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1.
Neuromuscul Disord ; 36: 6-15, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38306719

RESUMO

The aim of this study was to identify key routinely used myopathologic biomarkers of FSHD1. Needle muscle biopsies were taken in 34 affected muscles (m. quadriceps femoris (QF), n = 20, m. tibialis anterior (TA), n = 13, m. biceps brachii, n = 1) from 22 patients (age, 53.5 (10) years; M = 12, F = 10). Eleven patients had more than one biopsy (2xQF, n = 1; QF+TA, n = 9; 2xQF+TA, n = 1). Histochemistry, immunoperoxidase, and immunofluorescence stainings were performed and compared to age and muscle type matched muscle specimens of 11 healthy controls. Myopathologic features observed in our FSHD1 cohort were internalized nuclei, type 1 fibre hypertrophy and NADH central clearances/cores. We observed a prominent inflammatory response with MAC deposits, MHC I expression, and muscle regeneration that correlated with the inflammatory score. Our up-to-date characterization of FSHD1 points towards MHC I, MAC, and embryonic Myosin Heavy Chain/muscle regeneration as useful myopathologic readouts of FSHD1.


Assuntos
Distrofia Muscular Facioescapuloumeral , Humanos , Pessoa de Meia-Idade , Complexo de Ataque à Membrana do Sistema Complemento , Biópsia , Músculo Esquelético , Regeneração
2.
iScience ; 27(1): 108696, 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38205246

RESUMO

Muscular dystrophies (MDs) are incurable genetic myopathies characterized by progressive degeneration of skeletal muscles. Dystrophic mice lacking the transcription factor Nfix display morphological and functional improvements of the disease. Recently, we demonstrated that MAPK signaling pathway positively regulates Nfix in muscle development and that Cyanidin, a natural antioxidant molecule, strongly ameliorates the pathology. To explore a synergistic approach aimed at treating MDs, we administered Trametinib, a clinically approved MEK inhibitor, alone or combined with Cyanidin to adult Sgca null mice. We observed that chronic treatment with Trametinib and Cyanidin reduced Nfix in myogenic cells but, unexpectedly, caused ectopic calcifications exclusively in dystrophic muscles. The combined treatment with Cyanidin resulted in histological improvements by preventing Trametinib-induced calcifications in Diaphragm and Soleus. Collectively, this first pilot study revealed that Nfix is modulated by the MAPK pathway in MDs, and that Cyanidin partly rescued the unexpected ectopic calcifications caused by MEK inhibition.

3.
J Cachexia Sarcopenia Muscle ; 14(6): 2520-2531, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37909859

RESUMO

BACKGROUND: Duchenne muscular dystrophy (DMD) is a progressive muscle degenerative disorder, culminating in a complete loss of ambulation, hypertrophic cardiomyopathy and a fatal cardiorespiratory failure. Necroptosis is the form of necrosis that is dependent upon the receptor-interacting protein kinase (RIPK) 3; it is involved in several inflammatory and neurodegenerative conditions. We previously identified RIPK3 as a key player in the acute myonecrosis affecting the hindlimb muscles of the mdx dystrophic mouse model. Whether necroptosis also mediates respiratory and heart disorders in DMD is currently unknown. METHODS: Evidence of activation of the necroptotic axis was examined in dystrophic tissues from Golden retriever muscular dystrophy (GRMD) dogs and R-DMDdel52 rats. A functional assessment of the involvement of necroptosis in dystrophic animals was performed on mdx mice that were genetically depleted for RIPK3. Dystrophic mice aged from 12 to 18 months were analysed by histology and molecular biology to compare the phenotype of muscles from mdxRipk3+/+ and mdxRipk3-/- mice. Heart function was also examined by echocardiography in 40-week-old mice. RESULTS: RIPK3 expression in sartorius and biceps femoris muscles from GRMD dogs positively correlated to myonecrosis levels (r = 0.81; P = 0.0076). RIPK3 was also found elevated in the diaphragm (P ≤ 0.05). In the slow-progressing heart phenotype of GRMD dogs, the phosphorylated form of RIPK1 at the Serine 161 site was dramatically increased in cardiomyocytes. A similar p-RIPK1 upregulation characterized the cardiomyocytes of the severe DMDdel52 rat model, associated with a marked overexpression of Ripk1 (P = 0.007) and Ripk3 (P = 0.008), indicating primed activation of the necroptotic pathway in the dystrophic heart. MdxRipk3-/- mice displayed decreased compensatory hypertrophy of the heart (P = 0.014), and echocardiography showed a 19% increase in the relative wall thickness (P < 0.05) and 29% reduction in the left ventricle mass (P = 0.0144). Besides, mdxRipk3-/- mice presented no evidence of a regenerative default or sarcopenia in skeletal muscles, moreover around 50% less affected by fibrosis (P < 0.05). CONCLUSIONS: Our data highlight molecular and histological evidence that the necroptotic pathway is activated in degenerative tissues from dystrophic animal models, including the diaphragm and the heart. We also provide the genetic proof of concept that selective inhibition of necroptosis in dystrophic condition improves both histological features of muscles and cardiac function, suggesting that prevention of necroptosis is susceptible to providing multiorgan beneficial effects for DMD.


