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1.
Int J Mol Sci ; 22(14)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34299206

RESUMO

Despite the intensive investigation of the molecular mechanism of skeletal muscle hypertrophy, the underlying signaling processes are not completely understood. Therefore, we used an overload model, in which the main synergist muscles (gastrocnemius, soleus) of the plantaris muscle were surgically removed, to cause a significant overload in the remaining plantaris muscle of 8-month-old Wistar male rats. SIRT1-associated pro-anabolic, pro-catabolic molecular signaling pathways, NAD and H2S levels of this overload-induced hypertrophy were studied. Fourteen days of overload resulted in a significant 43% (p < 0.01) increase in the mass of plantaris muscle compared to sham operated animals. Cystathionine-ß-synthase (CBS) activities and bioavailable H2S levels were not modified by overload. On the other hand, overload-induced hypertrophy of skeletal muscle was associated with increased SIRT1 (p < 0.01), Akt (p < 0.01), mTOR, S6 (p < 0.01) and suppressed sestrin 2 levels (p < 0.01), which are mostly responsible for anabolic signaling. Decreased FOXO1 and SIRT3 signaling (p < 0.01) suggest downregulation of protein breakdown and mitophagy. Decreased levels of NAD+, sestrin2, OGG1 (p < 0.01) indicate that the redox milieu of skeletal muscle after 14 days of overloading is reduced. The present investigation revealed novel cellular interactions that regulate anabolic and catabolic processes in the hypertrophy of skeletal muscle.


Assuntos
Cistationina beta-Sintase/metabolismo , Proteínas Musculares/metabolismo , Músculo Esquelético/patologia , Animais , Hipertrofia/genética , Hipertrofia/metabolismo , Hipertrofia/patologia , Masculino , Proteínas Musculares/genética , Músculo Esquelético/metabolismo , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Wistar , Proteínas Quinases S6 Ribossômicas/genética , Proteínas Quinases S6 Ribossômicas/metabolismo , Sirtuína 1/genética , Sirtuína 1/metabolismo , Sirtuínas/antagonistas & inibidores , Sirtuínas/genética , Sirtuínas/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
2.
J Sport Health Sci ; 9(5): 405-414, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32780693

RESUMO

MicroRNAs (miRs) are small regulatory RNA transcripts capable of post-transcriptional silencing of mRNA messages by entering a cellular bimolecular apparatus called RNA-induced silencing complex. miRs are involved in the regulation of cellular processes producing, eliminating or repairing the damage caused by reactive oxygen species, and they are active players in redox homeostasis. Increased mitochondrial biogenesis, function and hypertrophy of skeletal muscle are important adaptive responses to regular exercise. In the present review, we highlight some of the redox-sensitive regulatory roles of miRs.


Assuntos
Adaptação Fisiológica , Exercício Físico/fisiologia , MicroRNAs/metabolismo , Músculo Esquelético/metabolismo , Oxirredução , Animais , Humanos , Biogênese de Organelas , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais
3.
J Sport Health Sci ; 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-32813644

RESUMO

PURPOSE: Blood flow restriction (BFR) with low-intensity resistance training has been shown to result in hypertrophy of skeletal muscle. In this study, we tested the hypothesis that BFR during the rest periods between acute, high-intensity resistance exercise sessions (70% of 1 repetition maximum, 7 sets with 10 repetitions) enhances the effects of the resistance training. METHODS: A total of 7 healthy young men performed squats, and between sets BFR was carried out on 1 leg while the other leg served as a control. Because BFR was applied during rest periods, even severe occlusion pressure (approximately 230 mm Hg), which almost completely blocked blood flow, was well-tolerated by the participants. Five muscle-specific microRNAs were measured from the biopsy samples, which were taken 2 h after the acute training. RESULTS: Doppler data showed that the pattern of blood flow recovery changed significantly between the first and last BFR. MicroRNA-206 levels significantly decreased in the BFR leg compared to the control. The mRNA levels of RAC-ß serine/threonine-protein kinase v22, nuclear respiratory factor 1, vascular endothelial growth factor, lupus Ku autoantigen protein p70 genes (p < 0.05), and paired box 7 (p < 0.01) increased in the BFR leg. The protein levels of paired box 7, nuclear respiratory factor 1, and peroxisome proliferator-activated receptor γ coactivator 1α did not differ between the BFR leg and the control leg. CONCLUSION: Data revealed that BFR, during the rest periods of high-load resistance training, could lead to mRNA elevation of those proteins that regulate angiogenesis, mitochondrial biogenesis, and muscle hypertrophy and repair. However, BFR also can cause DNA damage, judging from the increase in mRNA levels of lupus Ku autoantigen protein p70.

