Publications by year
2022
Jameson T, Islam H, Wall B, Little J, Stephens F (2022). Supplementary table 1 for: Oral ketone monoester supplementation does not accelerate recovery of muscle force or modulate circulating cytokine concentrations after muscle damaging eccentric exercise in healthy males and females.
Jameson T, Islam H, Wall B, Little J, Stephens F (2022). Supplementary table 1 for: Oral ketone monoester supplementation does not accelerate recovery of muscle force or modulate circulating cytokine concentrations after muscle damaging eccentric exercise in healthy males and females.
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Jameson T (2022). Supplementary table 1 for: Oral ketone monoester supplementation does not accelerate recovery of muscle force or modulate circulating cytokine concentrations after muscle damaging eccentric exercise in healthy males and females.
2021
Jameson T (2021). Damaging eccentric exercise attenuates disuse induced declines in daily myofibrillar protein synthesis and transiently prevents muscle atrophy in healthy men.
Frankum R, Jameson TSO, Knight BA, Stephens FB, Wall BT, Donlon TA, Torigoe T, Willcox BJ, Willcox DC, Allsopp RC, et al (2021). Extreme longevity variants at the FOXO3 locus may moderate FOXO3 isoform levels.
GeroScience,
44(2), 1129-1140.
Abstract:
Extreme longevity variants at the FOXO3 locus may moderate FOXO3 isoform levels
AbstractThe rs2802292, rs2764264 and rs13217795 variants of FOXO3 have been associated with extreme longevity in multiple human populations, but the mechanisms underpinning this remain unclear. We aimed to characterise potential effects of longevity-associated variation on the expression and mRNA processing of the FOXO3 gene. We performed a comprehensive assessment of FOXO3 isoform usage across a wide variety of human tissues and carried out a bioinformatic analysis of the potential for longevity-associated variants to disrupt regulatory regions involved in isoform choice. We then related the expression of full length and 5′ truncated FOXO3 isoforms to rs13217795 genotype in peripheral blood and skeletal muscle from individuals of different rs13217795 genotypes. FOXO3 isoforms displayed considerable tissue specificity. We determined that rs13231195 and its tightly aligned proxy variant rs9400239 may lie in regulatory regions involved in isoform choice. The longevity allele at rs13217795 was associated with increased levels of full length FOXO3 isoforms in peripheral blood and a decrease in truncated FOXO3 isoforms in skeletal muscle RNA. We suggest that the longevity effect of FOXO3 SNPs may in part derive from a shift in isoform usage in skeletal muscle away from the production of 5′ truncated FOXO3 isoforms lacking a complete forkhead DNA binding domain, which may have compromised functionality.
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Pavis GF, Jameson TSO, Dirks ML, Lee BP, Abdelrahman DR, Murton AJ, Porter C, Alamdari N, Mikus CR, Wall BT, et al (2021). Improved recovery from skeletal muscle damage is largely unexplained by myofibrillar protein synthesis or inflammatory and regenerative gene expression pathways.
Am J Physiol Endocrinol Metab,
320(2), E291-E305.
Abstract:
Improved recovery from skeletal muscle damage is largely unexplained by myofibrillar protein synthesis or inflammatory and regenerative gene expression pathways.
The contribution of myofibrillar protein synthesis (MyoPS) to recovery from skeletal muscle damage in humans is unknown. Recreationally active men and women consumed a daily protein-polyphenol beverage targeted at increasing amino acid availability and reducing inflammation (PPB; n = 9), both known to affect MyoPS, or an isocaloric placebo (PLA; n = 9) during 168 h of recovery from 300 maximal unilateral eccentric contractions (EE). Muscle function was assessed daily. Muscle biopsies were collected for 24, 27, 36, 72, and 168 h for MyoPS measurements using 2H2O and expression of 224 genes using RT-qPCR and pathway analysis. PPB improved recovery of muscle function, which was impaired for 5 days after EE in PLA (interaction P < 0.05). Acute postprandial MyoPS rates were unaffected by nutritional intervention (24-27 h). EE increased overnight (27-36 h) MyoPS versus the control leg (PLA: 33 ± 19%; PPB: 79 ± 25%; leg P < 0.01), and PPB tended to increase this further (interaction P = 0.06). Daily MyoPS rates were greater with PPB between 72 and 168 h after EE, albeit after function had recovered. Inflammatory and regenerative signaling pathways were dramatically upregulated and clustered after EE but were unaffected by nutritional intervention. These results suggest that accelerated recovery from EE is not explained by elevated MyoPS or suppression of inflammation.NEW & NOTEWORTHY the present study investigated the contribution of myofibrillar protein synthesis (MyoPS) and associated gene signaling to recovery from 300 muscle-damaging, eccentric contractions. Measured with 2H2O, MyoPS rates were elevated during recovery and observed alongside expression of inflammatory and regenerative signaling pathways. A nutritional intervention accelerated recovery; however, MyoPS and gene signaling were unchanged compared with placebo. These data indicate that MyoPS and associated signaling do not explain accelerated recovery from muscle damage.
