The COL5A1 gene: a novel marker of endurance running performance

Key genes and metabolites that regulate wool fibre diameter identified by combined transcriptome and metabolome analysis

BACKGROUND

Fibre diameter is an important economic trait of wool fibre. As the fibre diameter decreases, the economic value of wool increases. Therefore, understanding the mechanism of wool fibre diameter regulation is important in improving the value of wool.

RESULTS

In this study, we used non-targeted metabolome and reference transcriptome data to detect differences in metabolites and genes in groups of Alpine Merino sheep with different wool fibre diameter gradients, and integrated metabolome and transcriptome data to identify key genes and metabolites that regulate wool fibre diameter. We found 464 differentially abundant metabolites (DAMs) and 901 differentially expressed genes (DEGs) in four comparisons of groups with different wool fibre diameters. Approximately 25% of the differentially abundant metabolites were lipid and lipid-like molecules. These molecules were predicted to be associated with skin development and keratin filament by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analyses. Key genes, including COL5A2, COL5A3, CREB3L4, COL1A1, and SFRP4, were identified by gene set enrichment analysis.

CONCLUSIONS

Key genes regulating wool fibre diameter were identified, the effects of lipid molecules on wool performance were investigated, and potential synergies between genes and metabolites were postulated, providing a theoretical framework for fine wool sheep breeding.

Genomic predictors of physical activity and athletic performance

Physical activity and athletic performance are complex phenotypes influenced by environmental and genetic factors. Recent advances in lifestyle and behavioral genomics led to the discovery of dozens of DNA polymorphisms (variants) associated with physical activity and allowed to use them as genetic instruments in Mendelian randomization studies for identifying the causal links between physical activity and health outcomes. On the other hand, exercise and sports genomics studies are focused on the search for genetic variants associated with athlete status, sports injuries and individual responses to training and supplement use. In this review, the findings of studies investigating genetic markers and their associations with physical activity and athlete status are reported. As of the end of September 2023, a total of 149 variants have been associated with various physical activity traits (of which 42 variants are genome-wide significant) and 253 variants have been linked to athlete status (115 endurance-related, 96 power-related, and 42 strength-related).

Genes and Athletic Performance: The 2023 Update

Phenotypes of athletic performance and exercise capacity are complex traits influenced by both genetic and environmental factors. This update on the panel of genetic markers (DNA polymorphisms) associated with athlete status summarises recent advances in sports genomics research, including findings from candidate gene and genome-wide association (GWAS) studies, meta-analyses, and findings involving larger-scale initiatives such as the UK Biobank. As of the end of May 2023, a total of 251 DNA polymorphisms have been associated with athlete status, of which 128 genetic markers were positively associated with athlete status in at least two studies (41 endurance-related, 45 power-related, and 42 strength-related). The most promising genetic markers include the AMPD1 rs17602729 C, CDKN1A rs236448 A, HFE rs1799945 G, MYBPC3 rs1052373 G, NFIA-AS2 rs1572312 C, PPARA rs4253778 G, and PPARGC1A rs8192678 G alleles for endurance; ACTN3 rs1815739 C, AMPD1 rs17602729 C, CDKN1A rs236448 C, CPNE5 rs3213537 G, GALNTL6 rs558129 T, IGF2 rs680 G, IGSF3 rs699785 A, NOS3 rs2070744 T, and TRHR rs7832552 T alleles for power; and ACTN3 rs1815739 C, AR ≥21 CAG repeats, LRPPRC rs10186876 A, MMS22L rs9320823 T, PHACTR1 rs6905419 C, and PPARG rs1801282 G alleles for strength. It should be appreciated, however, that elite performance still cannot be predicted well using only genetic testing.

Collagen Gene Polymorphisms Previously Associated with Resistance to Soft-Tissue Injury Are More Common in Competitive Runners Than Nonathletes

ABSTRACT

Dines, HR, Nixon, J, Lockey, SJ, Herbert, AJ, Kipps, C, Pedlar, CR, Day, SH, Heffernan, SM, Antrobus, MR, Brazier, J, Erskine, RM, Stebbings, GK, Hall, ECR, and Williams, AG. Collagen gene polymorphisms previously associated with resistance to soft-tissue injury are more common in competitive runners than nonathletes. J Strength Cond Res 37(4): 799-805, 2023-Single-nucleotide polymorphisms (SNPs) of collagen genes have been associated with soft-tissue injury and running performance. However, their combined contribution to running performance is unknown. We investigated the association of 2 collagen gene SNPs with athlete status and performance in 1,429 Caucasian subjects, including 597 competitive runners (354 men and 243 women) and 832 nonathletes (490 men and 342 women). Genotyping for COL1A1 rs1800012 (C > A) and COL5A1 rs12722 (C > T) SNPs was performed by a real-time polymerase chain reaction. The numbers of "injury-resistant" alleles from each SNP, based on previous literature (rs1800012 A allele and rs12722 C allele), were combined as an injury-resistance score (RScore, 0-4; higher scores indicate injury resistance). Genotype frequencies, individually and combined as an RScore, were compared between cohorts and investigated for associations with performance using official race times. Runners had 1.34 times greater odds of being rs12722 CC homozygotes than nonathletes (19.7% vs. 15.5%, p = 0.020) with no difference in the rs1800012 genotype distribution ( p = 0.659). Fewer runners had an RScore 0 of (18.5% vs. 24.7%) and more had an RScore of 4 (0.6% vs. 0.3%) than nonathletes ( p < 0.001). Competitive performance was not associated with the COL1A1 genotype ( p = 0.933), COL5A1 genotype ( p = 0.613), or RScore ( p = 0.477). Although not associated directly with running performance among competitive runners, a higher combined frequency of injury-resistant COL1A1 rs1800012 A and COL5A1 rs12722 C alleles in competitive runners than nonathletes suggests these SNPs may be advantageous through a mechanism that supports, but does not directly enhance, running performance.