4.
Free Radic Biol Med ; 132: 33-41, 2019 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-30389495

RESUMO

The decrease in cognitive/motor functions and physical abilities severely affects the aging population in carrying out daily activities. These disabilities become a burden on individuals, families and society in general. It is known that aging conditions are ameliorated with regular exercise, which attenuates the age-associated decline in maximal oxygen uptake (VO2max), production of reactive oxygen species (ROS), decreases in oxidative damage to molecules, and functional impairment in various organs. While benefits of physical exercise are well-documented, the molecular mechanisms responsible for functional improvement and increases in health span are not well understood. Recent findings imply that exercise training attenuates the age-related deterioration in the cellular housekeeping system, which includes the proteasome, Lon protease, autophagy, mitophagy, and DNA repair systems, which beneficially impacts multiple organ functions. Accumulating evidence suggests that exercise lessens the deleterious effects of aging. However, it seems unlikely that systemic effects are mediated through a specific biomarker. Rather, complex multifactorial mechanisms are involved to maintain homeostatic functions that tend to decline with age.


Assuntos
Envelhecimento/fisiologia , Exercício Físico/fisiologia , Oxirredução , Idoso , Animais , Reparo do DNA , Genes Essenciais/genética , Homeostase , Humanos , Espécies Reativas de Oxigênio/metabolismo
5.
PLoS One ; 9(12): e114075, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25493948

RESUMO

The oxidative stress effect of exercise training on testis function is under debate. In the present study we used a unique rat model system developed by artificial selection for low and high intrinsic running capacity (LCR and HCR, respectively) to evaluate the effects of exercise training on apoptosis and spermatogenesis in testis. Twenty-four 13-month-old male rats were assigned to four groups: control LCR (LCR-C), trained LCR (LCR-T), control HCR (HCR-C), and trained HCR (HCR-T). Ten key proteins connecting aerobic exercise capacity and general testes function were assessed, including those that are vital for mitochondrial biogenesis. The VO2 max of LCR-C group was about 30% lower than that of HCR-C rats, and the SIRT1 levels were also significantly lower than HCR-C. Twelve weeks of training significantly increased maximal oxygen consumption in LCR by nearly 40% whereas HCR remained unchanged. LCR-T had significantly higher levels of peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC-1α), decreased levels of reactive oxygen species and increased acetylated p53 compared to LCR-C, while training produced no significant changes for these measures in HCR rats. BAX and Blc-2 were not different among all four groups. The levels of outer dense fibers -1 (Odf-1), a marker of spermatogenesis, increased in LCR-T rats, but decreased in HCR-TR rats. Moreover, exercise training increased the levels of lactate dehydrogenase C (LDHC) only in LCR rats. These data suggest that rats with low inborn exercise capacity can increase whole body oxygen consumption and running exercise capacity with endurance training and, in turn, increase spermatogenesis function via reduction in ROS and heightened activity of p53 in testes.


Assuntos
Biomarcadores/metabolismo , Condicionamento Físico Animal , Espermatogênese , Animais , Apoptose , Masculino , Estresse Oxidativo , Ratos , Espécies Reativas de Oxigênio/metabolismo , Corrida , Testículo/citologia , Testículo/metabolismo
6.
Brain Res Bull ; 107: 54-60, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25043449

RESUMO

Exercise capacity and dietary restriction (DR) are linked to improved quality of life, including enhanced brain function and neuro-protection. Brain derived neurotrophic factor (BDNF) is one of the key proteins involved in the beneficial effects of exercise on brain. Low capacity runner (LCR) and high capacity runner (HCR) rats were subjected to DR in order to investigate the regulation of BDNF. HCR-DR rats out-performed other groups in a passive avoidance test. BDNF content increased significantly in the hippocampus of HCR-DR groups compared to control groups (p<0.05). The acetylation of H3 increased significantly only in the LCR-DR group. However, chip-assay revealed that the specific binding between acetylated histone H3 and BNDF promoter was increased in both LCR-DR and HCR-DR groups. In spite of these increases in binding, at the transcriptional level only, the LCR-DR group showed an increase in BDNF mRNA content. Additionally, DR also induced the activity of cAMP response element-binding protein (CREB), while the content of SIRT1 was not altered. Peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) was elevated in HCR-DR groups. But, based on the levels of nuclear respiratory factor-1 and cytocrome c oxidase, it appears that DR did not cause mitochondrial biogenesis. The data suggest that DR-mediated induction of BDNF levels includes chromatin remodeling. Moreover, DR does not induce mitochondrial biogenesis in the hippocampus of LCR/HCR rats. DR results in different responses to a passive avoidance test, and BDNF regulation in LCR and HCR rats.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/genética , Epigênese Genética , Comportamento Alimentar/fisiologia , Hipocampo/metabolismo , Memória de Curto Prazo/fisiologia , Corrida/fisiologia , Animais , Proteína de Ligação a CREB/metabolismo , Histonas/metabolismo , Masculino , Fatores Nucleares Respiratórios/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Ratos , Sirtuína 1/metabolismo , Fatores de Transcrição/metabolismo
7.
Brain Res ; 1281: 47-57, 2009 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-19497308

