To Örebro University

oru.seÖrebro University Publications
Change search
Link to record
Permanent link

Direct link
Publications (10 of 52) Show all publications
Chaillou, T. & Montiel Rojas, D. (2023). Does the blunted stimulation of skeletal muscle protein synthesis by aging in response to mechanical load result from impaired ribosome biogenesis?. Frontiers in aging, 4, Article ID 1171850.
Open this publication in new window or tab >>Does the blunted stimulation of skeletal muscle protein synthesis by aging in response to mechanical load result from impaired ribosome biogenesis?
2023 (English)In: Frontiers in aging, E-ISSN 2673-6217, Vol. 4, article id 1171850Article, review/survey (Refereed) Published
Abstract [en]

Age-related loss of skeletal muscle mass leads to a reduction of strength. It is likely due to an inadequate stimulation of muscle protein synthesis (MPS) in response to anabolic stimuli, such as mechanical load. Ribosome biogenesis is a major determinant of translational capacity and is essential for the control of muscle mass. This mini-review aims to put forth the hypothesis that ribosome biogenesis is impaired by aging in response to mechanical load, which could contribute to the age-related anabolic resistance and progressive muscle atrophy. Recent animal studies indicate that aging impedes muscle hypertrophic response to mechanical overload. This is associated with an impaired transcription of ribosomal DNA (rDNA) by RNA polymerase I (Pol I), a limited increase in total RNA concentration, a blunted activation of AKT/mTOR pathway, and an increased phosphorylation of AMPK. In contrast, an age-mediated impairment of ribosome biogenesis is unlikely in response to electrical stimulations. In human, the hypertrophic response to resistance exercise training is diminished with age. This is accompanied by a deficit in long-term MPS and an absence of increased total RNA concentration. The results addressing the acute response to resistance exercise suggest an impaired Pol I-mediated rDNA transcription and attenuated activation/expression of several upstream regulators of ribosome biogenesis in muscles from aged individuals. Altogether, emerging evidence indicates that impaired ribosome biogenesis could partly explain age-related anabolic resistance to mechanical load, which may ultimately contribute to progressive muscle atrophy. Future research should develop more advanced molecular tools to provide in-depth analysis of muscle ribosome biogenesis.

Place, publisher, year, edition, pages
Frontiers Media S.A., 2023
Keywords
Anabolic resistance, elderly, muscle atrophy, rDNA transcription, resistance exercise, sarcopenia, translational capacity
National Category
Physiology
Identifiers
urn:nbn:se:oru:diva-106120 (URN)10.3389/fragi.2023.1171850 (DOI)001090837100001 ()37256189 (PubMedID)2-s2.0-85162161942 (Scopus ID)
Available from: 2023-06-01 Created: 2023-06-01 Last updated: 2023-11-15Bibliographically approved
Treigyte, V., Eimantas, N., Venckunas, T., Brazaitis, M. & Chaillou, T. (2023). Moderate muscle cooling induced by single and intermittent/prolonged cold-water immersions differently affects muscle contractile function in young males. Frontiers in Physiology, 14, Article ID 1172817.
Open this publication in new window or tab >>Moderate muscle cooling induced by single and intermittent/prolonged cold-water immersions differently affects muscle contractile function in young males
Show others...
2023 (English)In: Frontiers in Physiology, E-ISSN 1664-042X, Vol. 14, article id 1172817Article in journal (Refereed) Published
Abstract [en]

Background: We investigated the impact of moderate muscle cooling induced by single and intermittent/prolonged cold-water immersions (CWI) on muscle force and contractility in unfatigued state and during the development of fatigue resulting from electrically induced contractions.

