Longer leukocyte telomeres are associated with ultra-endurance exercise independent of cardiovascular risk factors
- Authors: Denham, Joshua , Nelson, Christopher , O'Brien, Brendan , Nankervis, Scott , Denniff, Matthew , Harvey, Jack , Marques, Francine , Codd, Veryan , Zukowska-Szczechowska, Ewa , Samani, Nilesh , Tomaszewski, Maciej , Charchar, Fadi
- Date: 2013
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 8, no. 7 (2013), p.
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- Description: Telomere length is recognized as a marker of biological age, and shorter mean leukocyte telomere length is associated with increased risk of cardiovascular disease. It is unclear whether repeated exposure to ultra-endurance aerobic exercise is beneficial or detrimental in the long-term and whether it attenuates biological aging. We quantified 67 ultra-marathon runners' and 56 apparently healthy males' leukocyte telomere length (T/S ratio) using real-time quantitative PCR. The ultra-marathon runners had 11% longer telomeres (T/S ratio) than controls (ultra-marathon runners: T/S ratio = 3.5±0.68, controls: T/S ratio = 3.1±0.41;
- Description: 2003011219
Acute exercise leads to regulation of Telomere-Associated genes and MicroRNA expression in immune Cells
- Authors: Chilton, Warrick , Marques, Francine , West, Jenny , Kannourakis, George , Berzins, Stuart , O'Brien, Brendan , Charchar, Fadi
- Date: 2014
- Type: Text , Journal article
- Relation: PloS One Vol. 9, no. 4 (2014), p. e92088
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- Description: Telomeres are specialized nucleoprotein structures that protect chromosomal ends from degradation. These structures progressively shorten during cellular division and can signal replicative senescence below a critical length. Telomere length is predominantly maintained by the enzyme telomerase. Significant decreases in telomere length and telomerase activity are associated with a host of chronic diseases; conversely their maintenance underpins the optimal function of the adaptive immune system. Habitual physical activity is associated with longer leukocyte telomere length; however, the precise mechanisms are unclear. Potential hypotheses include regulation of telomeric gene transcription and/or microRNAs (miRNAs). We investigated the acute exercise-induced response of telomeric genes and miRNAs in twenty-two healthy males (mean age = 24.1±1.55 years). Participants undertook 30 minutes of treadmill running at 80% of peak oxygen uptake. Blood samples were taken before exercise, immediately post-exercise and 60 minutes post-exercise. Total RNA from white blood cells was submitted to miRNA arrays and telomere extension mRNA array. Results were individually validated in white blood cells and sorted T cell lymphocyte subsets using quantitative real-time PCR (qPCR). Telomerase reverse transcriptase (TERT) mRNA (P = 0.001) and sirtuin-6 (SIRT6) (P<0.05) mRNA expression were upregulated in white blood cells after exercise. Fifty-six miRNAs were also differentially regulated post-exercise (FDR <0.05). In silico analysis identified four miRNAs (miR-186, miR-181, miR-15a and miR-96) that potentially targeted telomeric gene mRNA. The four miRNAs exhibited significant upregulation 60 minutes post-exercise (P<0.001). Telomeric repeat binding factor 2, interacting protein (TERF2IP) was identified as a potential binding target for miR-186 and miR-96 and demonstrated concomitant downregulation (P<0.01) at the corresponding time point. Intense cardiorespiratory exercise was sufficient to differentially regulate key telomeric genes and miRNAs in white blood cells. These results may provide a mechanistic insight into telomere homeostasis and improved immune function and physical health. Funding NHMRC
Exercise : Putting action into our epigenome
- Authors: Denham, Joshua , Marques, Francine , O'Brien, Brendan , Charchar, Fadi
- Date: 2014
- Type: Text , Journal article
- Relation: Sports Medicine Vol. 44, no. 2 (2014), p. 189-209
- Relation: http://purl.org/au-research/grants/nhmrc/1009490
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- Description: Most human phenotypes are influenced by a combination of genomic and environmental factors. Engaging in regular physical exercise prevents many chronic diseases, decreases mortality risk and increases longevity. However, the mechanisms involved are poorly understood. The modulating effect of physical (aerobic and resistance) exercise on gene expression has been known for some time now and has provided us with an understanding of the biological responses to physical exercise. Emerging research data suggest that epigenetic modifications are extremely important for both development and disease in humans. In the current review, we summarise findings on the effect of exercise on epigenetic modifications and their effects on gene expression. Current research data suggest epigenetic modifications (DNA methylation and histone acetylation) and microRNAs (miRNAs) are responsive to acute aerobic and resistance exercise in brain, blood, skeletal and cardiac muscle, adipose tissue and even