Atorvastatin protects vascular smooth muscle cells from TGF-β1-stimulated calcification by inducing autophagy via suppression of the β-catenin pathway.
BACKGROUND
Arterial calcification is a major event in the progression of atherosclerosis. It is reported that statins exhibit various protective effects against vascular smooth muscle cell (VSMC) inflammation and proliferation in cardiovascular remodeling. Although statins counteract atherosclerosis, the molecular mechanisms of statins on the calcium release from VSMCs have not been clearly elucidated.


METHODS
Calcium content of VSMCs was measured using enzyme-linked immunosorbent assay (ELISA). The expression of proteins involved in cellular transdifferentiation was analyzed by western blot. Cell autophagy was measured by fluorescence microscopic analysis for acridine orange staining and transmission electron microscopy analysis. The autophagic inhibitors (3-MA, chloroquine, NH4Cl and bafilomycin A1) and β-catenin inhibitor JW74 were used to assess the effects of atorvastatin on autophagy and the involvement of β-catenin on cell calcification respectively. Furthermore, cell transfection was performed to overexpress β-catenin.


RESULTS
In VSMCs, atorvastatin significantly suppressed transforming growth factor-β1 (TGF-β1)-stimulated calcification, accompanied by the induction of autophagy. Downregulation of autophagy with autophagic inhibitors significantly suppressed the inhibitory effect of atorvastatin on cell calcification. Moreover, the beneficial effect of atorvastatin on calcification and autophagy was reversed by β-catenin overexpression. Conversely, JW74 supplement enhanced this effect.


CONCLUSIONS
These data demonstrated that atorvastatin protect VSMC from TGF-β1-stimulated calcification by inducing autophagy through suppression of the β-catenin pathway, identifying autophagy induction might be a therapeutic strategy for use in vascular calcification.
Department of Cardiology, Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, PR China.
Demin
D
Liu
Wei
W
Cui
Bin
B
Liu
Haijuan
H
Hu
Jing
J
Liu
Ruiqin
R
Xie
Xiaohong
X
Yang
Guoqiang
G
Gu
Jidong
J
Zhang
Hongmei
H
Zheng
D000818:Animals; D000069059:Atorvastatin / Q000494:pharmacology*; D001343:Autophagy / Q000187:drug effects*; D019610:Cytoprotection / Q000187:drug effects*; D015536:Down-Regulation / Q000187:drug effects; D008297:Male; D008954:Models, Biological; D009131:Muscle, Smooth, Vascular / Q000473:pathology*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*; D061205:Vascular Calcification / Q000473:pathology*; D051176:beta Catenin / Q000378:metabolism*
D053773:Transforming Growth Factor beta1; D051176:beta Catenin; D000069059:Atorvastatin