Assuntos
Cardiomiopatias , Distrofia Muscular de Duchenne , Animais , Cães , Camundongos , Ratos , Distrofia Muscular de Duchenne/genética , Camundongos Endogâmicos mdx , Modelos Animais de Doenças , Cardiomiopatias/etiologia , Proteínas Quinases
4.
Acta Neuropathol Commun ; 11(1): 167, 2023 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-37858263

RESUMO

Duchenne muscular dystrophy (DMD) is a devastating X-linked muscular disease, caused by mutations in the DMD gene encoding Dystrophin and affecting 1:5000 boys worldwide. Lack of Dystrophin leads to progressive muscle wasting and degeneration resulting in cardiorespiratory failure. Despite the absence of a definitive cure, innovative therapeutic avenues are emerging. Myopathologic studies are important to further understand the biological mechanisms of the disease and to identify histopathologic benchmarks for clinical evaluations. We conducted a myopathologic analysis on twenty-four muscle biopsies from DMD patients, with particular emphasis on regeneration, fibro-adipogenic progenitors and muscle stem cells behavior. We describe an increase in content of fibro-adipogenic progenitors, central orchestrators of fibrotic progression and lipid deposition, concurrently with a decline in muscle regenerative capacity. This regenerative impairment strongly correlates with compromised activation and expansion of muscle stem cells. Furthermore, our study uncovers an early acquisition of a senescence phenotype by DMD-afflicted muscle stem cells. Here we describe the myopathologic trajectory intrinsic to DMD and establish muscle stem cell senescence as a pivotal readout for future therapeutic interventions.


Assuntos
Distrofia Muscular de Duchenne , Células Satélites de Músculo Esquelético , Humanos , Masculino , Distrofina/genética , Fibrose , Músculo Esquelético/patologia , Distrofia Muscular de Duchenne/patologia , Regeneração/genética , Senescência Celular/genética
5.
Neuromuscul Disord ; 33(10): 817-821, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37743183

RESUMO

Early onset myopathies are a clinically and histologically heterogeneous monogenic diseases linked to approximately 90 genes. Molecular diagnosis is challenging, especially in patients with a mild phenotype. We describe a 26-year-old man with neonatal hypotonia, motor delay and seizures during infancy, and non-progressive, mild muscular weakness in adulthood. Serum Creatine kinase level was normal. Whole-body muscle MRI showed thin muscles, and brain MRI was unremarkable. A deltoid muscle biopsy showed glycogen storage. WGS revealed a de novo 1.4 Mb-deletion of chromosome 14, confirmed by Array-CGH. This microdeletion causes the loss of ten genes including RALGAPA1, encoding for RalA, a regulator of glucose transporter 4 (GLUT4) expression at the membrane of myofibers. GLUT4 was overexpressed in patient's muscle. Here we highlight the importance to search for chromosomal alterations in the diagnostic workup of early onset myopathies.


