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1.
Reprod Domest Anim ; 54(3): 538-544, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30570178

RESUMO

The sheep callipyge (CLPG) phenotype, a well-known muscular hypertrophy syndrome, is caused by an A-to-G transition in the CLPG1 locus. The mechanisms of CLPG phenotype are very complicated and remain to be further studied. Lacking suitable animal models containing CLPG mutations may partially contribute to these unanswered mechanisms. In this study, we confirmed that the CLPG1 locus, especially the 12-bp CLPG1 motif, is conserved in mammalian animals including rabbit. Then, we generated seven CLPG1-edited rabbits with 100% efficiency using CRISPR/Cas9 system combined with cytoplasm injection technology. All the newborn rabbits were mosaicism with numerous kinds of mutations around the target sites. Among the nine screened potential off-target sites (POTs) for the two sgRNAs used in this study, none off-target effect was detected. This indicated that we efficiently and precisely generated CLPG1-edited rabbits, and we believe that these newly generated rabbits will do help to unravel the mechanisms of the CLPG phenotype in the future.


Assuntos
Sistemas CRISPR-Cas , Hipertrofia/genética , Modelos Animais , Músculo Esquelético/crescimento & desenvolvimento , Mutação , Animais , Animais Recém-Nascidos , Sequência de Bases , Fenótipo , Coelhos
2.
Elife ; 72018 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-30565562

RESUMO

Titin, the largest protein known, forms an elastic myofilament in the striated muscle sarcomere. To establish titin's contribution to skeletal muscle passive stiffness, relative to that of the extracellular matrix, a mouse model was created in which titin's molecular spring region was shortened by deleting 47 exons, the TtnΔ112-158 model. RNA sequencing and super-resolution microscopy predicts a much stiffer titin molecule. Mechanical studies with this novel mouse model support that titin is the main determinant of skeletal muscle passive stiffness. Unexpectedly, the in vivo sarcomere length working range was shifted to shorter lengths in TtnΔ112-158 mice, due to a ~ 30% increase in the number of sarcomeres in series (longitudinal hypertrophy). The expected effect of this shift on active force generation was minimized through a shortening of thin filaments that was discovered in TtnΔ112-158 mice. Thus, skeletal muscle titin is the dominant determinant of physiological passive stiffness and drives longitudinal hypertrophy. Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).


Assuntos
Conectina/química , Hipertrofia/genética , Músculo Esquelético/ultraestrutura , Músculo Estriado/ultraestrutura , Citoesqueleto de Actina/química , Citoesqueleto de Actina/genética , Animais , Conectina/genética , Tecido Elástico/química , Matriz Extracelular/química , Matriz Extracelular/genética , Humanos , Hipertrofia/fisiopatologia , Camundongos , Músculo Esquelético/química , Músculo Estriado/química , Músculo Estriado/fisiologia , Miocárdio/química , Miocárdio/patologia , Miofibrilas/química , Sarcômeros/química , Sarcômeros/genética
3.
Skelet Muscle ; 8(1): 39, 2018 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-30591079

RESUMO

BACKGROUND: ß2-adrenergic receptors (ß2ARs) are the target of catecholamines and play fundamental roles in cardiovascular, pulmonary, and skeletal muscle physiology. An important action of ß2AR stimulation on skeletal muscle is anabolic growth, which has led to the use of agonists such as clenbuterol by athletes to enhance muscle performance. While previous work has demonstrated that ß2ARs can engage distinct signaling and functional cascades mediated by either G proteins or the multifunctional adaptor protein, ß-arrestin, the precise role of ß-arrestin in skeletal muscle physiology is not known. Here, we tested the hypothesis that agonist activation of the ß2AR by clenbuterol would engage ß-arrestin as a key transducer of anabolic skeletal muscle growth. METHODS: The contractile force of isolated extensor digitorum longus muscle (EDL) and calcium signaling in isolated flexor digitorum brevis (FDB) fibers were examined from the wild-type (WT) and ß-arrestin 1 knockout mice (ßarr1KO) followed by chronic administration of clenbuterol (1 mg/kg/d). Hypertrophic responses including fiber composition and fiber size were examined by immunohistochemical imaging. We performed a targeted phosphoproteomic analysis on clenbuterol stimulated primary cultured myoblasts from WT and ßarr1KO mice. Statistical significance was determined by using a two-way analysis with Sidak's or Tukey's multiple comparison test and the Student's t test. RESULTS: Chronic administration of clenbuterol to WT mice enhanced the contractile force of EDL muscle and calcium signaling in isolated FDB fibers. In contrast, when administered to ßarr1KO mice, the effect of clenbuterol on contractile force and calcium influx was blunted. While clenbuterol-induced hypertrophic responses were observed in WT mice, this response was abrogated in mice lacking ß-arrestin 1. In primary cultured myoblasts, clenbuterol-stimulated phosphorylation of multiple pro-hypertrophy proteins required the presence of ß-arrestin 1. CONCLUSIONS: We have identified a previously unappreciated role for ß-arrestin 1 in mediating ß2AR-stimulated skeletal muscle growth and strength. We propose these findings could have important implications in the design of future pharmacologic agents aimed at reversing pathological conditions associated with skeletal muscle wasting.