Methods: Twelve young males participated in this study consisting of two phases [single phase (SP) followed by intermittent/prolonged phase (IPP)], with both phases including two conditions (i.e., four trials in total) performed randomly: control passive sitting (CON) and cold-water immersions (10°C). SP-CWI included one 45 min-bath (from 15 to 60 min). IPP-CWI included three baths (45 min-bath from 15 to 60 min, and 15 min-baths from 165 to 180 min and from 255 to 270 min), with participants sitting at room temperature the rest of the time until 300 min. Blood pressure and intramuscular (Tmu) temperature were assessed, and neuromuscular testing was performed at baseline and 60 min after baseline during SP, and at baseline, 60, 90, 150 and 300 min after baseline during IPP. A fatiguing protocol (100 electrical stimulations) was performed after the last neuromuscular testing of each trial.

Results: In unfatigued state, SP-CWI and IPP-CWI reduced electrically induced torque at 100 Hz (P100) but not at 20 Hz (P20), and increased P20/P100 ratio. The changes from baseline for P100 and P20/P100 ratio were lower in IPP-CWI than SP-CWI. Both cold-water immersion conditions slowed down muscle contraction and relaxation, and reduced maximal isokinetic contraction torque, but the changes from baseline were lower after IPP-CWI than SP-CWI. cold-water immersions did not impair maximal voluntary isometric contraction. During the fatiguing protocol, torque fatigue index and the changes in muscle contractile properties were larger after IPP-CWI than SP-CWI, but were in the same range as after CON conditions. The differences of muscle contractile function between SP-CWI and IPP-CWI were accompanied by a lower reduction of superficial Tmu and a smaller increase in systolic blood pressure after IPP-CWI than SP-CWI.

Conclusion: IPP-CWI induces a less pronounced fast-to-slow contractile transition compared to SP-CWI, and this may result from the reduced vasoconstriction response and enhanced blood perfusion of the superficial muscle vessels, which could ultimately limit the reduction of superficial Tmu.

Place, publisher, year, edition, pages
Frontiers Media S.A., 2023
Keywords
cold exposure, cold habituation, cold-water immersion, muscle contractility, muscle fatigue, muscle force, temperature
National Category
Physiology
Identifiers
urn:nbn:se:oru:diva-105445 (URN)10.3389/fphys.2023.1172817 (DOI)000963522200001 ()37025384 (PubMedID)2-s2.0-85151545832 (Scopus ID)
Note

Funding agency:

Swedish Research Council for Sports Sciences P2020-0119

Available from: 2023-04-14 Created: 2023-04-14 Last updated: 2024-01-17Bibliographically approved
Gineste, C., Youhanna, S., Vorrink, S. U., Henriksson, S., Hernández, A., Cheng, A. J., . . . Westerblad, H. (2022). Enzymatically dissociated muscle fibers display rapid dedifferentiation and impaired mitochondrial calcium control. iScience, 25(12), Article ID 105654.
Open this publication in new window or tab >>Enzymatically dissociated muscle fibers display rapid dedifferentiation and impaired mitochondrial calcium control
Show others...
2022 (English)In: iScience, E-ISSN 2589-0042 , Vol. 25, no 12, article id 105654Article in journal (Refereed) Published
Abstract [en]

Cells rapidly lose their physiological phenotype upon disruption of their extracellular matrix (ECM)-intracellular cytoskeleton interactions. By comparing adult mouse skeletal muscle fibers, isolated either by mechanical dissection or by collagenase-induced ECM digestion, we investigated acute effects of ECM disruption on cellular and mitochondrial morphology, transcriptomic signatures, and Ca2+ handling. RNA-sequencing showed striking differences in gene expression patterns between the two isolation methods with enzymatically dissociated fibers resembling myopathic phenotypes. Mitochondrial appearance was grossly similar in the two groups, but 3D electron microscopy revealed shorter and less branched mitochondria following enzymatic dissociation. Repeated contractions resulted in a prolonged mitochondrial Ca2+ accumulation in enzymatically dissociated fibers, which was partially prevented by cyclophilin inhibitors. Of importance, muscle fibers of mice with severe mitochondrial myopathy show pathognomonic mitochondrial Ca2+ accumulation during repeated contractions and this accumulation was concealed with enzymatic dissociation, making this an ambiguous method in studies of native intracellular Ca2+ fluxes.