Assuntos
Glicogênio , Doenças Musculares , Masculino , Recém-Nascido , Humanos , Adulto , Cromossomos Humanos Par 14 , Doenças Musculares/genética , Hipotonia Muscular/genética , Fenótipo , Proteínas do Tecido Nervoso/genética , Proteínas Ativadoras de GTPase/genética
6.
Acta Neuropathol Commun ; 11(1): 48, 2023 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-36945066

RESUMO

Congenital titinopathies are an emerging group of a potentially severe form of congenital myopathies caused by biallelic mutations in titin, encoding the largest existing human protein involved in the formation and stability of sarcomeres. In this study we describe a patient with a congenital myopathy characterized by multiple contractures, a rigid spine, non progressive muscular weakness, and a novel homozygous TTN pathogenic variant in a metatranscript-only exon: the c.36400A > T, p.Lys12134*. Muscle biopsies showed increased internalized nuclei, variability in fiber size, mild fibrosis, type 1 fiber predominance, and a slight increase in the number of satellite cells. RNA studies revealed the retention of intron 170 and 171 in the open reading frame, and immunoflourescence and western blot studies, a normal titin content. Single fiber functional studies showed a slight decrease in absolute maximal force and a cross-sectional area with no decreases in tension, suggesting that weakness is not sarcomere-based but due to hypotrophy. Passive properties of single fibers were not affected, but the observed increased calcium sensitivity of force generation might contribute to the contractural phenotype and rigid spine of the patient. Our findings provide evidence for a pathogenic, causative role of a metatranscript-only titin variant in a long survivor congenital titinopathy patient with distal arthrogryposis and rigid spine.


Assuntos
Músculo Esquelético , Doenças Musculares , Humanos , Conectina/genética , Conectina/metabolismo , Músculo Esquelético/patologia , Doenças Musculares/genética , Sarcômeros/metabolismo , Fenótipo
7.
Sci Transl Med ; 15(685): eadd5275, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36857434

RESUMO

Duchenne muscular dystrophy (DMD) is a severe and progressive myopathy leading to motor and cardiorespiratory impairment. We analyzed samples from patients with DMD and a preclinical rat model of severe DMD and determined that compromised repair capacity of muscle stem cells in DMD is associated with early and progressive muscle stem cell senescence. We also found that extraocular muscles (EOMs), which are spared by the disease in patients, contain muscle stem cells with long-lasting regenerative potential. Using single-cell transcriptomics analysis of muscles from a rat model of DMD, we identified the gene encoding thyroid-stimulating hormone receptor (Tshr) as highly expressed in EOM stem cells. Further, TSHR activity was involved in preventing senescence. Forskolin, which activates signaling downstream of TSHR, was found to reduce senescence of skeletal muscle stem cells, increase stem cell regenerative potential, and promote myogenesis, thereby improving muscle function in DMD rats. These findings indicate that stimulation of adenylyl cyclase leads to muscle repair in DMD, potentially providing a therapeutic approach for patients with the disease.


Assuntos
Distrofia Muscular de Duchenne , Receptores da Tireotropina , Animais , Ratos , Receptores Acoplados a Proteínas G , Fibras Musculares Esqueléticas , Células-Tronco , Regeneração , Tireotropina
8.
Acta Neuropathol Commun ; 10(1): 60, 2022 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-35468843

RESUMO

Duchenne muscular dystrophy (DMD) is a fatal muscle-wasting disorder caused by mutations in the Dystrophin gene and for which there is currently no cure. To bridge the gap between preclinical and therapeutic evaluation studies, we have generated a rat model for DMD that carries an exon 52 deletion (R-DMDdel52) causing a complete lack of dystrophin protein. Here we show that R-DMDdel52 animals recapitulated human DMD pathophysiological trajectory more faithfully than the mdx mouse model. We report that R-DMDdel52 rats displayed progressive and severe skeletal muscle loss associated with fibrotic deposition, fat infiltration and fibre type switch. Early fibrosis was also apparent in the cardiac muscle. These histological modifications led to severe muscle, respiratory and cardiac functional impairments leading to premature death around 1 year. Moreover, DMD muscle exhibited systemic inflammation with a mixed M1/M2 phenotype. A comparative single cell RNAseq analysis of the diaphragm muscle was performed, revealing cellular populations alteration and molecular modifications in all muscle cell types. We show that DMD fibroadipogenic progenitors produced elevated levels of cartilage oligomeric matrix protein, a glycoprotein responsible for modulating homeostasis of extracellular matrix, and whose increased concentration correlated with muscle fibrosis both in R-DMDdel52 rats and human patients. Fibrosis is a component of tissue remodelling impacting the whole musculature of DMD patients, at the tissue level but most importantly at the functional level. We therefore propose that this specific biomarker can optimize the prognostic monitoring of functional improvement of patients included in clinical trials.


