GW788388 is a potent and selective inhibitor of ALK5, also inhibits TGF-(beta) type II receptor and activin type II receptor activities.

ALK5:18 nM

在嘌呤霉素氨基核甙诱导的肾脏纤维化模型中,GW788388（10 mg/kg）能够诱导胶原A1 mRNA 表达.在患晚期糖尿病肾病鼠中,GW788388通过减少TGF-β 信号,降低纤维反应.在心肌梗塞鼠中,GW788388处理后,能够明显抑制收缩功能,降低心肌细胞肥大 ,且降低激活的Smad2, α-SMA.

GW788388能够抑制ALK5, ALK4, ALK7 和TGF-β调节的生长。在细胞实验中（IC50=93 nM）,GW788388具有抗TGF-β诱导的Smad激活,且抑制靶点基因表达。

ALK5 Fluorescence Polarization Binding Assay: GW788388 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 GW788388 is used to calculate a binding pIC50. GST?ALK5 is added to a buffer containing 62.5 mM N-(2-hydroxyethyl)piperazine-N'-2-ethanesulfonic acid (Hepes), pH 7.5, 1 mM dithiothreitol (DTT), 12.5 mM MgCl2, 1.25 mM 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonic acid (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. The enzyme/ligand reagent (40 μL) is added to 384-well assay plates containing 1 μL of different concentrations of GW788388. The plates are read immediately on a LJL Acquest 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.

Cell viability/proliferation assays are done according to the manufactures instructions (CellTiter 96 Aqueous One Solution Cell Proliferation Assay). Viability and proliferation are measured after 72 hours GW788388 treatment in the presence or absence of TGF-β.(Only for Reference)