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1.
Zool Res ; 42(5): 650-659, 2021 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-34472226

RESUMO

Phosphatidylserine (PS) is distributed asymmetrically in the plasma membrane of eukaryotic cells. Phosphatidylserine flippase (P4-ATPase) transports PS from the outer leaflet of the lipid bilayer to the inner leaflet of the membrane to maintain PS asymmetry. The ß subunit TMEM30A is indispensable for transport and proper function of P4-ATPase. Previous studies have shown that the ATP11A and TMEM30A complex is the molecular switch for myotube formation. However, the role of Tmem30a in skeletal muscle regeneration remains elusive. In the current study, Tmem30a was highly expressed in the tibialis anterior (TA) muscles of dystrophin-null ( mdx) mice and BaCl 2-induced muscle injury model mice. We generated a satellite cell (SC)-specific Tmem30a conditional knockout (cKO) mouse model to investigate the role of Tmem30a in skeletal muscle regeneration. The regenerative ability of cKO mice was evaluated by analyzing the number and diameter of regenerated SCs after the TA muscles were injured by BaCl 2-injection. Compared to the control mice, the cKO mice showed decreased Pax7 + and MYH3 + SCs, indicating diminished SC proliferation, and decreased expression of muscular regulatory factors (MYOD and MYOG), suggesting impaired myoblast proliferation in skeletal muscle regeneration. Taken together, these results demonstrate the essential role of Tmem30a in skeletal muscle regeneration.


Assuntos
Proteínas de Membrana/metabolismo , Músculo Esquelético/fisiologia , Regeneração/fisiologia , Células Satélites de Músculo Esquelético/metabolismo , Animais , Proliferação de Células , Distrofina/genética , Distrofina/metabolismo , Antagonistas de Estrogênios/toxicidade , Regulação da Expressão Gênica/fisiologia , Genótipo , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos mdx , Camundongos Knockout , Músculo Esquelético/efeitos dos fármacos , Proteína MyoD/genética , Proteína MyoD/metabolismo , Miogenina/genética , Miogenina/metabolismo , Cadeias Pesadas de Miosina/genética , Cadeias Pesadas de Miosina/metabolismo , Fator de Transcrição PAX7/genética , Fator de Transcrição PAX7/metabolismo , Regeneração/genética , Tamoxifeno/toxicidade
2.
Nutrients ; 13(8)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34444645

RESUMO

Older adults with knee osteoarthritis (KOA) are at high risk of sarcopenia. Protein-rich nutritional composition supplementation (PS) combined with resistance exercise training (RET) improves muscle gains and facilitates physical activity in older adults. However, whether PS augments the effects of RET on muscle mass and PA in patients with KOA remains unclear. Therefore, this study identified the effects of PS on sarcopenic indices and PA in older women with KOA subjected to an RET program. Eligible older women aged 60-85 years and diagnosed as having KOA were randomly assigned to either the experimental group (EG) or the control group (CG). Both groups performed RET twice a week for 12 weeks. The EG received additional PS during this period. Outcome measures included appendicular lean mass index, walking speed, physical activity, and scores on the Western Ontario and McMaster Universities Osteoarthritis Index-WOMAC). All measures were tested at baseline and after intervention. With participant characteristics and baseline scores as covariates, analysis of variance was performed to identify between-group differences in changes in all outcome measures after intervention. Statistical significance was defined as p < 0.05. Compared with the CG, the EG achieved greater changes in appendicular lean mass index (adjusted mean difference (aMD) = 0.19 kg/m2, p < 0.01), physical activity (aMD = 30.0 MET-hour/week, p < 0.001), walking speed (aMD = 0.09 m/s, p < 0.05), and WOMAC global function (aMD = -8.21, p < 0.001) after intervention. In conclusion, PS exerted augmentative effects on sarcopenic indices, physical activity, and perceived global WOMAC score in older women with KOA through 12 weeks of RET.


