Regulation Of Muscle Energy Metabolism Research Articles

The impact of different feeds on DNA methylation, glycolysis/gluconeogenesis signaling pathway, and gene expression of sheep muscle.

DNA methylation is an important epigenetic regulatory form that regulates gene expression and tissue development. This study compared the effects of high fiber, low protein (HFLP) and low fiber, high protein (LFHP) diets on the DNA methylation profile of twin lambs’ muscles, their effect on glycolysis/gluconeogenesis and related pathways by transcriptome and deep whole-genome bisulfite sequencing (WGBS). Results identified 1,945 differentially methylated regions (DMRs) and 1,471 differentially methylated genes (DMGs). Also, 487 differentially expressed transcripts belonging to 368 differentially expressed genes (DEGs) were discovered between the twin lambs under different diets. Eleven overlapped genes were detected between the DEGs and the DMGs. FKBP5 and FOXO1 were detected to be significantly different. The FOXO1 regulated cAMP and the glycolysis/gluconeogenesis pathways. The glycolysis/gluconeogenesis, and the FOXO pathways were significantly enriched. The expressions of HOMER1 and FOXO1 in the HFLP group were significantly higher than those in the LFHP group. There is a significant correlation between the upregulated gene expression and hypomethylation of HOMER1 and FOXO1 gene in HFLP group. The results showed that FOXO1 induces PDK4 expression in muscle while regulating FKBP5 activity, which stimulates glucose production by activating specific gluconeogenesis target genes. The FOXO1 was able to regulate the glucose metabolism, the cAMP and the occurrence of glycolysis/gluconeogenesis pathways. This study showed that feed type can affect the methylation levels of the glycolysis related gluconeogenesis genes and interaction pathways, providing new ideas for a better understanding of the regulation of muscle energy metabolism and feed development.

Treadmill exercise ameliorates the regulation of energy metabolism in skeletal muscle of NSE/PS2mtransgenic mice with Alzheimer's disease.

[Purpose]Alzheimer’s disease (AD) is classified as a progressive neurological disorder, which not only causes cognitive impairment but also abnormal weight loss, with a reduction of muscle mass related to the accumulation of amyloid-β (Aβ) in skeletal muscle. Thus, we investigated the effect of treadmill exercise on Aβ deposition, and p-AMPK, p-ACC, BDNF, and GLUT4 protein levels the regulation of muscle energy metabolism using an AD mouse. [Methods]At 13 months of age, NSE/PS2m mice (Tg) and control mice (non-Tg) were assigned to non-exercise control (Con) and exercise groups (Exe). The four groups were as follows: non-Tg Con, non-Tg Exe, Tg Con, and Tg Exe. The treadmill exercise was carried out for 12 weeks. [Results]The highest levels of Aβ expression in the skeletal muscle were in the Tg Con group. Aβ expression was significantly reduced in the Tg Exe group, compared to the Tg Con group. Congo red staining showed remarkable diffuse red amyloid deposition in the Tg Con group, while Aβ-deposition in the skeletal was reduced with muscle exercise in the Tg Exe group. Exercise also increased AMPK and ACC phosphorylation and BDNF and GLUT4 expression in the skeletal muscle of non-Tg and Tg mice. [Conclusion]Treadmill exercise reduces Aβ-deposition in the skeletal muscle and improves the regulation of energy metabolism. Thus, collectively, these results suggest that exercise could be a positive therapeutic strategy for skeletal muscle dysfunction in AD patients.

Study of the influence of age and weaning on the contractile and metabolic characteristics of bovine muscle

Weaning is an interesting period for the study of the nutritional regulation of muscle energy metabolism, since during this stage the nature of the substrates supplied to the muscle and their energy balance are profoundly changed. The aim of this study was to determine the effect of these modifications on the contractile and metabolic characteristics of bovine muscle. Two similar groups of 7 male Montbéliard calves were used with the same age and weight, and with the same energy intake. One group consisted of milk-fed calves, the other of weaned animals. The latter were progressively weaned over a period between 107 and 128 d. The average age at slaughter in the 2 groups was 170 d. Biopsy specimens of semitendinosus (ST) muscle were taken at the ages of 66 d, 94 d (before the beginning of weaning) and 136 d (at the end of weaning) to follow the evolution of muscle characteristics. Samples of longissimus thoracis (LT) muscle were taken 24 h after slaughter and used to study the changes in protein and DNA content. The proportion and area of the different types of fiber, I (slow, oxidative), IIA (fast, oxido-glycolytic), IIB (fast, glycolytic) and IIC (fast/slow, oxidoglycolytic) were measured by immunohistochemistry and image analysis. The metabolism of the muscles was determined by studying isocitrate dehydrogenase (ICDH, oxidative) and lactate dehydrogenase (LDH, glycolytic) activity. The results obtained between 2 and 6 months of life showed an overall increase in the area of the fibers (I, IIA, IIB and IIC) and a conversion of type IIA fibers into type IIB accompanied by a shift in the energy metabolism towards a glycolytic type. Weaning caused temporary stress, whose main consequences were to decrease overall muscle fiber area and the percentage of type IIB fibers, and increase the proportion of type IIC fibers in weaned animals. These effects may have been due to the nutritional and behavioral disturbances that accompany weaning, because 42 d after the end of weaning there was no difference in the size of ST and LT fibers between the 2 groups whereas the proportion of type IIA fibers was still higher in weaned animals.