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1.
Int J Mol Sci ; 22(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34360888

RESUMO

Osteoarthritis (OA) is a degenerative joint disease characterized by irreversible cartilage damage, inflammation and altered chondrocyte phenotype. Transforming growth factor-ß (TGF-ß) signaling via SMAD2/3 is crucial for blocking hypertrophy. The post-translational modifications of these SMAD proteins in the linker domain regulate their function and these can be triggered by inflammation through the activation of kinases or phosphatases. Therefore, we investigated if OA-related inflammation affects TGF-ß signaling via SMAD2/3 linker-modifications in chondrocytes. We found that both Interleukin (IL)-1ß and OA-synovium conditioned medium negated SMAD2/3 transcriptional activity in chondrocytes. This inhibition of TGF-ß signaling was enhanced if SMAD3 could not be phosphorylated on Ser213 in the linker region and the inhibition by IL-1ß was less if the SMAD3 linker could not be phosphorylated at Ser204. Our study shows evidence that inflammation inhibits SMAD2/3 signaling in chondrocytes via SMAD linker (de)-phosphorylation. The involvement of linker region modifications may represent a new therapeutic target for OA.


Assuntos
Condrócitos/metabolismo , Condrócitos/patologia , Osteoartrite/metabolismo , Transdução de Sinais/genética , Proteína Smad2/química , Proteína Smad2/metabolismo , Proteína Smad3/química , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Adulto , Animais , Bovinos , Linhagem Celular Tumoral , Humanos , Hipertrofia/metabolismo , Inflamação/metabolismo , Interleucina-1beta/farmacologia , Osteoartrite/genética , Osteoartrite/patologia , Fosforilação/efeitos dos fármacos , Fosforilação/genética , Domínios Proteicos/efeitos dos fármacos , Proteínas Recombinantes/farmacologia , Transdução de Sinais/efeitos dos fármacos , Proteína Smad2/genética , Proteína Smad3/genética , Membrana Sinovial/metabolismo , Transfecção , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/farmacologia
2.
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
3.
Int J Mol Sci ; 22(10)2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-34064664

RESUMO

Rutin is a flavonoid with antioxidant property. It has been shown to exert cardioprotection against cardiomyocyte hypertrophy. However, studies regarding its antihypertrophic property are still lacking, whether it demonstrates similar antihypertrophic effect to its metabolite, quercetin. Hence, this study aimed to investigate the effects of both flavonoids on oxidative stress and mitogen-activated protein kinase (MAPK) pathway in H9c2 cardiomyocytes that were exposed to angiotensin II (Ang II) to induce hypertrophy. Cardiomyocytes were exposed to Ang II (600 nM) with or without quercetin (331 µM) or rutin (50 µM) for 24 h. A group given vehicle served as the control. The concentration of the flavonoids was chosen based on the reported effective concentration to reduce cell hypertrophy or cardiac injury in H9c2 cells. Exposure to Ang II increased cell surface area, intracellular superoxide anion level, NADPH oxidase and inducible nitric oxide synthase activities, and reduced cellular superoxide dismutase activity and nitrite level, which were similarly reversed by both rutin and quercetin. Rutin had no significant effects on phosphorylated proteins of extracellular signal-related kinases (ERK1/2) and p38 but downregulated phosphorylated c-Jun N-terminal kinases (JNK1/2), which were induced by Ang II. Quercetin, on the other hand, had significantly downregulated the phosphorylated proteins of ERK1/2, p38, and JNK1/2. The quercetin inhibitory effect on JNK1/2 was stronger than the rutin. In conclusion, both flavonoids afford similar protective effects against Ang II-induced cardiomyocyte hypertrophy, but they differently modulate MAPK pathway.


Assuntos
Angiotensina II/toxicidade , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Hipertrofia/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Mioblastos Cardíacos/metabolismo , Quercetina/farmacologia , Rutina/farmacologia , Animais , Antioxidantes/farmacologia , Células Cultivadas , Hipertrofia/induzido quimicamente , Hipertrofia/tratamento farmacológico , Hipertrofia/patologia , Proteínas Quinases Ativadas por Mitógeno/genética , Mioblastos Cardíacos/citologia , Mioblastos Cardíacos/efeitos dos fármacos , NADPH Oxidases/metabolismo , Óxido Nítrico/metabolismo , Fosforilação , Ratos , Espécies Reativas de Oxigênio/metabolismo , Vasoconstritores/toxicidade
4.
Obesity (Silver Spring) ; 29(6): 976-984, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33943025