RESUMO

Although spatial discrimination of electrocutaneous stimuli can be improved by training, we do not know whether the improvement of spatial discrimination varies as a function of the type of stimulus presentation. In the present study, two groups of healthy human volunteers were trained over a period of 5 days to discriminate 23 patterns of one, two, three, or four simultaneously stimulated electrodes on the upper arm. In group one, two or three simultaneously stimulated electrodes were applied at different skin areas with an anchor electrode. This type of stimulation was hypothesised to facilitate discrimination performance by providing a cue about stimulus patterns applied. In group two, two or three simultaneously stimulated electrodes were applied at different skin areas with electrodes arranged as adjacent electrodes like a zoned field. Double and triple stimulus patterns presented with an anchor electrode were discriminated significantly better than double and triple patterns presented as zoned fields. This improvement in stimulus discrimination resulted primarily from a better discrimination of double stimulation patterns. However, there was a clear influence of spatial distance between simultaneously activated electrodes on the results. Thus, both spatial distances between stimulated electrodes and, to a minor extent, the anchor stimulation per se influenced this result. Furthermore, results revealed an overall significant improvement of stimulus discrimination in both groups and an improvement varying as a function of the number of stimulated electrodes. Overall, results indicate that the improvement of spatial discrimination of electrocutaneous stimuli varies as a function of the type of stimulus presentation.


Assuntos
Aprendizagem por Discriminação , Percepção Espacial , Percepção do Tato , Adulto , Análise de Variância , Braço , Sinais (Psicologia) , Discriminação Psicológica , Estimulação Elétrica/métodos , Feminino , Humanos , Masculino , Psicofísica , Pele , Fatores de Tempo , Adulto Jovem
8.
Anal Chim Acta ; 619(2): 173-82, 2008 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-18558110

RESUMO

This paper describes the fabrication, characterisation and the application of a Nafion/2,2'-bipyridyl/bismuth composite film-coated glassy carbon electrode (NC(Bpy)BiFE) for the anodic stripping voltammetric determination of trace metal ions (Zn2+, Cd2+ and Pb2+). The NC(Bpy)BiFE electrode is prepared by first applying a 2.5 mm3 drop of a coating solution containing 0.5 wt% Nafion and 0.1% (w/v) 2,2'-bipyridil (Bpy) onto the surface of a glassy carbon electrode, while the Bi film was plated in situ simultaneously with the target metal ions at -1.4V. The main advantage of the polymer coated bismuth film electrode is that the sensitivity of the stripping responses is increased considerably due to the incorporation of the neutral chelating agent of 2,2'-bipyridyl (Bpy) in the Nafion film, while the Nafion coating improved the mechanical stability of the bismuth film and its resistance to the interference of surfactants. The key experimental parameters relevant to both the electrode fabrication and the voltammetric measurement were optimized on the basis of the stripping signals. With a 2 min deposition time in the presence of oxygen, linear calibration curves were obtained in a wide concentration range (about 2-0.001 microM) with detection limits of 8.6 nM (0.56 microg dm(-3)) for Zn2+, 1.1 nM (0.12 microg dm(-3)) for Cd2+ and 0.37 nM (0.077 microg dm(-3)) for Pb(2+). For nine successive preconcentration/determination/electrode renewal experiments the standard deviations were between 3 and 5% at 1.2 microM for zinc and 0.3-0.3 microM concentration level for lead and cadmium, respectively, and the method exhibited excellent selectivity in the presence of the excess of several potential interfering metal ions. The analytical utility of the stripping voltammetric method elaborated was tested in the assay of heavy metals in some real samples and the method was validated by ICP-MS technique.

9.
Neurosci Lett ; 427(2): 83-7, 2007 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-17931775

RESUMO

The present study investigates whether the spatial discrimination of somatosensory stimuli can be improved with training when sets of 1, 2, 3, or 4 simultaneously stimulated electrodes (so called patterns) have to be discriminated. Healthy human subjects were trained over a period of 5 days to discriminate 23 different somatosensory stimulus patterns. Somatosensory stimulation was based on electrical stimuli applied through an array of eight electrodes attached with a cuff to the skin of the left upper arm. Daily sessions consisted of a pretest, a training phase, and a posttest. Pre- and posttests revealed subject's discrimination ability. Performance of a treatment group receiving sensory real training was compared to performance of a control group receiving sham training. Results revealed (1) improvements of discrimination ability in both groups, and (2) a significantly greater discrimination performance throughout the training period in the treatment group as compared to the control group. The present study demonstrates that discrimination of electrocutaneous stimuli can be improved through training. Results illustrate that electrocutaneous stimuli are a possible and easy-to-apply tool for biofeedback settings.


Assuntos
Aprendizagem por Discriminação/fisiologia , Estimulação Elétrica , Sensação/fisiologia , Pele/inervação , Córtex Somatossensorial/fisiologia , Adolescente , Adulto , Biorretroalimentação Psicológica/métodos , Biorretroalimentação Psicológica/fisiologia , Eletrodos , Feminino , Humanos , Masculino , Rememoração Mental/fisiologia
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