MOTS-c modulates skeletal muscle function by directly binding and activating CK2.

MOTS-c is a mitochondrial microprotein that improves metabolism. Here, we demonstrate CK2 is a direct and functional target of MOTS-c. MOTS-c directly binds to CK2 and activates it in cell-free systems.

Age-dependence of semitendinosus tendon properties used for anterior cruciate ligament reconstruction differs in males and females.

Background: The semitendinosus tendon is one of the most used autografts in anterior cruciate ligament reconstruction. Although recent evidence indicates that young patients, especially in females, may experience high rates of revision and residual instability, the reasons for the inferior outcomes in these patients remain unclear. To address this issue, we aimed to compare the mechanical properties of the semitendinosus tendon used for anterior cruciate ligament reconstruction in male and female patients of various ages.

Effect of Exogenous Acute β-Hydroxybutyrate Administration on Different Modalities of Exercise Performance in Healthy Rats.

Purpose: A ketone body (β-hydroxybutyrate [β-HB]) is used as an energy source in the peripheral tissues. However, the effects of acute β-HB supplementation on different modalities of exercise performance remain unclear. This study aimed to assess the effects of acute β-HB administration on the exercise performance of rats.

Age-related changes in mechanical properties of semitendinosus tendon used for anterior cruciate ligament reconstruction.

Background: Hamstring tendons are a popular choice for autografts in anterior cruciate ligament (ACL) reconstruction. However, there is increasing evidence that hamstring tendon autografts carry a high risk of revision and residual instability in young patients. To elucidate the reasons for the inferior outcome of the reconstructed ACL with hamstring tendon autografts in young patients, we investigated the Young's modulus and the extent of cyclic loading-induced slackening of the semitendinosus tendon used for ACL reconstruction across a broad range of ages.

High-throughput muscle fiber typing from RNA sequencing data.

Background: Skeletal muscle fiber type distribution has implications for human health, muscle function, and performance. This knowledge has been gathered using labor-intensive and costly methodology that limited these studies. Here, we present a method based on muscle tissue RNA sequencing data (totRNAseq) to estimate the distribution of skeletal muscle fiber types from frozen human samples, allowing for a larger number of individuals to be tested.

Sports activities at a young age decrease hypertension risk-The J-Fit study.

This study aimed to assess (1) blood pressure between young, current athletes, and non-athletes early in life; (2) hypertension prevalence between former athletes and the general population later in life; and (3) understand the mechanisms between exercise training and hypertension risks in the form of DNA methylation. Study 1: A total of 354 young male participants, including current athletes, underwent blood pressure assessment. Study 2: The prevalence of hypertension in 1269 male former athletes was compared with that in the Japanese general population.

Genetic polymorphisms related to muscular strength and flexibility are associated with artistic gymnastic performance in the Japanese population.

This study aimed to examine how genetic polymorphisms related to muscular strength and flexibility influence artistic gymnastic performance in an attempt to identify a novel polymorphism associated with flexibility. In study 1, the passive straight-leg-raise (PSLR) score and aromatase gene rs936306 polymorphism, a key enzyme for estrogen biosynthesis, were assessed in 278 individuals. In study 2, athletes (281 gymnasts and 1908 other athletes) were asked about their competition level, and gymnasts were assessed using the difficulty score (D-score) for each event.

Genetic polymorphisms in and are associated with serum CK activity after prolonged running in men.

This study aimed to clarify ) the influence of genetic polymorphisms in the cytochrome P450 aromatase gene () on circulating estradiol levels in men and ) whether estrogen-related genetic polymorphisms, such as the rs936306 and estrogen receptor-α () rs2234693 polymorphisms, predict exercise-induced serum creatine kinase (CK) activity, which is an index of skeletal muscle membrane disruption. Serum estradiol levels were examined in young men ( = 167). In a different cohort, serum CK activity was analyzed in a 2-day ultramarathon race: baseline, after the first day, and after the second day (114 males and 25 females).

Genotype Score for Iron Status Is Associated with Muscle Fiber Composition in Women.

Human muscle fiber composition is heterogeneous and mainly determined by genetic factors. A previous study reported that experimentally induced iron deficiency in rats increases the proportion of fast-twitch muscle fibers. Iron status has been reported to be affected by genetic factors.

Genetic variants within the gene are associated with ligament injuries in physically active populations from Australia, South Africa, and Japan.

Previous small-scale studies have shown an association between the gene and anterior cruciate ligament (ACL) injury risk. In this larger study, the genotype and allele frequency distributions of the rs12722 C/T and rs10628678 AGGG/deletion (AGGG/-) indel variants were compared between participants: (i) with ACL injury in independent and combined cohorts from South-Africa (SA) and Australia (AUS) vs controls (CON), and (ii) with any ligament (ALL) or only ACL injury in a Japanese (JPN) cohort vs CON. Samples were collected from SA (235 cases; 232 controls), AUS (362 cases; 80 controls) and JPN (500 cases; 1,403 controls).