RESUMO

OBJECTIVE: Morphological alterations including adipocyte hypertrophy and fibrosis deposition are important surrogate markers of visceral adipose tissue function, but the relationships between these morphological changes and type 2 diabetes mellitus (T2DM) and impaired insulin sensitivity are poorly defined. METHODS: Omental adipose tissue was obtained from 66 individuals with obesity but without T2DM (OB group), 93 individuals with both obesity and T2DM (T2DM group), and 15 individuals with normal BMI and normal glucose tolerance (NGT group). Adipocyte diameter and volume were measured through pathological section analysis. Pericellular and perilobular fibrosis was determined through picrosirius red staining and immunochemistry, while fibrosis-related genes were tested through gene expression and hydroxyproline content. RESULTS: Compared with the NGT and OB groups, individuals from the T2DM group displayed increased adipocyte diameter and volume levels. Increased adipocyte size (diameter and volume) was positively associated with hyperglycemia and insulin resistance and inversely correlated with insulin sensitivity (using the Matsuda whole-body insulin sensitivity index assessment of insulin sensitivity) and ß-cell function (disposition index 30 and disposition index 120). The fibrosis levels of the OB group were the highest out of the three groups, whereas the fibrosis levels of T2DM individuals were lower than the OB group but higher than the NGT group. Although fibrosis was negatively correlated with T2DM, fibrosis deposition was not remarkably associated with impaired systemic insulin sensitivity and glucose metabolism. CONCLUSIONS: Compared with fibrosis deposition, adipocyte hypertrophy is more closely associated with T2DM and impaired systemic insulin sensitivity.


Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Gordura Intra-Abdominal/patologia , Obesidade/epidemiologia , Omento/metabolismo , Adipócitos/metabolismo , Adipócitos/patologia , Adulto , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Feminino , Fibrose/complicações , Fibrose/epidemiologia , Fibrose/metabolismo , Humanos , Hipertrofia/complicações , Hipertrofia/epidemiologia , Hipertrofia/metabolismo , Resistência à Insulina/fisiologia , Gordura Intra-Abdominal/metabolismo , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/metabolismo , Obesidade/patologia , Omento/patologia
5.
Front Immunol ; 12: 648064, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33995367

RESUMO

Immune responses at the boundary between the host and the world beyond are complex and mucosal tissue homeostasis relies on them. Obstructive sleep apnea (OSA) is a syndrome suffered by children with hypertrophied tonsils. We have previously demonstrated that these tonsils present a defective regulatory B cell (Breg) compartment. Here, we extend those findings by uncovering the crucial role of resident pro-inflammatory B and T cells in sustaining tonsillar hypertrophy and hyperplasia by producing TNFα and IL17, respectively, in ex vivo cultures. Additionally, we detected prominent levels of expression of CD1d by tonsillar stratified as well as reticular epithelium, which have not previously been reported. Furthermore, we evidenced the hypertrophy of germinal centers (GC) and the general hyperplasia of B lymphocytes within the tissue and the lumen of the crypts. Of note, such B cells resulted mainly (IgG/IgM)+ cells, with some IgA+ cells located marginally in the follicles. Finally, by combining bacterial culture from the tonsillar core and subsequent identification of the respective isolates, we determined the most prevalent species within the cohort of OSA patients. Although the isolated species are considered normal oropharyngeal commensals in children, we confirmed their capacity to breach the epithelial barrier. Our work sheds light on the pathological mechanism underlying OSA, highlighting the relevance taken by the host immune system when defining infection versus colonization, and opening alternatives of treatment.


Assuntos
Bactérias/imunologia , Infecções Bacterianas/imunologia , Mucosa Bucal/imunologia , Mucosa Bucal/microbiologia , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/imunologia , Tonsilite/complicações , Tonsilite/imunologia , Adolescente , Linfócitos B/imunologia , Bactérias/isolamento & purificação , Infecções Bacterianas/microbiologia , Células Cultivadas , Criança , Pré-Escolar , Doença Crônica , Estudos de Coortes , Citocinas/metabolismo , Feminino , Centro Germinativo/imunologia , Humanos , Hipertrofia/imunologia , Hipertrofia/metabolismo , Inflamação/imunologia , Inflamação/metabolismo , Masculino , Tonsila Palatina/imunologia , Linfócitos T/imunologia , Tonsilectomia , Tonsilite/microbiologia , Tonsilite/cirurgia
6.
Aging (Albany NY) ; 13(8): 10891-10919, 2021 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-33864446

RESUMO

Alzheimer's disease (AD) is frequently accompanied by progressing weight loss, correlating with mortality. Counter-intuitively, weight loss in old age might predict AD onset but obesity in midlife increases AD risk. Furthermore, AD is associated with diabetes-like alterations in glucose metabolism. Here, we investigated metabolic features of amyloid precursor protein overexpressing APP23 female mice modeling AD upon long-term challenge with high-sucrose (HSD) or high-fat diet (HFD). Compared to wild type littermates (WT), APP23 females were less prone to mild HSD-induced and considerable HFD-induced glucose tolerance deterioration, despite unaltered glucose tolerance during normal-control diet. Indirect calorimetry revealed increased energy expenditure and hyperactivity in APP23 females. Dietary interventions, especially HFD, had weaker effects on lean and fat mass gain, steatosis and adipocyte hypertrophy of APP23 than WT mice, as shown by 1H-magnetic-resonance-spectroscopy, histological and biochemical analyses. Proteome analysis revealed differentially regulated expression of mitochondrial proteins in APP23 livers and brains. In conclusion, hyperactivity, increased metabolic rate, and global mitochondrial dysfunction potentially add up to the development of AD-related body weight changes in APP23 females, becoming especially evident during diet-induced metabolic challenge. These findings emphasize the importance of translating this metabolic phenotyping into human research to decode the metabolic component in AD pathogenesis.