Assuntos
Proteínas na Dieta/administração & dosagem , Suplementos Nutricionais , Osteoartrite do Joelho/terapia , Treinamento de Força , Sarcopenia/terapia , Idoso , Idoso de 80 Anos ou mais , Ingestão de Alimentos , Metabolismo Energético , Exercício Físico , Feminino , Humanos , Pessoa de Meia-Idade , Força Muscular , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/fisiologia , Osteoartrite do Joelho/dietoterapia , Osteoartrite do Joelho/fisiopatologia , Sarcopenia/dietoterapia , Sarcopenia/fisiopatologia
3.
Nat Commun ; 12(1): 4900, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385433

RESUMO

Skeletal muscle subsarcolemmal mitochondria (SSM) and intermyofibrillar mitochondria subpopulations have distinct metabolic activity and sensitivity, though the mechanisms that localize SSM to peripheral areas of muscle fibers are poorly understood. A protein interaction study and complexome profiling identifies PERM1 interacts with the MICOS-MIB complex. Ablation of Perm1 in mice reduces muscle force, decreases mitochondrial membrane potential and complex I activity, and reduces the numbers of SSM in skeletal muscle. We demonstrate PERM1 interacts with the intracellular adaptor protein ankyrin B (ANKB) that connects the cytoskeleton to the plasma membrane. Moreover, we identify a C-terminal transmembrane helix that anchors PERM1 into the outer mitochondrial membrane. We conclude PERM1 functions in the MICOS-MIB complex and acts as an adapter to connect the mitochondria with the sarcolemma via ANKB.


Assuntos
Anquirinas/metabolismo , Mitocôndrias Musculares/metabolismo , Complexos Multiproteicos/metabolismo , Proteínas Musculares/metabolismo , Sarcolema/metabolismo , Animais , Membrana Celular/metabolismo , Citoesqueleto/metabolismo , Potencial da Membrana Mitocondrial/genética , Potencial da Membrana Mitocondrial/fisiologia , Camundongos Knockout , Proteínas Mitocondriais/metabolismo , Proteínas Musculares/genética , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiologia
4.
Undersea Hyperb Med ; 48(3): 227-238, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34390627

RESUMO

Background: The optimal timing of hyperbaric oxygen (HBO2) treatments for the best recovery following muscle injury has yet to be determined. Thus, the optimal number and timing of HBO2 treatments for maximal muscle regeneration were explored. Methods: The HBO2 treatment protocol consisted of 2.5 ATA 100% oxygen for 120 minutes. Muscle-injured rats were randomized to one of 10 groups: single HBO2 treatment immediately after injury (HBO 1T day 0), one day (HBO 1T day 1), three days (HBO 1T day 3) and five days (HBO 1T day 5) after injury; three HBO2 treatments from immediately after injury to two days after injury (HBO 3T day 0-2), from one to three days after injury (HBO 3T day 1-3), from three to five days after injury (HBO 3T day 3-5), from five to seven days after injury (HBO 3T day 5-7); five daily HBO2 treatments (HBO 5T); and no treatment (NT). Results: HBO 5T and HBO 3T day 0-2, days 1-3 and days 3-5 significantly promoted CD206-positive cell infiltration, satellite cell differentiation and muscle regeneration compared to the NT group. Conclusion: Five HBO2 treatments and three HBO2 treatments within three days of injury promote muscle regeneration.


Assuntos
Contusões/terapia , Oxigenação Hiperbárica/métodos , Músculo Esquelético/lesões , Células Satélites de Músculo Esquelético/fisiologia , Tempo para o Tratamento , Cicatrização/fisiologia , Animais , Diferenciação Celular , Proliferação de Células/fisiologia , Contusões/fisiopatologia , Oxigenação Hiperbárica/estatística & dados numéricos , Macrófagos/fisiologia , Masculino , Contração Muscular/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/patologia , Músculo Esquelético/fisiologia , Projetos Piloto , Distribuição Aleatória , Ratos , Ratos Wistar
5.
FASEB J ; 35(9): e21830, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34342902

RESUMO

Muscle disuse leads to a rapid decline in muscle mass, with reduced muscle protein synthesis (MPS) considered the primary physiological mechanism. Here, we employed a systems biology approach to uncover molecular networks and key molecular candidates that quantitatively link to the degree of muscle atrophy and/or extent of decline in MPS during short-term disuse in humans. After consuming a bolus dose of deuterium oxide (D2 O; 3 mL.kg-1 ), eight healthy males (22 ± 2 years) underwent 4 days of unilateral lower-limb immobilization. Bilateral muscle biopsies were obtained post-intervention for RNA sequencing and D2 O-derived measurement of MPS, with thigh lean mass quantified using dual-energy X-ray absorptiometry. Application of weighted gene co-expression network analysis identified 15 distinct gene clusters ("modules") with an expression profile regulated by disuse and/or quantitatively connected to disuse-induced muscle mass or MPS changes. Module scans for candidate targets established an experimentally tractable set of candidate regulatory molecules (242 hub genes, 31 transcriptional regulators) associated with disuse-induced maladaptation, many themselves potently tied to disuse-induced reductions in muscle mass and/or MPS and, therefore, strong physiologically relevant candidates. Notably, we implicate a putative role for muscle protein breakdown-related molecular networks in impairing MPS during short-term disuse, and further establish DEPTOR (a potent mTOR inhibitor) as a critical mechanistic candidate of disuse driven MPS suppression in humans. Overall, these findings offer a strong benchmark for accelerating mechanistic understanding of short-term muscle disuse atrophy that may help expedite development of therapeutic interventions.