Assuntos
Distrofia Muscular de Duchenne , Animais , Biomarcadores , Proteína de Matriz Oligomérica de Cartilagem/uso terapêutico , Distrofina/metabolismo , Fibrose , Humanos , Camundongos , Camundongos Endogâmicos mdx , Distrofia Muscular de Duchenne/terapia , Ratos
9.
Cell Death Dis ; 11(2): 127, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-32071288

RESUMO

Muscular Dystrophies are severe genetic diseases due to mutations in structural genes, characterized by progressive muscle wasting that compromises patients' mobility and respiratory functions. Literature underlined oxidative stress and inflammation as key drivers of these pathologies. Interestingly among different myofiber classes, type I fibers display a milder dystrophic phenotype showing increased oxidative metabolism. This work shows the benefits of a cyanidin-enriched diet, that promotes muscle fiber-type switch and reduced inflammation in dystrophic alpha-sarcoglyan (Sgca) null mice having, as a net outcome, morphological and functional rescue. Notably, this benefit is achieved also when the diet is administered in dystrophic animals when the signs of the disease are seriously evident. Our work provides compelling evidence that a cyanidin-rich diet strongly delays the progression of muscular dystrophies, paving the way for a combinatorial approach where nutritional-based reduction of muscle inflammation and oxidative stress facilitate the successful perspectives of definitive treatments.


Assuntos
Antocianinas/administração & dosagem , Suplementos Nutricionais , Mediadores da Inflamação/metabolismo , Mitocôndrias Musculares/metabolismo , Músculo Esquelético/metabolismo , Estresse Oxidativo , Sarcoglicanopatias/dietoterapia , Animais , Modelos Animais de Doenças , Progressão da Doença , Feminino , Masculino , Camundongos Knockout , Mitocôndrias Musculares/patologia , Músculo Esquelético/patologia , Biogênese de Organelas , Fenótipo , Carbonilação Proteica , Sarcoglicanopatias/genética , Sarcoglicanopatias/metabolismo , Sarcoglicanopatias/patologia , Sarcoglicanas/deficiência , Sarcoglicanas/genética
10.
Head Neck ; 41(6): 1854-1862, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30636181

RESUMO

BACKGROUND: In nasal-ethmoidal malignancies, brain involvement is associated with dismal prognosis. METHOD: Patients undergoing endoscopic resection with transnasal craniectomy and subpial dissection (ERTC-SD) for brain-invading nasal-ethmoidal cancer between 2008 and 2016 were included. Complications were analyzed in all patients, whereas oncological outcomes only in patients with pathological brain invasion. The prognostic impact of previous treatments, brain edema, and histology was assessed. Hospitalization ratio was calculated. RESULTS: Nineteen patients received ERTC-SD and 11 had pathological-proven brain invasion. Histologies were 6 olfactory neuroblastomas (ONB), 3 neuroendocrine carcinomas, and 2 intestinal-type adenocarcinomas. Mean follow-up was 21.9 months. Three-year overall, local recurrence-free, and distance recurrence-free survivals were 65.5%, 81.8%, and 68.2%, respectively. Overall and distant recurrence-free survivals were significantly better in patients with ONB (P = 0.032 and P = 0.013, respectively). Hospitalization ratio was 4.1%. Complication rate was 10.5%. CONCLUSION: In selected nasal-ethmoidal tumors with brain invasion, ERTC-SD can provide good local control, satisfactory survival, and limited morbidity.


