Effect of Exercise Training On Autophagic Process in White Adipose Tissue of High Fat Diet-Induced Obese Mice
Abstract Background. Some studies have established a relationship between obesity and the autophagic process in adipose tissue. This study aimed to investigate the effect of exercise training on the autophagic process in white adipose tissue (WAT) of high fat diet-induced obese mice.Methods and Results. C57BL/6 mice were assigned into three groups included: 1) Control 2), High-Fat Diet-induced Obesity (HFD-Ob), and 3) High-Fat Diet with Exercise Training (HFD-Ex). The subjects of HFD-Ob were fed a high-fat diet for 14 weeks. The mice of HFD-Ex had eight weeks of endurance training on a treadmill in addition to having the HFD. The Real-Time–PCR and western blot methods were used to measure the mRNA and protein levels of markers of the autophagic process. HFD caused an upregulation in the factors of the autophagosome formation, including ATG5 and ATG7, LC3, and the exercise training could augment the upregulation. Further, the training program prevented the change in LAMP2 expression (a marker of autophagolysosome), which being reduced by HFD. The lysosomal clearance factors (CTSB and CTSL) were raised in HFD-Ob and differently changed in HFD-Ex.Conclusion. HFD-induced obesity promoted the early and last steps of autophagy whereas defected the intermediate-step of it. Interestingly, the exercise training enhanced the early phase of autophagy, which being increased by HFD. Further, the training program could modify the rising effect of HFD on the last step of autophagy. It seems that a part of the protective effect of exercise training on obesity-related complications may be mediated by modulating the autophagic process in white adipose tissue.