tcsc0199 SB 525334

SB525334 is a potent and selective inhibitor of TGFβ receptor I (ALK5) with IC50 of 14.3 nM, is 4-fold less potent to ALK4 than ALK5 and inactive to ALK2, 3, and 6.

IC50 value: 14.3 nM

Target: ALK5

in vitro: SB 525334 shows no inhibition in the enzymes ALK2, 3, and 6, with IC50 values > 10 μM. SB 525334 blocks phosphorylation induced by TGF-β1 and nuclear translocation of Smad2/3 in renal proximal tubule cells. SB 525334 also inhibits the increased mRNA expression levels of plasminogen activator inhibitor-1 (PAI-1) and procollagen α1(I) induced by TGF-β1 in A498 renal epithelial carcinoma cells at 1 μM) [1]. SB 525334 (1 μM) attenuates the heightened sensitivity to TGF-β1 exhibited by pulmonary artery smooth muscle cells (PASMCs) from patients with familial forms of idiopathic pulmonary arterial hypertension (PAH) [2].

in vivo: SB 525334 (10 mg/kg/day) decreases the renal mRNA levels of PAI-1, procollagen α1(I), and procollagen α1(III) in a nephritis-induced renal fibrosis rat model. Furthermore, PAN-induced proteinuria is significantly inhibited by SB 525334 (10 mg/kg/day) [1]. SB 525334 may also be efficacious in mesenchymal tumors. SB 525334 (10 mg/kg/day) significantly decreases uterine mesenchymal tumor incidence, multiplicity, and size in Eker rats [3].