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Jameson TSO, Pavis GF, Dirks ML, Lee BP, Abdelrahman DR, Murton AJ, Porter C, Alamdari N, Mikus CR, Wall BT, et al (2021). Reducing NF-κB Signaling Nutritionally is Associated with Expedited Recovery of Skeletal Muscle Function After Damage.
The Journal of Clinical Endocrinology & Metabolism,
106(7), 2057-2076.
Abstract:
Reducing NF-κB Signaling Nutritionally is Associated with Expedited Recovery of Skeletal Muscle Function After Damage
Abstract
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. Context
. The early events regulating the remodeling program following skeletal muscle damage are poorly understood.
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. Objective
. The objective of this study was to determine the association between myofibrillar protein synthesis (myoPS) and nuclear factor-kappa B (NF-κB) signaling by nutritionally accelerating the recovery of muscle function following damage.
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. Design, Setting, Participants, and Interventions
. Healthy males and females consumed daily postexercise and prebed protein-polyphenol (PP; n = 9; 4 females) or isocaloric maltodextrin placebo (PLA; n = 9; 3 females) drinks (parallel design) 6 days before and 3 days after 300 unilateral eccentric contractions of the quadriceps during complete dietary control.
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. Main Outcome Measures
. Muscle function was assessed daily, and skeletal muscle biopsies were taken after 24, 27, and 36 hours for measurements of myoPS rates using deuterated water, and gene ontology and NF-κB signaling analysis using a quantitative reverse transcription PCR (RT-qPCR) gene array.
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. Results
. Eccentric contractions impaired muscle function for 48 hours in PLA intervention, but just for 24 hours in PP intervention (P = 0.047). Eccentric quadricep contractions increased myoPS compared with the control leg during postexercise (24–27 hours; 0.14 ± 0.01 vs 0.11 ± 0.01%·h-1, respectively; P = 0.075) and overnight periods (27–36 hours; 0.10 ± 0.01 vs 0.07 ± 0.01%·h-1, respectively; P = 0.020), but was not further increased by PP drinks (P &gt; 0.05). Protein-polyphenol drinks decreased postexercise and overnight muscle IL1R1 (PLA = 2.8 ± 0.4, PP = 1.1 ± 0.4 and PLA = 1.9 ± 0.4, PP = 0.3 ± 0.4 log2 fold-change, respectively) and IL1RL1 (PLA = 4.9 ± 0.7, PP = 1.6 ± 0.8 and PLA = 3.7 ± 0.6, PP = 0.7 ± 0.7 log2 fold-change, respectively) messenger RNA expression (P &lt; 0.05) and downstream NF-κB signaling compared with PLA.
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. Conclusion
. Protein-polyphenol drink ingestion likely accelerates recovery of muscle function by attenuating inflammatory NF-κB transcriptional signaling, possibly to reduce aberrant tissue degradation rather than increase myoPS rates.
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Jameson T (2021). Supplementary table 1 for: Damaging eccentric exercise attenuates disuse induced declines in daily myofibrillar protein synthesis and transiently prevents muscle atrophy in healthy men.
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2020
Davenport AD, Jameson TSO, Kilroe SP, Monteyne AJ, Pavis GF, Wall BT, Dirks ML, Alamdari N, Mikus CR, Stephens FB, et al (2020). A Randomised, Placebo-Controlled, Crossover Study Investigating the Optimal Timing of a Caffeine-Containing Supplement for Exercise Performance.
Sports Med Open,
6(1).
Abstract:
A Randomised, Placebo-Controlled, Crossover Study Investigating the Optimal Timing of a Caffeine-Containing Supplement for Exercise Performance.
BACKGROUND: Pre-exercise supplements containing low doses of caffeine improve endurance exercise performance, but the most efficacious time for consumption before intense endurance exercise remains unclear, as does the contribution of caffeine metabolism. METHODS: This study assessed the timing of a commercially available supplement containing 200 mg of caffeine, 1600 mg of β-alanine and 1000 mg of quercetin [Beachbody Performance Energize, Beachbody LLC, USA] on exercise performance, perception of effort and plasma caffeine metabolites. Thirteen cyclists (V̇O2max 64.5 ± 1.4 ml kg- 1 min- 1 (± SEM)) completed four experimental visits consisting of 30 min of steady-state exercise on a cycle ergometer at 83 ± 1% V̇O2max followed by a 15-min time trial, with perceived exertion measured regularly. On three of the visits, participants consumed caffeine either 35 min before steady-state exercise (PRE), at the onset of steady-state (ONS) or immediately before the time trial (DUR) phases, with a placebo consumed at the other two time points (i.e. three drinks per visit). The other visit (PLA) consisted of consuming the placebo supplement at all three time points. The placebo was taste-, colour- and calorie-matched. RESULTS: Total work performed during the time trial in PRE was 5% greater than PLA (3.53 ± 0.14 vs. 3.36 ± 0.13 kJ kg- 1 body mass; P = 0.0025), but not ONS (3.44 ± 0.13 kJ kg- 1; P = 0.3619) or DUR (3.39 ± 0.13 kJ kg- 1; P = 0.925), which were similar to PLA. Perceived exertion was lowest during steady-state exercise in the PRE condition (P
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Monteyne AJ, Coelho MOC, Porter C, Abdelrahman DR, Jameson TSO, Finnigan TJA, Stephens FB, Dirks ML, Wall BT (2020). Branched-Chain Amino Acid Fortification Does Not Restore Muscle Protein Synthesis Rates following Ingestion of Lower- Compared with Higher-Dose Mycoprotein.