The MOTS-c K14Q polymorphism in the mtDNA is associated with muscle fiber composition and muscular performance.

Human skeletal muscle fiber is heterogenous due to its diversity of slow- and fast-twitch fibers. In human, slow-twitched fiber gene expression is correlated to MOTS-c, a mitochondria-derived peptide that has been characterized as an exercise mimetic. Within the MOTS-c open reading frame, there is an East Asian-specific m.

A pro-diabetogenic mtDNA polymorphism in the mitochondrial-derived peptide, MOTS-c.

Type 2 Diabetes (T2D) is an emerging public health problem in Asia. Although ethnic specific mtDNA polymorphisms have been shown to contribute to T2D risk, the functional effects of the mtDNA polymorphisms and the therapeutic potential of mitochondrial-derived peptides at the mtDNA polymorphisms are underexplored. Here, we showed an Asian-specific mitochondrial DNA variation m.

eQTL variants in are associated with muscle injury in athletes.

The myotendinous junction (MTJ) is at high risk of muscle injury, and collagen XXII is strictly expressed at tissue junctions, specifically at the MTJ. We investigated the hypothesis that single-nucleotide polymorphisms (SNPs) related to collagen type XXII α-1 chain gene () mRNA expression are associated with susceptibility to muscle injury in athletes. History of muscle injury was assessed in 3,320 Japanese athletes using a questionnaire, and two expression quantitative trait loci (eQTL) SNPs for (rs11784270 A/C and rs6577958 T/C) were analyzed using the TaqMan SNP Genotyping Assay.

A rs936306 C/T Polymorphism in the CYP19A1 Is Associated With Stress Fractures.

Kumagai, H, Miyamoto-Mikami, E, Kikuchi, N, Kamiya, N, Zempo, H, and Fuku, N. A rs936306 C/T polymorphism in the CYP19A1 is associated with stress fractures. J Strength Cond Res 36(8): 2322-2325, 2022-A stress fracture (SF) is an overuse injury, and low bone mineral density (BMD) is the risk factor for the SF.

rs8192678 and rs6949152 Polymorphisms Are Associated with Muscle Fiber Composition in Women.

rs8192678 G/A (Gly482Ser) and rs6949152 A/G polymorphisms have been associated with endurance athlete status, endurance performance phenotypes, and certain health-related markers of different pathologies such as metabolic syndrome, diabetes, and dyslipidemia. We hypothesized that they could be considered interesting candidates for explaining inter-individual variations in muscle fiber composition in humans. We aimed to examine possible associations of these polymorphisms with myosin heavy-chain (MHC) isoforms as markers of muscle fiber compositions in vastus lateralis muscle in a population of 214 healthy Japanese subjects, aged between 19 and 79 years.

Association between the ACE I/D polymorphism and muscle injuries in Italian and Japanese elite football players.

ACE I/D polymorphism has been recently associated with the susceptibility to inflammation and muscle damage after exercise. The aim of this study was to understand the association between the I/D polymorphism and muscle injuries in a large cohort of elite football players from two different countries. Seven hundred and ten male elite football players from Italy (n = 341) and Japan (n = 369) were recruited for the study.

COL5A1 rs12722 polymorphism is not associated with passive muscle stiffness and sports-related muscle injury in Japanese athletes.

Background: Poor joint flexibility has been repeatedly proposed as a risk factor for muscle injury. The C-to-T polymorphism (rs12722) in the 3'-untranslated region of the collagen type V α1 chain gene (COL5A1) is reportedly associated with joint flexibility. Flexibility of a normal joint is largely determined by passive muscle stiffness, which is influenced by intramuscular collagenous connective tissues including type V collagen.

AGTR2 and sprint/power performance: a case-control replication study for rs11091046 polymorphism in two ethnicities.

We aimed to replicate, in a specific athletic event cohort (only track and field) and in two different ethnicities (Japanese and East European, i.e. Russian and Polish), original findings showing the association of the angiotensin-II receptor type-2 gene () rs11091046 A>C polymorphism with athlete status.

Gene expression profile of muscle adaptation to high-intensity intermittent exercise training in young men.

High-intensity intermittent exercise training (HIIT) has been proposed as an effective approach for improving both, the aerobic and anaerobic exercise capacity. However, the detailed molecular response of the skeletal muscle to HIIT remains unknown. We examined the effects of the HIIT on the global gene expression in the human skeletal muscle.

ESR1 rs2234693 Polymorphism Is Associated with Muscle Injury and Muscle Stiffness.

Purpose: Muscle injury is the most common sports injury. Muscle stiffness, a risk factor for muscle injury, is lower in females than in males, implying that sex-related genetic polymorphisms influence muscle injury associated with muscle stiffness. The present study aimed to clarify the associations between two genetic polymorphisms (rs2234693 and rs9340799) in the estrogen receptor 1 gene (ESR1) and muscle injury or muscle stiffness.