Assuntos
Adipócitos/patologia , Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/genética , Fígado Gorduroso/diagnóstico , Intolerância à Glucose/diagnóstico , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Encéfalo/patologia , Dieta Hiperlipídica/efeitos adversos , Sacarose na Dieta/administração & dosagem , Sacarose na Dieta/efeitos adversos , Modelos Animais de Doenças , Metabolismo Energético/genética , Fígado Gorduroso/etiologia , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Feminino , Intolerância à Glucose/etiologia , Intolerância à Glucose/metabolismo , Intolerância à Glucose/patologia , Humanos , Hipertrofia/diagnóstico , Hipertrofia/etiologia , Hipertrofia/metabolismo , Hipertrofia/patologia , Fígado/patologia , Camundongos , Camundongos Transgênicos , Índice de Gravidade de Doença
7.
FASEB J ; 35(5): e21587, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33891350

RESUMO

We examined the association between genotype and resistance training-induced changes (12 wk) in dual x-ray energy absorptiometry (DXA)-derived lean soft tissue mass (LSTM) as well as muscle fiber cross-sectional area (fCSA; vastus lateralis; n = 109; age = 22 ± 2 y, BMI = 24.7 ± 3.1 kg/m2 ). Over 315 000 genetic polymorphisms were interrogated from muscle using DNA microarrays. First, a targeted investigation was performed where single nucleotide polymorphisms (SNP) identified from a systematic literature review were related to changes in LSTM and fCSA. Next, genome-wide association (GWA) studies were performed to reveal associations between novel SNP targets with pre- to post-training change scores in mean fCSA and LSTM. Our targeted investigation revealed no genotype-by-time interactions for 12 common polymorphisms regarding the change in mean fCSA or change in LSTM. Our first GWA study indicated no SNP were associated with the change in LSTM. However, the second GWA study indicated two SNP exceeded the significance level with the change in mean fCSA (P = 6.9 × 10-7 for rs4675569, 1.7 × 10-6 for rs10263647). While the former target is not annotated (chr2:205936846 (GRCh38.p12)), the latter target (chr7:41971865 (GRCh38.p12)) is an intron variant of the GLI Family Zinc Finger 3 (GLI3) gene. Follow-up analyses indicated fCSA increases were greater in the T/C and C/C GLI3 genotypes than the T/T GLI3 genotype (P < .05). Data from the Auburn cohort also revealed participants with the T/C and C/C genotypes exhibited increases in satellite cell number with training (P < .05), whereas T/T participants did not. Additionally, those with the T/C and C/C genotypes achieved myonuclear addition in response to training (P < .05), whereas the T/T participants did not. In summary, this is the first GWA study to examine how polymorphisms associate with the change in hypertrophy measures following resistance training. Future studies are needed to determine if the GLI3 variant differentiates hypertrophic responses to resistance training given the potential link between this gene and satellite cell physiology.


Assuntos
Hipertrofia/patologia , Íntrons , Fibras Musculares Esqueléticas/patologia , Proteínas do Tecido Nervoso/genética , Polimorfismo de Nucleotídeo Único , Treinamento de Força/efeitos adversos , Proteína Gli3 com Dedos de Zinco/genética , Adulto , Estudo de Associação Genômica Ampla , Humanos , Hipertrofia/etiologia , Hipertrofia/metabolismo , Masculino , Fibras Musculares Esqueléticas/metabolismo , Adulto Jovem
8.
Am J Physiol Cell Physiol ; 320(6): C987-C999, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33881936

RESUMO

Polyamines have been shown to be absolutely required for protein synthesis and cell growth. The serine/threonine kinase, the mechanistic target of rapamycin complex 1 (mTORC1), also plays a fundamental role in the regulation of protein turnover and cell size, including in skeletal muscle, where mTORC1 is sufficient to increase protein synthesis and muscle fiber size, and is necessary for mechanical overload-induced muscle hypertrophy. Recent evidence suggests that mTORC1 may regulate the polyamine metabolic pathway, however, there is currently no evidence in skeletal muscle. This study examined changes in polyamine pathway proteins during muscle hypertrophy induced by mechanical overload (7 days), with and without the mTORC1 inhibitor, rapamycin, and during muscle atrophy induced by food deprivation (48 h) and denervation (7 days) in mice. Mechanical overload induced an increase in mTORC1 signaling, protein synthesis and muscle mass, and these were associated with rapamycin-sensitive increases in adenosylmethione decarboxylase 1 (Amd1), spermidine synthase (SpdSyn), and c-Myc. Food deprivation decreased mTORC1 signaling, protein synthesis, and muscle mass, accompanied by a decrease in spermidine/spermine acetyltransferase 1 (Sat1). Denervation, resulted increased mTORC1 signaling and protein synthesis, and decreased muscle mass, which was associated with an increase in SpdSyn, spermine synthase (SpmSyn), and c-Myc. Combined, these data show that polyamine pathway enzymes are differentially regulated in models of altered mechanical and metabolic stress, and that Amd1 and SpdSyn are, in part, regulated in a mTORC1-dependent manner. Furthermore, these data suggest that polyamines may play a role in the adaptive response to stressors in skeletal muscle.