Assuntos
Proteínas Musculares/genética , Músculo Esquelético/fisiologia , Atrofia Muscular/genética , Doenças Musculares/genética , Biossíntese de Proteínas/genética , Transcriptoma/genética , Adulto , Humanos , Masculino , Força Muscular/genética , Adulto Jovem
6.
FASEB J ; 35(9): e21861, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34416029

RESUMO

Duchenne muscular dystrophy (DMD) is an intractable genetic disease associated with progressive skeletal muscle weakness and degeneration. Recently, it was reported that intraperitoneal injections of ketone bodies partially ameliorated muscular dystrophy by increasing satellite cell (SC) proliferation. Here, we evaluated whether a ketogenic diet (KD) with medium-chain triglycerides (MCT-KD) could alter genetically mutated DMD in model rats. We found that the MCT-KD significantly increased muscle strength and fiber diameter in these rats. The MCT-KD significantly suppressed the key features of DMD, namely, muscle necrosis, inflammation, and subsequent fibrosis. Immunocytochemical analysis revealed that the MCT-KD promoted the proliferation of muscle SCs, suggesting enhanced muscle regeneration. The muscle strength of DMD model rats fed with MCT-KD was significantly improved even at the age of 9 months. Our findings suggested that the MCT-KD ameliorates muscular dystrophy by inhibiting myonecrosis and promoting the proliferation of muscle SCs. As far as we can ascertain, this is the first study to apply a functional diet as therapy for DMD in experimental animals. Further studies are needed to elucidate the underlying mechanisms of the MCT-KD-induced improvement of DMD.


Assuntos
Dieta Cetogênica , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/fisiologia , Distrofia Muscular de Duchenne/dietoterapia , Distrofia Muscular de Duchenne/fisiopatologia , Triglicerídeos/química , Triglicerídeos/farmacologia , Animais , Peso Corporal/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Progressão da Doença , Feminino , Fibrose/dietoterapia , Fibrose/patologia , Inflamação/dietoterapia , Inflamação/patologia , Cetonas/sangue , Cetose , Masculino , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Distrofia Muscular de Duchenne/patologia , Necrose/dietoterapia , Necrose/patologia , Ratos , Células Satélites de Músculo Esquelético/citologia , Células Satélites de Músculo Esquelético/efeitos dos fármacos , Triglicerídeos/uso terapêutico
7.
Neurology ; 97(7 Suppl 1): S99-S110, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34230196

RESUMO

OBJECTIVE: To determine a suitable outcome measure for assessing muscle strength in neurofibromatosis (NF) type 1 and NF2 clinical trials, we evaluated the intraobserver reliability of handheld dynamometry (HHD) and developed consensus recommendations for its use in NF clinical trials. METHODS: Patients ≥5 years of age with weakness in at least 1 muscle group by manual muscle testing (MMT) were eligible. Maximal isometric muscle strength of a weak muscle group and the biceps of the dominant arm was measured by HHD. An average of 3 repetitions per session was used as an observation, and 3 sessions with rest period between each were performed on the same day by a single observer. Intrasession and intersession intraclass correlation coefficients (ICCs) and coefficients of variation (CVs) were calculated to assess reliability and measurement error. RESULTS: Twenty patients with NF1 and 13 with NF2 were enrolled; median age was 12 years (interquartile range [IQR] 9-17 years) and 29 years (IQR 22-38 years), respectively. By MMT, weak muscle strength ranged from 2-/5 to 4+/5. Biceps strength was 5/5 in all patients. Intersession ICCs for the weak muscles were 0.98 and 0.99 in the NF1 and NF2 cohorts, respectively, and for biceps were 0.97 and 0.97, respectively. The median CVs for average session strength were 5.4% (IQR 2.6%-7.3%) and 2.9% (IQR 2.0%-6.2%) for weak muscles and biceps, respectively. CONCLUSION: HHD performed by a trained examiner with a well-defined protocol is a reliable technique to measure muscle strength in NF1 and NF2. Recommendations for strength testing in NF1 and NF2 trials are provided.