Assuntos
Contração Muscular , Fibras Musculares Esqueléticas/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , beta-Arrestina 1/metabolismo , Agonistas de Receptores Adrenérgicos beta 2/farmacologia , Animais , Sinalização do Cálcio , Células Cultivadas , Clembuterol/farmacologia , Feminino , Hipertrofia/etiologia , Hipertrofia/genética , Hipertrofia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fibras Musculares Esqueléticas/efeitos dos fármacos , Fibras Musculares Esqueléticas/patologia , Fibras Musculares Esqueléticas/fisiologia , Força Muscular , beta-Arrestina 1/genética
4.
Medicine (Baltimore) ; 97(38): e12506, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30235762

RESUMO

Limb-girdle muscular dystrophy 2L (LGMD2L) is mainly characterized by late adult onset, atrophy of proximal muscles, chronic progressive and asymmetric weakness, accompanied by increased creatine kinase (CK) levels, dystrophic pathological changes and electromyography showing myogenic damage. To date, familial LGMD2L was reported in European countries and had not been reported in China.A careful investigation of the clinical manifestations, muscle performance imaging, biopsy, and target next-generation sequencing (NGS) technology was utilized to identify pathogenic genetic variants in a 4-generation pedigree that includes 6 affected individuals.The results revealed mild-to-moderate hypertrophy of bilateral gastrocnemii and slight weakness and atrophy in the proximal muscles of the lower limbs, with obviously increased serum creatine kinase levels. The symptoms were more serious in the male proband but were also observed in females. Obvious and symmetric atrophy and fat infiltration of posterior segments of the thigh was evident in muscle magnetic resonance imaging (MRI). The pathological changes included a small amount of atrophic and hypertrophic fibers, scattered necrotizing fibers, a small number of increased nuclei, inward migration, mild proliferation of interstitial connective tissue, and no inflammatory cell infiltration. The pathogenic allele was a c.220C > T mutation in the anoctamin 5 (ANO5) gene.The LGMD2L family was characterized by mild chronic myopathy and bilateral gastrocnemius hypertrophy with obviously increased CK levels. Pathological changes included atrophy of fibers with interstitial connective tissues hyperplasia. The pathogenic allele was a c.220C> T mutation in the ANO5 gene.


Assuntos
Anoctaminas/genética , Músculo Esquelético/patologia , Distrofia Muscular do Cíngulo dos Membros/genética , Linhagem , Alelos , Biópsia , China , Creatina Quinase/sangue , Eletromiografia , Feminino , Humanos , Hipertrofia/genética , Hipertrofia/patologia , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/diagnóstico por imagem , Atrofia Muscular/genética , Atrofia Muscular/patologia , Distrofia Muscular do Cíngulo dos Membros/diagnóstico por imagem , Distrofia Muscular do Cíngulo dos Membros/patologia , Mutação
5.
Biochem Biophys Res Commun ; 498(4): 940-945, 2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-29545179

RESUMO

The regulatory function of Fbxo40 has been well characterized in mice. As a key component of the SCF-E3 ubiquitin ligase complex, Fbxo40 induces IRS1 ubiquitination, thus inactivating the IGF1/Akt pathway. The expression of Fbxo40 is restricted to muscle, and mice with an Fbxo40 null mutation exhibit muscle hypertrophy. However, the function of FBXO40 has not been elucidated in pigs, and it is not known whether FBXO40 mutations affect their health. We therefore generated FBXO40 knockout pigs using somatic cell nuclear transfer (SCNT) technology. CRISPR/Cas9 technology was combined with G418 selection, making it possible to generate donor cells at an efficiency of 75.86%. In muscle from FBXO40 knockout pigs, IRS1 levels were higher, and the IGF1/Akt pathway was stimulated. Mutant animals also had approximately 4% more muscle mass compared to WT controls. The knockout pigs developed normally and no pathological changes were found in major organs. These results demonstrate that FBXO40 is a promising candidate gene for improving production traits in agricultural livestock and for developing therapeutic interventions for muscle diseases.