Place, publisher, year, edition, pages
Cell Press, 2022
National Category
Physiology
Identifiers
urn:nbn:se:oru:diva-104631 (URN)10.1016/j.isci.2022.105654 (DOI)000924079500006 ()36479146 (PubMedID)2-s2.0-85143507463 (Scopus ID)
Funder
Swedish Research Council, 2018-02576Knut and Alice Wallenberg FoundationThe Kempe Foundations
Note

Funding agencies:

Swedish Research Council for Sport Science P2019-0060

Association Francaise contre les Myopathies 16798

German Research Foundation (DFG) FR2993/13-1

United States Department of Health & Human Services

National Institutes of Health (NIH) - USA

NIH National Institute of Arthritis & Musculoskeletal & Skin Diseases (NIAMS)

1F32AR057619

 

Available from: 2023-03-03 Created: 2023-03-03 Last updated: 2023-03-17Bibliographically approved
Mader, T., Chaillou, T., Alves, E. S., Jude, B., Cheng, A. J., Kenne, E., . . . Lanner, J. T. (2022). Exercise reduces intramuscular stress and counteracts muscle weakness in mice with breast cancer. Journal of Cachexia, Sarcopenia and Muscle, 13(2), 1151-1163
Open this publication in new window or tab >>Exercise reduces intramuscular stress and counteracts muscle weakness in mice with breast cancer
Show others...
2022 (English)In: Journal of Cachexia, Sarcopenia and Muscle, ISSN 2190-5991, E-ISSN 2190-6009, Vol. 13, no 2, p. 1151-1163Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Patients with breast cancer exhibit muscle weakness, which is associated with increased mortality risk and reduced quality of life. Muscle weakness is experienced even in the absence of loss of muscle mass in breast cancer patients, indicating intrinsic muscle dysfunction. Physical activity is correlated with reduced cancer mortality and disease recurrence. However, the molecular processes underlying breast cancer-induced muscle weakness and the beneficial effect of exercise are largely unknown.

METHODS: Eight-week-old breast cancer (MMTV-PyMT, PyMT) and control (WT) mice had access to active or inactive in-cage voluntary running wheels for 4 weeks. Mice were also subjected to a treadmill test. Muscle force was measured ex vivo. Tumour markers were determined with immunohistochemistry. Mitochondrial biogenesis and function were assessed with transcriptional analyses of PGC-1α, the electron transport chain (ETC) and antioxidants superoxide dismutase (Sod) and catalase (Cat), combined with activity measurements of SOD, citrate synthase (CS) and β-hydroxyacyl-CoA-dehydrogenase (βHAD). Serum and intramuscular stress levels were evaluated by enzymatic assays, immunoblotting, and transcriptional analyses of, for example, tumour necrosis factor-α (TNF-α) and p38 mitogen-activated protein kinase (MAPK) signalling.

RESULTS: PyMT mice endured shorter time and distance during the treadmill test (~30%, P < 0.05) and ex vivo force measurements revealed ~25% weaker slow-twitch soleus muscle (P < 0.001). This was independent of cancer-induced alteration of muscle size or fibre type. Inflammatory stressors in serum and muscle, including TNF-α and p38 MAPK, were higher in PyMT than in WT mice (P < 0.05). Cancer-induced decreases in ETC (P < 0.05, P < 0.01) and antioxidant gene expression were observed (P < 0.05). The exercise intervention counteracted the cancer-induced muscle weakness and was accompanied by a less aggressive, differentiated tumour phenotype, determined by increased CK8 and reduced CK14 expression (P < 0.05). In PyMT mice, the exercise intervention led to higher CS activity (P = 0.23), enhanced β-HAD and SOD activities (P < 0.05), and reduced levels of intramuscular stressors together with a normalization of the expression signature of TNFα-targets and ETC genes (P < 0.05, P < 0.01). At the same time, the exercise-induced PGC-1α expression, and CS and β-HAD activity was blunted in muscle from the PyMT mice as compared with WT mice, indicative that breast cancer interfere with transcriptional programming of mitochondria and that the molecular adaptation to exercise differs between healthy mice and those afflicted by disease.