Assuntos
Hipertrofia/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Músculo Esquelético/metabolismo , Atrofia Muscular/metabolismo , Poliaminas/metabolismo , Transdução de Sinais/fisiologia , Acetiltransferases/metabolismo , Adenosilmetionina Descarboxilase/metabolismo , Animais , Feminino , Camundongos , Proteínas Musculares/metabolismo , Espermidina Sintase/metabolismo
9.
J Physiol ; 599(13): 3363-3384, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33913170

RESUMO

KEY POINTS: Ribosome biogenesis and MYC transcription are associated with acute resistance exercise (RE) and are distinct from endurance exercise in human skeletal muscle throughout a 24 h time course of recovery. A PCR-based method for relative ribosomal DNA (rDNA) copy number estimation was validated by whole genome sequencing and revealed that rDNA dosage is positively correlated with ribosome biogenesis in response to RE. Acute RE modifies rDNA methylation patterns in enhancer, intergenic spacer and non-canonical MYC-associated regions, but not the promoter. Myonuclear-specific rDNA methylation patterns with acute mechanical overload in mice corroborate and expand on rDNA findings with RE in humans. A genetic predisposition for hypertrophic responsiveness may exist based on rDNA gene dosage. ABSTRACT: Ribosomes are the macromolecular engines of protein synthesis. Skeletal muscle ribosome biogenesis is stimulated by exercise, although the contribution of ribosomal DNA (rDNA) copy number and methylation to exercise-induced rDNA transcription is unclear. To investigate the genetic and epigenetic regulation of ribosome biogenesis with exercise, a time course of skeletal muscle biopsies was obtained from 30 participants (18 men and 12 women; 31 ± 8 years, 25 ± 4 kg m-2 ) at rest and 30 min, 3 h, 8 h and 24 h after acute endurance (n = 10, 45 min cycling, 70% V ̇ O 2 max ) or resistance exercise (n = 10, 4 × 7 × 2 exercises); 10 control participants underwent biopsies without exercise. rDNA transcription and dosage were assessed using quantitative PCR and whole genome sequencing. rDNA promoter methylation was investigated using massARRAY EpiTYPER and global rDNA CpG methylation was assessed using reduced-representation bisulphite sequencing. Ribosome biogenesis and MYC transcription were associated primarily with resistance but not endurance exercise, indicating preferential up-regulation during hypertrophic processes. With resistance exercise, ribosome biogenesis was associated with rDNA gene dosage, as well as epigenetic changes in enhancer and non-canonical MYC-associated areas in rDNA, but not the promoter. A mouse model of in vivo metabolic RNA labelling and genetic myonuclear fluorescence labelling validated the effects of an acute hypertrophic stimulus on ribosome biogenesis and Myc transcription, and also corroborated rDNA enhancer and Myc-associated methylation alterations specifically in myonuclei. The present study provides the first information on skeletal muscle genetic and rDNA gene-wide epigenetic regulation of ribosome biogenesis in response to exercise, revealing novel roles for rDNA dosage and CpG methylation.


Assuntos
Epigênese Genética , Ribossomos , Animais , Humanos , Hipertrofia/metabolismo , Camundongos , Músculo Esquelético/metabolismo , Biossíntese de Proteínas , Ribossomos/metabolismo
10.
FASEB J ; 35(4): e21459, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33710687

RESUMO

Chronic muscle loading (overload) induces skeletal muscles to undergo hypertrophy and to increase glucose uptake. Although AMP-activated protein kinase (AMPK) reportedly serves as a negative regulator of hypertrophy and a positive regulator of glucose uptake, its role in overload-induced skeletal muscle hypertrophy and glucose uptake is unclear. This study aimed to determine whether AMPK regulates overload-induced hypertrophy and glucose uptake in skeletal muscles. To this end, skeletal muscle overload was induced through unilateral synergist ablations in wild-type (WT) and transgenic mice, expressing the dominant-negative mutation of AMPK (AMPK-DN). After 14 days, parameters, including muscle fiber cross-sectional area (CSA), glycogen level, and in vivo [3 H]-2-deoxy-D-glucose uptake, were assessed. No significant difference was observed in body weight or blood glucose level between the WT and AMPK-DN mice. However, the 14-day muscle overload activated the AMPK pathway in WT mice skeletal muscle, whereas this response was impaired in the AMPK-DN mice. Despite a normal CSA gain in each fiber type, the AMPK-DN mice demonstrated a significant impairment of overload-induced muscle glucose uptake and glycogenesis, compared to WT mice. Moreover, 14-day overload-induced changes in GLUT4 and HKII expression levels were reduced in AMPK-DN mice, compared to WT mice. This study demonstrated that AMPK activation is indispensable for overload-induced muscle glucose uptake and glycogenesis; however, it is dispensable for the induction of hypertrophy in AMPK-DN mice. Furthermore, the AMPK/GLUT4 and HKII axes may regulate overload-induced muscle glucose uptake and glycogenesis.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Glucose/metabolismo , Hipertrofia/metabolismo , Músculos/metabolismo , Animais , Glicogênio/metabolismo , Camundongos Transgênicos , Músculo Esquelético/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo
11.
J Physiol Biochem ; 77(2): 331-339, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33635524