Assuntos
Proteínas F-Box/genética , Hipertrofia/etiologia , Músculos/patologia , Animais , Sistemas CRISPR-Cas , Técnicas de Inativação de Genes , Hipertrofia/genética , Proteínas Substratos do Receptor de Insulina/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Proteína Oncogênica v-akt/metabolismo , Sus scrofa
6.
Redox Biol ; 16: 146-156, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29502044

RESUMO

The endonuclease G gene (Endog), which codes for a mitochondrial nuclease, was identified as a determinant of cardiac hypertrophy. How ENDOG controls cardiomyocyte growth is still unknown. Thus, we aimed at finding the link between ENDOG activity and cardiomyocyte growth. Endog deficiency induced reactive oxygen species (ROS) accumulation and abnormal growth in neonatal rodent cardiomyocytes, altering the AKT-GSK3ß and Class-II histone deacethylases (HDAC) signal transduction pathways. These effects were blocked by ROS scavengers. Lack of ENDOG reduced mitochondrial DNA (mtDNA) replication independently of ROS accumulation. Because mtDNA encodes several subunits of the mitochondrial electron transport chain, whose activity is an important source of cellular ROS, we investigated whether Endog deficiency compromised the expression and activity of the respiratory chain complexes but found no changes in these parameters nor in ATP content. MtDNA also codes for humanin, a micropeptide with possible metabolic functions. Nanomolar concentrations of synthetic humanin restored normal ROS levels and cell size in Endog-deficient cardiomyocytes. These results support the involvement of redox signaling in the control of cardiomyocyte growth by ENDOG and suggest a pathway relating mtDNA content to the regulation of cell growth probably involving humanin, which prevents reactive oxygen radicals accumulation and hypertrophy induced by Endog deficiency.


Assuntos
Endodesoxirribonucleases/genética , Hipertrofia/genética , Peptídeos e Proteínas de Sinalização Intracelular/administração & dosagem , Mitocôndrias/genética , Animais , Apoptose/efeitos dos fármacos , DNA Mitocondrial/efeitos dos fármacos , Endodesoxirribonucleases/deficiência , Endodesoxirribonucleases/metabolismo , Humanos , Hipertrofia/tratamento farmacológico , Hipertrofia/enzimologia , Hipertrofia/metabolismo , Camundongos , Mitocôndrias/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/enzimologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Oxirredução/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
8.
Hum Cell ; 31(1): 1-9, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28916968

RESUMO

The high-mobility group box (HMGB) family includes four members: HMGB1, 2, 3 and 4. HMGB proteins have two functions. In the nucleus, HMGB proteins bind to DNA in a DNA structure-dependent but nucleotide sequence-independent manner to function in chromatin remodeling. Extracellularly, HMGB proteins function as alarmins, which are endogenous molecules released upon tissue damage to activate the immune system. HMGB1 acts as a late mediator of inflammation and contributes to prolonged and sustained systemic inflammation in subjects with rheumatoid arthritis. By contrast, Hmgb2 -/- mice represent a relevant model of aging-related osteoarthritis (OA), which is associated with the suppression of HMGB2 expression in cartilage. Hmgb2 mutant mice not only develop early-onset OA but also exhibit a specific phenotype in the superficial zone (SZ) of articular cartilage. Given the similar expression and activation patterns of HMGB2 and ß-catenin in articular cartilage, the loss of these pathways in the SZ of articular cartilage may lead to altered gene expression, cell death and OA-like pathogenesis. Moreover, HMGB2 regulates chondrocyte hypertrophy by mediating Runt-related transcription factor 2 expression and Wnt signaling. Therefore, one possible mechanism explaining the modulation of lymphoid enhancer binding factor 1 (LEF1)-dependent transactivation by HMGB2 is that a differential interaction between HMGB2 and nuclear factors affects the transcription of genes containing LEF1-responsive elements. The multiple functions of HMGB proteins reveal the complex roles of these proteins as innate and endogenous regulators of inflammation in joints and their cooperative roles in cartilage hypertrophy as well as in the maintenance of joint tissue homeostasis.


Assuntos
Artrite Reumatoide/genética , Proteína HMGB1/fisiologia , Proteína HMGB2/fisiologia , Osteoartrite/genética , Alarminas , Animais , Artrite Reumatoide/imunologia , Cartilagem Articular/metabolismo , Condrócitos/patologia , Montagem e Desmontagem da Cromatina/genética , Subunidade alfa 1 de Fator de Ligação ao Core , DNA/metabolismo , Modelos Animais de Doenças , Expressão Gênica , Proteína HMGB1/metabolismo , Proteína HMGB2/metabolismo , Humanos , Hidroxietilrutosídeo , Hipertrofia/genética , Mediadores da Inflamação , Fator 1 de Ligação ao Facilitador Linfoide , Camundongos , Osteoartrite/imunologia , Ligação Proteica , Via de Sinalização Wnt
9.
Biomed Res Int ; 2017: 9716087, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29238726

