bims-exemet 2021-05-23 papers

bims-exemet

Biomed News

on Exercise metabolism

Issue of 2021–05–23
six papers selected by
Javier Botella Ruiz, Victoria University

Effects of exercise training with weight loss on skeletal muscle expression of angiogenic factors in overweight and obese older men.
Circulating microRNAs after a 24-h ultramarathon run in relation to muscle damage markers in elite athletes.
The effect of repeated bouts of electrical stimulation-induced muscle contractions on proteolytic signaling in rat skeletal muscle.
The Role of Irisin in Exercise-Mediated Bone Health.
Effects of exercise on cellular and tissue aging.
Electrical Stimulation of Cultured Myotubes in vitro as a Model of Skeletal Muscle Activity: Current State and Future Prospects.

J Appl Physiol (1985). 2021 May 20.

Effects of exercise training with weight loss on skeletal muscle expression of angiogenic factors in overweight and obese older men.

William S Evans, Jacob B Blumenthal, James M Heilman, Alice S Ryan, Steven J Prior.

  Low skeletal muscle capillarization is associated with impaired glucose tolerance (IGT); however, aerobic exercise training with weight loss (AEX+WL) increases skeletal muscle capillarization and improves glucose tolerance in adults with IGT. Given that expression of angiogenic growth factors mediates skeletal muscle capillarization, we sought to determine whether angiogenic growth factor levels are associated with low capillarization in those with IGT vs. normal glucose tolerance (NGT), or to the benefits of AEX+WL in both groups. Sixteen overweight or obese men 50-75 years of age completed 6 months of AEX+WL with oral glucose tolerance tests and vastus lateralis muscle biopsies for measurement of muscle vascular endothelial growth factor (VEGF), placental growth factor (PlGF), soluble fms-like tyrosine kinase receptor-1 (sFlt-1) and basic fibroblast growth factor (bFGF). At baseline, all growth factor levels were numerically lower in IGT compared with NGT, but these did not reach statistical significance (P=0.06-0.33). Following AEX+WL, aerobic capacity (VO2max) increased by 16%, while body weight and 120-minute postprandial glucose levels decreased by 10% and 15%, respectively (P ≤ 0.001 for all). There was a main effect of AEX+WL to increase VEGF (0.095±0.016 vs. 0.114±0.018 ng/µg, P<0.05), PlGF (0.004±0.001 vs. 0.005±0.001 ng/µg, P<0.05), and sFlt-1 (0.216±0.029 vs. 0.264±0.036 ng/µg, P<0.01) with overall increases driven by the IGT group. These results suggest that 6 months of AEX+WL increases skeletal muscle angiogenic growth factor levels in older, obese adults with IGT and NGT, which may contribute to our previous findings that AEX+WL increases capillarization to improve glucose tolerance in those with IGT.

Keywords:  angiogenesis; impaired glucose tolerance; vascular endothelial growth factor

DOI:  https://doi.org/10.1152/japplphysiol.00084.2021
Scand J Med Sci Sports. 2021 May 22.

Circulating microRNAs after a 24-h ultramarathon run in relation to muscle damage markers in elite athletes.

Emeric Chalchat, Keyne Charlot, Sebastian Garcia-Vicencio, Pierre Hertert, Stéphane Baugé, Stéphanie Bourdon, Julie Bompard, Cédric Farges, Vincent Martin, Cyprien Bourrilhon, Julien Siracusa.

  Ultra-endurance sports are growing in popularity but can be associated with adverse health effects; such as exercise-induced muscle damage (EIMD), which can lead to exertional rhabdomyolysis. Circulating microRNAs (miRNAs) may be useful to approach the degree of EIMD. We aimed to: 1) investigate the relevance of circulating miRNAs as biomarkers of muscle damage and 2) examine the acute response of skeletal/cardiac muscle and kidney biomarkers to a 24-h run in elite athletes. Eleven elite athletes participated in the 24-h Run World Championships. Counter-movement jump (CMJ), creatine kinase (CK), myoglobin (Mb), creatinine (Cr), high-sensitive cardiac troponin T (hs-cTnT) and muscle-specific miRNA (myomiR) levels were measured before, immediately after, and 24 and 48h after the race. CMJ height was reduced immediately after the race (-84.0±25.2%, p<0.001) and remained low at 24h (-43.6±20.4%, p=0.002). We observed high CK activity (53,239±63,608 U/L, p<0.001) immediately after the race and it remained elevated 24h after (p<0.01). Circulating myomiRs levels (miR-1-3p, miR-133a-3p, miR-133b, miR-208a-3p, miR-208b-3p, and miR-499a-5p) were elevated immediately after the 24-h run (fold changes: 18-124,723, p<0.001) and significantly (p<0.05) correlated or tended to significantly (p<0.07) correlate with the reduction in CMJ height at 24h. We found no significant correlation between CMJ height loss at 24h and CK (p=0.23) or Mb (p=0.41) values. All elite ultramarathon runners included in our study were diagnosed with exertional rhabdomyolysis after the 24-h ultramarathon race. MyomiR levels may be useful to approach the degree of muscle damage.

Keywords:  acute kidney injury; biomarkers; cardiac stress; exercise-induced muscle damage; muscle function; rhabdomyolysis; ultra-endurance

DOI:  https://doi.org/10.1111/sms.14000
Physiol Rep. 2021 May;9(9): e14842

The effect of repeated bouts of electrical stimulation-induced muscle contractions on proteolytic signaling in rat skeletal muscle.