Advances in sports genomics

Sports genomics is the scientific discipline that focuses on the organization and function of the genome in elite athletes, and aims to develop molecular methods for talent identification, personalized exercise training, nutritional need and prevention of exercise-related diseases. It postulates that both genetic and environmental factors play a key role in athletic performance and related phenotypes. This update on the panel of genetic markers (DNA polymorphisms) associated with athlete status and soft-tissue injuries covers advances in research reported in recent years, including one whole genome sequencing (WGS) and four genome-wide association (GWAS) studies, as well as findings from collaborative projects and meta-analyses. At end of 2020, the total number of DNA polymorphisms associated with athlete status was 220, of which 97 markers have been found significant in at least two studies (35 endurance-related, 24 power-related, and 38 strength-related). Furthermore, 29 genetic markers have been linked to soft-tissue injuries in at least two studies. The most promising genetic markers include HFE rs1799945, MYBPC3 rs1052373, NFIA-AS2 rs1572312, PPARA rs4253778, and PPARGC1A rs8192678 for endurance; ACTN3 rs1815739, AMPD1 rs17602729, CPNE5 rs3213537, CKM rs8111989, and NOS3 rs2070744 for power; LRPPRC rs10186876, MMS22L rs9320823, PHACTR1 rs6905419, and PPARG rs1801282 for strength; and COL1A1 rs1800012, COL5A1 rs12722, COL12A1 rs970547, MMP1 rs1799750, MMP3 rs679620, and TIMP2 rs4789932 for soft-tissue injuries. It should be appreciated, however, that hundreds and even thousands of DNA polymorphisms are needed for the prediction of athletic performance and injury risk.

The Hypoxia-Related Gene COL5A1 Is a Prognostic and Immunological Biomarker for Multiple Human Tumors

Background

Collagen type V alpha 1 chain (COL5A1) is a hypoxia-related gene (a collagen family protein) and participates in the formation of the extracellular matrix. Although some evidence supports a significant role for COL5A1 in the progression of several cancers, a pan-cancer analysis of COL5A1 is not currently available. Herein, we aimed to assess the prognostic value of COL5A1 in 33 human cancers and to investigate its underlying immunological function.

Methods

Through multiple bioinformatics methods, we analyzed the data from Oncomine, TCGA, CCLE, HPA, DNMIVD, and cBioPortal database to explore the potential underlying carcinogenic effect of COL5A1, including the relevance of COL5A1 to the outcome, DNA methylation, tumor microenvironment, immune cells infiltration, and drug sensitivity in 33 human cancers. The effects of COL5A1 on glioma cell proliferation, migration, and invasion were verified in cellular experiments.

Results

Our findings indicated that COL5A1 was expressed at high levels in 13 cancers and was negatively related to the prognosis of 11 cancers. Additionally, COL5A1 was coexpressed with genes encoding the major histocompatibility complex, immune activators, immune suppressors, chemokines, chemokine receptors, mismatch repair genes, and immune checkpoints. We also identified different roles for COL5A1 in the immunocyte infiltration in different cancers. The correlation between COL5A1 and drug sensitivity was found in several cancers. COL5A1 potentially influenced the tumor progression through immune-related pathways, negative regulation of immune system processes, chemokine signaling pathways, JAK-STAT pathways, T cell receptor pathways, lymphocyte migration, and antigen processing and presentation, among other processes.

Conclusions

Based on our study, COL5A1 may be employed as a prognostic marker in different malignancies because of its impact on tumorigenesis and immune cell infiltration and have implications for cancer immune checkpoint inhibitors and chemotherapy.