J Nutr,
150(11), 2931-2941.
Abstract:
Branched-Chain Amino Acid Fortification Does Not Restore Muscle Protein Synthesis Rates following Ingestion of Lower- Compared with Higher-Dose Mycoprotein.
BACKGROUND: We have shown that ingesting a large bolus (70 g) of the fungal-derived, whole food mycoprotein robustly stimulates muscle protein synthesis (MPS) rates. OBJECTIVE: the aim of this study was to determine if a lower dose (35 g) of mycoprotein enriched with branched-chain amino acids (BCAAs) stimulates MPS to the same extent as 70 g of mycoprotein in resistance-trained young men. METHODS: Nineteen men [aged 22 ± 1 y, BMI (kg/m2): 25 ± 1] took part in a randomized, double-blind, parallel-group study. Participants received primed, continuous infusions of l-[ring-2H5]phenylalanine and ingested either 70 g mycoprotein (31.5 g protein; MYCO; n = 10) or 35 g BCAA-enriched mycoprotein (18.7 g protein: matched on BCAA content; ENR; n = 9) following a bout of unilateral resistance exercise. Blood and bilateral quadriceps muscle samples were obtained before exercise and protein ingestion and during a 4-h postprandial period to assess MPS in rested and exercised muscle. Two- and 3-factor ANOVAs were used to detect differences in plasma amino acid kinetics and mixed muscle fractional synthetic rates, respectively. RESULTS: Postprandial plasma BCAA concentrations increased more rapidly and to a larger degree in ENR compared with MYCO. MPS increased with protein ingestion (P ≤ 0.05) but to a greater extent following MYCO (from 0.025% ± 0.006% to 0.057% ± 0.004% · h-1 in rested muscle, and from 0.024% ± 0.007% to 0.072% ± 0.005% · h-1 in exercised muscle; P
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Monteyne AJ, Coelho MOC, Porter C, Abdelrahman DR, Jameson TSO, Jackman SR, Blackwell JR, Finnigan TJA, Stephens FB, Dirks ML, et al (2020). Mycoprotein ingestion stimulates protein synthesis rates to a greater extent than milk protein in rested and exercised skeletal muscle of healthy young men: a randomized controlled trial.
Am J Clin Nutr,
112(2), 318-333.
Abstract:
Mycoprotein ingestion stimulates protein synthesis rates to a greater extent than milk protein in rested and exercised skeletal muscle of healthy young men: a randomized controlled trial.
BACKGROUND: Mycoprotein is a fungal-derived sustainable protein-rich food source, and its ingestion results in systemic amino acid and leucine concentrations similar to that following milk protein ingestion. OBJECTIVE: We assessed the mixed skeletal muscle protein synthetic response to the ingestion of a single bolus of mycoprotein compared with a leucine-matched bolus of milk protein, in rested and exercised muscle of resistance-trained young men. METHODS: Twenty resistance-trained healthy young males (age: 22 ± 1 y, body mass: 82 ± 2 kg, BMI: 25 ± 1 kg·m-2) took part in a randomized, double-blind, parallel-group study. Participants received primed, continuous infusions of L-[ring-2H5]phenylalanine and ingested either 31 g (26.2 g protein: 2.5 g leucine) milk protein (MILK) or 70 g (31.5 g protein: 2.5 g leucine) mycoprotein (MYCO) following a bout of unilateral resistance-type exercise (contralateral leg acting as resting control). Blood and m. vastus lateralis muscle samples were collected before exercise and protein ingestion, and following a 4-h postprandial period to assess mixed muscle fractional protein synthetic rates (FSRs) and myocellular signaling in response to the protein beverages in resting and exercised muscle. RESULTS: Mixed muscle FSRs increased following MILK ingestion (from 0.036 ± 0.008 to 0.052 ± 0.006%·h-1 in rested, and 0.035 ± 0.008 to 0.056 ± 0.005%·h-1 in exercised muscle; P
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2019
Jameson TSO, Pavis GF, Dirks ML, Wall BT, Mikus C, Alamdari N, Stephens FB (2019). Post-exercise and Pre-sleep Protein-polyphenol Supplementation Improves Recovery Following Muscle-damaging Eccentric Exercise: Preliminary Findings.
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