Assuntos
Contração Isométrica/fisiologia , Força Muscular/fisiologia , Debilidade Muscular/fisiopatologia , Músculo Esquelético/fisiologia , Adolescente , Adulto , Criança , Humanos , Masculino , Pessoa de Meia-Idade , Dinamômetro de Força Muscular , Debilidade Muscular/diagnóstico , Neurofibromatoses/fisiopatologia
8.
Nat Genet ; 53(8): 1156-1165, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34211177

RESUMO

The most prevalent post-transcriptional mRNA modification, N6-methyladenosine (m6A), plays diverse RNA-regulatory roles, but its genetic control in human tissues remains uncharted. Here we report 129 transcriptome-wide m6A profiles, covering 91 individuals and 4 tissues (brain, lung, muscle and heart) from GTEx/eGTEx. We integrate these with interindividual genetic and expression variation, revealing 8,843 tissue-specific and 469 tissue-shared m6A quantitative trait loci (QTLs), which are modestly enriched in, but mostly orthogonal to, expression QTLs. We integrate m6A QTLs with disease genetics, identifying 184 GWAS-colocalized m6A QTL, including brain m6A QTLs underlying neuroticism, depression, schizophrenia and anxiety; lung m6A QTLs underlying expiratory flow and asthma; and muscle/heart m6A QTLs underlying coronary artery disease. Last, we predict novel m6A regulators that show preferential binding in m6A QTLs, protein interactions with known m6A regulators and expression correlation with the m6A levels of their targets. Our results provide important insights and resources for understanding both cis and trans regulation of epitranscriptomic modifications, their interindividual variation and their roles in human disease.


Assuntos
Adenosina/análogos & derivados , Encéfalo/fisiologia , Pulmão/fisiologia , Músculo Esquelético/fisiologia , Locos de Características Quantitativas , Adenosina/genética , Adenosina/metabolismo , Estudo de Associação Genômica Ampla , Coração/fisiologia , Humanos , Metilação , Especificidade de Órgãos , Polimorfismo de Nucleotídeo Único , Processamento Pós-Transcricional do RNA , Proteínas de Ligação a RNA/genética , Reprodutibilidade dos Testes
9.
J Clin Neurosci ; 90: 363-369, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34275577

RESUMO

OBJECTIVE: To investigate the effects of paired associated stimulation (PAS) with different stimulation position on motor cortex excitability and upper limb motor function in patients with cerebral infarction. METHOD: A total of 120 volunteers with cerebral infarction were randomly divided into four groups. Based on conventional rehabilitation treatment, the PAS stimulation group was given the corresponding position of PAS treatment once a day for 28 consecutive days. The MEP amplitude and RMT of both hemispheres were assessed before and after treatment, and a simple upper limb Function Examination Scale (STEF) score, simplified upper limb Fugl-Meyer score (FMA), and improved Barthel Index (MBI) were used to assess upper limb motor function in the four groups. RESULTS: Following PAS, the MEP amplitude decreased, and the RMT of abductor pollicis brevis (APB) increased on the contralesional side, while the MEP amplitude increased and the RMT of APB decreased on the ipsilesional side. After 28 consecutive days the scores of STEF, FMA, and MBI in the bilateral stimulation group were significantly better than those in the ipsilesional stimulation group and the contralesional stimulation group, but there was no significant difference in the scores of STEF, FMA, and MBI between the ipsilesional stimulation group and the contralesional stimulation group. CONCLUSION: The excitability of the motor cortex can be changed when the contralesional side or the ipsilesional side was given the corresponding PAS stimulation, while the bilateral PAS stimulation can more easily cause a change of excitability of the motor cortex, resulting in better recovery of the upper limb function.


Assuntos
Infarto Cerebral/fisiopatologia , Infarto Cerebral/reabilitação , Terapia por Estimulação Elétrica , Córtex Motor/fisiopatologia , Extremidade Superior/fisiopatologia , Adulto , Potencial Evocado Motor , Feminino , Lateralidade Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/inervação , Músculo Esquelético/fisiologia , Reabilitação do Acidente Vascular Cerebral/métodos , Estimulação Magnética Transcraniana
10.
Int J Mol Sci ; 22(12)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203705