The Roles of MicroRNAs in Tendon Healing and Regeneration

Tendons connect the muscle abdomen of skeletal muscles to the bone, which transmits the force generated by the muscle abdomen contraction and pulls the bone into motion. Tendon injury is a common clinical condition occurring in certain populations, such as repeated tendon strains in athletes. And it can lead to substantial pain and loss of motor function, in severe cases, significant disability. Tendon healing and regeneration have attracted growing interests. Some treatments including growth factors, stem cell therapies and rehabilitation programs have been tried to improve tendon healing. However, the basic cellular biology and pathology of tendons are still not fully understood, and the management of tendon injury remains a considerable challenge. Regulating gene expression at post-transcriptional level, microRNA (miRNA) has been increasingly recognized as essential regulators in the biological processes of tendon healing and regeneration. A wide range of miRNAs in tendon injury have been shown to play vital roles in maintaining and regulating its physiological function, as well as regulating the tenogenic differentiation potential of stem cells. In this review, we show the summary of the latest information on the role of miRNAs in tendon healing and regeneration, and also discuss potentials for miRNA-directed diagnosis and therapy in tendon injuries and tendinopathy, which may provide new theoretical foundation for tenogenesis and tendon healing.

Genetic test for the personalization of sport training

Genetic variants may contribute to confer elite athlete status. However, this does not mean that a person with favourable genetic traits would become a champion because multiple genetic interactions and epigenetic contributions coupled with confounding environmental factors shape the overall phenotype. This opens up a new area in sports genetics with respect to commercial genetic testing. The analysis of genetic polymorphisms linked to sport performance would provide insights into the potential of becoming an elite endurance or power performer. This mini-review aims to highlight genetic interactions that are associated with performance phenotypes and their potentials to be used as markers for talent identification and trainability.

A Potential Endurance Algorithm Prediction in the Field of Sports Performance

Sport performance is influenced by several factors, including genetic susceptibility. In the past years, specific single nucleotide polymorphisms have been associated to sport performance; however, these effects should be considered in multivariable prediction systems since they are related to a polygenic inheritance. The aim of this study was to design a genetic endurance prediction score (GES) of endurance performance and analyze its association with anthropometric, nutritional and sport efficiency variables in a cross-sectional study within fifteen male cyclists. A statistically significant positive relationship between GES and the VO₂ maximum (P = 0.033), VO₂ VT1 (P = 0.049) and VO₂ VT2 (P < 0.001) was observed. Moreover, additional remarkable associations between genotype and the anthropometric, nutritional and sport performance variables, were achieved. In addition, an interesting link between the habit of consuming caffeinated beverages and the GES was observed. The outcomes of the present study indicate a potential use of this genetic prediction algorithm in the sports' field, which may facilitate the finding of genetically talented athletes, improve their training and food habits, as well as help in the improvement of physical conditions of amateurs.

What are the Limiting Factors During an Ultra-Marathon? A Systematic Review of the Scientific Literature

This review aimed to analyse factors that limited performance in ultra-marathons and mountain ultra-marathons. A literature search in one database (PubMed) was conducted in February 2019. Quality of information of the articles was evaluated using the Oxford´s level of evidence and the Physiotherapy Evidence Database (PEDro) scale. The search strategy yielded 111 total citations from which 23 met the inclusion criteria. Twenty one of the 23 included studies had a level of evidence 2b (individual cohort study), while the 2 remaining studies had a level of evidence of 5 (expert opinion). Also, the mean score in the PEDro scale was 3.65 ± 1.61, with values ranging from 0 to 7. Participants were characterised as experienced or well-trained athletes in all of the studies. The total number of participants was 1002 (893 men, 86 women and 23 unknown). The findings of this review suggest that fatigue in ultra-endurance events is a multifactorial phenomenon that includes physiological, neuromuscular, biomechanical and cognitive factors. Improved exercise performance during ultra-endurance events seems to be related to higher VO_2max values and maximal aerobic speed (especially during submaximal efforts sustained over a long time), lower oxygen cost of transport and greater running experience.

Interactions between COL5A1 Gene and Risk of the Anterior Cruciate Ligament Rupture

Collagen alpha-1(V) chain, encoded by the COL5A1 gene, plays a crucial role in abundant fibrillar collagens supporting many tissues in the body containing type I collagen and appears to regulate the association between heterotypic fibers composed of both type I and type V collagen occurring among others in muscles, tendons and ligaments. Taking this fact into consideration we decided to examine the association between COL5A1 rs12722 and rs13946 polymorphisms, individually and as inferred haplotypes, with anterior cruciate ligament rupture risk (ACLR) in professional soccer players. A total of 134 male professional soccer players with surgically diagnosed primary anterior cruciate ligament ruptures and 211 apparently healthy male professional soccer players, who were without any self-reported history of ligament or tendon injury, were included in the study. Both the cases and the healthy controls were recruited from the same soccer teams, of a similar age category, and had a comparable level of exposure to anterior cruciate ligament injury. Genomic DNA was extracted from oral epithelial cells using GenElute Mammalian Genomic DNA MiniprepKit. All samples were genotyped for the rs12722 and rs13946 polymorphisms using a Rotor-Gene realtime polymerase chain reaction. Statistically significant differences in the genotype frequencies for the COL5A1 rs13946 polymorphisms in dominant modes of inheritance occurred (p = 0.039). Statistically significant differences were documented only in the dominant model under the representation tendency of the C-C haplotype in the ACLR group compared to controls (p = 0.038). Our results suggest that variation in the COL5A1 gene may be one of the non-modifiable factors associated with the ACL injury in professional soccer players. The C-C rs12722-rs13946 haplotype provides a protective effect against the ACL tear.

