWJ56110 is approximately 10 μM[2].RWJ56110 (0.1-10 μM; 6 hours) inhibits DNA synthesis of endothelial cells in a thymidine incorporation assays. Endothelial cells are in fast-growing state (50-60% confluence), RWJ56110 inhibits cell DNA synthesis in a dose-dependent manner, but when cells that are in the quiescent state (100% confluent), the inhibitory effect of PAR-1 antagonists is much less pronounced[2].RWJ56110 (0.1-10 μM; pretreatment for 15 min) inhibits thrombin-induced Erk1/2 activation in a concentration-dependent manner. However, when endothelial cells are stimulated by FBS (final concentration 4%), it reduces partially the activated levels of Erk1/2[2].RWJ56110 (30 μM; 24 hours) has an inhibitory effect on endothelial cell cycle progression. It reduces the percentage of cells in the S phase, while alterations in the percentages of G1 and G2/M cells are less pronounced[2]. Western Blot Analysis[2] Cell Line: Endothelial cells
[1]. Andrade-Gordon, et al.Design, synthesis, and biological characterization of a peptide-mimetic antagonist for a tethered-ligand receptor. oc Natl Acad Sci U S A. 1999 Oct 26;96(22):12257-62. [2]. Panagiota Zania, et al. Blockade of angiogenesis by small molecule antagonists to protease-activated receptor-1: association with endothelial cell growth suppression and induction of apoptosis. J Pharmacol Exp Ther. 2006 Jul;318(1):246-54.
R-8507 is a small molecule antagonist of the TNF-α type 1 receptor (TNF-αRI). It inhibits the expression of intercellular adhesion molecule-1 (ICAM-1) induced by TNF-α and IL-1β with EC50 values of 2.45 and 3.79 μM, respectively, in an ELISA using A549 lung epithelial cells.{|Gururaja2007|} It also disrupts the interaction of the TNF-αRI with receptor interacting protein 1 (RIP1) and TNF-αR-associated death domain protein (TRADD), preventing internalization of the receptor complex.