CONCLUSIONS: Four-week voluntary wheel running counteracted muscle weakness in PyMT mice which was accompanied by reduced intrinsic stress and improved mitochondrial and antioxidant profiles and activities that aligned with muscles of healthy mice.

Place, publisher, year, edition, pages
John Wiley & Sons, 2022
Keywords
Breast cancer, Mitochondria, Muscle weakness, Stress
National Category
Physiology Cancer and Oncology
Identifiers
urn:nbn:se:oru:diva-97593 (URN)10.1002/jcsm.12944 (DOI)000755356300001 ()35170227 (PubMedID)2-s2.0-85124627012 (Scopus ID)
Funder
Swedish Research Council, 2017-03056 2019-01282Wenner-Gren FoundationsSwedish Cancer Society, 2018/875The Karolinska Institutet's Research Foundation
Available from: 2022-02-21 Created: 2022-02-21 Last updated: 2023-12-08Bibliographically approved
Chaillou, T., Treigyte, V., Mosely, S., Brazaitis, M., Venckunas, T. & Cheng, A. J. (2022). Functional Impact of Post-exercise Cooling and Heating on Recovery and Training Adaptations: Application to Resistance, Endurance, and Sprint Exercise. Sports medicine - open, 8(1), Article ID 37.
Open this publication in new window or tab >>Functional Impact of Post-exercise Cooling and Heating on Recovery and Training Adaptations: Application to Resistance, Endurance, and Sprint Exercise
Show others...
2022 (English)In: Sports medicine - open, ISSN 2199-1170, Vol. 8, no 1, article id 37Article in journal (Refereed) Published
Abstract [en]

The application of post-exercise cooling (e.g., cold water immersion) and post-exercise heating has become a popular intervention which is assumed to increase functional recovery and may improve chronic training adaptations. However, the effectiveness of such post-exercise temperature manipulations remains uncertain. The aim of this comprehensive review was to analyze the effects of post-exercise cooling and post-exercise heating on neuromuscular function (maximal strength and power), fatigue resistance, exercise performance, and training adaptations. We focused on three exercise types (resistance, endurance and sprint exercises) and included studies investigating (1) the early recovery phase, (2) the late recovery phase, and (3) repeated application of the treatment. We identified that the primary benefit of cooling was in the early recovery phase (< 1 h post-exercise) in improving fatigue resistance in hot ambient conditions following endurance exercise and possibly enhancing the recovery of maximal strength following resistance exercise. The primary negative impact of cooling was with chronic exposure which impaired strength adaptations and decreased fatigue resistance following resistance training intervention (12 weeks and 4-12 weeks, respectively). In the early recovery phase, cooling could also impair sprint performance following sprint exercise and could possibly reduce neuromuscular function immediately after endurance exercise. Generally, no benefits of acute cooling were observed during the 24-72-h recovery period following resistance and endurance exercises, while it could have some benefits on the recovery of neuromuscular function during the 24-48-h recovery period following sprint exercise. Most studies indicated that chronic cooling does not affect endurance training adaptations following 4-6 week training intervention. We identified limited data employing heating as a recovery intervention, but some indications suggest promise in its application to endurance and sprint exercise.