COL5A1 gene variants previously associated with reduced soft tissue injury risk are associated with elite athlete status in rugby

Background

Two common single nucleotide polymorphisms within the COL5A1 gene (SNPs; rs12722 C/T and rs3196378 C/A) have previously been associated with tendon and ligament pathologies. Given the high incidence of tendon and ligament injuries in elite rugby athletes, we hypothesised that both SNPs would be associated with career success.

Results

In 1105 participants (RugbyGene project), comprising 460 elite rugby union (RU), 88 elite rugby league athletes and 565 non-athlete controls, DNA was collected and genotyped for the COL5A1 rs12722 and rs3196378 variants using real-time PCR. For rs12722, the injury-protective CC genotype and C allele were more common in all athletes (21% and 47%, respectively) and RU athletes (22% and 48%) than in controls (16% and 41%, P ≤ 0.01). For rs3196378, the CC genotype and C allele were overrepresented in all athletes (23% and 48%) and RU athletes (24% and 49%) compared with controls (16% and 41%, P ≤ 0.02). The CC genotype in particular was overrepresented in the back and centres (24%) compared with controls, with more than twice the odds (OR = 2.25, P = 0.006) of possessing the injury-protective CC genotype. Furthermore, when considering both SNPs simultaneously, the CC–CC SNP-SNP combination and C–C inferred allele combination were higher in all the athlete groups (≥18% and ≥43%) compared with controls (13% and 40%; P = 0.01). However, no genotype differences were identified for either SNP when RU playing positions were compared directly with each other.

Conclusion

It appears that the C alleles, CC genotypes and resulting combinations of both rs12722 and rs3196378 are beneficial for rugby athletes to achieve elite status and carriage of these variants may impart an inherited resistance against soft tissue injury, despite exposure to the high-risk environment of elite rugby. These data have implications for the management of inter-individual differences in injury risk amongst elite athletes.

Impact of stretching on the performance and injury risk of long-distance runners

Stretching, either prior to exercise or at the end, or both, is typically carried out by all individuals undertaking sporting activity whether they be elite or recreational athletes. The many forms of stretching available to the athlete, either passive or active, have long been thought to improve performance, decrease injury and generally be advantageous to the athlete. This review examines the current state of the literature and evaluates what athletes can and should do with respect to this controversial topic.

Human COL5A1 polymorphisms and quadriceps muscle-tendon mechanical stiffness in vivo

NEW FINDINGS

What is the central question of the study? Do COL5A1 gene variants, previously reported to have diminished transcript stability, manifest in physiological phenotypes of quadriceps muscle-tendon contractile properties and mechanical stiffness in humans? What is the main finding and its importance? COL5A1 gene variants influence mechanical stiffness, not seeming to affect low-level contractile properties in humans. Functional differences in COL5A1 manifest during moderate- to high-level contractions. Polymorphisms of the collagen type V alpha 1 chain (COL5A1) gene are purported to influence mechanical properties of collagenous tissues. Our purpose was to assess musculotendinous contractile properties of the quadriceps in relationship to the genetic influence of mechanical stiffness. Eighty recreationally active males (aged 19-31 years) were assessed for the presence of three genetic polymorphisms associated with COL5A1 mRNA stability (rs4919510, rs1536482 and rs12722). Genotypes were determined using real-time PCR. Stiffness and contractile properties of the knee musculotendinous complex were assessed by maximal isometric voluntary contractions, ramp isometric voluntary contractions, electrically stimulated contractile events and ultrasonography. All genotype groups were able to activate their knee extensors fully (>97%) as assessed by the interpolated twitch technique and presented no differences in muscle-tendon contractile properties at low submaximal contraction intensities. For the quadriceps muscle-tendon at moderate ramp contractions of 50 and 60% maximal voluntary contraction, the rs12722 CT and TT genotypes had ∼30% greater mean stiffness. The rs1536482 AG and GG genotypes showed a similar trend, but did not achieve statistical significance. Variants of the COL5A1 gene seem to influence quadriceps muscle-tendon stiffness but do not affect low-level contractile properties.

