ABSTRACT
Luminespib (AUY922), a heat shock proteins 90 inhibitor, has anti-neoplastic and antitumor effects. However, it is not clear whether AUY922 affects events in vascular diseases. We investigated the effects of AUY922 on the platelet-derived growth factor (PDGF)-BB-stimulated proliferation and migration of vascular smooth muscle cells (VSMC). VSMC viability was detected using the XTT (2,3-bis-(2-methoxy- 4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) reagent. To detect the attenuating effects of AUY922 on PDGF-BB-induced VSMCs migration in vitro, we performed the Boyden chamber and scratch wound healing assays. To identify AUY922- mediated changes in the signaling pathway, the phosphorylation of protein kinase B (Akt) and extracellular signal-regulated kinase (ERK) 1/2 was analyzed by immunoblotting. The inhibitory effects of AUY922 on migration and proliferation ex vivo were tested using an aortic ring assay. AUY922 was not cytotoxic at concentrations up to 5 nM. PDGF-BB-induced VSMC proliferation, migration, and sprout outgrowth were significantly decreased by AUY922 in a dose-dependent manner. AUY922 significantly reduced the PDGF-BB-stimulated phosphorylation of Akt and ERK1/2. Furthermore, PD98059 (a selective ERK1/2 inhibitor) and LY294002 (a selective Akt inhibitor) decreased VSMC migration and proliferation by inhibiting phosphorylation of Akt and ERK1/2. Greater attenuation of PDGF-BB-induced cell viability and migration was observed upon treatment with PD98059 or LY294002 in combination with AUY922. AUY922 showed anti-proliferation and anti-migration effects towards PDGF-BBinduced VSMCs by regulating the phosphorylation of ERK1/2 and Akt. Thus, AUY922 is a candidate for the treatment of atherosclerosis and restenosis.
ABSTRACT
OBJECTIVE@#To investigate the effects of Korean Magnolia obovata crude extract (KME) on plateletderived growth factor (PDGF)-BB-induced proliferation and migration of vascular smooth muscle cells (VSMCs).@*METHODS@#KME composition was analyzed by high-performance liquid chromatography (HPLC). VSMCs were isolated from the aorta of a Sprague-Dawley rat, incubated in serum free-Dulbecco's modified Eagle's medium in the presence or absence of KME (10, 30, 100, and 300 μg/mL), then further treated with PDGF-BB (10 ng/mL). VSMC proliferation was detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and VSMC migration was determined using the Boyden chamber and scratch wound healing assays. Western blot analysis was used to detect phosphorylation of extracellular signal-regulated protein kinases 1 and 2 (p-ERK1/2), protein kinase B (p-Akt), and stress-activated protein kinase/c-Jun NH2-terminal kinase (p-SAPK/JNK). The antimigration and proliferation effects of KME were tested using aortic sprout outgrowth.@*RESULTS@#The HPLC analysis identified honokiol (0.45 mg/g) and magnolol (0.34 mg/g) as the major components of KME. KME (30, 100, and 300 μg/mL) significantly decreased the proliferation and migration of PDGF-BB-stimulated (10 ng/mL) VSMCs and the PDGF-BB-induced phosphorylation of EKR1/2, Akt, and SAPK/JNK (P<0.05). Furthermore, PDGF-BBinduced VSMCs treated with 300 μg/mL of KME showed reduction in aortic sprout outgrowth.@*CONCLUSION@#KME could inhibit abnormal proliferation and migration of VSMCs by down-regulating the phosphorylation of EKR1/2 and Akt. Thus, KME might be a functional food for preventing vascular disorders.
ABSTRACT
Luminespib (AUY922), a heat shock proteins 90 inhibitor, has anti-neoplastic and antitumor effects. However, it is not clear whether AUY922 affects events in vascular diseases. We investigated the effects of AUY922 on the platelet-derived growth factor (PDGF)-BB-stimulated proliferation and migration of vascular smooth muscle cells (VSMC). VSMC viability was detected using the XTT (2,3-bis-(2-methoxy- 4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) reagent. To detect the attenuating effects of AUY922 on PDGF-BB-induced VSMCs migration in vitro, we performed the Boyden chamber and scratch wound healing assays. To identify AUY922- mediated changes in the signaling pathway, the phosphorylation of protein kinase B (Akt) and extracellular signal-regulated kinase (ERK) 1/2 was analyzed by immunoblotting. The inhibitory effects of AUY922 on migration and proliferation ex vivo were tested using an aortic ring assay. AUY922 was not cytotoxic at concentrations up to 5 nM. PDGF-BB-induced VSMC proliferation, migration, and sprout outgrowth were significantly decreased by AUY922 in a dose-dependent manner. AUY922 significantly reduced the PDGF-BB-stimulated phosphorylation of Akt and ERK1/2. Furthermore, PD98059 (a selective ERK1/2 inhibitor) and LY294002 (a selective Akt inhibitor) decreased VSMC migration and proliferation by inhibiting phosphorylation of Akt and ERK1/2. Greater attenuation of PDGF-BB-induced cell viability and migration was observed upon treatment with PD98059 or LY294002 in combination with AUY922. AUY922 showed anti-proliferation and anti-migration effects towards PDGF-BBinduced VSMCs by regulating the phosphorylation of ERK1/2 and Akt. Thus, AUY922 is a candidate for the treatment of atherosclerosis and restenosis.