RESUMO

Cardiomyocytes hypertrophy and apoptosis induced by advanced glycation end products (AGEs) is the crucial pathological foundation contributing to the onset and development of diabetic cardiomyopathy (DCM). However, the mechanism remains poorly understood. Here, we report that profilin-1 (PFN-1), a well-known actin-binding protein, serves as a potent regulator in AGEs-induced cardiomyocytes hypertrophy and apoptosis. PFN-1 was upregulated in AGEs-treated H9c2 cells, which was associated with increased cardiomyocytes hypertrophy and apoptosis. Silencing PFN-1 expression remarkably attenuated AGEs-induced H9c2 cell hypertrophy and apoptosis. Mechanistically, AGEs increased PFN-1 expression through elevating ROS production and RhoA and ROCK2 expression. Consequently, elevated PFN-1 promoted actin cytoskeleton disorganization. When either ROS production/ROCK activation was blocked or cells were treated with Cytochalasin D (actin depolymerizer), H9c2 cells were protected against AGEs-induced cardiac myocyte abnormalities, concomitantly with downregulated expression of PFN-1 and improved actin cytoskeleton alteration. Collectively, these data suggest that PFN-1 may play an important role in AGEs-induced hypertrophy and apoptosis in H9c2 cells.


Assuntos
Cardiomiopatias Diabéticas/genética , Produtos Finais de Glicação Avançada/genética , Hipertrofia/genética , Profilinas/genética , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Citocalasina D/farmacologia , Citoesqueleto/genética , Cardiomiopatias Diabéticas/metabolismo , Cardiomiopatias Diabéticas/patologia , Regulação da Expressão Gênica , Humanos , Hipertrofia/patologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Profilinas/antagonistas & inibidores , Ratos , Espécies Reativas de Oxigênio , Proteínas rho de Ligação ao GTP/genética , Quinases Associadas a rho/genética
10.
Nat Commun ; 8(1): 1104, 2017 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-29062100

RESUMO

Exercise induces expression of the myokine irisin, which is known to promote browning of white adipose tissue and has been shown to mediate beneficial effects following exercise. Here we show that irisin induces expression of a number of pro-myogenic and exercise response genes in myotubes. Irisin increases myogenic differentiation and myoblast fusion via activation of IL6 signaling. Injection of irisin in mice induces significant hypertrophy and enhances grip strength of uninjured muscle. Following skeletal muscle injury, irisin injection improves regeneration and induces hypertrophy. The effects of irisin on hypertrophy are due to activation of satellite cells and enhanced protein synthesis. In addition, irisin injection rescues loss of skeletal muscle mass following denervation by enhancing satellite cell activation and reducing protein degradation. These data suggest that irisin functions as a pro-myogenic factor in mice.


Assuntos
Atrofia/prevenção & controle , Fibronectinas/metabolismo , Hipertrofia/metabolismo , Desenvolvimento Muscular , Músculo Esquelético/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Atrofia/etiologia , Atrofia/genética , Atrofia/metabolismo , Denervação/efeitos adversos , Fibronectinas/administração & dosagem , Fibronectinas/genética , Humanos , Hipertrofia/genética , Hipertrofia/fisiopatologia , Interleucina-6/genética , Interleucina-6/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/citologia , Células-Tronco/citologia , Células-Tronco/metabolismo
11.
J Proteome Res ; 16(10): 3477-3490, 2017 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-28810121

RESUMO

Skeletal muscle, the most abundant body tissue, plays vital roles in locomotion and metabolism. Myostatin is a negative regulator of skeletal muscle mass. In addition to increasing muscle mass, Myostatin inhibition impacts muscle contractility and energy metabolism. To decipher the mechanisms of action of the Myostatin inhibitors, we used proteomic and transcriptomic approaches to investigate the changes induced in skeletal muscles of transgenic mice overexpressing Follistatin, a physiological Myostatin inhibitor. Our proteomic workflow included a fractionation step to identify weakly expressed proteins and a comparison of fast versus slow muscles. Functional annotation of altered proteins supports the phenotypic changes induced by Myostatin inhibition, including modifications in energy metabolism, fiber type, insulin and calcium signaling, as well as membrane repair and regeneration. Less than 10% of the differentially expressed proteins were found to be also regulated at the mRNA level but the Biological Process annotation, and the KEGG pathways analysis of transcriptomic results shows a great concordance with the proteomic data. Thus this study describes the most extensive omics analysis of muscle overexpressing Follistatin, providing molecular-level insights to explain the observed muscle phenotypic changes.


Assuntos
Hipertrofia/genética , Doenças Musculares/genética , Miostatina/genética , Proteômica , Transcriptoma/genética , Animais , Modelos Animais de Doenças , Folistatina/farmacologia , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica , Humanos , Hipertrofia/induzido quimicamente , Hipertrofia/patologia , Camundongos , Camundongos Transgênicos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Doenças Musculares/induzido quimicamente , Doenças Musculares/patologia , Miostatina/antagonistas & inibidores , Regeneração/genética
12.
PLoS One ; 12(7): e0179835, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28686615