Lack of replication of associations between multiple genetic polymorphisms and endurance athlete status in Japanese population

The aim of this study was to examine a polygenic profile related to endurance performance, based on current knowledge, in the Japanese population. We analyzed 21 genetic polymorphisms that have been reported to be associated with endurance performance and its related phenotypes in 175 endurance runners (60 international‐, 94 national‐, and 21 regional‐level) and 649 controls in the Japanese population. Then, we calculated the total genotype score (TGS) (maximum value of 100 for the theoretically optimum polygenic score) for endurance performance. There was no association between the TGS and endurance athlete status (Control: 49.0 ± 7.6, Regional: 47.3 ± 7.6, National: 49.1 ± 5.7, and International: 48.2 ± 7.0, P = 0.626). These results suggested that TGSs based on the 21 previously published endurance performance‐associated polymorphisms do not influence endurance running performance in the Japanese population. Nevertheless, some marginal tendencies have to be noted: the frequencies of the ACTN3 R577X rs1815739 RR+RX genotype and the GNB3 rs5443 CC+CT genotype were higher in international athletes than in controls (85% vs. 73.6%, P = 0.042 and 90% vs. 76%, P = 0.007, respectively), but not significantly different after Bonferroni correction.

A genetic-based algorithm for personalized resistance training

Association studies have identified dozens of genetic variants linked to training responses and sport-related traits. However, no intervention studies utilizing the idea of personalised training based on athlete's genetic profile have been conducted. Here we propose an algorithm that allows achieving greater results in response to high- or low-intensity resistance training programs by predicting athlete's potential for the development of power and endurance qualities with the panel of 15 performance-associated gene polymorphisms. To develop and validate such an algorithm we performed two studies in independent cohorts of male athletes (study 1: athletes from different sports (n = 28); study 2: soccer players (n = 39)). In both studies athletes completed an eight-week high- or low-intensity resistance training program, which either matched or mismatched their individual genotype. Two variables of explosive power and aerobic fitness, as measured by the countermovement jump (CMJ) and aerobic 3-min cycle test (Aero3) were assessed pre and post 8 weeks of resistance training. In study 1, the athletes from the matched groups (i.e. high-intensity trained with power genotype or low-intensity trained with endurance genotype) significantly increased results in CMJ (P = 0.0005) and Aero3 (P = 0.0004). Whereas, athletes from the mismatched group (i.e. high-intensity trained with endurance genotype or low-intensity trained with power genotype) demonstrated non-significant improvements in CMJ (P = 0.175) and less prominent results in Aero3 (P = 0.0134). In study 2, soccer players from the matched group also demonstrated significantly greater (P < 0.0001) performance changes in both tests compared to the mismatched group. Among non- or low responders of both studies, 82% of athletes (both for CMJ and Aero3) were from the mismatched group (P < 0.0001). Our results indicate that matching the individual's genotype with the appropriate training modality leads to more effective resistance training. The developed algorithm may be used to guide individualised resistance-training interventions.

The BstUI and DpnII Variants of the COL5A1 Gene Are Associated With Tennis Elbow

BACKGROUND

Tennis elbow entails pain and tenderness over the lateral epicondyle. The exact cause of the condition is not fully understood. Type V collagen is a minor fibrillar collagen that intercalates with type I collagen and forms collagen fibrils. It is encoded by the COL5A1 gene. Sequence variants within COL5A1 3'-UTR have been implicated in musculoskeletal diseases.

PURPOSE

To determine whether rs12722 (BstUI C414T polymorphism) and rs13946 (DpnII C230T polymorphism) of the COL5A1 gene are associated with an increased risk of tennis elbow.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 152 patients with tennis elbow and 195 healthy participants were enrolled in this study. The rs12722 (BstUI C414T) and rs13946 (DpnII C230T) polymorphisms were investigated with the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

There was a significant difference in both BstUI and DpnII genotype frequencies between patients with tennis elbow and healthy participants. The A2 allele of BstUI and the B1 allele of DpnII were significantly underrepresented in the patient group.

CONCLUSION

Individuals with the BstUI A1 allele and DpnII B2 allele of the COL5A1 gene have a high likelihood of developing symptoms of the tennis elbow. This is the first study reporting that rs12722 and rs13946 SNPs (single nucleotide polymorphisms) are genetic risk factors for tennis elbow.

The COL5A1 genotype is associated with range of motion

PURPOSE

The aim of our study was to investigate the association between COL5A1 genotype and Range of Motion as measured by the passive straight leg raise (SLR) and whole body join laxity (WBJL) in Asian population.

METHODS

One hundred and seventy seven participants including Korean and Japanese college students (male = 109, female = 68) participated in the study. Each subject performed the passive straight leg raise and whole body join laxity test. Genotyping for the COL5A1 (rs 12722) polymorphism was performed using the TaqMan approach. The COL5A1 genotype exhibited a Hardy-Weinberg equilibrium distribution in our population.

RESULTS

The physical parameters including height, weight, and BMI were higher in < 90° group than > 90° group. The SLR exhibited significant difference among the COL5A1 group. However, the WBJL did not differ significantly among the COL5A1 genotype, but significant difference was seen in CC genotype when compared to CT (2.99 ± 1.72) or TT (2.70 ± 1.52) genotype.

CONCLUSION

We concluded that COL5A1 gene polymorphism is associated with increased SLR ROM in Asian population.

