6-[2-tert-Butyl-5-(6-methyl-pyridin-2-yl)-1H-imidazol-4-yl]-quinoxaline

Biological activity

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

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). 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).

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). 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. SB 525334 significantly reverses pulmonary arterial pressure and inhibits right ventricular hypertrophy in a rat model of PAH. This is revealed by a significant reduction in pulmonary arteriole muscularization induced by monocrotaline (used to induce PAH) after treatment with SB 525334 (3 or 30 mg/kg). In a Bleomycin-induced pulmonary fibrosis mice model, SB 525334 (10 mg/kg or 30 mg/kg) attenuates the histopathological alterations in the lung, and significantly decreased mRNA expression of Type I and III procollagen and fibronectin. SB 525334 also attenuates Smad2/3 nuclear translocation, myofibroblast proliferation, deposition of Type I collagen, and decreases CTGF-expressing cells.

References

http://www.selleckchem.com/products/SB-525334.html

Description

SB-525334 is a potent inhibitor of the TGF-β receptor 1 (TGF-β R1, ALK5) kinase (IC₅₀ = 14.36 nM). It is ~4-fold less effective against ALK4 and inactive against ALK2, ALK3, and ALK6. SB-525334 blocks TGF-β1-induced phosphorylation and nuclear translocation of SMAD2/3 as well as TGF-β1-directed gene expression. It is effective in vivo, preventing puromycin aminonucleoside-induced renal fibrosis and bleomycin-induced pulmonary fibrosis. SB-525334 also modulates carcinogenesis and suppresses the development of pulmonary arterial hypertension in animals.

Uses

SB-525334 is a potent activin receptor-like kinase (ALK5)/ type I TGFβ-receptor kinase inhibitor with IC50 = 14.3 nM.

Uses

SB-525334 was used to study TGFβ1-mediated human trophoblast differentiation.⁷

Definition

ChEBI: 6-[2-tert-butyl-5-(6-methyl-2-pyridinyl)-1H-imidazol-4-yl]quinoxaline is a quinoxaline derivative.

Biological Activity

Selective inhibitor of transforming growth factor- β receptor I (ALK5, TGF- β RI) (IC 50 = 14.3 nM). Inhibits TGF- β 1-induced smad2/3 nuclear localisation and TGF- β 1-induced mRNA expression in kidney cells. Attenuates bleomycin-induced pulmonary fibrosis.

Biochem/physiol Actions

SB-525334 is a potent activin receptor-like kinase (ALK5)/ type I TGFβ-receptor kinase inhibitor with IC50 = 14.3 nM.

storage

Store at -20°C

References

1) Grygielko?et al.?(2005),?Inhibition of gene markers of fibrosis with a novel inhibitor of transforming growth factor-beta type I receptor kinase in puromycin-induced nephritis;? J. Pharmacol. Exp. Ther.,?313?943 2) Higashiyama?et al. (2007),?Inhibition of activin receptor-like kinase 5 attenuates bleomycin-induced pulmonary fibrosis;? Exp. Mol. Pathol.,?83?39 3) Kim?et al. (2012),?Transforming growth factor beta receptor I inhibitor sensitizes drug-resistant pancreatic cancer cells to gemcitabine;? Anticancer Res.,?32?799