Place, publisher, year, edition, pages
Springer Open, 2022
Keywords
Cooling, Fatigue, Heating, Muscle function, Physical performance, Recovery, Temperature, Training, Water immersion
National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:oru:diva-97848 (URN)10.1186/s40798-022-00428-9 (DOI)000765765600002 ()35254558 (PubMedID)2-s2.0-85126258975 (Scopus ID)
Note

Funding agencies:

Örebro University

Swedish Research Council for Sport Science P20190119

Natural Sciences and Engineering Research Council of Canada (NSERC) RGPIN-2020-06443 DGECR-2020-00136

Muscle Health Research Centre Student Fellowship Award (York University, Toronto, Canada)

Available from: 2022-03-08 Created: 2022-03-08 Last updated: 2022-03-30Bibliographically approved
Järvinen, L., Lundin Petersdotter, S. & Chaillou, T. (2022). High-intensity resistance exercise is not as effective as traditional high-intensity interval exercise for increasing the cardiorespiratory response and energy expenditure in recreationally active subjects. European Journal of Applied Physiology, 122(2), 459-474
Open this publication in new window or tab >>High-intensity resistance exercise is not as effective as traditional high-intensity interval exercise for increasing the cardiorespiratory response and energy expenditure in recreationally active subjects
2022 (English)In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 122, no 2, p. 459-474Article in journal (Refereed) Published
Abstract [en]

PURPOSE: Traditional high-intensity interval exercise (HIIE) highly stimulates the cardiorespiratory system and increases energy expenditure (EE) during exercise. High-intensity resistance exercise (HIRE) has become more popular in recreationally active subjects. The physiological responses to HIRE performed with light or moderate load is currently largely unknown. Here, we examined the effect of the type of interval exercise [HIRE at 40% (HIRE40) and 60% (HIRE60) 1-RM vs. traditional HIIE] on the cardiorespiratory response and EE during and after exercise.

METHODS: Fifteen recreationally active adults randomly completed traditional HIIE on an ergocyle, HIRE40 and HIRE60. The sessions consisted of two sets of ten 30-s intervals (power at 100% VO2max during HIIE; maximal number of repetitions for 10 different free-weight exercises during HIRE40 and HIRE60) separated by 30-s active recovery periods. Gas exchange, heart rate (HR) and EE were assessed during and after exercise.

RESULTS: VO2mean, VO2peak, HRmean, the time spent above 90% VO2max and HRmax, and aerobic EE were lower in both HIRE sessions compared with HIIE (P < 0.05). Anaerobic glycolytic contribution to total exercise EE was higher in HIRE40 and HIRE60 compared with HIIE (P < 0.001). EE from excess post-exercise oxygen consumption (EPOC) was similar after the three sessions. Overall, similar cardiorespiratory responses and EE were found in HIRE40 and HIRE60.

CONCLUSIONS: HIRE is not as effective as HIIE for increasing the cardiorespiratory response and EE during exercise, while EPOC remains similar in HIRE and HIIE. These parameters are not substantially different between HIRE40 and HIRE60.

Place, publisher, year, edition, pages
Springer, 2022
Keywords
Aerobic fitness, HIIT, Heart rate, Maximal oxygen uptake, RPE, Resistance exercise
National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:oru:diva-95548 (URN)10.1007/s00421-021-04849-4 (DOI)000720602300004 ()34799752 (PubMedID)2-s2.0-85119493322 (Scopus ID)
Note

Funding agency:

Örebro University

Available from: 2021-11-22 Created: 2021-11-22 Last updated: 2022-02-03Bibliographically approved
Chaillou, T., Treigyte, V., Eimantas, N., Venckunas, T. & Brazaitis, M. (2022). Impact of acute and prolonged cooling on skeletal muscle force in young males. In: : . Paper presented at 27th ECSS, European Congress of Sport Science, Sevilla, Spain, August 31-September 2, 2022.
Open this publication in new window or tab >>Impact of acute and prolonged cooling on skeletal muscle force in young males
Show others...
2022 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

Introduction

In athletes, exposure to cold during winter sports may impair physical performance. Severe muscle cooling appears to reduce maximal force and induces a shift towards a slower contractile profile. However, whether moderate muscle cooling and the duration of cooling affect muscle contractile profile (assessed from electrically evoked torque at low and high frequencies) and maximal voluntary force (isometric and isokinetic contractions) remains to be clarified. Therefore, the aim of this study was to investigate the impact of acute and prolonged cooling on electrically evoked torque and maximal voluntary contraction torque in young males. 