RESUMO

The origin of the Oxytocin/Vasopressin system dates back about 600 million years. Oxytocin (Oxt) together with Vasopressin (VP) regulate a diversity of physiological functions that are important for osmoregulation, reproduction, metabolism, and social behavior. Oxt/VP-like peptides have been identified in several invertebrate species and they are functionally related across the entire animal kingdom. Functional conservation enables future exploitation of invertebrate models to study Oxt's functions not related to pregnancy and the basic mechanisms of central Oxt/VP signaling. Specifically, Oxt is well known for its effects on uteri contractility and milk ejection as well as on metabolism and energy homeostasis. Moreover, the striking evidence that Oxt is linked to energy regulation is that Oxt- and Oxytocin receptor (Oxtr)-deficient mice show late onset obesity. Interestingly Oxt-/- or Oxtr-/- mice develop weight gain without increasing food intake, suggesting that a lack of Oxt reduce metabolic rate. Oxt is expressed in a diversity of skeletal muscle phenotypes and regulates thermogenesis and bone mass. Oxt may increases skeletal muscle tonicity and/or increases body temperature. In this review, the author compared the three most recent theories on the effects of Oxt on body composition.


Assuntos
Composição Corporal/efeitos dos fármacos , Ocitocina/farmacologia , Animais , Feminino , Humanos , Invertebrados/efeitos dos fármacos , Invertebrados/metabolismo , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/fisiologia , Gravidez , Termogênese/efeitos dos fármacos , Vasopressinas/metabolismo
11.
Nutrients ; 13(6)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203776

RESUMO

Living longer is associated with an increased risk of chronic diseases, including impairments of the musculoskeletal and immune system as well as metabolic disorders and certain cancers, each of which can negatively affect the relationship between host and microbiota up to the occurrence of dysbiosis. On the other hand, lifestyle factors, including regular physical exercise and a healthy diet, can affect skeletal muscle and immune aging positively at all ages. Accordingly, health benefits could partly depend on the effect of such interventions that influence the biodiversity and functionality of intestinal microbiota. In the present review, we first discuss the physiological effects of aging on the gut microbiota, immune system, and skeletal muscle. Secondly, we describe human epidemiological evidence about the associations between physical activity and fitness and the gut microbiota composition in older adults. The third part highlights the relevance and restorative mechanisms of immune protection through physical activity and specific exercise interventions during aging. Fourth, we present important research findings on the effects of exercise and protein as well as other nutrients on skeletal muscle performance in older adults. Finally, we provide nutritional recommendations to prevent malnutrition and support healthy active aging with a focus on gut microbiota. Key nutrition-related concerns include the need for adequate energy and protein intake for preventing low muscle mass and a higher demand for specific nutrients (e.g., dietary fiber, polyphenols and polyunsaturated fatty acids) that can modify the composition, diversity, and metabolic capacity of the gut microbiota, and may thus provide a practical means of enhancing gut and systemic immune function.


Assuntos
Envelhecimento/fisiologia , Dieta , Microbioma Gastrointestinal/fisiologia , Inflamação , Estilo de Vida , Imunidade Adaptativa , Envelhecimento/imunologia , Desempenho Atlético/fisiologia , Fibras na Dieta , Disbiose , Exercício Físico , Humanos , Sistema Imunitário , Músculo Esquelético/fisiologia , Músculos , Estado Nutricional , Sarcopenia
12.
Curr Sports Med Rep ; 20(7): 359-365, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34234091

RESUMO

ABSTRACT: This article discusses the "bidirectional" relationship between inflammatory bowel disease (IBD) and physical activity. Intestinal symptoms and extraintestinal manifestations of IBD negatively impact a patient's ability to participate in sports. IBD also impacts athletic performance via its effects on muscle mass, muscle function, bone density, and fatigue. Surveys of IBD patients consistently show that IBD interferes with athletic participation. While IBD negatively affects physical activity, there is growing evidence that physical activity can be beneficial for IBD patients. Prospective studies have revealed that structured physical activities may positively influence inflammatory markers, disease activity, muscle strength, bone density, fatigue, stress, anxiety, and quality of life. This suggests that physical activity may be a simple and safe adjuvant therapy for IBD patients. Future studies assessing the optimal activity regimen are warranted. Finally, a cohort of professional athletes with IBD are described for the first time - football players in the National Football League.