RESUMO

Signal transducers and activators of transcription 3 (STAT3) is known to participate in various cardiovascular signal transduction pathways, including those responsible for cardiac hypertrophy and cytoprotection. However, the role of STAT3 signaling in cardiomyocyte autophagy remains unclear. We tested the hypothesis that Angiotensin II (Ang II)-induced cardiomyocyte hypertrophy is effected, at least in part, through STAT3-mediated inhibition of cellular autophagy. In H9c2 cells, Ang II treatment resulted in STAT3 activation and cellular hypertrophy in a dose-dependent manner. Ang II enhanced autophagy, albeit without impacting AMPKα/mTOR signaling or cellular ADP/ATP ratio. Pharmacologic inhibition of STAT3 with WP1066 suppressed Ang II-induced myocyte hypertrophy and mRNA expression of hypertrophy-related genes ANP and ß-MHC. These molecular events were recapitulated in cells with STAT3 knockdown. Genetic or pharmacologic inhibition of STAT3 significantly increased myocyte ADP/ATP ratio and enhanced autophagy through AMPKα/mTOR signaling. Pharmacologic activation and inhibition of AMPKα attenuated and exaggerated, respectively, the effects of Ang II on ANP and ß-MHC gene expression, while concomitant inhibition of STAT3 accentuated the inhibition of hypertrophy. Together, these data indicate that novel nongenomic effects of STAT3 influence myocyte energy status and modulate AMPKα/mTOR signaling and autophagy to balance the transcriptional hypertrophic response to Ang II stimulation. These findings may have significant relevance for various cardiovascular pathological processes mediated by Ang II signaling.


Assuntos
Proteínas Quinases Ativadas por AMP/genética , Autofagia/genética , Hipertrofia/genética , Fator de Transcrição STAT3/genética , Serina-Treonina Quinases TOR/genética , Proteínas Quinases Ativadas por AMP/biossíntese , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Angiotensina II/administração & dosagem , Angiotensina II/genética , Animais , Autofagia/efeitos dos fármacos , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Hipertrofia/metabolismo , Hipertrofia/patologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Piridinas , Ratos , Fator de Transcrição STAT3/antagonistas & inibidores , Fator de Transcrição STAT3/biossíntese , Transdução de Sinais , Serina-Treonina Quinases TOR/biossíntese , Tirfostinas
13.
Biochem Biophys Res Commun ; 490(3): 1106-1111, 2017 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-28669725

RESUMO

The molecular mechanism underlying the fibrosis of ligamentum flavum(LF) in patients with lumbar spinal canal stenosis(LSCS) remains unknown. MicroRNAs are reported to play important roles in regulating fibrosis in different organs. The present study aimed to identify fibrosis related miR-21 expression profile and investigate the pathological process of miR-21 in the fibrosis of LF hypertrophy and associated regulatory mechanisms. 15 patients with LSCS underwent surgical treatment were enrolled in this study. For the control group, 11 patients with lumbar disc herniation(LDH) was included. The LF thickness was measured on MRI. LF samples were obtained during the surgery. Fibrosis score was assessed by Masson's trichrome staining. The expression of miR-21 in LF tissues were determined by RT-PCR. Correlation among LF thickness, fibrosis score, and miR-21 expression was analyzed. In addition, Lentiviral vectors for miR-21 mimic were constructed and transfected into LF cells to examine the role of miR-21 in LF fibrosis. Types I and III collagen were used as indicators of fibrosis. IL-6 expression in LF cells after transfection was investigated by RT-PCR and ELISA. Patients in two groups showed similar outcomes regarding age, gender, level of LF tissue. The thickness and fibrosis score of LF in the LSCS group were significantly greater than those in LDH group (all P < 0.05). Similarly, the expression of miR-21 in LSCS group was substantially higher than that in LDH group(P < 0.05). Furthermore, the miR-21 expression exhibited positive correlations with the LF thickness (r = 0.595, P < 0.05) and fibrosis score (r = 0.608, P < 0.05). Of note, miR-21 over-expression increased the expression levels of collagen I and III (P < 0.05). Also, IL-6 expression and secretion in LF cells was elevated after transfection of miR-21 mimic. MiR-21 is a fibrosis-associated miRNA and promotes inflammation in LF tissue by activating IL-6 expression, leading to LF fibrosis and hypertrophy.


Assuntos
Regulação da Expressão Gênica , Inflamação/patologia , Interleucina-6/genética , Ligamento Amarelo/patologia , Vértebras Lombares/patologia , MicroRNAs/genética , Estenose Espinal/patologia , Idoso , Células Cultivadas , Feminino , Fibrose , Humanos , Hipertrofia/complicações , Hipertrofia/genética , Hipertrofia/imunologia , Hipertrofia/patologia , Inflamação/complicações , Inflamação/genética , Inflamação/imunologia , Interleucina-6/imunologia , Ligamento Amarelo/imunologia , Vértebras Lombares/imunologia , Masculino , MicroRNAs/imunologia , Pessoa de Meia-Idade , Estudos Prospectivos , Estenose Espinal/complicações , Estenose Espinal/genética , Estenose Espinal/imunologia , Transcriptoma
14.
Can J Physiol Pharmacol ; 95(8): 945-953, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28704617

