These findings suggest that exercise stimulates SPARC secretion from muscle tissues and that SPARC inhibits colon tumorigenesis by increasing apoptosis.

Several changes in gut microbiota were associated with age and sex. Stool consistency and gut microbiota associations emphasized the importance of stool consistency assessments to understand intestinal function.

Background: MicroRNAs (miRNAs) are small non-coding RNAs involved in post-transcriptional gene regulation. miRNAs are taken in by intracellular exosomes, secreted into circulation, and taken up by other cells, where they regulate cellular functions. We hypothesized that muscle-enriched miRNAs existing in circulation mediate beneficial metabolic responses induced by exercise. To test this hypothesis, we measured changes in muscle-enriched circulating miRNAs (c-miRNAs) in response to acute and chronic aerobic exercise.Methods: Eleven healthy young men (age, 21.5 ± 4.5 y; height, 168.6 ± 5.3 cm; and body weight, 62.5 ± 9.0 kg) performed a single bout of steady-state cycling exercise at 70% VO2max for 60 min (acute exercise) and cycling training 3 days per week for 4 weeks (chronic exercise). Blood samples were collected from the antecubital vein before and after acute and chronic exercise. RNA was extracted from serum, and the levels of muscle-enriched miRNAs (miR-1, miR-133a, miR-133b, miR-206, miR-208b, miR-486, and miR-499) were measured.Results: All of these miRNAs, except for miR-486, were found at too low copy numbers at baseline to be compared. miR-486 was significantly decreased by both acute (P = 0.013) and chronic exercise (P = 0.014). In addition, the change ratio of miR-486 due to acute exercise showed a significant negative correlation with VO2max for each subject (R = 0.58, P = 0.038).Conclusion: The reduction in circulating miR-486 may be associated with metabolic changes during exercise and adaptation induced by training.

Background Species-level genetic characterization of complex bacterial communities has important clinical applications in both diagnosis and treatment. Amplicon sequencing of the 16S ribosomal RNA (rRNA) gene has proven to be a powerful strategy for the taxonomic classification of bacteria. This study aims to improve the method for full-length 16S rRNA gene analysis using the nanopore long-read sequencer MinION™. We compared it to the conventional short-read sequencing method in both a mock bacterial community and human fecal samples. Results We modified our existing protocol for full-length 16S rRNA gene amplicon sequencing by MinION™. A new strategy for library construction with an optimized primer set overcame PCR-associated bias and enabled taxonomic classification across a broad range of bacterial species. We compared the performance of full-length and short-read 16S rRNA gene amplicon sequencing for the characterization of human gut microbiota with a complex bacterial composition. The relative abundance of dominant bacterial genera was highly similar between full-length and short-read sequencing. At the species level, MinION™ long-read sequencing had better resolution for discriminating between members of particular taxa such as Bifidobacterium, allowing an accurate representation of the sample bacterial composition. Conclusions Our present microbiome study, comparing the discriminatory power of full-length and short-read sequencing, clearly illustrated the analytical advantage of sequencing the full-length 16S rRNA gene.

T. The microRNA miR-696 regulates PGC-1␣ in mouse skeletal muscle in response to physical activity. Am J Physiol Endocrinol Metab 298: E799 -E806, 2010. First published January 19, 2010 doi:10.1152/ajpendo.00448.2009 are small noncoding RNAs involved in posttranscriptional gene regulation that have been shown to be involved in growth, development, function, and stress responses of various organs. The purpose of this study was to identify the miRNA response to physical activity, which was related to functions such as nutrient metabolism, although the miRNAs involved are currently unknown. C57BL/6 mice were divided into exercise and control groups. The exercise group performed running exercise, with a gradual increase of the load over 4 wk. On the other hand, to examine the effect of muscle inactivity, the unilateral hindlimbs of other mice were fixed in a cast for 5 days. Microarray analysis for miRNA in gastrocnemius revealed that miR-696 was markedly affected by both exercise and immobilization, showing opposite responses to these two interventions. Peroxisome proliferator-activated receptor-␥ coactivator-1␣ (PGC-1␣), which was increased by exercise and decreased by immobilization in the protein level, was predicted as a target regulated by miR-696. In cultured myocytes, intracellular miR-696 variation led to negative regulation of PGC-1␣ protein along with the expression of mRNAs for downstream genes. In addition, we found decreases in the biogenesis of mitochondria and fatty acid oxidation in miR-696-overexpressing myocytes compared with normal control myocytes. These observations demonstrate that miR-696 is a physical activity-dependent miRNA involved in the translational regulation of PGC-1␣ and skeletal muscle metabolism in mice.peroxisome proliferator-activated receptor-␥ coactivator-1␣; exercise; immobilization; muscle metabolism; mitochondria biogenesis; microarray PHYSICAL ACTIVITY IMPROVES VARIOUS BODILY FUNCTIONS, including metabolism, cardiovascular function, and immune function. The skeletal muscles comprise the major organ supporting physical activity, and muscle function is altered dramatically by contractile activity. Numerous studies have shown that daily exercise improves muscle energy metabolism and strength (9, 21, 23), along with changes of the expression or activity of muscle enzymes and proteins, as well as alterations of their mRNA transcription. Conversely, low levels of physical activity and immobilization induce the atrophy of skeletal muscle and decrease its metabolic capacity (9,15,20,52), with the expression/activity of many proteins and mRNAs being negatively regulated by inactivity compared with the effect of exercise. Although considerable progress has been made in understanding the functions of muscles that are associated with physical activity, the underlying molecular pathways remain obscure, especially those related to translational regulation. In fact, the level of expression of a particular mRNA does not necessarily reflect the abundance of the corresponding protein becau...

