Studies in humans show global changes in mRNA and protein expression occur in human skeletal muscle during bed rest. As microRNAs are important regulators of expression, we analysed the global microRNA expression changes in human muscle following 10 days of sustained bed rest, with the rationale that miRNAs play key roles in atrophy of skeletal muscle. We analysed expression of miRNA and selected target proteins before and after 10 days of bed rest in muscle biopsies obtained from 6 healthy males. 15 out of 152 miRNAs detected in human muscle tissue were differentially expressed and all of them with exception of two were downregulated. The downregulated miRNA include: miR206, a myomir involved in function and maintenance of skeletal muscle; miR23a, involved in insulin response and atrophy defence; and several members of the let7 family involved in cell cycle, cell differentiation and glucose homeostasis. Predicted gene targets of these miRNA are members of the MAPK, TNF receptor, ALK1, TGFbeta receptor and SMAD signalling pathways. All of these pathways were previously indicated to be involved in skeletal muscle response to physical inactivity. We also measured protein expression of selected miRNA targets and observed a decrease in HDAC4. Our data demonstrates that miRNAs in postural muscles are affected by sustained inactivity and unloading, as induced by prolonged bed rest, and hence are potentially involved in regulation of skeletal muscle adjustments to inactivity.
COBISS.SI-ID: 27392551
This study aimed to determine whether daily moderate exercise training performed during a 10-day exposure to normobaric hypoxia alters hormonal appetite regulation and augments metabolic health. Fourteen healthy, male participants underwent a 10-day hypoxic confinement at ~4000 m simulated altitude either combined with daily moderate intensity exercise or without any exercise. A meal tolerance test was performed before (Pre) and after the confinement (Post) to quantify fasting and postprandial concentrations of selected appetite-related hormones and metabolic risk markers. The findings suggest that performing daily moderate intensity exercise training during continuous hypoxic exposure does not alter hormonal appetite regulation but can improve the lipid profile in healthy young males.
COBISS.SI-ID: 27737639
This study aimed to scrutinize the hypothesis that moderate exercise alleviates chronic hypoxia induced oxidative stress. Our obtain results confirm the proposed hypothesis and show the ability of daily, moderate intensity exercise training to reduce the oxidative stress levels and improve redox equilibrium. These findings also have significant applied value, since moderate training can be used to blunt oxidative stress induced by health/disease related chronic hypoxic exposures as experienced by patients with pulmonary disease, obesity etc.
COBISS.SI-ID: 26881063
The paper presents the effects of simulated planetary habitation on body mass and body composition. Our main finding was that hypoxia per se does not seem to influence body mass and composition modulation during inactivity. In addition, the obtained results indicate that confinement per se might also be an important factor contributing to the body composition modulation.
COBISS.SI-ID: 27184167