Methods

Twelve active males (27.2 ± 6.6 years old) were recruited for this study, consisting of 2 phases: acute and prolonged exposures. During each phase, participants were randomly exposed to cold water immersion (CWI, 10°C, up to the iliac crest) or passive resting (PR). Exposure to CWI was either continuous during 45min (acute CWI, A-CWI) or intermittent during a period of 300min [prolonged CWI (P-CWI) including immersions between baseline to 45min, 165 to 180min, and 255 to 270min]. Muscle (Tmu, average across 1, 2 and 3cm depth) and rectal (Trec) temperatures were assessed using thermo-sensors. Transcutaneous electrical stimulation of the quadriceps muscle was performed to determine torques at low (20 Hz: P20) and high (100 Hz: P100) frequencies, and P20/P100 ratio was calculated. Maximal voluntary isometric torque of the knee extensors (MVIC), as well as peak isokinetic torques (90°/s) of knee extensors (KE-IsoC) and flexors (KF-isoC) were determined. Neuromuscular tests were performed at baseline (BL) and 60min after BL during acute exposure, and at BL, 60, 90, 150 and 300min after BL during prolonged exposure.

Results

Trec did not change after A-CWI while it was reduced (0.8 ± 0.4°C, p<0.001) after P-CWI compared to BL. Tmu decreased during A-CWI and P-CWI compared to BL (6.1 ± 2.2°C and 4.6 ± 1.1°C, respectively, p<0.001), with larger reduction of Tmu after A-CWI than P-CWI (p<0.05). P20 was not affected by the conditions. P100 was lower after 60min in A-CWI and P-CWI compared to PR (p<0.05). After the last bath (60min in A-CWI and 300min in P-CWI), P100 was nearly significantly higher in A-CWI than P-CWI (p=0.05). P20/P100 was higher after 60min in A-CWI and P-CWI compared to PR (p<0.001), but this ratio was lower in P-CWI than A-CWI after the last bath (p<0.05). MVIC torque remained unchanged during A-CWI and P-CWI, while KE-IsoC and KF-IsoC torques were similarly reduced after A-CWI and P-CWI compared to PR (p<0.05).

Conclusion

Moderate muscle cooling preferentially impairs maximal force production of dynamic contractions, but not isometric contractions, regardless of exposure duration. A shift towards a slower contractile profile (i.e., increased P20/P100) is more evident after A-CWI than P-CWI, which may be partially explained by a larger reduction of Tmu rather than the exposure duration or reduced Trec.

National Category
Physiology
Research subject
Physiology
Identifiers
urn:nbn:se:oru:diva-102857 (URN)
Conference
27th ECSS, European Congress of Sport Science, Sevilla, Spain, August 31-September 2, 2022
Available from: 2022-12-26 Created: 2022-12-26 Last updated: 2023-01-11Bibliographically approved
Kamandulis, S., Mickevicius, M., Snieckus, A., Streckis, V., Montiel Rojas, D., Chaillou, T., . . . Venckunas, T. (2022). Increasing the resting time between drop jumps lessens delayed-onset muscle soreness and limits the extent of prolonged low-frequency force depression in human knee extensor muscles. European Journal of Applied Physiology, 122(1), 255-266
Open this publication in new window or tab >>Increasing the resting time between drop jumps lessens delayed-onset muscle soreness and limits the extent of prolonged low-frequency force depression in human knee extensor muscles
Show others...
2022 (English)In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 122, no 1, p. 255-266Article in journal (Refereed) Published
Abstract [en]

PURPOSE: Unaccustomed eccentric contractions generally result in a long-lasting contractile impairment, referred to as prolonged low-frequency force depression (PLFFD), and delayed-onset muscle soreness (DOMS). We here used repeated drop jumps (DJs) as an eccentric contraction model and studied the effects of increasing the time between DJs from 20 s to 5 min. We hypothesized that both PLFFD and DOMS would be less marked at the longer DJ interval due to the longer time to restore structural elements between DJs.