RESUMO

The unfolded protein response (UPR) plays a pivotal role in some exercise training-induced physiological adaptation. Our aim was to evaluate the changes in the protein kinase R-like endoplasmic reticulum kinase (PERK) arm of the UPR and hypertrophy signaling pathway following 8 weeks of resistance training and creatine (Cr) supplementation in rats. Thirty-two adult male Wistar rats (8 weeks old) were randomly divided into 4 groups of 8: untrained + placebo (UN+P), resistance training + placebo (RT+P), untrained + Cr (UN+Cr), and resistance training + Cr (RT+Cr). Trained animals were submitted to the ladder-climbing exercise training 5 days per week for a total of 8 weeks. Cr supplementation groups received creatine diluted with 1.5 ml of 5% dextrose orally. The flexor hallucis longus (FHL) muscle was extracted 48 h after the last training session and used for western blotting. After training period, the RT+Cr and RT+P groups presented a significant increase in phosphorylated and phosphorylated/total ratio hypertrophy indices, phosphorylated and phosphorylated/total ratio PERK pathway proteins, and other downstream proteins of the PERK cascade compared with their untrained counterparts (P < 0.05). The increase in hypertrophy indices were higher but PERK pathway proteins were lower in the RT-Cr group than in the RT+P group (P < 0.05). There was no significant difference between the untrained groups (P > 0.05). Our study suggests that resistance training in addition to Cr supplementation modifies PERK pathway response and improves skeletal muscle hypertrophy.


Assuntos
Creatina/administração & dosagem , Hipertrofia/genética , Músculo Esquelético/metabolismo , Condicionamento Físico Animal/métodos , Processamento de Proteína Pós-Traducional , Resposta a Proteínas não Dobradas , eIF-2 Quinase/genética , Fator 4 Ativador da Transcrição/genética , Fator 4 Ativador da Transcrição/metabolismo , Adaptação Fisiológica , Animais , Suplementos Nutricionais , Fator de Iniciação 2 em Eucariotos/genética , Fator de Iniciação 2 em Eucariotos/metabolismo , Hipertrofia/etiologia , Hipertrofia/metabolismo , Masculino , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Wistar , Treinamento de Força , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Fator de Transcrição CHOP/genética , Fator de Transcrição CHOP/metabolismo , eIF-2 Quinase/metabolismo
12.
Molecules ; 26(4)2021 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-33561994

RESUMO

Duchenne muscular dystrophy (DMD) is a progressive fatal neuromuscular disorder with no cure. Therapies to restore dystrophin deficiency have been approved in some jurisdictions but long-term effectiveness is yet to be established. There is a need to develop alternative strategies to treat DMD. Resveratrol is a nutraceutical with anti-inflammatory properties. Previous studies have shown high doses (100-400 mg/kg bodyweight/day) benefit mdx mice. We treated 4-week-old mdx and wildtype mice with a lower dose of resveratrol (5 mg/kg bodyweight/day) for 15 weeks. Voluntary exercise was used to test if a lower dosage than previously tested could reduce exercise-induced damage where a greater inflammatory infiltrate is present. We found resveratrol promoted skeletal muscle hypertrophy in wildtype mice. In dystrophic muscle, resveratrol reduced exercise-induced muscle necrosis. Gene expression of immune cell markers, CD86 and CD163 were reduced; however, signalling targets associated with resveratrol's mechanism of action including Sirt1 and NF-κB were unchanged. In conclusion, a lower dose of resveratrol compared to the dosage used by other studies reduced necrosis and gene expression of inflammatory cell markers in dystrophic muscle suggesting it as a therapeutic candidate for treating DMD.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Resveratrol/farmacologia , Animais , Biomarcadores/metabolismo , Hipertrofia/induzido quimicamente , Hipertrofia/metabolismo , Hipertrofia/patologia , Inflamação/metabolismo , Camundongos , Necrose/tratamento farmacológico , Resveratrol/uso terapêutico
13.
Lasers Med Sci ; 36(4): 791-802, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32638240

