ECSS Paris 2023: OP-PN06
INTRODUCTION: The aim of the study was to conduct a genome-wide association study (GWAS) against measures of human performance in a discovery cohort, and subsequently develop and test a total genotype score (TGS) made out of only significantly associated gene markers in a validation cohort. METHODS: A total of 51,123 individuals participated in the UK Biobank study were split into a discovery (34,046 individuals) and a validation (17,077 individuals) cohort. Then a GWAS was performed in the discovery cohort for three main outcomes of interest, including handgrip strength (HGS), maximum aerobic power (MAP) and their composite score that was named total fitness score (TFS). Associated SNPs were used to create weighted total genotype scores (TGS) and were then grouped into tertiles into high, medium, and low TGS groups. Subsequently, a one-way ANCOVA was performed to examine associations between TGS and the main outcomes of interest. RESULTS: No individual SNPs were associated with any of the main outcomes at the genome wide significance level. However, when examining less stringent p value thresholds we identified new SNPs associated with HGS (rs6087577, rs6059844, and rs6060003). TGS created with SNPs associated with performance when examining higher p value thresholds showed mixed results. However, a higher TGS made up by SNPs associated with HGS in the discovery cohort was associated with better HGS and TFS performance in the validation cohort. CONCLUSION: In summary, we identified novel SNPs to be associated with HGS at nominal p significance level but no SNPs reached genome-wide significance. Only TGS created by SNPs associated with HGS showed great consistency, where individuals with higher TGS have a higher TFS and HGS performance.
Read CV Maria GrammenouECSS Paris 2023: OP-PN06
INTRODUCTION: The higher demands of the basketball game expose the athletes to some high injury risk situations. Gene variation is known to predispose athletes to injury, but also the epigenetic role has only recently been discovered. ACTN3 gene alteration has been related with deficiency in functional α-actinin-3, a key component of the skeletal muscle fast-twitch fibers. Although no single study has investigated the relationship between DNA methylation on ACTN3 gene with injury risk in basketball. The aims of the present study were (1) to compare the percentage of methylation of each ACTN3 CpG site between injured and non-injured players and (2) to investigate the relationship between the ACTN3 methylation and time-loss due to sport injuries. METHODS: The sample included 57 young basketball players from 12 to 18 years old. The players were recruited from the youth teams of Bàsquet Girona club and performed three ninety-minute training sessions and a game per week. The experimental design of the DNA methylation study included a pre-test and a post-test assessment of salivary samples. The Illumina Methylation Epic Array v2.0 (Illumina) was used to analyse methylation status of 25 CpG sites within the ACTN3 gene. Injuries occurring throughout this period were recorded following the protocol outlined in the International Olympic Committee consensus and the OSICS classification system. An independent sample t-test was used to compare the percentage of methylation of each ACTN3 CpG site between the injured and non-injured players. In the case of a not normal distribution, a Mann-Whitney test was used. The significance level was set at p < 0.05 and Cohens d was used to evaluate the effect size (values for d of ≤0.2, ≤0.5, and ≥0.8 are considered as small, medium, and large, respectively). Finally, Spearman’s Rho correlation analysis was used to assess the relationship between methylation levels and time-loss. The protocol was approved by the ethics committee. RESULTS: Significant differences in the percentage of DNA methylation levels between non-injured and injured basketball players were found at three CpG probes within the ACTN3 gene. Before the injury, the injured group showed hypomethylation on the cg20608119 probe (p = 0.004, d = -0.912, large differences) while after the injury, hypomethylation on the cg10523820 (p = 0.004, d = -0.923, large differences) and hypermethylation on the cg18257026 (p = 0.042, d = 0.362, medium differences) probes were seen. No significant relationship between pre-test methylation levels and time-loss were found. In contrast, at the post-test assessment a significant negative relationship between methylation levels and time-loss was found in cg10523820 (r = -0.416, p = 0.001). CONCLUSION: Our preliminary data suggests that DNA methylation levels in ACTN3 differs between injured and non-injured young basketball players. Those epigenetic alterations seem to indicate that hypomethylation in ACTN3 could be related with more time-loss.
Read CV Anna Jòdar-PortasECSS Paris 2023: OP-PN06
INTRODUCTION: The increase in postprandial amino acid availability in the skeletal muscle cell facilitates muscle protein synthesis and is dependent on transmembrane-bound amino acid transporters (AAT) transporting amino acids from the blood into the cell. Dysfunctional AATs may be involved in the reduced muscle protein synthetic response to protein intake, termed anabolic resistance, in older and sedentary adults. We have previously shown, using Western blot analyses, that older, compared to younger adults, had lower cytosolic protein expression of the L-type amino acid transporter 1 (LAT1) in the untrained state (p<0.05) and that this difference was abolished after 12-weeks of strength training. Resistance training can increase the uptake of amino acids into the cell and may normalize the anabolic resistance of aging. The purpose of this study was therefore to investigate the peripheral localization of LAT1, which facilitates the uptake of essential amino acids, in type I and type II muscle fibers in young and older adults, before and after 12-weeks of strength training. METHODS: Healthy young (n=24, 20-40 yrs) and older (n=24, 70-80 yrs) adults completed a 12-week whole-body strength training intervention (3 sessions/week). Before and after the intervention, leg lean mass (LLM) was measured by dual-energy X-ray absorptiometry and strength was tested by leg press as one repetition maximum (1RM). Muscle biopsies were obtained from m. vastus lateralis and sectioned. Immunofluorescent analyses were performed for 16 young and 16 older participants, with the membrane as region of interest for LAT1 protein in type I and type II fibers. Data were analyzed for LAT1 protein in type I, type II and type I+type II combined (total LAT1) using two-way ANOVA for comparisons between time and age group and t-test was used to compare the relative changes between young and old and between relative fiber-specific changes in each group. RESULTS: Training increased LLM by ~1 kg in both groups (p<0.001). 1RM leg press increased more in the young than old (78±32 kg vs. 50±20 kg, p<0.001). An age effect (p<0.05) was found for total LAT1 protein as well as tendencies for age effects for fiber-specific LAT1 protein (type I: p=0.054, type II: p=0.067). Compared with the young, total LAT1 protein was higher in older participants. There was no effect of training on total LAT1 protein (young and old: p>0.999) or type I (young: p=0.776, old: p=0.853) or type II (young and old: p>0.999) fiber-specific LAT1 protein. CONCLUSION: Strength training increased muscle mass and strength but did not affect membrane LAT1 protein regardless of age. The greater total LAT1 protein at the periphery of skeletal muscle in older adults is consistent with previous Western blot analysis by our group and could be related to a compensatory mechanism for anabolic resistance. Future research should determine the biological impact of differential total and transmembrane-bound LAT1 on transport activity and anabolism in human skeletal muscle.
Read CV Elise LanderECSS Paris 2023: OP-PN06