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Autophagy mediates tumor necrosis factor-α-induced phenotype switching in vascular smooth muscle A7r5 cell line.
- Source :
-
PloS one [PLoS One] 2018 May 11; Vol. 13 (5), pp. e0197210. Date of Electronic Publication: 2018 May 11 (Print Publication: 2018). - Publication Year :
- 2018
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Abstract
- Vascular smooth muscle cells (VSMC) dedifferentiation from a contractile to a synthetic phenotype contributes to atherosclerosis. Atherosclerotic tissue has a chronic inflammatory component with high levels of tumor necrosis factor-α (TNF-α). VSMC of atheromatous plaques have increased autophagy, a mechanism responsible for protein and intracellular organelle degradation. The aim of this study was to evaluate whether TNF-α induces phenotype switching of VSMCs and whether this effect depends on autophagy. Rat aortic Vascular smooth A7r5 cell line was used as a model to examine the phenotype switching and autophagy. These cells were stimulated with TNF-α 100 ng/mL. Autophagy was determined by measuring LC3-II and p62 protein levels. Autophagy was inhibited using chloroquine and siRNA Beclin1. Cell dedifferentiation was evaluated by measuring the expression of contractile proteins α-SMA and SM22, extracellular matrix protein osteopontin and type I collagen levels. Cell proliferation was measured by [3H]-thymidine incorporation and MTT assay, and migration was evaluated by wound healing and transwell assays. Expression of IL-1β, IL-6 and IL-10 was assessed by ELISA. TNF-α induced autophagy as determined by increased LC3-II (1.91±0.21, p<0.001) and decreased p62 (0.86±0.02, p<0.05) when compared to control. Additionally, TNF-α decreased α-SMA (0.74±0.12, p<0.05) and SM22 (0.54±0.01, p<0.01) protein levels. Consequently, TNF-α induced migration (1.25±0.05, p<0.05), proliferation (2.33±0.24, p<0.05), and the secretion of IL-6 (258±53, p<0.01), type I collagen (3.09±0.85, p<0.01) and osteopontin (2.32±0.46, p<0.01). Inhibition of autophagy prevented all the TNF-α-induced phenotypic changes. TNF-α induces phenotype switching in A7r5 cell line by a mechanism that required autophagy. Therefore, autophagy may be a potential therapeutic target for the treatment of atherosclerosis.
- Subjects :
- Animals
Atherosclerosis pathology
Cell Line
Interleukin-10 metabolism
Interleukin-1beta metabolism
Interleukin-6 metabolism
Muscle, Smooth, Vascular pathology
Myocytes, Smooth Muscle pathology
Rats
Atherosclerosis metabolism
Autophagy
Muscle, Smooth, Vascular metabolism
Myocytes, Smooth Muscle metabolism
Tumor Necrosis Factor-alpha metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1932-6203
- Volume :
- 13
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- PloS one
- Publication Type :
- Academic Journal
- Accession number :
- 29750813
- Full Text :
- https://doi.org/10.1371/journal.pone.0197210