INTRODUCTION
MATERIALS AND METHODS
1. Reagents and antibodies
2. Cell culture
3. Carotid artery ligation model
4. Histology and Immunohistochemical staining
5. Western blotting
6. MTT assay
7. Flow cytometric analysis
8. Cell count
RESULTS
1. Anti-malarial drugs induce AMPK activation in primary rat VSMCs
![]() | Fig. 1Anti-malarial drugs increase AMPK phosphorylation in primary rat VSMCs. Primary rat VSMCs were treated with CQ or HCQ at the indicated concentrations for 1 hour. Phosphorylation of AMPK was determined by immunoblotting with anti-phospho-AMPK antibody. Amount of protein was normalized to total amount of AMPK and tubulin expression. Bar graphs present the densitometric quantification of western blot bands. Results are expressed as mean±standard deviation and are representative of 3 independent experiments.AMPK, adenosine monophosphate-activated protein kinase; VSMC, vascular smooth muscle cell; CQ, chloroquine; HCQ, hydroxychloroquine; p-AMPK, phospho-adenosine monophosphate-activated protein kinase.
*p<0.05; †p<0.01 compared with controls.
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2. Anti-malarial drugs inhibit cell proliferation and cell cycle progression in rat VSMCs
![]() | Fig. 2Anti-malarial drugs inhibit PDGF-induced cell proliferation and cell cycle progression in rat VSMCs. (A) Rat VSMCs were pretreated with CQ or HCQ (10, 20 μM) for 2 hours and then incubated with PDGF (10 ng/mL) for indicated times (1, 2, or 3 days). Cell proliferation was determined by cell counting. (B) Serum-starved rat VSMCs were pretreated with CQ or HCQ (20, 40 μM) for 2 hours and then incubated with PDGF (10 ng/mL) for 24 hours. Protein expression of cyclin D was determined by immunoblotting with anti-cyclin D antibody. Amount of protein was normalized to tubulin expression. Bar graphs present the densitometric quantification of western blot bands. Results are expressed as mean±standard deviation and are representative of 3 independent experiments. (C) Serum-starved rat VSMCs were pretreated with CQ or HCQ (20, 40 μM) for 2 hours and then incubated with PDGF (10 ng/mL) for 24 hours. For cell cycle analysis, cells were detached, stained with PI, and subjected to flow cytometry. Results are representative of 3 independent experiments that yielded similar results.PDGF, platelet-derived growth factor; VSMC, vascular smooth muscle cell; CQ, chloroquine; HCQ, hydroxychloroquine.
*p<0.05; †p<0.01 compared with cells treated with PDGF.
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3. Anti-malarial drugs inhibit TGF-β1-induced Smad3 phosphorylation and cell proliferation in rat VSMCs
![]() | Fig. 3Anti-malarial drugs inhibit TGF-β1-induced Smad3 phosphorylation in rat VSMCs. (A) Rat VSMCs were pretreated with CQ or HCQ (40 μM) for 2 hours and then incubated with TGF-β1 (2 ng/mL) for 10 or 30 minutes. Phosphorylation of Smad3 and AMPK was determined by immunoblotting with anti-phospho-Smad3 and anti-phospho-AMPK antibodies, respectively. Amount of protein was normalized to total amount of Smad3, AMPK, and tubulin. Bar graphs present densitometric quantification of western blot bands. Results are expressed as mean±standard deviation and are representative of 3 independent experiments. (B) Rat VSMCs were pretreated with CQ or HCQ (10 μM) for 2 hours and then incubated with TGF-β1 (2 ng/mL) for 3 days. Cell viabilities were determined with the MTT assay. The data represent the mean values of 3 wells. (C) Rat VSMCs were pretreated with CQ or HCQ (10 μM) for 2 hours and then incubated with TGF-β1 (2 ng/mL) for 3 days. Cell proliferation was determined by cell counting. Results are representative of 3 independent experiments that yielded similar results.TGF-β1, transforming growth factor-β1; VSMC, vascular smooth muscle cell; CQ, chloroquine; HCQ, hydroxychloroquine; AMPK, adenosine monophosphate-activated protein kinase; p-AMPK, phospho-adenosine monophosphate-activated protein kinase; p-Smad3, phospho-Smad3.
*p<0.05; †p<0.01 compared with controls. ‡p<0.01 vs. TGF-β1 2 ng/mL-treated. §p<0.01 vs. control, ∥p<0.01 vs. TGF-β1 2 ng/mL-treated.
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4. Anti-malarial drugs attenuate carotid artery ligation-induced neointimal hyperplasia in vivo
![]() | Fig. 4Carotid artery ligation-induced neointimal hyperplasia is significantly attenuated in animals treated with anti-malarial drugs. (A) Partial carotid ligation was performed on 8-week-old male C57BL/6 mice. After surgery, mice were treated with CQ (50 mg/kg, i.p.) or HCQ (50 mg/kg, i.p.) every other day for 3 weeks. Top panel: H&E staining of C57BL/6 arteries under 200× magnification. Elastin was visualized by autofluorescence. Images are representative of n=4. Bottom panel: graphical representation of the media, intima, and intima/media ratio (n=4; mean±standard error of mean). (B) C57BL/6 arteries were isolated and homogenized. Protein levels were measured by western blot analysis with specific antibodies against collagen I, collagen III, and tubulin. Results are representative of 3 independent experiments.CQ, chloroquine; HCQ, hydroxychloroquine; i.p., intraperitoneal; R, non-ligated right common carotid artery; L, ligated left common carotid artery; I, intima; M, media; H&E, hematoxylin and eosin; LCA, left common carotid artery; RCA, right common carotid artery.
*p<0.05.
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