buccal cells. Six months of aerobic exercise alters whole-genome DNA methylation in skeletal muscle and adipose tissue and directly influences lipogenesis. Some miRNAs are related to maximal oxygen consumption (VO 2max) and VO2max trainability, and are differentially expressed amongst individuals with high and low VO2max. Remarkably, miRNA expression profiles discriminate between low and high responders to resistance exercise (miR-378, -26a, -29a and -451) and correlate to gains in lean body mass (miR-378). The emerging field of exercise epigenomics is expected to prosper and additional studies may elucidate the clinical relevance of miRNAs and epigenetic modifications, and delineate mechanisms by which exercise confers a healthier phenotype and improves performance. © 2013 Springer International Publishing Switzerland. Funded by NHMRC; National Health and Medical Research Council
Changes in the leukocyte methylome and its effect on cardiovascular-related genes after exercise
- Authors: Denham, Joshua , O'Brien, Brendan , Marques, Francine , Charchar, Fadi
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Applied Physiology Vol. 118, no. 4 (2015), p. 475-488
- Relation: http://purl.org/au-research/grants/nhmrc/1009490
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- Description: Physical exercise has proven cardiovascular benefits, yet there is no clear understanding of the related molecular mechanisms leading to this. Here we determined the beneficial epigenetic effects of exercise after sprint interval training, a form of exercise known to improve cardiometabolic health. We quantified genome-wide leukocyte DNA methylation of 12 healthy young (18-24 yr) men before and after 4 wk (thrice weekly) of sprint interval training using the 450K BeadChip (Illumina) and validated gene expression changes in an extra seven subjects. Exercise increased subjects' cardiorespiratory fitness and maximal running performance, and decreased low-density lipoprotein cholesterol concentration in conjunction with genome-wide DNA methylation changes. Notably, many CpG island and gene promoter regions were demethylated after exercise, indicating increased genome-wide transcriptional changes. Among genes with DNA methylation changes, epidermal growth factor (EGF), a ligand of the epidermal growth factor receptor known to be involved in cardiovascular disease, was demethylated and showed decreased mRNA expression. Additionally, we found that in microRNAs miR-21 and miR-210, gene DNA methylation was altered by exercise causing a cascade effect on the expression of the mature microRNA involved in cardiovascular function. Our findings demonstrate that exercise alters DNA methylation in circulating blood cells in microRNA and protein-coding genes associated with cardiovascular physiology. Copyright © 2015 the American Physiological Society
The acute effects of intense cardiorespiratory exercise on human telomerase reverse transcriptase and sirtuin 6 expression in white blood cells
- Authors: Chilton, Warrick , Marques, Francine , O'Brien, Brendan , Charchar, Fadi
- Date: 2012
- Type: Text , Journal article
- Relation: Journal of Hypertension Vol. 30, no. e-Supplement (September 2012), p. e49
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- Description: Background: Compelling epidemiological data demonstrates that regular physical exercise reduces cardiovascular mortality. Telomeres are specialised DNA structures located at the end of linear chromosomes where they protect them from degradation during DNA replication. Telomerase reverse transcriptase (TERT) expression is essential for telomere length maintenance. Accelerated telomere shortening is associated with increased risk of cardiovascular disease (CVD). Sirtuin 6 (SIRT6) is associated with increased longevity and protection against cardiac hypertrophy. Importantly, SIRT6 maintains genomic stability by specifically associating with telomeric chromatin. We hypothesized that acute cardiorespiratory exercise will affect the immediate expression of TERT and SIRT6. Methods: Twenty four healthy adults (19-39 years old) undertook 30 minutes of continuous treadmill running at 80% of maximal oxygen uptake (VO2max). Blood samples were taken before and immediately after exercise. Total RNA was extracted from white blood cells using TRIzol(R) LS reagent. TERT and SIRT6 mRNA expression were measured by real-time PCR. Results: There was no difference in TERT (P = 0.13) and SIRT6 (P = 0.73) mRNA levels immediately after acute cardiorespiratory exercise. Resting TERT levels, however, were negatively correlated with body mass index (BMI) (P = 0.03), waist to hip ratio (P = 0.01) and diastolic blood pressure (BP) (P = 0.05), while a marginal negative correlation was observed with systolic BP (P = 0.07). Conclusions: The results indicate that intense cardiorespiratory exercise does not result in acute modulation of TERT and SIRT6 mRNA. The negative correlations between BP, BMI, waist to hip ratio and TERT levels may provide a mechanistic insight into the established negative correlations between telomere length, hypertension and obesity.