RESUMO

Compensatory hypertrophy (CH) occurs due to excessive mechanical load on a muscle, promoting an increase in the size of muscle fibers. In clinical practice, situations such as partial nerve injuries, denervation, and muscle imbalance caused by trauma to muscles and nerves or diseases that promote the loss of nerve conduction can induce CH in muscle fibers. Photobiomodulation (PBM) has demonstrated beneficial effects on muscle tissue during CH. The aim of the present study was to evaluate the effect of PBM on the inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) as well as type 2 metalloproteinases (MMP-2) during the process of CH due to excessive load on the plantaris muscle in rats. Forty-five Wistar rats weighing 250 g were divided into three groups: control group (n = 10), hypertrophy (H) group (n = 40), and H + PBM group (n = 40). CH was induced through the ablation of synergist muscles of the plantaris muscle. The tendons of the gastrocnemius and soleus muscles were isolated and sectioned to enable the partial removal of each of muscle. The preserved plantaris muscle below the removed muscles was submitted to excessive functional load. PBM was performed with low-level laser (AsGaAl, λ = 780 nm; 40 mW; energy density: 10 J/cm2; 10 s on each point, 8 points; 3.2 J). Animals from each group were euthanized after 7 and 14 days. The plantaris muscles were carefully removed and sent for analysis of the gene and protein expression of IL-6 and TNF-α using qPCR and ELISA, respectively. MMP-2 activity was analyzed using zymography. The results were submitted to statistical analysis (ANOVA + Tukey's test, p < 0.05). The protein expression analysis revealed an increase in IL-6 levels in the H + PBM group compared to the H group and a reduction in the H group compared to the control group. A reduction in TNF-α was found in the H and H + PBM groups compared to the control group at 7 days. The gene expression analysis revealed an increase in IL-6 in the H + PBM group compared to the H group at 14 days as well as an increase in TNF-α in the H + PBM group compared to the H group at 7 days. Increases in MMP-2 were found in the H and H + PBM groups compared to the control group at both 7 and 14 days. Based on findings in the present study, it is concluded that PBM was able to modulate pro-inflammatory cytokines that are essential for the compensatory hypertrophy process. However, it has not shown a modulation effect directly in MMP-2 activity during the same period evaluated.


Assuntos
Citocinas/metabolismo , Regulação da Expressão Gênica/efeitos da radiação , Terapia com Luz de Baixa Intensidade , Músculo Esquelético/patologia , Músculo Esquelético/efeitos da radiação , Animais , Hipertrofia/metabolismo , Hipertrofia/patologia , Hipertrofia/radioterapia , Interleucina-6/metabolismo , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Músculo Esquelético/metabolismo , Ratos , Ratos Wistar , Tendões/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
15.
Int J Mol Sci ; 21(22)2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33233559

RESUMO

BACKGROUND: Dyslipidemia may be linked to meibomian gland dysfunction (MGD) and altered meibum lipid composition. The purpose was to determine if plasma and meibum cholesteryl esters (CE), triglycerides (TG), ceramides (Cer) and sphingomyelins (SM) change in a mouse model of diet-induced obesity where mice develop dyslipidemia. METHODS: Male C57/BL6 mice (8/group, age = 6 wks) were fed a normal (ND; 15% kcal fat) or an obesogenic high-fat diet (HFD; 42% kcal fat) for 10 wks. Tear production was measured and meibography was performed. Body and epididymal adipose tissue (eAT) weights were determined. Nano-ESI-MS/MS and LC-ESI-MS/MS were used to detect CE, TG, Cer and SM species. Data were analyzed by principal component analysis, Pearson's correlation and unpaired t-tests adjusted for multiple comparisons; significance set at p ≤ 0.05. RESULTS: Compared to ND mice, HFD mice gained more weight and showed heavier eAT and dyslipidemia with higher levels of plasma CE, TG, Cer and SM. HFD mice had hypertrophic meibomian glands, increased levels of lipid species acylated by saturated fatty acids in plasma and meibum and excessive tear production. CONCLUSIONS: The majority of meibum lipid species with saturated fatty acids increased with HFD feeding with evidence of meibomian gland hypertrophy and excessive tearing. The dyslipidemia is associated with altered meibum composition, a key feature of MGD.


Assuntos
Dislipidemias/metabolismo , Hipertrofia/metabolismo , Glândulas Tarsais/metabolismo , Obesidade/metabolismo , Lágrimas/química , Tecido Adiposo/química , Tecido Adiposo/metabolismo , Animais , Ceramidas/classificação , Ceramidas/isolamento & purificação , Ceramidas/metabolismo , Ésteres do Colesterol/classificação , Ésteres do Colesterol/isolamento & purificação , Ésteres do Colesterol/metabolismo , Dieta Hiperlipídica/efeitos adversos , Dislipidemias/etiologia , Dislipidemias/patologia , Epididimo/química , Epididimo/metabolismo , Humanos , Hipertrofia/etiologia , Hipertrofia/patologia , Masculino , Glândulas Tarsais/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/etiologia , Obesidade/patologia , Análise de Componente Principal , Esfingomielinas/classificação , Esfingomielinas/isolamento & purificação , Esfingomielinas/metabolismo , Lágrimas/metabolismo , Triglicerídeos/classificação , Triglicerídeos/isolamento & purificação , Triglicerídeos/metabolismo
16.
Int J Mol Sci ; 21(19)2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-33003470

