SAG hydrochloride

SAG (hydrochloride) is a potent Smo receptor agonist, and activates the Hedgehog signaling pathway, with a Kd of 59 nM. Kd: 59 nM (Smo)[1].

SAG (hydrochloride) acts downstream of Ptch1 in the Hh pathway and counteracts cyclopamine inhibition of Smo. SAG induces firefly luciferase expression in Shh-LIGHT2 cells with an EC50 of 3 nM and then inhibits expression at higher concentrations. In Smo-expressing Cos-1 cells, SAG yields an apparent dissociation constant (KD) of 59 nM for the SAG/Smo complex[1]. SAG and purmorphamine verride the inhibitory effect of robotnikinin since Smo functions downstream of Shh/Ptc1[2].

In CD-1 mice, SAG (1.0 mM) or NELL-1 (600 μg/ml) alone results in increased bone formation at 4 and 8 weeks, but significantly greater bone formation with both components combined (SAG + NELL-1). The combination of the two compounds exhibits a significant increase in new bone formation, accompanied by increased defect vascularization[3]. SAG (15, 17, or 20 mg/kg, i.p.) induces pre-axial polydactyly prevalently. The highest SAG dose is effective in ca. 80% of the embryos and increased Gli1 and Gli2 mRNA expression in the limb bud, with Gli1 mRNA being the most upregulated[4].

[1]. Chen JK, et al. Small molecule modulation of Smoothened activity. Proc Natl Acad Sci U S A. 2002 Oct 29;99(22):14071-6. [2]. Stanton BZ, et al. A small molecule that binds Hedgehog and blocks its signaling in human cells. Nat Chem Biol. 2009 Mar;5(3):154-6. [3]. Lee S, et al. Combining Smoothened Agonist (SAG) and NEL-like protein-1 (NELL-1) Enhances Bone Healing. Plast Reconstr Surg. 2017 Feb 13. [4]. Fish EW, et al. Preaxial polydactyly following early gestational exposure to the smoothened agonist, SAG, in C57BL/6J mice. Birth Defects Res A Clin Mol Teratol. 2016 Nov 1.