Assuntos
Adenocarcinoma/secundário , Neoplasias Encefálicas/cirurgia , Carcinoma Neuroendócrino/cirurgia , Seio Etmoidal , Cirurgia Endoscópica por Orifício Natural , Neuroblastoma/cirurgia , Neoplasias dos Seios Paranasais/cirurgia , Adenocarcinoma/patologia , Adulto , Idoso , Neoplasias Encefálicas/patologia , Carcinoma Neuroendócrino/patologia , Craniotomia , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cavidade Nasal , Invasividade Neoplásica , Neuroblastoma/patologia , Neoplasias dos Seios Paranasais/patologia , Seleção de Pacientes , Estudos Retrospectivos , Resultado do Tratamento
11.
Development ; 145(21)2018 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-30266829

RESUMO

The transcription factor Nfix belongs to the nuclear factor one family and has an essential role in prenatal skeletal muscle development, where it is a master regulator of the transition from embryonic to foetal myogenesis. Recently, Nfix was shown to be involved in adult muscle regeneration and in muscular dystrophies. Here, we have investigated the signalling that regulates Nfix expression, and show that JunB, a member of the AP-1 family, is an activator of Nfix, which then leads to foetal myogenesis. Moreover, we demonstrate that their expression is regulated through the RhoA/ROCK axis, which maintains embryonic myogenesis. Specifically, RhoA and ROCK repress ERK kinase activity, which promotes JunB and Nfix expression. Notably, the role of ERK in the activation of Nfix is conserved postnatally in satellite cells, which represent the canonical myogenic stem cells of adult muscle. As lack of Nfix in muscular dystrophies rescues the dystrophic phenotype, the identification of this pathway provides an opportunity to pharmacologically target Nfix in muscular dystrophies.


Assuntos
Sistema de Sinalização das MAP Quinases , Desenvolvimento Muscular , Mioblastos/metabolismo , Fatores de Transcrição NFI/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo , Animais , Animais Recém-Nascidos , Embrião de Mamíferos/metabolismo , Feminino , Feto/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Inativação Gênica , Masculino , Camundongos , Fatores de Transcrição NFI/genética , Células-Tronco/metabolismo , Fatores de Transcrição/metabolismo , Quinases Associadas a rho/metabolismo
12.
Nat Commun ; 8(1): 1055, 2017 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-29057908

RESUMO

Muscular dystrophies are severe disorders due to mutations in structural genes, and are characterized by skeletal muscle wasting, compromised patient mobility, and respiratory functions. Although previous works suggested enhancing regeneration and muscle mass as therapeutic strategies, these led to no long-term benefits in humans. Mice lacking the transcription factor Nfix have delayed regeneration and a shift toward an oxidative fiber type. Here, we show that ablating or silencing the transcription factor Nfix ameliorates pathology in several forms of muscular dystrophy. Silencing Nfix in postnatal dystrophic mice, when the first signs of the disease already occurred, rescues the pathology and, conversely, Nfix overexpression in dystrophic muscles increases regeneration and markedly exacerbates the pathology. We therefore offer a proof of principle for a novel therapeutic approach for muscular dystrophies based on delaying muscle regeneration.


Assuntos
Músculos/fisiologia , Distrofias Musculares/genética , Fatores de Transcrição NFI/fisiologia , Regeneração , Animais , Feminino , Inativação Gênica , Masculino , Camundongos , Músculos/patologia , Distrofias Musculares/patologia , Sarcoglicanas/genética
13.
Laryngoscope ; 127(12): 2731-2737, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28573675