RESUMO

Skeletal muscle has a remarkable plasticity, and its phenotype is strongly influenced by hormones, transcription factors, and physical activity. However, whether skeletal phenotype can be oriented or not during early embryonic stages has never been investigated. Here, we report that pyruvate as the only source of carbohydrate in the culture medium of mouse one cell stage embryo influenced the establishment of the muscular phenotype in adulthood. We found that pyruvate alone induced changes in the contractile phenotype of the skeletal muscle in a sexually dependent manner. For male mice, a switch to a more glycolytic phenotype was recorded, whereas, in females, the pyruvate induced a switch to a more oxidative phenotype. In addition, the influence of pyruvate on the contractile phenotypes was confirmed in two mouse models of muscle hypertrophy: the well-known myostatin deficient mouse (Mstn-/-) and a mouse carrying a specific deletion of p43, a mitochondrial triiodothyronine receptor. Finally, to understand the link between these adult phenotypes and the early embryonic period, we assessed the levels of two histone H3 post-translational modifications in presence of pyruvate alone just after the wave of chromatin reprogramming specific of the first cell cycle. We showed that H3K4 acetylation level was decreased in Mstn-/- 2-cell embryos, whereas no difference was found for H3K27 trimethylation level, whatever the genotype. These findings demonstrate for the first time that changes in the access of energy substrate during the very first embryonic stage can induce a precocious orientation of skeletal muscle phenotype in adulthood.


Assuntos
Citocinas/genética , Hipertrofia/genética , Músculo Esquelético/metabolismo , Miostatina/genética , Acetilação , Animais , Metabolismo dos Carboidratos/genética , Modelos Animais de Doenças , Embrião de Mamíferos , Desenvolvimento Embrionário/genética , Feminino , Genótipo , Glicólise/genética , Hipertrofia/metabolismo , Hipertrofia/patologia , Masculino , Camundongos , Mitocôndrias/metabolismo , Contração Muscular/genética , Músculo Esquelético/patologia , Oxirredução , Fenótipo , Ácido Pirúvico/metabolismo
17.
FASEB J ; 34(12): 16552-16566, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33118211

RESUMO

Human osteoarthritis cartilage contains chondrocytes (OAC) and mesenchymal stromal cells (OA-MSC). Here, we found that TGF-ß had different effects on OA-MSC and OAC, and revealed its lateral signaling mechanism in OA. RNAseq analysis indicated that OA-MSC expressed the same level of Bone Morphogenetic Protein (BMP) Receptor-1A as OAC but only 1/12 of Transforming Growth Factor beta (TGF-ß) Receptor-1. While TGF-ß specifically activated SMAD2 in OAC, it also activated BMP signaling-associated SMAD1 in OA-MSC. While TGF-ß stimulated chondrogenesis in OAC, it induced hypertrophy, mineralization, and MMP-13 in OA-MSC. Inhibiting TGF-ßR1 suppressed MMP-13 in OA-MSC but stimulated it in OAC. In contrast, by specifically targeting BMPR1A/ACVR1 in both cell types, LDN193189 inhibits cartilage degeneration through suppressing hypertrophy and MMP-13 in a mouse osteoarthritis model. Thus, LDN193189, a drug under development to inhibit constitutive BMP signaling during heterotopic ossification, may be re-purposed for OA treatment.


Assuntos
Cartilagem Articular/metabolismo , Células-Tronco Mesenquimais/metabolismo , Osteoartrite/metabolismo , Transdução de Sinais/fisiologia , Fator de Crescimento Transformador beta/metabolismo , Animais , Células Cultivadas , Condrócitos/metabolismo , Condrogênese/fisiologia , Humanos , Hipertrofia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Receptor do Fator de Crescimento Transformador beta Tipo I/metabolismo , Proteína Smad2/metabolismo
18.
EMBO J ; 39(22): e105098, 2020 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-32960481

RESUMO

Chromatin remodeling complexes have functions in transcriptional regulation and chromosome maintenance, but it is mostly unknown how the function of these normally ubiquitous complexes is specified in the cellular context. Here, we describe that the evolutionary conserved long non-coding RNA linc-MYH regulates the composition of the INO80 chromatin remodeler complex in muscle stem cells and prevents interaction with WDR5 and the transcription factor YY1. Linc-MYH acts as a selective molecular switch in trans that governs the pro-proliferative function of the ubiquitous INO80 complex but does not affect its role in maintaining genomic stability. The molecular switch is essential for restricting generation of quiescent MuSCs and proliferation of myoblasts in homeostasis and regeneration. Since linc-MYH is expressed in proliferating myoblasts but not in quiescent MuSCs, we reason that the extent of myoblast proliferation has decisive effects on the size of the quiescent MuSC pool.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/metabolismo , Proteínas de Ligação a DNA/metabolismo , Hipertrofia/metabolismo , Músculo Esquelético/metabolismo , Mioblastos/metabolismo , RNA Longo não Codificante/metabolismo , ATPases Associadas a Diversas Atividades Celulares/genética , Animais , Proliferação de Células , Cromatina , DNA Glicosilases/genética , Proteínas de Ligação a DNA/genética , Epigenômica , Regulação Enzimológica da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Knockout , Músculo Esquelético/citologia , Mioblastos/citologia , RNA Longo não Codificante/genética , RNA não Traduzido , Regeneração/fisiologia , Transcriptoma , Fator de Transcrição YY1/genética
19.
Proc Natl Acad Sci U S A ; 117(35): 21469-21479, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32817558