Assuntos
Atletas , Desempenho Atlético/fisiologia , Exercício Físico/fisiologia , Doenças Inflamatórias Intestinais/fisiopatologia , Esportes/fisiologia , Ansiedade/terapia , Densidade Óssea/fisiologia , Eritema Nodoso/etiologia , Fadiga/fisiopatologia , Futebol Americano/fisiologia , Futebol Americano/estatística & dados numéricos , Humanos , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/epidemiologia , Doenças Inflamatórias Intestinais/prevenção & controle , Artropatias/classificação , Artropatias/etiologia , Músculo Esquelético/fisiologia , Desempenho Físico Funcional , Pioderma Gangrenoso/etiologia , Qualidade de Vida , Esclerite/etiologia , Dermatopatias/etiologia , Estresse Fisiológico/fisiologia , Uveíte/etiologia
13.
Science ; 373(6551): 223-225, 2021 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-34244415

RESUMO

Basal metabolic rate generally scales with body mass in mammals, and variation from predicted levels indicates adaptive metabolic remodeling. As a thermogenic adaptation for living in cool water, sea otters have a basal metabolic rate approximately three times that of the predicted rate; however, the tissue-level source of this hypermetabolism is unknown. Because skeletal muscle is a major determinant of whole-body metabolism, we characterized respiratory capacity and thermogenic leak in sea otter muscle. Compared with that of previously sampled mammals, thermogenic muscle leak capacity was elevated and could account for sea otter hypermetabolism. Muscle respiratory capacity was modestly elevated and reached adult levels in neonates. Premature metabolic development and high leak rate indicate that sea otter muscle metabolism is regulated by thermogenic demand and is the source of basal hypermetabolism.


Assuntos
Músculo Esquelético/fisiologia , Lontras/fisiologia , Termogênese , Envelhecimento , Animais , Animais Recém-Nascidos/fisiologia , Metabolismo Basal , Tamanho Corporal , Temperatura Baixa , Músculo Esquelético/metabolismo , Lontras/metabolismo , Consumo de Oxigênio
14.
Nutrients ; 13(6)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200501

RESUMO

Adequate dietary protein is important for many aspects of health with current evidence suggesting that exercising individuals need greater amounts of protein. When assessing protein quality, animal sources of protein routinely rank amongst the highest in quality, largely due to the higher levels of essential amino acids they possess in addition to exhibiting more favorable levels of digestibility and absorption patterns of the amino acids. In recent years, the inclusion of plant protein sources in the diet has grown and evidence continues to accumulate on the comparison of various plant protein sources and animal protein sources in their ability to stimulate muscle protein synthesis (MPS), heighten exercise training adaptations, and facilitate recovery from exercise. Without question, the most robust changes in MPS come from efficacious doses of a whey protein isolate, but several studies have highlighted the successful ability of different plant sources to significantly elevate resting rates of MPS. In terms of facilitating prolonged adaptations to exercise training, multiple studies have indicated that a dose of plant protein that offers enough essential amino acids, especially leucine, consumed over 8-12 weeks can stimulate similar adaptations as seen with animal protein sources. More research is needed to see if longer supplementation periods maintain equivalence between the protein sources. Several practices exist whereby the anabolic potential of a plant protein source can be improved and generally, more research is needed to best understand which practice (if any) offers notable advantages. In conclusion, as one considers the favorable health implications of increasing plant intake as well as environmental sustainability, the interest in consuming more plant proteins will continue to be present. The evidence base for plant proteins in exercising individuals has seen impressive growth with many of these findings now indicating that consumption of a plant protein source in an efficacious dose (typically larger than an animal protein) can instigate similar and favorable changes in amino acid update, MPS rates, and exercise training adaptations such as strength and body composition as well as recovery.


Assuntos
Adaptação Fisiológica , Exercício Físico/fisiologia , Proteínas de Plantas/farmacologia , Animais , Humanos , Proteínas Musculares/metabolismo , Músculo Esquelético/fisiologia , Plantas/química
15.
Artigo em Inglês | MEDLINE | ID: mdl-34299795

RESUMO

BACKGROUND/AIMS: Elevated levels of serum myostatin have been proposed as a biomarker for sarcopenia. Recent studies have shown that elevated level of serum myostatin was associated with physical fitness and performance. This study aimed to examine the significance of myostatin in the association between muscle mass and physical performance in the elderly. METHODS: This cross-sectional study is based on the Korean Frailty and Aging Cohort study involving 1053 people aged 70 years or over. Anthropometric, physical performance, and laboratory data were collected. RESULTS: The mean age of the participants was 75.8 years, and 50.7% of them were female. Serum myostatin levels in men (3.7 ± 1.2 vs. 3.2 ± 1.1 ng/mL, p < 0.001) were higher compared with that in women. Serum myostatin level was associated with appendicular skeletal muscle mass (ASM) index and eGFR by cystatin C. Serum myostatin/ASM ratio was associated with handgrip strength in women. CONCLUSION: Higher serum myostatin levels were related with higher muscle mass and better physical performances in the elderly. Serum myostatin/ASM ratio may be a predictor for physical performance rather than myostatin.