- Description: C1
Telomeres, exercise and cardiovascular disease : Finding the means to justify the ends
- Authors: Chilton, Warrick , O'Brien, Brendan , Grace, Fergal , Charchar, Fadi
- Date: 2017
- Type: Text , Journal article
- Relation: Acta Physiologica Vol. 220, no. 2 (2017), p. 186-188
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Genome-wide sperm DNA methylation changes after 3 months of exercise training in humans
- Authors: Denham, Joshua , O'Brien, Brendan , Harvey, Jack , Charchar, Fadi
- Date: 2015
- Type: Text , Journal article
- Relation: Epigenomics Vol. 7, no. 5 (2015), p. 717-731
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- Description: Aim: DNA methylation programs gene expression and is involved in numerous biological processes. Accumulating evidence supports transgenerational inheritance of DNA methylation changes in mammals via germ cells. Our aim was to determine the effect of exercise on sperm DNA methylation. Materials & methods: Twenty-four men were recruited and assigned to an exercise intervention or control group. Clinical parameters were measured and sperm samples were donated by subjects before and after the 3-month time-period. Mature sperm global and genome-wide DNA methylation was assessed using an ELISA assay and the 450K BeadChip (Illumina). Results: Global and genome-wide sperm DNA methylation was altered after 3 months of exercise training. DNA methylation changes occurred in genes related to numerous diseases such as schizophrenia and Parkinson's disease. Conclusions: Our study provides the first evidence showing exercise training reprograms the sperm methylome. Whether these DNA methylation changes are inherited to future generations warrants attention.
Increased expression of telomere-regulating genes in endurance athletes with long leukocyte telomeres
- Authors: Denham, Joshua , O'Brien, Brendan , Prestes, Priscilla , Brown, Nicholas , Charchar, Fadi
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Applied Physiology Vol. 120, no. 2 (2015), p. 148-158
- Relation: http://purl.org/au-research/grants/nhmrc/1009490
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- Description: Leukocyte telomeres shorten with age, and excessive shortening is associated with age-related cardiometabolic diseases. Exercise training may prevent disease through telomere length maintenance although the optimal amount of exercise that attenuates telomere attrition is unknown. Furthermore, the underlying molecular mechanisms responsible for the enhanced telomere maintenance observed in endurance athletes is poorly understood. We quantified the leukocyte telomere length and analyzed the expression of telomere-regulating genes in endurance athletes and healthy controls (both n = 61), using quantitative PCR. We found endurance athletes have significantly longer (7.1%, 208-416 nt) leukocyte telomeres and upregulated TERT (2.0-fold) and TPP1 (1.3-fold) mRNA expression compared with controls in age-adjusted analysis. The telomere length and telomere-regulating gene expression differences were no longer statistically significant after adjustment for resting heart rate and relative (V) over dotO(2 max) (all P > 0.05). Resting heart rate emerged as an independent predictor of leukocyte telomere length and TERT and TPP1 mRNA expression in stepwise regression models. To gauge whether volume of exercise was associated with leukocyte telomere length, we divided subjects into running and cycling tertiles (distance covered per week) and found individuals in the middle and highest tertiles had longer telomeres than individuals in the lowest tertile. These data emphasize the importance of cardiorespiratory fitness and exercise training in the prevention of biological aging. They also support the concept that moderate amounts of exercise training protects against biological aging, while higher amounts may not elicit additional benefits.