RESUMO

During the postnatal period in mammals, the cardiac muscle transitions from hyperplasic to hypertrophic growth, the extracellular matrix (ECM) undergoes remodeling, and the heart loses regenerative capacity. While ECM maturation and crosstalk between cardiac fibroblasts (CFs) and cardiomyocytes (CMs) have been implicated in neonatal heart development, not much is known about specialized fibroblast heterogeneity and function in the early postnatal period. In order to better understand CF functions in heart maturation and postnatal cardiomyocyte cell-cycle arrest, we have performed gene expression profiling and ablation of postnatal CF populations. Fibroblast lineages expressing Tcf21 or Periostin were traced in transgenic GFP reporter mice, and their biological functions and transitions during the postnatal period were examined in sorted cells using RNA sequencing. Highly proliferative Periostin (Postn)+ lineage CFs were found from postnatal day 1 (P1) to P11 but were not detected at P30, due to a repression of Postn gene expression. This population was less abundant and transcriptionally different from Tcf21+ resident CFs. The specialized Postn+ population preferentially expresses genes related to cell proliferation and neuronal development, while Tcf21+ CFs differentially express genes related to ECM maturation at P7 and immune crosstalk at P30. Ablation of the Postn+ CFs from P0 to P6 led to altered cardiac sympathetic nerve patterning and a reduction in binucleation and hypertrophic growth with increased fetal troponin (TroponinI1) expression in CM. Thus, postnatal CFs are heterogeneous and include a transient proliferative Postn+ population required for cardiac nerve development and cardiomyocyte maturation soon after birth.


Assuntos
Diferenciação Celular/genética , Fibroblastos/metabolismo , Miócitos Cardíacos/metabolismo , Animais , Animais Recém-Nascidos , Moléculas de Adesão Celular/metabolismo , Proliferação de Células , Matriz Extracelular , Feminino , Fibroblastos/fisiologia , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica no Desenvolvimento/genética , Hipertrofia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Miocárdio/metabolismo , Análise de Sequência de RNA
20.
Am J Physiol Cell Physiol ; 319(5): C858-C876, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32783659

RESUMO

Human skeletal muscle is a heterogeneous tissue composed of multiple fiber types that express unique contractile and metabolic properties. While analysis of mixed fiber samples predominates and holds value, increasing attention has been directed toward studying proteins segregated by fiber type, a methodological distinction termed "fiber type-specific." Fiber type-specific protein studies have the advantage of uncovering key molecular effects that are often missed in mixed fiber homogenate studies but also require greater time and resource-intensive methods, particularly when applied to human muscle. This review summarizes and compares current methods used for fiber type-specific protein analysis, highlighting their advantages and disadvantages for human muscle studies, in addition to recent advances in these techniques. These methods can be grouped into three categories based on the initial processing of the tissue: 1) muscle-specific fiber homogenates, 2) cross sections of fiber bundles, and 3) isolated single fibers, with various subtechniques for performing fiber type identification and protein quantification. The relative implementation for each unique methodological approach is analyzed from 83 fiber type-specific studies of proteins in live human muscle found in the literature to date. These studies have investigated several proteins involved in a wide range of cellular functions that are important to muscle tissue. The second half of this review summarizes key findings from this ensemble of fiber type-specific human protein studies. We highlight examples of where this analytical approach has helped to improve understanding of important physiological topics such as insulin sensitivity, muscle hypertrophy, muscle fatigue, and adaptation to different exercise programs.


Assuntos
Hipertrofia/fisiopatologia , Fadiga Muscular/fisiologia , Fibras Musculares de Contração Rápida/fisiologia , Fibras Musculares de Contração Lenta/fisiologia , Proteínas Musculares/genética , Doenças Musculares/fisiopatologia , Misturas Complexas/química , Exercício Físico/fisiologia , Expressão Gênica , Humanos , Hipertrofia/genética , Hipertrofia/metabolismo , Resistência à Insulina/fisiologia , Microtomia/métodos , Proteínas Musculares/classificação , Proteínas Musculares/metabolismo , Doenças Musculares/genética , Doenças Musculares/metabolismo , Especificidade de Órgãos , Resistência Física/fisiologia
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