[SIGNALING PATHWAYS INVOLVED IN THE REGULATION OF PROTEIN METABOLISM IN SKELETAL MUSCLE].

The ability of muscle cells to respond to certain signaling molecules depends on the presence of specific proteins-receptors, ion channels and transporters, which create a system of metabolic inputs. All cells in the human body have a transmembrane signaling system that allows to get information from extracellular stimuli such as hormones, neurotransmitters, proteins, peptides, derivatives of amino acids and fat acids, sensor molecules. The results of researches published in the last two years, which expand knowledge of action of various factors on protein metabolism in skeletal muscles are presented in the review.

[THE ROLE OF microRNAs IN THE REGULATION OF MUSCLE METABOLTSM].

MicroRNAs, class of the small RNA containing approximately 22 nucleotides take part in regulation of metabolism of skeletal muscles as enzymes, hormones and transcription factors. They are able to regulate the intensity of the translation process through complementary. interaction with mRNA.

[The role of mTOR in the regulation of skeletal muscle metabolism].

mTOR enzyme belongs to a family of specific serine/threonine protein kinases. mTOR plays an important role in the transmission of extracellular signals by phosphorylation of various substrates in many metabolic reactions in humans. Protein mTOR, having protein kinase activity, is encoded by a gene FRAP1, which is localized on chromosome 1 (1p36.

[Molecular mechanisms of skeletal muscle hypertrophy].

Enzymes Akt, AMPK, mTOR, S6K and PGC-1a coactivator take part in skeletal muscles in the regulation of synthesis of proteins. The expression of these proteins is regulated by growth factors, hormones, nutrients, mechanical loading and leads to an increase in muscle mass and skeletal muscle hypertrophy. The review presents the results of studies published in the past four years, which expand knowledge on the effects of various factors on protein synthesis in skeletal muscle.

[Participation AMPK in the regulation of skeletal muscles metabolism].

Enzyme AMPK is a part of the family of serine/threonine specific protein kinases. AMPK plays important role in the transfer extracellular signals through phosphorylation of multiple substrates in different metabolic reactions of skeletal muscles. AMPK is geterotrimetric complex, consisting of the catalytic subunit (AMPKalpha) and two regulatory subunits (AMPKbeta and AMPKgamma), which are encoded by seven different high-homologous genes (alpha1, alpha2, beta1, beta2, gamma1, gamma2, gamma3).

[Involvement of Akt in regulation of skeletal muscle metabolism].

The enzyme Akt 1 is a member of serine/threonine specific protein kinases family. Akt plays an important role in the transmission of extracellular signals and mechanical stimuli via phosphorylation of its numerous substrates involved in anabolic and catabolic processes as well as mechanical responses of skeletal muscle. Expression of the Akt is increased during skeletal muscle hypertrophy and decreased during muscle atrophy.

Association analysis of ACE and ACTN3 in elite Caucasian and East Asian swimmers.

Purpose: Polymorphic variation in the angiotensin-converting enzyme (ACE) and α-actinin-3 (ACTN3) genes has been reported to be associated with endurance and/or power-related human performance. Our aim was to investigate whether polymorphisms in ACE and ACTN3 are associated with elite swimmer status in Caucasian and East Asian populations.

Methods: ACE I/D and ACTN3 R577X genotyping was carried out for 200 elite Caucasian swimmers from European, Commonwealth, Russian, and American cohorts (short and middle distance, ≤400 m, n = 130; long distance, >400 m, n = 70) and 326 elite Japanese and Taiwanese swimmers (short distance, ≤100 m, n = 166; middle distance, 200-400 m, n = 160).

The association of ACE, ACTN3 and PPARA gene variants with strength phenotypes in middle school-age children.

The aim of the study was to determine the association between ACE I/D, ACTN3 R577X and PPARA intron 7 G/C gene polymorphisms and strength-related traits in 457 middle school-age children (219 boys and 238 girls; aged 11 ± 0.4 years). The assessment of different phenotypes was conducted with a number of performance tests.

[Association of the mitochondrial transcription factor (TFAM) gene polymorphism with physical performance of athletes].

The aim of the study was to investigate allelic distribution of the mitochondrial transcription factor gene (TFAM) Ser12Thr polymorphism in athletes (n = 1537) and controls (n = 1113), and to find interrelation between genotypes and aerobic capacity in rowers (n = 90). Genotyping was performed by restriction fragment length polymorphism analysis. Aerobic capacity (maximal oxygen consumption (VO2max) and maximal power production capacity (Wmax)) was determined using an incremental test to exhaustion by rower ergometer.

[The analysis of PPARGC1B gene polymorphism in athletes].

The aim of the study was to investigate allelic distribution of the peroxisome proliferator-activated receptor gamma coactivator 1beta gene (PPARGC1B; Ala203Pro polymorphism) in athletes (n = = 1535) and controls (n = 1113), and to find interrelation between genotypes and aerobic performance of athletes. Genotyping was performed by restriction of the fragment length polymorphism. Aerobic capacity was determined using incremental test to exhaustion by rower ergometer.

Genes, athlete status and training -- An overview.

Significant data confirming the influence of genes on human physical performance and elite athlete status have been accumulated in recent years. Research of gene variants that may explain differences in physical capabilities and training-induced effects between subjects is widely carried out. In this review, the findings of genetic studies investigating DNA polymorphisms and their association with elite athlete status and training responses are reported.

The combined impact of metabolic gene polymorphisms on elite endurance athlete status and related phenotypes.

