Acute exercise leads to regulation of Telomere-Associated genes and MicroRNA expression in immune Cells
- Chilton, Warrick, Marques, Francine, West, Jenny, Kannourakis, George, Berzins, Stuart, O'Brien, Brendan, Charchar, Fadi
- 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
- Full Text:
- Reviewed:
- 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
- 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
- Full Text:
- Reviewed:
- 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
The acute effects of aerobic exercise on Leukocyte Telomere biology
- Authors: Chilton, Warrick
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Doctor of Philosophy
- Description: Habitual exercise is unequivocally associated with decreased all-cause mortality and morbidity. Despite the strength of the association, a large part of the decreased risk is physiologically unaccounted for. Accumulating evidence indicates that leukocyte telomere length (LTL) may be one such explanatory mechanism. Telomeres are specialized deoxyribonucleic acid (DNA) sequences located at chromosomal ends where they protect the genomic DNA from enzymatic degradation. Excessive and/or premature telomere shortening in leukocytes is associated with a host of chronic diseases and impaired immune function. Observational associations exist between LTL and habitual physical activity/exercise in multiple cohorts. However, correlation does not imply causal story and the underpinning mechanisms behind the association are unclear. The current consensus is that long-term exercise-induced reductions in oxidative stress and inflammation mediate the association. The acute dynamics of telomere biology are poorly understood; however, a growing body of evidence suggests that telomeres may be amenable to acute modulation via expression of telomereassociated genes and microRNAs. Accordingly, the overarching aim of this thesis was to characterize the acute effects of aerobic exercise on leukocyte telomere biology.
- Authors: Chilton, Warrick
- Date: 2018
- Type: Text , Thesis , PhD
- Full Text:
- Description: Doctor of Philosophy
- Description: Habitual exercise is unequivocally associated with decreased all-cause mortality and morbidity. Despite the strength of the association, a large part of the decreased risk is physiologically unaccounted for. Accumulating evidence indicates that leukocyte telomere length (LTL) may be one such explanatory mechanism. Telomeres are specialized deoxyribonucleic acid (DNA) sequences located at chromosomal ends where they protect the genomic DNA from enzymatic degradation. Excessive and/or premature telomere shortening in leukocytes is associated with a host of chronic diseases and impaired immune function. Observational associations exist between LTL and habitual physical activity/exercise in multiple cohorts. However, correlation does not imply causal story and the underpinning mechanisms behind the association are unclear. The current consensus is that long-term exercise-induced reductions in oxidative stress and inflammation mediate the association. The acute dynamics of telomere biology are poorly understood; however, a growing body of evidence suggests that telomeres may be amenable to acute modulation via expression of telomereassociated genes and microRNAs. Accordingly, the overarching aim of this thesis was to characterize the acute effects of aerobic exercise on leukocyte telomere biology.
Telomeres, aging and exercise : Guilty by association?
- Chilton, Warrick, O’Brien, Brendan, Charchar, Fadi
- Authors: Chilton, Warrick , O’Brien, Brendan , Charchar, Fadi
- Date: 2017
- Type: Text , Journal article , Review
- Relation: International Journal of Molecular Sciences Vol. 18, no. 12 (2017), p. 1-32
- Full Text:
- Reviewed:
- Description: Telomeres are repetitive tandem DNA sequences that cap chromosomal ends protecting genomic DNA from enzymatic degradation. Telomeres progressively shorten with cellular replication and are therefore assumed to correlate with biological and chronological age. An expanding body of evidence suggests (i) a predictable inverse association between telomere length, aging and age-related diseases and (ii) a positive association between physical activity and telomere length. Both hypotheses have garnered tremendous research attention and broad consensus; however, the evidence for each proposition is inconsistent and equivocal at best. Telomere length does not meet the basic criteria for an aging biomarker and at least 50% of key studies fail to find associations with physical activity. In this review, we address the evidence in support and refutation of the putative associations between telomere length, aging and physical activity. We finish with a brief review of plausible mechanisms and potential future research directions. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.
- Authors: Chilton, Warrick , O’Brien, Brendan , Charchar, Fadi
- Date: 2017
- Type: Text , Journal article , Review
- Relation: International Journal of Molecular Sciences Vol. 18, no. 12 (2017), p. 1-32
- Full Text:
- Reviewed:
- Description: Telomeres are repetitive tandem DNA sequences that cap chromosomal ends protecting genomic DNA from enzymatic degradation. Telomeres progressively shorten with cellular replication and are therefore assumed to correlate with biological and chronological age. An expanding body of evidence suggests (i) a predictable inverse association between telomere length, aging and age-related diseases and (ii) a positive association between physical activity and telomere length. Both hypotheses have garnered tremendous research attention and broad consensus; however, the evidence for each proposition is inconsistent and equivocal at best. Telomere length does not meet the basic criteria for an aging biomarker and at least 50% of key studies fail to find associations with physical activity. In this review, we address the evidence in support and refutation of the putative associations between telomere length, aging and physical activity. We finish with a brief review of plausible mechanisms and potential future research directions. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.
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