Takaya Kotani, Junya Takegaki, Yuki Tamura, Karina Kouzaki, Koichi Nakazato, Naokata Ishii.

  Mechanistic target of rapamycin complex 1 (mTORC1) plays a central role in muscle protein synthesis and repeated bouts of resistance exercise (RE) blunt mTORC1 activation. However, the changes in the proteolytic signaling when recurrent RE bouts attenuate mTORC1 activation are unclear. Using a RE model of electrically stimulated rat skeletal muscle, this study aimed to clarify the effect of repeated RE bouts on acute proteolytic signaling, particularly the calpain, autophagy-lysosome, and ubiquitin-proteasome pathway. p70S6K and rpS6 phosphorylation, indicators of mTORC1 activity, were attenuated by repeated RE bouts. Calpain 3 protein was decreased at 6 h post-RE in all exercised groups regardless of the bout number. Microtubule-associated protein 1 light chain 3 beta-II, an indicator of autophagosome formation, was increased at 3 h and repeated RE bouts increased at 6 h, post-RE. Ubiquitinated proteins were increased following RE, but these increases were independent of the number of RE bouts. These results suggest that the magnitude of autophagosome formation was increased following RE when mTORC1 activity was attenuated with repeated bouts of RE.

Keywords:  LC3; calpain; mTORC1; muscle protein breakdown; resistance exercise; ubiquitinated protein

DOI:  https://doi.org/10.14814/phy2.14842
Front Cell Dev Biol. 2021 ;9 668759

The Role of Irisin in Exercise-Mediated Bone Health.

Lifei Liu, Jianmin Guo, Xi Chen, Xiaoyang Tong, Jiake Xu, Jun Zou.

  Exercise training promotes physical and bone health, and is the first choice of non-drug strategies that help to improve the prognosis and complications of many chronic diseases. Irisin is a newly discovered peptide hormone that modulates energy metabolism and skeletal muscle mass. Here, we discuss the role of irisin in bone metabolism via exercise-induced mechanical forces regulation. In addition, the role of irisin in pathological bone loss and other chronic diseases is also reviewed. Notably, irisin appears to be a key determinant of bone mineral status and thus may serve as a novel biomarker for bone metabolism. Interestingly, the secretion of irisin appears to be mediated by different forms of exercise and pathological conditions such as diabetes, obesity, and inflammation. Understanding the mechanism by which irisin is regulated and how it regulates skeletal metabolism via osteoclast and osteoblast activities will be an important step toward applying new knowledge of irisin to the treatment and prevention of bone diseases such as osteolysis and other chronic disorders.

Keywords:  bone health; exercise; irisin; mechanical force; skeleton

DOI:  https://doi.org/10.3389/fcell.2021.668759
Aging (Albany NY). 2021 May 13. 13

Effects of exercise on cellular and tissue aging.

Priscila Viana Carapeto, Cristina Aguayo-Mazzucato.

  The natural aging process is carried out by a progressive loss of homeostasis leading to a functional decline in cells and tissues. The accumulation of these changes stem from a multifactorial process on which both external (environmental and social) and internal (genetic and biological) risk factors contribute to the development of adult chronic diseases, including type 2 diabetes mellitus (T2D). Strategies that can slow cellular aging include changes in diet, lifestyle and drugs that modulate intracellular signaling. Exercise is a promising lifestyle intervention that has shown antiaging effects by extending lifespan and healthspan through decreasing the nine hallmarks of aging and age-associated inflammation. Herein, we review the effects of exercise to attenuate aging from a clinical to a cellular level, listing its effects upon various tissues and systems as well as its capacity to reverse many of the hallmarks of aging. Additionally, we suggest AMPK as a central regulator of the cellular effects of exercise due to its integrative effects in different tissues. These concepts are especially relevant in the setting of T2D, where cellular aging is accelerated and exercise can counteract these effects through the reviewed antiaging mechanisms.

Keywords:  AMPK; aging; exercise; type 2 diabetes

DOI:  https://doi.org/10.18632/aging.203051
Biochemistry (Mosc). 2021 05;86(5): 597-610

Electrical Stimulation of Cultured Myotubes in vitro as a Model of Skeletal Muscle Activity: Current State and Future Prospects.

Tatiana F Vepkhvadze, Alexander V Vorotnikov, Daniil V Popov.

  Skeletal muscles comprise more than a third of human body mass and critically contribute to regulation of body metabolism. Chronic inactivity reduces metabolic activity and functional capacity of muscles, leading to metabolic and other disorders, reduced life quality and duration. Cellular models based on progenitor cells isolated from human muscle biopsies and then differentiated into mature fibers in vitro can be used to solve a wide range of experimental tasks. The review discusses the aspects of myogenesis dynamics and regulation, which might be important in the development of an adequate cell model. The main function of skeletal muscle is contraction; therefore, electrical stimulation is important for both successful completion of myogenesis and in vitro modeling of major processes induced in the skeletal muscle by acute or regular physical exercise. The review analyzes the drawbacks of such cellular model and possibilities for its optimization, as well as the prospects for its further application to address fundamental aspects of muscle physiology and biochemistry and explore cellular and molecular mechanisms of metabolic diseases.

Keywords:  electrical stimulation; gene expression; metabolism; myogenesis; physical exercise; satellite cells; skeletal muscle

DOI:  https://doi.org/10.1134/S0006297921050084