Assuntos
Força da Mão , Músculo Esquelético/fisiologia , Miostatina , Idoso , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Masculino
16.
Int J Mol Sci ; 22(13)2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34281225

RESUMO

Thyroid hormones (THs) are key regulators of different biological processes. Their action involves genomic and non-genomic mechanisms, which together mediate the final effects of TH in target tissues. However, the proportion of the two processes and their contribution to the TH-mediated effects are still poorly understood. Skeletal muscle is a classical target tissue for TH, which regulates muscle strength and contraction, as well as energetic metabolism of myofibers. Here we address the different contribution of genomic and non-genomic action of TH in skeletal muscle cells by specifically silencing the deiodinase Dio2 or the ß3-Integrin expression via CRISPR/Cas9 technology. We found that myoblast proliferation is inversely regulated by integrin signal and the D2-dependent TH activation. Similarly, inhibition of the nuclear receptor action reduced myoblast proliferation, confirming that genomic action of TH attenuates proliferative rates. Contrarily, genomic and non-genomic signals promote muscle differentiation and the regulation of the redox state. Taken together, our data reveal that integration of genomic and non-genomic signal pathways finely regulates skeletal muscle physiology. These findings not only contribute to the understanding of the mechanisms involved in TH modulation of muscle physiology but also add insight into the interplay between different mechanisms of action of TH in muscle cells.


Assuntos
Células Musculares/fisiologia , Músculo Esquelético/fisiologia , Hormônios Tireóideos/fisiologia , Animais , Diferenciação Celular , Integrina beta3/fisiologia , Iodeto Peroxidase/fisiologia , Camundongos , Músculo Esquelético/citologia
17.
Gene ; 801: 145853, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34274464

RESUMO

Fish skeletal muscle is comprised of fast muscle (FM) and slow muscle (SM), which constitutes 60% of total the body mass. Fish skeletal muscle can affect fish swimming activity, which is important for aquaculture due to its growth-potentiating effects. DNA methylation can influence gene expression level. We previously identified multiple differentially expressed genes (DEGs) between FM and SM in Takifugu rubripes. However, it is unknown if the expression levels of these DEGs are influenced by DNA methylation. In the present study, we used DNA methylation sequencing to study the DNA methylation profiles of FM and SM in T. rubripes. SM had higher overall methylation levels than FM. A total of 8479 differentially methylated genes (DMGs) and 3407 DMGs containing differentially methylated regions (DMRs) in the promoter regions between FM and SM were identified. After enrichment analysis, we found functionally relevant DMGs between FM and SM, including Kapca, Plcd3a, Plcd1, Pi3k, Tsp4b and Pgfrb in the hedgehog signaling pathway and phosphatidylinositol (PI)-related pathways. Due to the different methylation levels of these genes between FM and SM, the expression levels of Kapca, Plcd3a, Plcd1, Pi3k, and Tsp4b were higher in FM and Pgfrb was higher in SM. There were differences in the hedgehog signaling pathway and PI-related pathways between FM and SM. In SM, the cytokine-cytokine receptor interaction promoted focal adhesion, while ECM-receptor interactions promoted focal adhesion in FM. These results provide information regarding the difference between FM and SM in T. rubripes.


Assuntos
Metilação de DNA , Proteínas de Peixes/genética , Músculo Esquelético/fisiologia , Takifugu/genética , Animais , Ontologia Genética , Regiões Promotoras Genéticas , Takifugu/fisiologia
18.
FASEB J ; 35(8): e21773, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34324735

RESUMO

Acute hypoxia has previously been suggested to potentiate resistance training-induced hypertrophy by activating satellite cell-dependent myogenesis rather than an improvement in protein balance in human. Here, we tested this hypothesis after a 4-week hypoxic vs normoxic resistance training protocol. For that purpose, 19 physically active male subjects were recruited to perform 6 sets of 10 repetitions of a one-leg knee extension exercise at 80% 1-RM 3 times/week for 4 weeks in normoxia (FiO2 : 0.21; n = 9) or in hypoxia (FiO2 : 0.135, n = 10). Blood and skeletal muscle samples were taken before and after the training period. Muscle fractional protein synthetic rate was measured over the whole period by deuterium incorporation into the protein pool and muscle thickness by ultrasound. At the end of the training protocol, the strength gain was higher in the hypoxic vs the normoxic group despite no changes in muscle thickness and in the fractional protein synthetic rate. Only early myogenesis, as assessed by higher MyoD and Myf5 mRNA levels, appeared to be enhanced by hypoxia compared to normoxia. No effects were found on myosin heavy chain expression, markers of oxidative metabolism and lactate transport in the skeletal muscle. Though the present study failed to unravel clearly the mechanisms by which hypoxic resistance training is particularly potent to increase muscle strength, it is important message to keep in mind that this training strategy could be effective for all athletes looking at developing and optimizing their maximal muscle strength.