Relationship between functional hamstring: quadriceps ratios and running economy in highly trained and recreational female runners

The purpose of this study was to investigate the relationship between running economy (RE), functional hamstring:quadriceps peak torque ratios (f-H:Q), and flexibility among female runners. Seven highly trained (HT) female runners (age: 25.7 ± 4.7 years, VO2peak of 62.0 ± 4.8 ml·kg-1·min-1) and 11 recreational female runners (age of 28.8 ± 5.6 years, VO2peak of 49.2 ± 4.6 ml·kg-1·min-1) were measured for maximal aerobic power (VO2peak), RE, heart rate, respiratory exchange ratio, f-H:Q (Hecc:Qcon and Hcon:Qecc), and sit-and-reach hamstring/trunk flexibility. On 2 separate days, RE was measured on a treadmill at 1% grade at 2 velocities (160.9 and 201.2 m·min-1) for 6 minutes each, and isokinetic knee strength was measured at 3 angular velocities (60, 120, and 180°·s-1) for both concentric and eccentric muscle actions. The unpaired t-tests showed a consistent trend toward higher f-H:Q ratios at all angular velocities among the HT runners. Highly trained runners had significantly higher Hecc:Qcon at 120°·s-1 (p ≤ 0.05) and 180°·s-1 (p ≤ 0.05). Whole group correlations demonstrated a significant correlation between Hcon:Qecc at 180°·s-1 and RE (ml·kg-1·km-1) at 201.2 m·min-1 (R = -0.48, p ≤ 0.05). No significant relationships were found between flexibility, or hamstring and quadriceps peak torque (N·m) and RE (p > 0.05). This cross-sectional analysis suggests that higher f-H:Q torque ratios, and not muscle strength per se, are associated with a lower metabolic cost of running. Therefore, runners should consider implementing hamstring exercises to improve their f-H:Q ratios.

Current Progress in Sports Genomics

Understanding the genetic architecture of athletic performance is an important step in the development of methods for talent identification in sport. Research concerned with molecular predictors has highlighted a number of potentially important DNA polymorphisms contributing to predisposition to success in certain types of sport. This review summarizes the evidence and mechanistic insights on the associations between DNA polymorphisms and athletic performance. A literature search (period: 1997-2014) revealed that at least 120 genetic markers are linked to elite athlete status (77 endurance-related genetic markers and 43 power/strength-related genetic markers). Notably, 11 (9%) of these genetic markers (endurance markers: ACE I, ACTN3 577X, PPARA rs4253778 G, PPARGC1A Gly482; power/strength markers: ACE D, ACTN3 Arg577, AMPD1 Gln12, HIF1A 582Ser, MTHFR rs1801131 C, NOS3 rs2070744 T, PPARG 12Ala) have shown positive associations with athlete status in three or more studies, and six markers (CREM rs1531550 A, DMD rs939787 T, GALNT13 rs10196189 G, NFIA-AS1 rs1572312 C, RBFOX1 rs7191721 G, TSHR rs7144481 C) were identified after performing genome-wide association studies (GWAS) of African-American, Jamaican, Japanese, and Russian athletes. On the other hand, the significance of 29 (24%) markers was not replicated in at least one study. Future research including multicenter GWAS, whole-genome sequencing, epigenetic, transcriptomic, proteomic, and metabolomic profiling and performing meta-analyses in large cohorts of athletes is needed before these findings can be extended to practice in sport.

The Variants Within the COL5A1 Gene are Associated with Reduced Risk of Anterior Cruciate Ligament Injury in Skiers

The purpose of this study was to examine the association of the BstUI RFLP C/T (rs 12722) and DpnII RFLP C/T (rs 13946) COL5A1 polymorphisms, individually and as haplotypes, with anterior cruciate ligament ruptures in recreational skiers. Subjects were 138 male recreational skiers with surgically diagnosed primary anterior cruciate ligament ruptures. The control group consisted of 183 apparently healthy male recreational skiers, who were without any self-reported history of ligament or tendon injury. DNA was extracted from buccal cells donated by the subjects and genotyping was carried out using real-time PCR. The genotype distributions for both polymorphisms met Hardy-Weinberg expectations in both groups. There were no significant differences in genotype distribution of allele frequencies of COL5A1 BstUI RFLP C/T and COL5A1 DpnII RFLP C/T polymorphisms between the ACL rupture and control groups. The T-T (BstUI RFLP T, DpnII RFLP T) haplotype was the most common (55.6%). The haplotype T-C was not present in any of the subjects. There was an underrepresentation tendency of the C-T haplotype in the study group compared to controls under recessive mode of inheritance. Higher frequency of the COL5A1 BstUI RFLP C/T and COL5A1DpnII RFLP C/T polymorphisms haplotype is associated with reduced risk of anterior cruciate ligament injury in a group of apparently healthy male recreational skiers.

