KAG-308 is an effective selective and orally active agonist of the EP4 receptor (Ki: 2.57 nM and EC50: 17 nM for human EP4 receptor), more selective over EP1, EP2, EP3, and IP receptor. KAG-308 suppresses colitis and promotes histological mucosal healing,
Butaprost is a chemical compound that functions as a selective agonist for the prostaglandin E receptor (EP2). It exhibits an EC50 of 33 nM and a Ki of 2.4 μM when interacting with the murine EP2 receptor. However, Butaprost demonstrates lower activity against murine EP1, EP3, and EP4 receptors. Furthermore, it effectively attenuates fibrosis by inhibiting the TGF-β Smad2 signaling pathway [1] [2] [3].
Prostaglandin E2 activates four distinct G protein-coupled receptors, EP1-4. Rivenprost is a potent and selective agonist for the EP4 receptor (Ki = 0.7, 56, 620, and >10,000 nM for EP4, EP3, EP2, and EP1, respectively). It has been used to promote EP4-mediated bone formation, prevent bone loss related to osteoporosis, drive osteoblast differentiation, and stabilize bone implants.[1][2][3][4][5] Rivenprost has also been used to support wound healing.[6]
The prostaglandin E receptor 4 (EP4) is one of four G protein-coupled receptors that mediate the actions of prostaglandin E2 . Binding of PGE2 to the EP4 receptor causes an increase in intracellular cyclic AMP, which plays important roles in bone formation and resorption, cancer, and atherosclerosis. KMN-80 is a substituted γ-lactam (pyrrolidinone) derivative of PGE1 that acts as a selective and potent agonist of EP4 with an IC50 value of 3 nM (IC50 = 1.4 μM for EP3 and > 10 μM for all other prostanoid receptors). In functional assays it has been shown to stimulate secreted alkaline phosphatase gene reporter activity in EP4-transfected HEK293 cells with an EC50 value of 0.19 nM, demonstrating >5,000 and 50,000-fold selectivity against EP2 and TP, respectively. KMN-80 can induce the differentiation of bone marrow stem cells from both young and aged rats into osteoblasts in vitro (EC50s = 20 and 153 nM, respectively) and exhibits favorable tolerability up to at least 10 μM, whereas the EP4 agonist L-902,688 is highly cytotoxic at similar concentrations in these cells. KMN-80 has been used to repair calvarial defects in an in vivo rat craniomaxillofacial reconstruction model (rate of reduction in defect size equivalent to BMP-2 treated rats) and to promote bone formation in a rat incisor tooth socket model.