RESUMO

OBJECTIVES/HYPOTHESIS: Different reconstructive options are available for defects following total laryngectomy (TL) and circumferential (CH) or partial hypopharyngectomy (PH). We evaluated the flap success, pharyngocutaneous fistula, and pharyngoesophageal stenosis rates in two groups of patients treated by different policies. STUDY DESIGN: Comparison between two cohorts of patients treated by TL with PH/CH ± cervical esophagectomy and reconstructed according to different strategies. METHODS: Group A (historical) was composed of 89 patients reconstructed by pectoralis major myocutaneous (PMMC), radial forearm (RF), and anterolateral thigh (ALT) flaps. A salivary bypass stent (SBPS) was not routinely applied and left in place for a maximum of 14 days. Forty-four (49%) patients received preoperative radiotherapy/chemoradiotherapy (RT/CRT). Group B (prospective) included 105 patients reconstructed by RF or ALT with long-lasting SBPS left in place for a maximum of 45 days. Sixty-one (59%) received preoperative RT/CRT. RESULTS: In group A, flap failure occurred in four (4%) cases, and all were managed by PMMC. We encountered 22 (26%) fistulas and 14 (16%) stenoses. In group B, flap failure occurred in six (6%) cases and was managed by PMMC. We encountered seven (7%) fistulas and three (3%) stenoses. Comparing complications among the two groups, we encountered a statistically significant difference in favor of group B for both fistula (P < .001) and stenosis (P = .001). We did not evidence any significant difference in terms of flap success rate. CONCLUSIONS: First-line application of RF and ALT free flaps with long-lasting SBPS in reconstruction after PH/CH allows obtaining reduced incidences of both fistula and stenosis. LEVEL OF EVIDENCE: 4. Laryngoscope, 127:2731-2737, 2017.


Assuntos
Carcinoma de Células Escamosas/cirurgia , Retalhos de Tecido Biológico , Neoplasias Hipofaríngeas/cirurgia , Hipofaringe/cirurgia , Laringectomia , Faringectomia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Fáscia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/prevenção & controle , Estudos Prospectivos , Estudos Retrospectivos , Pele , Adulto Jovem
14.
Eur Arch Otorhinolaryngol ; 274(2): 939-945, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27538738

RESUMO

The angular branch (AB)-based tip of scapula free flap is a valuable reconstructive option in palato-maxillary defects needing significant structural support. We herein retrospectively evaluate our surgical series with special focus on functional outcomes and postoperative morbidity. Ninety-seven consecutive palatomaxillary oncologic resections were performed at our institution between August 2008 and November 2015. The analysis focused on those reconstructed by an AB-based tip of scapula free flap (N = 18; 19 %). A prospective assessment of donor site morbidity was performed by the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire in 12 (67 %) patients. Among patients reconstructed by an AB-based tip of scapula free flap, 13 (72 %) had a Class II and 5 (28 %) a Class III defect according to Okay classification. Flap success rate was 94 %, with one failure requiring an anterolateral thigh flap. Eight (44 %) patients experienced recipient site complications, while donor site problems occurred in two only (11 %). Eleven (61 %) subjects were able to maintain a normal and 7 (39 %) a soft-to-firm diet. The mean DASH score was 10.5. Our results confirm that the AB-based tip of scapula free flap is a reliable choice in palatomaxillary reconstruction, with both satisfactory functional outcomes and negligible donor site morbidity.


Assuntos
Carcinoma/cirurgia , Retalhos de Tecido Biológico , Neoplasias Maxilomandibulares/cirurgia , Procedimentos Cirúrgicos Ortognáticos , Procedimentos de Cirurgia Plástica/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Escápula
15.
Cell Stress ; 2(1): 17-19, 2017 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31225448

RESUMO

Muscular dystrophies (MDs) are still incurable heterogeneous diseases, characterized by muscle wasting, replacement by fibrotic tissue, and increasing weakness, which in severe cases, such as Duchenne MD, lead to premature death. MDs are due to mutations encompassing different dystrophin-glycoprotein complex (DGC) genes, which code for structural proteins that anchor the cytoskeleton to the extracellular matrix, thus conferring myofiber stability. All mutations destabilizing this complex result in different MD forms, with varying levels of severity. Independently of the genetic defect, MDs share common hallmarks, characterized by continuous cycles of muscle degeneration, due to lack of structural support during contraction, followed by regeneration cycles by satellite cells (SCs), the canonical myogenic stem cells of adult muscle. However, dystrophic SCs generate new fibres which are also prone to degeneration so that, after many cycles of degeneration/regeneration, this cell population is exhausted and muscle is replaced by connective and adipose tissue. At this stage, any therapeutic intervention is likely to fail.