RESUMO

We previously showed that augmented levels of endogenous angiotensin II (AngII) contribute to vascular smooth muscle cell (VSMC) hypertrophy through the transactivation of growth factor receptors in spontaneously hypertensive rats. Resveratrol (RV), a polyphenolic component of red wine, has also been shown to attenuate AngII-evoked VSMC hypertrophy; however, the molecular mechanism mediating this response is obscure. The present study was therefore undertaken to examine whether RV could prevent AngII-induced VSMC hypertrophy through the transactivation of growth factor receptor and associated signaling pathways. AngII treatment of VSMC enhanced the protein synthesis that was attenuated towards control levels by RV pretreatment as well as by the inhibitors of NADPH oxidase, c-Src, and growth factor receptors. Furthermore, RV pretreatment also inhibited enhanced levels of superoxide anion, NADPH oxidase activity, increased expression of NADPH oxidase subunits, and phosphorylation of c-Src, EGF-R, PDGE-R, ERK1/2, and AKT1/2. In conclusion, these results indicate that RV attenuates AngII-induced VSMC hypertrophy through the inhibition of enhanced oxidative stress and activation of c-Src, growth factor receptors, and MAPK/AKT signaling. We suggest that RV could be used as a therapeutic agent in the treatment of vascular complications associated with hypertension and hypertrophy.


Assuntos
Angiotensina II/farmacologia , Anti-Hipertensivos/farmacologia , Músculo Liso Vascular/patologia , Receptores de Fatores de Crescimento/genética , Estilbenos/farmacologia , Ativação Transcricional/efeitos dos fármacos , Animais , Linhagem Celular , Ativação Enzimática/efeitos dos fármacos , Hipertrofia/induzido quimicamente , Hipertrofia/genética , Hipertrofia/metabolismo , Hipertrofia/prevenção & controle , Masculino , Músculo Liso Vascular/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Resveratrol , Transdução de Sinais/efeitos dos fármacos , Quinases da Família src/metabolismo
15.
Eur J Pharmacol ; 813: 94-104, 2017 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-28743391

RESUMO

The present study was aimed to determine whether stimulating Npr1 gene activity using Valporic acid (VA), a small short chain fatty acid molecule can enhance ANP mediated anti-hypertrophic activity in isoproterenol (ISO) - treated H9c2 cells in vitro. H9c2 cells were treated with ISO (10-5 M) and co-treated with VA (10-5 M) in the presence and absence of ANP (10-8M), for 48h. ATRA (10-5 M) was used as a positive inducer of Npr1 gene transcription. The mRNA expression of Npr1 and PKG-I genes, proto-oncogenes (c-fos, c-jun and c-myc) and hypertrophic markers (ANP, BNP, α-sk and ß-MyHC), genes were determined by quantitative PCR (qPCR). The protein profiling of NPR-A, PKG-I and cGMP were evaluated by Western blot, immunofluorescence and ELISA respectively. A marked reduction in the level of expression of Npr1 (3- fold) and PKG-I (2.5-fold) genes and increased expression of proto-oncogenes (p< 0.001, respectively) and hypertrophic marker genes (p<0.001, respectively) were noticed in the ISO-treated H9c2 cells as compared with control cells. In contrast, the VA treated cells showed maximal Npr1 gene expression (3.5-fold) as compared with ATRA treated cells (2 fold), which is well correlated with the intracellular cGMP levels (80% vs 60%) and reduced (2.5-fold) HDAC -1&-2 mRNA expression. Furthermore, VA or ATRA treatment effectively reversed the ISO-induced altered expression of Npr1 and PKG-I genes, proto-oncogenes, and hypertrophic markers genes. Interestingly, the results of the present study suggest that ANP mediated anti-hypertrophic activity was enhanced with either VA (p<0.001) or ATRA (p<0.01) co-treatment. Together, we conclude that VA in combination with ANP can be a novel therapeutical approach for the treatment and management of left ventricular cardiac hypertrophy.


Assuntos
Fator Natriurético Atrial/farmacologia , Hipertrofia/tratamento farmacológico , Hipertrofia/genética , Miocárdio/patologia , Receptores do Fator Natriurético Atrial/genética , Transcrição Genética/efeitos dos fármacos , Ácido Valproico/farmacologia , Animais , Fator Natriurético Atrial/uso terapêutico , Biomarcadores/metabolismo , Linhagem Celular , GMP Cíclico/metabolismo , Sinergismo Farmacológico , Regulação da Expressão Gênica/efeitos dos fármacos , Histona Desacetilase 1/genética , Histona Desacetilase 2/genética , Hipertrofia/patologia , Miocárdio/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos
16.
Afr J Tradit Complement Altern Med ; 14(4): 278-288, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28638891

