Proteomics‐Based Identification of the Molecular Signatures of Liver Tissues from Aged Rats following Eight Weeks of Medium‐Intensity Exercise

Abstract

Physical activity has emerged as a powerful intervention that promotes healthy aging by maintaining the functional capacity of critical organ systems. Here, by combining functional and proteomics analyses, we examined how hepatic phenotypes might respond to exercise treatment in aged rats. 16 male aged (20 months old) SD rats were divided into exercise and parallel control groups at random; the exercise group had 8 weeks of treadmill training with medium intensity. Whole protein samples of the liver were extracted from both groups and separated by two-dimensional gel electrophoresis. Alternatively objective protein spots with >2-fold difference in expression were selected for enzymological extraction and MS/MS identification. Results show increased activity of the manganese superoxide dismutase and elevated glutathione levels in the livers of exercise-treated animals, but malondialdehyde contents obviously decreased in the liver of the exercise group. Proteomics-based identification of differentially expressed proteins provided an integrated view of the metabolic adaptations occurring in the liver proteome during exercise, which significantly altered the expression of several proteins involved in key liver metabolic pathways including mitochondrial sulfur, glycolysis, methionine, and protein metabolism. These findings indicate that exercise may be beneficial to aged rats through modulation of hepatic protein expression profiles.

Proteomic analysis reveals exercise training induced remodelling of hepatokine secretion and uncovers syndecan-4 as a regulator of hepatic lipid metabolism

“…The effects of exercise on liver metabolism are becoming increasingly well described [ 56 ] and include increased mitochondrial content and glycolysis, and reduced expression of lipid synthesis proteins [ 57 , 58 ], which is associated with partial resolution of hepatic steatosis [ 7 ]. Furthermore, transcriptomic analysis conducted in the liver of mice immediately after an acute bout of exercise revealed marked increases in the expression of genes involved in mitogen-activated protein kinase (MAPK) and PPAR signalling, and fatty acid metabolism [ 17 ].…”

“…Furthermore, transcriptomic analysis conducted in the liver of mice immediately after an acute bout of exercise revealed marked increases in the expression of genes involved in mitogen-activated protein kinase (MAPK) and PPAR signalling, and fatty acid metabolism [ 17 ]. However, whether such acute changes lead to stable adaptations at the protein level is not well defined [ 58 ]. To address this knowledge gap, we performed unbiased assessment of the hepatocyte proteome following chronic exercise training.…”

The effect of varied exercise intensity on antioxidant function, and aortic endothelial cell function and serum lipids in a non-alcoholic fatty liver disease rats

“…Li et al . reported that SOD activity and GSH were significantly raised after rats were exercised at medium intensity (24). Radak et al .…”

The effect of varied exercise intensity on antioxidant function, aortic endothelial function, and serum lipids in rats with non-alcoholic fatty liver disease.

“…Pereira et al also showed high-intensity exercise might induce oxidative stress 31 . Li et al reported that SOD activity and GSH were significantly raised after rats were exercised at medium intensity 32 . Radak et al also indicated that moderate exercise significantly increased the activity of antioxidant enzymes 33 .…”