Upregulated miRNA may be responsible for the development of intestinal inflammation in UC.

Fibroblast growth factor 21, a metabolic regulator, plays roles in lipolysis and glucose uptake in adipose tissues and skeletal muscles. Its expression in skeletal muscle is upregulated upon activation of the phosphatidylinositol 3‐kinase/Akt signaling pathway, which is induced by exercise and muscle contraction. We examined the increase of fibroblast growth factor 21 after acute exercise in metabolic organs, especially skeletal muscles and circulation. Participants exercised on bicycle ergometers for 60 min at 75% of their trueV˙O2max. Venous blood samples were taken before exercise and immediately after exercise. In an animal study, male ICR mice were divided into sedentary and exercise groups. Mice in the exercise group performed treadmill exercises at 30 m min−1 for 60 min. Shortly thereafter, blood, liver, and skeletal muscle samples were taken from mice. Acute exercise induced the increase of serum fibroblast growth factor 21 in both humans and mice, and increased fibroblast growth factor 21 expression in the skeletal muscles and the liver of mice. Acute exercise activated Akt in mice skeletal muscle. Acute exercise increases fibroblast growth factor 21 concentrations in both serum and metabolic organs. Moreover, results show that acute exercise increased the expression of fibroblast growth factor 21 in skeletal muscle, accompanied by the phosphorylation of Akt in mice.

Gut microbiota have profound effects on bile acid metabolism by promoting deconjugation, dehydrogenation, and dehydroxylation of primary bile acids in the distal small intestine and colon. High fat diet induced dysbiosis of gut microbiota and bile acid dysregula tion may be involved in the pathology of steatosis in patients with non alcoholic fatty liver disease. Epigallocatechin 3 gallate (EGCG), the most abundant polyphenolic catechin in green tea, has been widely investigated for its inhibitory or preventive effects against fatty liver. The aim of the present study was to investigate the effects of EGCG on the abundance of gut microbiota and the composition of serum bile acids in high fat diet fed mice and determine the specific bacterial genera that can improve the serum bile acid dysregulation associated with EGCG anti hepatic steatosis action. Male C57BL/6N mice were fed with the control diet, high fat diet, or high fat diet + EGCG at a concentration of 0.32% for 8 weeks. EGCG significantly inhibited the increases in weight, the area of fatty lesions, and the triglyceride content in the liver induced by the high fat diet. Principal coordinate analysis revealed significant differences in microbial structure among the groups. At the genus level, EGCG induced changes in the micro biota composition in high fat diet fed mice, showing a significantly higher abundance of Adlercreutzia, Akkermansia, Allobaculum and a significantly lower abundance of Desulfovibrionaceae. EGCG significantly reversed the decreased population of serum primary cholic acid and β muricholic acid as well as the increased popula tion of taurine conjugated cholic acid, β muricholic acid and deoxy cholic acid in high fat diet fed mice. Finally, the correlation analysis between bile acid profiles and gut microbiota demonstrated the contribution of Akkermansia and Desulfovibrionaceae in the improvement of bile acid dysregulation in high fat diet fed mice by treatment with EGCG. In conclusion, the present study suggests that EGCG could alter bile acid metabolism, especially taurine deconjugation, and suppress fatty liver disease by improving the intestinal luminal environment.