RESUMO

BACKGROUND: Astragaloside, which is one of the main components of Astragalus membranaceus, has been widely used in the treatment of congestive heart failure in China, and it can protect cardiomyocytes. Its mechanism of action remains unclear. Therefore, the present study was carried out to investigate the influence of astragaloside on rat cardiomyocytes stimulated with endothelin-1 (ET-1), and explored the underlying mechanism. MATERIALS AND METHODS: ET-1 was used to stimulate primary rat cardiomyocytes and establish a cardiomyocyte hypertrophy model. Different astragaloside doses were administered in combination with ET-1. Cardiomyocyte hypertrophy and apoptosis were examined using transmission electron microscopy (TEM) and flow cytometry, respectively. The molecular mechanism was explored by analyzing the mRNA of the vitamin D receptor (VDR), cytochrome P450 family 27 subfamily B member 1(CYP27B), cytochrome P450 family 24 subfamily A member 1(CYP24A) and renin mRNA levels by quantificational real-time polymerase chain reaction(qRT-PCR). RESULTS: Rat cardiomyocyte hypertrophy model was established successfully. Astragaloside administration significantly affected cell apoptosis and significantly inhibited ET-1-induced cardiomyocyte hypertrophy in a dose-dependent manner. Astragaloside treatment affected the expression of signaling molecules in the vitamin D axis. CONCLUSION: Astragaloside inhibits ET-1-induced cardiomyocyte hypertrophy. This effect can be reversed by regulating the levels of the relevant factors in the vitamin D axis.


Assuntos
Apoptose/efeitos dos fármacos , Astrágalo (Planta)/química , Medicamentos de Ervas Chinesas/farmacologia , Endotelina-1/metabolismo , Hipertrofia/genética , Miócitos Cardíacos/efeitos dos fármacos , Receptores de Calcitriol/genética , Saponinas/farmacologia , Animais , Células Cultivadas , Humanos , Hipertrofia/tratamento farmacológico , Hipertrofia/metabolismo , Hipertrofia/fisiopatologia , Miócitos Cardíacos/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Calcitriol/metabolismo , Vitamina D/metabolismo
17.
BMC Genomics ; 18(1): 447, 2017 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-28592307

RESUMO

BACKGROUND: Compensatory growth is a phase of rapid growth, greater than the growth rate of control animals, that occurs after a period of growth-stunting conditions. Fish show a capacity for compensatory growth after alleviation of dietary restriction, but the underlying cellular mechanisms are unknown. To learn more about the contribution of genes regulating hypertrophy (an increase in muscle fibre size) and hyperplasia (the generation of new muscle fibres) in the compensatory muscle growth response in fish, we used high-density microarray analysis to investigate the global gene expression in muscle of trout during a fasting-refeeding schedule and in muscle of control-fed trout displaying normal growth. RESULTS: The compensatory muscle growth signature, as defined by genes up-regulated in muscles of refed trout compared with control-fed trout, showed enrichment in functional categories related to protein biosynthesis and maturation, such as RNA processing, ribonucleoprotein complex biogenesis, ribosome biogenesis, translation and protein folding. This signature was also enriched in chromatin-remodelling factors of the protein arginine N-methyl transferase family. Unexpectedly, functional categories related to cell division and DNA replication were not inferred from the molecular signature of compensatory muscle growth, and this signature contained virtually none of the genes previously reported to be up-regulated in hyperplastic growth zones of the late trout embryo myotome and to potentially be involved in production of new myofibres, notably genes encoding myogenic regulatory factors, transmembrane receptors essential for myoblast fusion or myofibrillar proteins predominant in nascent myofibres. CONCLUSION: Genes promoting myofibre growth, but not myofibre formation, were up-regulated in muscles of refed trout compared with continually fed trout. This suggests that a compensatory muscle growth response, resulting from the stimulation of hypertrophy but not the stimulation of hyperplasia, occurs in trout after refeeding. The generation of a large set of genes up-regulated in muscle of refed trout may yield insights into the molecular and cellular mechanisms controlling skeletal muscle mass in teleost and serve as a useful list of potential molecular markers of muscle growth in fish.


Assuntos
Jejum/metabolismo , Perfilação da Expressão Gênica , Hipertrofia/genética , Células Musculares/metabolismo , Células Musculares/patologia , Regulação para Cima , Animais , Desenvolvimento Muscular/genética , Oncorhynchus mykiss/genética , Oncorhynchus mykiss/crescimento & desenvolvimento
18.
Clin Exp Dermatol ; 42(7): 763-766, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28598037

RESUMO

Neurofibromatosis type 1 (NF1; OMIM 162200), a dominantly inherited multitumor syndrome, results from mutations in the Neurofibromin 1 (NF1) gene. We present the case of a Hungarian woman with the clinical phenotype of NF1 over her whole body and the clinical features of unilateral overgrowth involving her entire left leg. This unusual phenotype suggested either the atypical form of NF1 or the coexistence of NF1 and overgrowth syndrome. Direct sequencing of the genomic DNA isolated from peripheral blood revealed a novel frameshift mutation (c.5727insT, p.V1909fsX1912) in the NF1 gene. Next-generation sequencing of 50 oncogenes and tumour suppressor genes, performed on the genomic DNAs isolated from tissue samples and peripheral blood, detected only wild-type sequences. Based on these results, we concluded that the patient is affected by an unusual phenotype of NF1, and that the observed unilateral overgrowth of the left leg might be a rare consequence of the identified c.5727insT mutation.