Endurance performance is a complex phenotype subject to the influence of both environmental and genetic factors. Although the last decade has seen a variety of specific genetic factors proposed, many in metabolic pathways, each is likely to make a limited contribution to an 'elite' phenotype: it seems more likely that such status depends on the simultaneous presence of multiple such variants. The aim of the study was to investigate individually and in combination the association of common metabolic gene polymorphisms with endurance athlete status, the proportion of slow-twitch muscle fibers and maximal oxygen consumption.

PPARG Gene polymorphism and locomotor activity in humans.

The distribution of PPARG gene allele frequencies (Pro/Ala polymorphism) was studied in sportsmen specialized in speed and force athletics. A relationship between genotypes and human muscle transverse section area was evaluated. The PPARG Ala allele was significantly more incident in athletes than in controls, the incidence increasing with higher athletic qualification.

Association of the VEGFR2 gene His472Gln polymorphism with endurance-related phenotypes.

Vascular endothelial growth factor receptor 2 (VEGFR2) is essential to induce the full spectrum of VEGF angiogenic responses to aerobic training. In the present study, we examined the impact of the functional His472Gln polymorphism of the VEGFR2 gene on elite athlete status, endurance performance and muscle fibre type composition. Four hundred and seventy-one Russian athletes were prospectively stratified into four groups according to event duration, distance and type of activity, covering a spectrum from the more endurance-oriented to the more power-oriented.

Effect of HIF1A gene polymorphism on human muscle performance.

Allele distribution of hypoxia-inducible factor gene (HIF1A; Pro582Ser polymorphism) was studied in power-oriented athletes and controls practicing no athletics; genotype relationships with muscle fiber composition were studied in speed skaters. Genotyping was carried out by PCR. The composition of muscle fibers was evaluated by the immunohistochemical analysis of m.

[The influence of calcineurin gene polymorphism on morphofunctional characteristics of cardiovascular system of athletes].

The aim of the study was to investigate allelic distribution of calcineurin gene (CNB; 5I/5D polymorphism) in athletes of cyclic sports (n = 673) and controls (n = 1073), and to find interrelation between genotypes and risk of left ventricular hypertrophy and physical performance of athletes. Genotyping was performed by restriction fragment length polymorphism. Echocardiography was performed by ultrasound scanner Aloka-3500.

The ACTN3 R577X polymorphism in Russian endurance athletes.

Objective: The functional 577R allele of the alpha-actinin-3 (ACTN3) gene has been reported to be associated with elite power athlete status, while the nonfunctional 577XX genotype (predicts an alpha-actinin-3 deficient phenotype) has been hypothesised as providing some sort of advantage for endurance athletes. In the present study, the distribution of ACTN3 genotypes and alleles in Russian endurance-oriented athletes were examined and association between ACTN3 genotypes and the competition results of rowers were sought.

Methods: 456 Russian endurance-oriented athletes of regional or national competitive standard were involved in the study.

Association of the ACTN3 R577X polymorphism with power athlete status in Russians.

The alpha-actinin-3 (ACTN3) gene encodes a Z-disc structural protein which is found only in fast glycolytic muscle fibers. A common nonsense polymorphism in codon 577 of the ACTN3 gene (R577X) results in alpha-actinin-3 deficiency in XX homozygotes. Previous reports have shown a lower proportion of the ACTN3 XX genotype in power-oriented athletes compared to the general population.

[Association of PPARD gene polymorphism with human physical performance].

Peroxisome proliferator-activated receptor delta (PPARdelta) regulates expression of genes involved in lipid and carbohydrate metabolism. To examine the association of a functional +294T/C polymorphism of PPARD gene with human physical performance, we have studied the distribution of PPARD alleles and genotypes in a cohort of athletes (n=1256; stratified by specialty and skill level) and controls (n=610). We found that the frequency of PPARD C allele (with higher transcriptional activity compared to T allele) in a group of endurance-oriented athletes (n=898) is significantly higher than in controls (18.

[Association of regulatory genes polymorphisms with aerobic and anaerobic performance of athletes].

The aim of study was to investigate an allelic distribution of PPARA (G/C polymorphism), PPARG (Pro/Ala), PPARD (+294T/C) and PGCIA (Gly482Ser) genes in rowers (n=205) and controls (n=659), and to find correlation between genotypes and physiological parameters. Genotyping was performed by restriction fragment length polymorphism analysis. Physiological parameters were evaluated by PM 3 Rower Ergometer and MetaMax 3B Gas Analyzer.

[The association of gene polymorphisms with the muscle fiber type composition].

Muscle fiber composition of m. vastus lateralis has significant individual variability mainly depending on genetic factors. Present study shows analysis of association between polymorphisms of three muscle performance-related genes and muscle fiber type composition in 48 young healthy men.

PPARalpha gene variation and physical performance in Russian athletes.

Peroxisome proliferator-activated receptor alpha (PPARalpha) regulates genes responsible for skeletal and heart muscle fatty acid oxidation. Previous studies have shown that the PPARalpha intron 7 G/C polymorphism was associated with left ventricular growth in response to exercise. We speculated that GG homozygotes should be more prevalent within a group of endurance-oriented athletes, have normal fatty acid metabolism, and increased percentages of slow-twitch fibers.

Effect of exercise to exhaustion on myeloperoxidase and lysozyme release from blood neutrophils.

Exercise sessions (swimming in rats and treadmill running in humans) resulted in stimulation of neutrophil degranulation in the experiments with animals and in the human study. Myeloperoxidase (MPO) (+67%) and lysozyme (+51%) quantities in the plasma of rats increased significantly immediately after exercise. The blood plasma lysozyme concentration was increased by 41% at the 6th min of treadmill exercise in athletes.