Manganese superoxide dismutase and oxidative stress modulation

Oxidative stress is characterized by imbalanced reactive oxygen species (ROS) production and antioxidant defenses. Two main antioxidant systems exist. The nonenzymatic system relies on molecules to directly quench ROS and the enzymatic system is composed of specific enzymes that detoxify ROS. Among the latter, the superoxide dismutase (SOD) family is important in oxidative stress modulation. Of these, manganese-dependent SOD (MnSOD) plays a major role due to its mitochondrial location, i.e., the main site of superoxide (O(2)(·-)) production. As such, extensive research has focused on its capacity to modulate oxidative stress. Early data demonstrated the relevance of MnSOD as an O(2)(·-) scavenger. More recent research has, however, identified a prominent role for MnSOD in carcinogenesis. In addition, SOD downregulation appears associated with health risk in heart and brain. A single nucleotide polymorphism which alters the mitochondria signaling sequence for the cytosolic MnSOD form has been identified. Transport into the mitochondria was differentially affected by allelic presence and a new chapter in MnSOD research thus begun. As a result, an ever-increasing number of diseases appear associated with this allelic variation including metabolic and cardiovascular disease. Although diet and exercise upregulate MnSOD, the relationship between environmental and genetic factors remains unclear.

Is the COL5A1 rs12722 gene polymorphism associated with running economy?

The COL5A1 rs12722 polymorphism is considered to be a novel genetic marker for endurance running performance. It has been postulated that COL5A1 rs12722 may influence the elasticity of tendons and the energetic cost of running. To date, there are no experimental data in the literature supporting the relationship between range of motion, running economy, and the COL5A1 rs12722 gene polymorphism. Therefore, the main purpose of the current study was to analyze the influence of the COL5A1rs12722 polymorphism on running economy and range of motion. One hundred and fifty (n = 150) physically active young men performed the following tests: a) a maximal incremental treadmill test, b) two constant-speed running tests (10 km•h⁻¹ and 12 km•h⁻¹) to determine the running economy, and c) a sit-and-reach test to determine the range of motion. All of the subjects were genotyped for the COL5A1 rs12722 single-nucleotide polymorphism. The genotype frequencies were TT = 27.9%, CT = 55.8%, and CC = 16.3%. There were no significant differences between COL5A1 genotypes for running economy measured at 10 km•h⁻¹ (p = 0.232) and 12 km•h⁻¹ (p = 0.259). Similarly, there were no significant differences between COL5A1 genotypes for range of motion (p = 0.337). These findings suggest that the previous relationship reported between COL5A1 rs12722 genotypes and running endurance performance might not be mediated by the energetic cost of running.

A Polymorphism in a Functional Region of the COL5A1 Gene: Association With Ultraendurance-Running Performance and Joint Range of Motion

Purpose:

Endurance-running performance and joint range of motion (ROM) are both multifactorial phenotypes. A single-nucleotide polymorphism, rs172722 (C/T), in the COL5A1 3′-untranslated region (UTR) was shown to independently associate with both phenotypes. Two major functional forms of the COL5A1 3′-UTR have been identified and differ by 7 tightly linked polymorphisms that include rs12722 and a short tandem-repeat polymorphism (STRP rs71746744, –/AGGG). It has been proposed that STRP rs71746744 plays a role in the predicted secondary structures and mRNA stability of the 2 major forms of the COL5A1 3′-UTR, therefore implying a regulatory role. The aim of this study was to determine whether STRP rs71746744 is independently associated with running performance and prerace sit-and-reach range of motion (SR ROM) in a cohort of ultramarathon road runners.

Methods:

One hundred six (74 men and 32 women, age 22–67 y) white runners who participated in either the 2009 or 2011 Two Oceans 56-km ultramarathon were included in this cross-sectional study. Their SR ROM measurements, COL5A1 rs71746744 genotype, and overall race times were determined.

Results:

COL5A1 rs71746744 was independently associated with running performance (P = .024) and prerace sr rom (P = .020). Moreover, the AGGG/AGGG genotype was significantly overrepresented in the fastest and inflexible athletes compared with those with either the –/AGGG or –/– genotype.

Conclusions:

These findings provide further evidence for a relationship between COL5A1, running performance, and SR ROM. Further studies are needed to investigate the effect of this variant on the mechanical properties of connective tissue.

Polymorphisms within the COL5A1 3'-UTR that alters mRNA structure and the MIR608 gene are associated with Achilles tendinopathy

COL5A1 encodes for the α1 chain of type V collagen, an important regulator of fibril assembly in tendons, ligaments and other connective tissues. A polymorphism (rs12722) within the functional COL5A1 3'-untranslated region (UTR) has been shown to associate with chronic Achilles tendinopathy and other exercise-related phenotypes. The COL5A1 3'-UTR contains several putative cis-acting elements including a functional Hsa-miR-608 binding site. The aim of this study was to determine whether previously uncharacterized polymorphisms within a functional region of the COL5A1 3'-UTR or the MIR608 gene are associated with chronic Achilles tendinopathy. The effect of these COL5A1 3'-UTR polymorphisms on the 3'-UTR predicted mRNA secondary structure was also investigated. One hundred and sixty Caucasian chronic Achilles tendinopathic and 342 control participants were genotyped for the COL5A1 3'-UTR markers rs71746744, rs16399 and rs1134170, as well as marker rs4919510 within MIR608. All four genetic markers were independently associated with chronic Achilles tendinopathy. The COL5A1 polymorphisms appear to alter the predicted secondary structure of the 3'-UTR. We propose that the secondary structure plays a role in the regulation of the COL5A1 mRNA stability and by implication type V collagen production.

