RepSox (E-616452)

RepSox inhibits ATP binding to ALK5 and ALK5 autophosphorylation with IC50 of 23 nM and 4 nM, respectively. RepSox inhibits TGF-β induced cellular PAI-1 luciferase activity with IC50 of 18 nM. ^[1]

RepSox is able to successfully replace Sox2 in reprogramming by inhibiting transforming growth factor-β (Tgf-β) signaling, which in turn induces Nanog expression. Effect of RepSox inducing reprogramming does not require chromatin remodeling. RepSox is found to be efficient at generating iPSCs. ^[2]

RepSox is able to be contribute to forming chimeric embryos in vivo when injected into blastocysts. A one-day treatment with RepSox is sufficient to replace transgenic Sox2. ^[2]

• ALK5 fluorescence polarization binding assay

  Compound binding to ALK5 is tested on purified recombinant GST- ALK5 (residues 198-503). Displacement of rhodamine green fluorescently labeled ATP competitive inhibitor by different concentrations of test compounds is used to calculate a binding pIC50. GST -ALK5 is added to a buffer containing 62.5 mM Hepes, pH 7.5, 1 mM DTT, 12.5 mM MgCl₂, 1.25 mM CHAPS, and 1 nM rhodamine green-labeled ligand so that the final ALK5 concentration is 10 nM based on active site titration of the enzyme. Forty microliters of the enzyme/ligand reagent is added to 384 well assay plates containing 1 μL of different concentrations of test compound. The plates are read immediately on a fluorescence reader with excitation, emission, and dichroic filters of 485, 530, and 505 nm, respectively. The fluorescence polarization for each well is calculated by the Acquest and is then imported into curve fitting software for construction of concentration -response curves.

• Animal Models

  Male C57BL/6 mice

• Dosages

  10 mg/kg

• Administration

  i.p.