METHODS: Young men (n = 12) randomly performed 50 DJs with either 20-s (DJ-20 s) or 5-min (DJ-5 min) rest between DJs. Voluntary, 20 Hz and 100 Hz electrically stimulated isometric knee extension torques and muscle soreness were monitored before and for 7 days after DJs; serum CK activity was measured to assess muscle fibre protein leakage. In additional experiments, changes in mRNA levels were assessed in muscle biopsies collected before and 1 h after exercise.

RESULTS: A marked PLFFD was observed with both protocols and the extent of 20 Hz torque depression was smaller immediately and 1 day after DJ-5 min than after DJ-20 s (p < 0.05), whereas the MVC and 100 Hz torques were similarly decreased with the two protocols. Markedly larger differences between the two protocols were observed for the muscle soreness score, which 1-4 days after exercise was about two times larger with DJ-20 s than with DJ-5 min (p < 0.01).

CONCLUSIONS: The larger protective effect of the longer DJ interval against DOMS than against PLFFD indicates that their underlying mechanisms involve different structural elements.

Place, publisher, year, edition, pages
Springer, 2022
Keywords
Electrical stimulation, Low-frequency fatigue, Sarcomere damage, Stretch–shortening cycle exercise
National Category
Physiology
Identifiers
urn:nbn:se:oru:diva-95191 (URN)10.1007/s00421-021-04834-x (DOI)000709769800001 ()34674024 (PubMedID)2-s2.0-85117487475 (Scopus ID)
Available from: 2021-10-27 Created: 2021-10-27 Last updated: 2022-02-03Bibliographically approved
Ramos, C., Cheng, A. J., Kamandulis, S., Subocius, A., Brazaitis, M., Venckunas, T. & Chaillou, T. (2021). Carbohydrate restriction following strenuous glycogen-depleting exercise does not potentiate the acute molecular response associated with mitochondrial biogenesis in human skeletal muscle. European Journal of Applied Physiology, 121(4), 1219-1232
Open this publication in new window or tab >>Carbohydrate restriction following strenuous glycogen-depleting exercise does not potentiate the acute molecular response associated with mitochondrial biogenesis in human skeletal muscle
Show others...
2021 (English)In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 121, no 4, p. 1219-1232Article in journal (Refereed) Published
Abstract [en]

PURPOSE: Carbohydrate (CHO) restriction could be a potent metabolic regulator of endurance exercise-induced muscle adaptations. Here, we determined whether post-exercise CHO restriction following strenuous exercise combining continuous cycling exercise (CCE) and sprint interval exercise could affect the gene expression related to mitochondrial biogenesis and oxidative metabolism in human skeletal muscle.

METHODS: In a randomized cross-over design, 8 recreationally active males performed two cycling exercise sessions separated by 4 weeks. Each session consisted of 60-min CCE and six 30-s all-out sprints, which was followed by ingestion of either a CHO or placebo beverage in the post-exercise recovery period. Muscle glycogen concentration and the mRNA levels of several genes related to mitochondrial biogenesis and oxidative metabolism were determined before, immediately after, and at 3 h after exercise.

RESULTS: Compared to pre-exercise, strenuous cycling led to a severe muscle glycogen depletion (> 90%) and induced a large increase in PGC1A and PDK4 mRNA levels (~ 20-fold and ~ 10-fold, respectively) during the acute recovery period in both trials. The abundance of the other transcripts was not changed or was only moderately increased during this period. CHO restriction during the 3-h post-exercise period blunted muscle glycogen resynthesis but did not increase the mRNA levels of genes associated with muscle adaptation to endurance exercise, as compared with abundant post-exercise CHO consumption.

CONCLUSION: CHO restriction after a glycogen-depleting and metabolically-demanding cycling session is not effective for increasing the acute mRNA levels of genes involved in mitochondrial biogenesis and oxidative metabolism in human skeletal muscle.