Collagen genes and exercise-associated muscle cramping

OBJECTIVE

The authors hypothesized that variants within genes, such as COL5A1, COL3A1, COL6A1, and COL12A1, that code for connective tissue components of the musculoskeletal system may modulate susceptibility to exercise-associated muscle cramping (EAMC). Specifically, the aim of this study was to investigate if the COL5A1 rs12722 (C/T), COL3A1 rs1800255 (G/A), COL6A1 rs35796750 (T/C), and COL12A1 rs970547 (A/G) polymorphisms are associated with a history of EAMC.

DESIGN

Retrospective genetic case-control association study.

SETTING

Participants were recruited at triathlon and ultra-marathon events and were asked to report physical activity, medical history, and cramping history.

PARTICIPANTS

One hundred sixteen participants with self-reported history of EAMC within the past 12 months before an ultra-endurance event were included as cases in this study (EAMC group). One hundred fifty participants with no self-reported history of previous (lifelong) EAMC were included as controls (NON group).

INTERVENTIONS

All participants were genotyped for the selected variants.

MAIN OUTCOME MEASURES

Differences in genotype frequency distributions, for COL5A1 rs12722, COL3A1 rs1800255, COL6A1 rs35796750, and COL12A1 rs970547, among the cases and controls.

RESULTS

The COL5A1 CC genotype was significantly overrepresented (P = 0.031) among the NON group (21.8%) when compared with the EAMC group (11.1%). No significant genotype differences were found for the COL3A1 (P = 0.828), COL6A1 (P = 0.300), or COL12A1 (P = 0.120) genotypes between the EAMC and NON groups.

CONCLUSIONS

This study identified, for the first time, the COL5A1 gene as a potential marker for a history of EAMC.

No association between COL3A1, COL6A1 or COL12A1 gene variants and range of motion

Approximately 64-70% of the variability in joint range of motion (ROM) is heritable. A common variant within a type V collagen (COL5A1) gene is associated with joint range of motion. Like type V collagen, types III, VI and XII collagen are also involved in fibril assembly and/or diameter regulation. Mutations within the genes that encode these proteins, COL3A1, COL6A1 and COL12A1, also cause connective tissue hypermobility disorders and phenotypes. The aim of this study was to determine if variants within these genes are associated with measures of joint range of motion. Three hundred and fifty apparently healthy and physically active Caucasian participants were recruited. Anthropometric measurements were taken. Sit-and-reach (SR), straight leg raise (SLR) and total shoulder rotation (ShTR) range of motion were measured. All participants were genotyped for COL3A1 rs1800255, COL6A1 rs35796750 and COL12A1 rs970547. COL3A1 rs1800255, COL6A1 rs35796750 and COL12A1 rs970547 were not significantly associated with sit-and-reach, straight leg raise or total shoulder rotation range of motion. Furthermore, no significant age-genotype interaction effects were identified between the variants and range of motion measurements. None of the variants investigated in this study were significantly associated with any of the measures of range of motion used. Further studies are required to identify additional intrinsic and extrinsic factors that may determine range of motion, including the genetic component.

The COL5A1 Gene, Ultra-Marathon Running Performance, and Range of Motion

Purpose:

Endurance running performance is a multifactorial phenotype that is strongly associated with running economy. Sit and reach range of motion (SR ROM) is negatively associated with running economy, suggesting that reduced SR ROM is advantageous for endurance running performance. The COL5A1 gene has been associated with both endurance running performance and SR ROM in separate cohorts. The aim of this study was to investigate whether COL5A1 is associated with ultra-marathon running performance and whether this relationship could be partly explained by prerace SR ROM.

Methods:

Seventy-two runners (52 male, 20 female) were recruited from the 56 km Two Oceans ultra-marathon and were assessed for prerace SR ROM. The cohort was genotyped for the COL5A1 BsfUI restriction fragment length polymorphism, and race times were collected after the event.

Results:

Participants with a TT genotype (341 ± 41 min, N = 21) completed the 56 km Two Oceans ultra-marathon significantly (P = 0.014) faster than participants with TC and CC genotypes (365 ± 39 min, N = 50). The COL5A1 genotype and age accounted for 19% of performance variance. When the cohort was divided into performance and flexibility quadrants, the T allele was significantly (P = 0.044) over-represented within the fast and inflexible quadrant.

Conclusion:

The COL5A1 genotype was found to be significantly associated with performance in a 56 km ultra-endurance run. This study confirms previous findings and it furthers our understanding of the relationships among ROM, COL5A1, and endurance running performance. We continue to speculate that the COL5A1 gene alters muscle-tendon stiffness.