Swimming exercise activates aortic autophagy and limits atherosclerosis in ApoE^-/- mice

The aim of this study was to investigate the beneficial effect of swimming exercise on autophagy and atherosclerosis in mice aorta, so as to clarify the possible causal relationship between autophagy activation and atherosclerosis.

The body weight was monitored regularly. Hematoxylin-eosin staining and Oil Red O staining was conducted to observe vascular morphology and plaque burden respectively. The levels of serum total cholesterol (TC), triglyceride (TG), soluble intercellular adhesion molecule-1 (sICAM-1), matrix metalloproteinase-9 (MMP-9) and interleukin-6 (IL-6) was examined via Enzyme-linked immu-nosorbent assays (ELISA). The mRNA expression level of autophagy markers, including LC3 and Beclin-1, was examined by real-time quantitative polymerase chain reaction (RT-PCR). The expressions of LC3-II/LC3-I and Beclin-1 are detected by Western blotting and immunohistochemistry.

Compared with the model group, long-term swimming exercise decreased the weight gain of ApoE^-/- mice, improved the structural disorder of artery, reduced the load of atherosclerotic lesion, and attenuated the concentrations of serum TC, TG, sICAM-1, MMP-9, and IL-6. In addition, the expression of autophagy markers LC3 and Beclin-1 increased significantly at the mRNA and protein levels.

Long-term swimming exercise could activate the autophagy and reduce atherosclerotic lesion in the aorta of ApoE^-/- mice. Autophagy activation may be one of the mechanisms by which atherosclerosis is improved through exercise.