Place, publisher, year, edition, pages
Springer, 2021
Keywords
Endurance exercise, Muscle glycogen, Oxidative metabolism, PGC1A, Sprint interval exercise, Train-low
National Category
Physiology
Identifiers
urn:nbn:se:oru:diva-89507 (URN)10.1007/s00421-021-04594-8 (DOI)000616442200001 ()33564963 (PubMedID)2-s2.0-85100719578 (Scopus ID)
Note

Funding Agency:

Swedish Research Council for Sports Sciences P2017-0138 FO2017-0018 FO2018-0019

Available from: 2021-02-11 Created: 2021-02-11 Last updated: 2023-12-08Bibliographically approved
Liu, Z., Chaillou, T., Santos Alves, E., Mader, T., Jude, B., Ferreira, D. M. S., . . . Lanner, J. T. (2021). Mitochondrial NDUFA4L2 is a novel regulator of skeletal muscle mass and force. The FASEB Journal, 35(12), Article ID e22010.
Open this publication in new window or tab >>Mitochondrial NDUFA4L2 is a novel regulator of skeletal muscle mass and force
Show others...
2021 (English)In: The FASEB Journal, ISSN 0892-6638, E-ISSN 1530-6860, Vol. 35, no 12, article id e22010Article in journal (Refereed) Published
Abstract [en]

The hypoxia-inducible nuclear-encoded mitochondrial protein NADH dehydrogenase (ubiquinone) 1 alpha subcomplex, 4-like 2 (NDUFA4L2) has been demonstrated to decrease oxidative phosphorylation and production of reactive oxygen species in neonatal cardiomyocytes, brain tissue and hypoxic domains of cancer cells. Prolonged local hypoxia can negatively affect skeletal muscle size and tissue oxidative capacity. Although skeletal muscle is a mitochondrial rich, oxygen sensitive tissue, the role of NDUFA4L2 in skeletal muscle has not previously been investigated. Here we ectopically expressed NDUFA4L2 in mouse skeletal muscles using adenovirus-mediated expression and in vivo electroporation. Moreover, femoral artery ligation (FAL) was used as a model of peripheral vascular disease to induce hind limb ischemia and muscle damage. Ectopic NDUFA4L2 expression resulted in reduced mitochondrial respiration and reactive oxygen species followed by lowered AMP, ADP, ATP, and NAD(+) levels without affecting the overall protein content of the mitochondrial electron transport chain. Furthermore, ec-topically expressed NDUFA4L2 caused a similar to 20% reduction in muscle mass that resulted in weaker muscles. The loss of muscle mass was associated with increased gene expression of atrogenes MurF1 and Mul1, and apoptotic genes caspase 3 and Bax. Finally, we showed that NDUFA4L2 was induced by FAL and that the Ndufa4l2 mRNA expression correlated with the reduced capacity of the muscle to generate force after the ischemic insult. These results show, for the first time, that mitochondrial NDUFA4L2 is a novel regulator of skeletal muscle mass and force. Specifically, induced NDUFA4L2 reduces mitochondrial activity leading to lower levels of important intramuscular metabolites, including adenine nucleotides and NAD(+), which are hallmarks of mitochondrial dysfunction and hence shows that dysfunctional mitochondrial activity may drive muscle wasting.

Place, publisher, year, edition, pages
John Wiley & Sons, 2021
Keywords
mitochondria, muscle mass, NDUFA4L2, skeletal muscle
National Category
Physiology
Identifiers
urn:nbn:se:oru:diva-95839 (URN)10.1096/fj.202100066R (DOI)000722321300034 ()34724256 (PubMedID)
Funder
Swedish Research CouncilDiabetesfondenWenner-Gren Foundations
Note

Funding agencies:

Strategic research program in Diabetes at Karolinska Institutet

Sigrid Juselius Foundation

China Scholarship Council

Available from: 2021-12-09 Created: 2021-12-09 Last updated: 2021-12-09Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-5322-4150

Search in DiVA

Show all publications