Assuntos
Proteínas Musculares/metabolismo , Força Muscular/fisiologia , Músculo Esquelético/anatomia & histologia , Oxigênio/metabolismo , Treinamento de Força/métodos , Regulação da Expressão Gênica , Humanos , Masculino , Músculo Esquelético/fisiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Células Satélites de Músculo Esquelético/fisiologia , Adulto Jovem
19.
Scand J Med Sci Sports ; 31(9): 1809-1821, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34170574

RESUMO

The etiology of changes in lower-limb neuromuscular function, especially to the central nervous system, may be affected by exercise duration. Direct evidence is lacking as few studies have directly compared different race distances. This study aimed to investigate the etiology of deficits in neuromuscular function following short versus long trail-running races. Thirty-two male trail runners completed one of five trail-running races as LONG (>100 km) or SHORT (<60 km). Pre- and post-race, maximal voluntary contraction (MVC) torque and evoked responses to electrical nerve stimulation during MVCs and at rest were used to assess voluntary activation and muscle contractile properties of knee-extensor (KE) and plantar-flexor (PF) muscles. Transcranial magnetic stimulation (TMS) was used to assess evoked responses and corticospinal excitability in maximal and submaximal KE contractions. Race distance correlated with KE MVC (ρ = -0.556) and twitch (ρ = -0.521) torque decreases (p ≤ .003). KE twitch torque decreased more in LONG (-28 ± 14%) than SHORT (-14 ± 10%, p = .005); however, KE MVC time × distance interaction was not significant (p = .073). No differences between LONG and SHORT for PF MVC or twitch torque were observed. Maximal voluntary activation decreased similarly in LONG and SHORT in both muscle groups (p ≥ .637). TMS-elicited silent period decreased in LONG (p = .021) but not SHORT (p = .912). Greater muscle contractile property impairment in longer races, not central perturbations, contributed to the correlation between KE MVC loss and race distance. Conversely, PF fatigability was unaffected by race distance.


Assuntos
Potencial Evocado Motor/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Corrida/fisiologia , Adulto , Desempenho Atlético/fisiologia , Proteína C-Reativa/análise , Creatina Quinase/sangue , Estimulação Elétrica , Eletromiografia , Nervo Femoral/fisiologia , Humanos , Contagem de Leucócitos , Masculino , Fadiga Muscular/fisiologia , Resistência Física/fisiologia , Nervo Tibial/fisiologia , Fatores de Tempo , Torque , Estimulação Magnética Transcraniana
20.
J Biol Chem ; 297(1): 100874, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34129875

RESUMO

In skeletal muscle tissue, an intriguing mechanical coupling exists between two ion channels from different membranes: the L-type voltage-gated calcium channel (CaV1.1), located in the plasma membrane, and ryanodine receptor 1 (RyR1) located in the sarcoplasmic reticulum membrane. Excitable cells rely on Cavs to initiate Ca2+ entry in response to action potentials. RyRs can amplify this signal by releasing Ca2+ from internal stores. Although this process can be mediated through Ca2+ as a messenger, an overwhelming amount of evidence suggests that RyR1 has recruited CaV1.1 directly as its voltage sensor. The exact mechanisms that underlie this coupling have been enigmatic, but a recent wave of reports have illuminated the coupling protein STAC3 as a critical player. Without STAC3, the mechanical coupling between Cav1.1 and RyR1 is lost, and muscles fail to contract. Various sequence variants of this protein have been linked to congenital myopathy. Other STAC isoforms are expressed in the brain and may serve as regulators of L-type CaVs. Despite the short length of STACs, several points of contacts have been proposed between them and CaVs. However, it is currently unclear whether STAC3 also forms direct interactions with RyR1, and whether this modulates RyR1 function. In this review, we discuss the 3D architecture of STAC proteins, the biochemical evidence for their interactions, the relevance of these connections for functional modulation, and their involvement in myopathy.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Acoplamento Excitação-Contração , Domínios de Homologia de src , Proteínas Adaptadoras de Transdução de Sinal/química , Animais , Canais de Cálcio/química , Canais de Cálcio/metabolismo , Humanos , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiologia
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