Assuntos
Mutação da Fase de Leitura , Hipertrofia/genética , Perna (Membro)/patologia , Neurofibromatose 1/genética , Diagnóstico Diferencial , Feminino , Humanos , Hipertrofia/diagnóstico , Pessoa de Meia-Idade , Neurofibromatose 1/diagnóstico , Linhagem , Fenótipo
19.
Am J Physiol Cell Physiol ; 313(3): C257-C261, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28659288

RESUMO

Although the signal pathways mediating muscle protein synthesis and degradation are well characterized, the transcriptional processes modulating skeletal muscle mass and adaptive growth are poorly understood. Recently, studies in mouse models of muscle wasting or acutely exercised human muscle have suggested a potential role for the transcription factor signal transducer and activator of transcription 3 (STAT3), in adaptive growth. Hence, in the present study we sought to define the contribution of STAT3 to skeletal muscle adaptive growth. In contrast to previous work, two different resistance exercise protocols did not change STAT3 phosphorylation in human skeletal muscle. To directly address the role of STAT3 in load-induced (i.e., adaptive) growth, we studied the anabolic effects of 14 days of synergist ablation (SA) in skeletal muscle-specific STAT3 knockout (mKO) mice and their floxed, wild-type (WT) littermates. Plantaris muscle weight and fiber area in the nonoperated leg (control; CON) was comparable between genotypes. As expected, SA significantly increased plantaris weight, muscle fiber cross-sectional area, and anabolic signaling in WT mice, although interestingly, this induction was not impaired in STAT3 mKO mice. Collectively, these data demonstrate that STAT3 is not required for overload-mediated hypertrophy in mouse skeletal muscle.


Assuntos
Músculo Esquelético/fisiopatologia , Miofibrilas/metabolismo , Miofibrilas/patologia , Treinamento de Resistência/efeitos adversos , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Animais , Técnicas de Inativação de Genes , Hipertrofia/etiologia , Hipertrofia/genética , Hipertrofia/patologia , Hipertrofia/fisiopatologia , Masculino , Camundongos , Camundongos Knockout , Músculo Esquelético/patologia , Tamanho do Órgão
20.
Neuroscience ; 354: 196-207, 2017 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-28457820

RESUMO

Mutations in the PI3K/Akt/mTOR signaling pathway or in the upstream negative regulator Pten cause human brain overgrowth disorders, such as focal cortical dysplasia and megalencephaly, and are characterized by the presence of hypertrophic neurons. These disorders often have a pediatric onset and a high comorbidity with drug-resistant epilepsy; however, effective pharmacological treatments are lacking. We established forebrain excitatory neuron-specific Pten-deficient cultures as an in vitro model of brain overgrowth disorders, and investigated the effects of this Pten mutation on PI3K/Akt/mTOR signaling and neuronal growth. Mutant neurons exhibit excessive PI3K/Akt/mTOR signaling activity, enlarged somas and increased dendritic arborization. To understand the contributions of Akt and mTORC1 kinases to the hypertrophy phenotype, we evaluated the effects of short-term treatment with the Akt inhibitor MK-2206, and the mTORC1 inhibitor RAD001, which have shown safety and efficacy in human cancer clinical trials. We found that RAD001 treatment only partially reversed the morphological abnormalities of Pten mutant neurons, whereas MK-2206 treatment completely rescued the phenotype. Interestingly, neither treatment altered the size or morphology of normal neurons. Our results suggest that Akt is a major determinant of neuronal growth, and that Akt inhibition may be an effective strategy for pharmacological intervention in brain overgrowth disorders.


Assuntos
Regulação da Expressão Gênica/genética , Hipertrofia/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Mutação/genética , Proteína Oncogênica v-akt/metabolismo , PTEN Fosfo-Hidrolase/genética , Animais , Animais Recém-Nascidos , Encéfalo/citologia , Células Cultivadas , Dendritos/efeitos dos fármacos , Dendritos/metabolismo , Inibidores Enzimáticos/farmacologia , Everolimo/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Glutamato Descarboxilase/metabolismo , Compostos Heterocíclicos com 3 Anéis/farmacologia , Hipertrofia/metabolismo , Hipertrofia/patologia , Imunossupressores/farmacologia , Camundongos , Camundongos Transgênicos , Proteínas Associadas aos Microtúbulos/metabolismo , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
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