16.
Cell Rep ; 17(9): 2354-2366, 2016 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-27880909

RESUMO

Sox6 belongs to the Sox gene family and plays a pivotal role in fiber type differentiation, suppressing transcription of slow-fiber-specific genes during fetal development. Here, we show that Sox6 plays opposite roles in MyHC-I regulation, acting as a positive and negative regulator of MyHC-I expression during embryonic and fetal myogenesis, respectively. During embryonic myogenesis, Sox6 positively regulates MyHC-I via transcriptional activation of Mef2C, whereas during fetal myogenesis, Sox6 requires and cooperates with the transcription factor Nfix in repressing MyHC-I expression. Mechanistically, Nfix is necessary for Sox6 binding to the MyHC-I promoter and thus for Sox6 repressive function, revealing a key role for Nfix in driving Sox6 activity. This feature is evolutionarily conserved, since the orthologs Nfixa and Sox6 contribute to repression of the slow-twitch phenotype in zebrafish embryos. These data demonstrate functional cooperation between Sox6 and Nfix in regulating MyHC-I expression during prenatal muscle development.


Assuntos
Feto/embriologia , Músculo Esquelético/embriologia , Cadeias Pesadas de Miosina/metabolismo , Fatores de Transcrição NFI/metabolismo , Fatores de Transcrição SOXD/genética , Transcrição Gênica , Proteínas de Peixe-Zebra/metabolismo , Animais , Sequência Conservada , Embrião não Mamífero/metabolismo , Evolução Molecular , Feto/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Fatores de Transcrição MEF2/metabolismo , Camundongos , Modelos Biológicos , Desenvolvimento Muscular/genética , Músculo Esquelético/metabolismo , Mioblastos/metabolismo , Fenótipo , Regiões Promotoras Genéticas , Ligação Proteica/genética , Peixe-Zebra/embriologia , Peixe-Zebra/genética
17.
Head Neck ; 38 Suppl 1: E1488-92, 2016 04.
Artigo em Inglês | MEDLINE | ID: mdl-26561407

RESUMO

BACKGROUND: Microvascular reconstruction in head and neck surgery is increasing in the elderly because of prolonged life expectancy. The purpose of this study was to evaluate the impact of age on outcomes after microvascular reconstruction. METHODS: We retrospectively reviewed 453 microvascular reconstructions and stratified patients according to age (40.8% >65 years old). Medical and surgical complications and flap success rates were evaluated according to the American Society of Anesthesiologists (ASA) score for physical status and age. RESULTS: Overall flap success and perioperative mortality were 96.1% and 0.7%, respectively. Minor medical complications were higher in the elderly (28.1% vs 15.3%; p = .001). High ASA scores affected rates of major surgical (20% vs 9.2%; p = .001) and minor medical complications (27.2% vs 13.3%; p < .001). CONCLUSION: Microvascular reconstruction is reliable in the elderly. Age should not be considered a contraindication by itself; comorbidities play a stronger role in predicting adverse events. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1488-E1492, 2016.


Assuntos
Neoplasias de Cabeça e Pescoço/cirurgia , Procedimentos de Cirurgia Plástica , Retalhos Cirúrgicos/transplante , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Estudos Retrospectivos
18.
Otolaryngol Head Neck Surg ; 152(5): 796-802, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25820590

RESUMO

OBJECTIVE: To provide surgeons and clinicians with a critical review of microvascular reconstructive options and their expected outcomes after head and neck cancer resection in the elderly. DATA SOURCES: Medline, Isiweb, and Cochrane databases. REVIEW METHODS: A literature search was performed in May 2014 and included studies published between 2000 and 2014. Keywords were used for articles identification, and inclusion criteria were defined for consideration in the present review. CONCLUSIONS: Evaluation of the pertinent literature is hampered by a number of biases, such as a lack of general consensus of a definition of "elderly," differences among scales used to quantify comorbidities, and subjective evaluation of flap-related and systemic complications. However, our findings showed no differences in terms of free flap success, surgical complications, or mortality rate between older and younger patients. Moreover, recipient site complications do not seem to be affected by age. IMPLICATION FOR PRACTICE: Microvascular reconstruction in the elderly can be performed with high success rates, even though medical complications can occur more frequently compared to younger patients. Minor and major surgical complications in the elderly appear to be comparable to those in the younger population and do not affect final outcome or the perioperative mortality rate. Flap outcome does not seem to be significantly affected by age. Careful preoperative assessment and postoperative monitoring are mandatory to prevent adverse events, and prompt management is warranted whenever present.