Telomere length maintenance and cardio-metabolic disease prevention through exercise training
- Authors: Denham, Joshua , O'Brien, Brendan , Charchar, Fadi
- Date: 2016
- Type: Text , Journal article , Review
- Relation: Sports Medicine Vol. 46, no. 9 (2016), p. 1213-1237
- Relation: http://purl.org/au-research/grants/nhmrc/1009490
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- Description: Telomeres are tandem repeat DNA sequences located at distal ends of chromosomes that protect against genomic DNA degradation and chromosomal instability. Excessive telomere shortening leads to cellular senescence and for this reason telomere length is a marker of biological age. Abnormally short telomeres may culminate in the manifestation of a number of cardio-metabolic diseases. Age-related cardio-metabolic diseases attributable to an inactive lifestyle, such as obesity, type 2 diabetes mellitus and cardiovascular disease, are associated with short leukocyte telomeres. Exercise training prevents and manages the symptoms of many cardio-metabolic diseases whilst concurrently maintaining telomere length. The positive relationship between exercise training, physical fitness and telomere length raises the possibility of a mediating role of telomeres in chronic disease prevention via exercise. Further elucidation of the underpinning molecular mechanisms of how exercise maintains telomere length should provide crucial information on how physical activity can be best structured to combat the chronic disease epidemic and improve the human health span. Here, we synthesise and discuss the current evidence on the impact of physical activity and cardiorespiratory fitness on telomere dynamics. We provide the molecular mechanisms with a known role in exercise-induced telomere length maintenance and highlight unexplored, alternative pathways ripe for future investigations.
Epigenetic changes in leukocytes after 8 weeks of resistance exercise training
- Authors: Denham, Joshua , Marques, Francine , Bruns, Emma , O'Brien, Brendan , Charchar, Fadi
- Date: 2016
- Type: Text , Journal article
- Relation: European Journal of Applied Physiology Vol. 116, no. 6 (2016), p. 1245-1253
- Relation: http://purl.org/au-research/grants/nhmrc/1009490
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- Description: PURPOSE: Regular engagement in resistance exercise training elicits many health benefits including improvement to muscular strength, hypertrophy and insulin sensitivity, though the underpinning molecular mechanisms are poorly understood. The purpose of this study was to determine the influence 8 weeks of resistance exercise training has on leukocyte genome-wide DNA methylation and gene expression in healthy young men. METHODS: Eight young (21.1 +/- 2.2 years) men completed one repetition maximum (1RM) testing before completing 8 weeks of supervised, thrice-weekly resistance exercise training comprising three sets of 8-12 repetitions with a load equivalent to 80 % of 1RM. Blood samples were collected at rest before and after the 8-week training intervention. Genome-wide DNA methylation and gene expression were assessed on isolated leukocyte DNA and RNA using the 450K BeadChip and HumanHT-12 v4 Expression BeadChip (Illumina), respectively. RESULTS: Resistance exercise training significantly improved upper and lower body strength concurrently with diverse genome-wide DNA methylation and gene expression changes (p = 0. 01). DNA methylation changes occurred at multiple regions throughout the genome in context with genes and CpG islands, and in genes relating to axon guidance, diabetes and immune pathways. There were multiple genes with increased expression that were enriched for RNA processing and developmental proteins. Growth factor genes-GHRH and FGF1-showed differential methylation and mRNA expression changes after resistance training. CONCLUSIONS: Our findings indicate that resistance exercise training improves muscular strength and is associated with reprogramming of the leukocyte DNA methylome and transcriptome.