Assuntos
Retalhos de Tecido Biológico , Neoplasias de Cabeça e Pescoço/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Comorbidade , Idoso Fragilizado , Neoplasias de Cabeça e Pescoço/epidemiologia , Humanos , Resultado do Tratamento
19.
Artigo em Inglês | MEDLINE | ID: mdl-24504225

RESUMO

PURPOSE OF REVIEW: To summarize recent acquisitions in three-dimensional tongue and floor of mouth anatomy that can help in better evaluation of the pathways of cancer progression within these oral subsites, thus giving some hints for refining of the current TNM staging system. RECENT FINDINGS: The Visual Human Project is an initiative aimed at establishing a three-dimensional dataset of anatomy of two cadavers made available free to the scientific community. Visual human data have been analyzed by specific software thus improving our three-dimensional understanding of the tongue myostructure. It is already known that there is limited prognostic utility in using the two-dimensional surface diameter alone as criterion for T1-T3 definition. Recently, also the T4a categorization for the infiltration of 'deep' or extrinsic tongue muscles has been criticized. This is largely because the descriptor 'deep' does not take into account the fact that considerable portions of these muscles lie in a very superficial plane. Different prognosticators have been proposed for inclusion into the TNM staging system of oral cancer but 'depth of tumor infiltration' seems to be the most robust, universally recognized, and reproducible in the preoperative, intraoperative, and postoperative settings. SUMMARY: Oral tongue and floor of mouth cancer needs to be classified according to a revised TNM staging system in which 'depth of infiltration' should be taken into account. An 'ideal cut off' for distinguishing 'low' (T1-T2) from 'high-risk' (T3-T4) categories has been proposed based on the literature review, but needs retrospective as well as large prospective trials before its validation.


Assuntos
Carcinoma de Células Escamosas/patologia , Soalho Bucal/patologia , Soalho Bucal/ultraestrutura , Neoplasias Bucais/patologia , Neoplasias da Língua/patologia , Língua/ultraestrutura , Cadáver , Humanos , Estadiamento de Neoplasias
20.
Eur Arch Otorhinolaryngol ; 271(1): 157-62, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23605305

RESUMO

Venous thrombosis (VT) is the primary reason for microvascular free flaps (MFFs) failure. Different series have addressed the influence of venous anastomosis, end-to-end (ETE) vs. end-to-side (ETS), on this issue in head and neck (HN) microsurgery, but a consensus about the optimal technique to be adopted is still lacking. The aim of this study is to prospectively compare the venous complication rates of ETE and ETS techniques in 422 homogeneously treated patients who underwent MFF for HN oncologic defects between 2000 and 2012 at our Institution. Patients were divided into two groups: Group A (n = 269 patients) receiving an ETE and Group B (n = 153) an ETS venous anastomosis. The choice between the type of venous anastomosis was based on the several variables: availability of adequate caliber recipient veins in the neck, length and caliber of the donor vein, geometry and orientation of the vascular pedicle, and possibility to create a tensionless anastomosis. An ETE anastomosis was always preferred when feasible, while an ETS (performed on the internal jugular vein) was reserved to cases in which the abovementioned considerations contraindicated an ETE. Overall, the MFF failure rate was 3%. Among the 13 failures, five had VT (1.1%): three had received an ETE, and two an ETS. Venous anastomosis re-exploration and failure rates of the two groups were compared by the Chi-squared test showing no statistically significant differences. In conclusion, our data show how ETS venous anastomosis is a safe alternative to ETE whenever the latter cannot be properly accomplished for the previously mentioned contraindications.


Assuntos
Neoplasias de Cabeça e Pescoço/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anastomose Cirúrgica/métodos , Feminino , Humanos , Masculino , Microcirurgia , Pessoa de Meia-Idade , Estudos Prospectivos , Procedimentos de Cirurgia Plástica , Técnicas de Sutura , Grau de Desobstrução Vascular
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