Le muscle strié squelettique est un tissu richement vascularisé. Au delà de l'apport en oxygène et en nutriments, de nouvelles fonctions des vaisseaux ont été récemment identifiées, par le biais des interactions établies entre les cellules du vaisseau (cellules endothéliales) et les cellules du muscle, en particulier les cellules souches musculaires (cellules satellites). Celles-ci interagissent étroitement avec les cellules endothéliales pour leur expansion et leur différenciation, puis avec les cellules péri-endothéliales pour leur auto-renouvellement et leur retour à la quiescence. Les vaisseaux participent ainsi au contrôle de l’homéostasie du muscle squelettique. Grâce à ces interactions, les cellules vasculaires jouent donc un rôle central dans le remodelage tissulaire après un phénomène destructif, survenant par exemple au cours d’un trauma ou d’une myopathie. Pour étudier, les mécanismes de la plasticité vasculaire au cours du remodelage tissulaire, deux situations paradigmatiques de muscle en régénération chez l’enfant : la dermatomyosite juvénile (DMJ) et la dystrophie musculaire de Duchenne (DMD) ont été étudiées. Il existe, dans ces deux pathologies une souffrance musculaire associée à des cycles de nécrose/régénération. Elles se différencient par leur plasticité vasculaire et par leur évolution. En effet, la DMJ, la myopathie inflammatoire la plus fréquente de l’enfant est caractérisée par une vasculopathie avec perte en capillaires. L’évolution peut être favorable avec restitution ad integrum du muscle. La DMD est une myopathie génétique conduisant à une dégradation progressive de la force musculaire associée à une néovascularisation compensatrice. Le volet clinique/histologique incluant une analyse multiparamétrique des critères évolutifs cliniques et de réponse thérapeutique couplée à une réévaluation des données histologiques de la DMJ (analyse morphométrique des muscles DMJ) a permis de montrer qu’il existait des sous groupes phénotypiques homogènes de sévérité différente dans la DMJ. Le degré de sévérité clinique est relié à la gravité de la vasculopathie musculaire Par ailleurs, des marqueurs cliniques et histologiques simples permettant de repérer au diagnostic les patients nécessitant une escalade thérapeutique rapide (CMAS>34, atteinte gastrointestinale, fibrose endomysiale musculaire au diagnostic) ont été identifiés. Le volet cellulaire a permis l’identification in vitro des interactions cellulaires spécifiques et différentielles des myoblastes issues de patients DMD et DMJ sur les cellules endothéliales normales par l’analyse de leur rôle sur la prolifération, migration et différenciation des cellules vasculaires. Dans la DMD, les myoblastes entrainent une réponse angiogénique importante mais non efficace (néovascularisation anarchique). Dans la DMJ, les myoblastes participent efficacement à la reconstruction vasculaire notamment via la sécrétion de facteurs proangiogéniques. Ces résultats ont été renforcés par analyse transcriptomique effectuée à partir de cellules endothéliales et satellites isolées de muscles de patients confirmant le rôle central de la vasculopathie associée à un contexte inflammatoire spécifique lié à l’interféron dans la physiopathologie de la DMJ et montrant dans la DMD une dérégulation de l’homéostasie normale des interactions vaisseau-muscle avec mise en jeu d’un remodelage tissulaire non efficace. Ces données permettent d'identifier de nouvelles fonctions des cellules vasculaires dans le remodelage du muscle strié squelettique au cours des pathologies musculaires de l'enfant, et devraient ouvrir la voie à de nouvelles approches thérapeutiques. / Skeletal muscle is highly vascularised. Beyond oxygen and nutriment supply, new functions for vessels have been recently identified, through the interactions that vessel cells (endothelial cells) establish with muscle cells, particularly with muscle stem cells (satellite cells). These latter closely interact with endothelial cells for their expansion and their differentiation, then with periendothelial cells for their self-renewal and return to quiescence. During skeletal muscle regeneration endothelial cells reciprocally interact with myogenic cells by direct contact or by releasing soluble factors to promote both myogenesis and angiogenesis processes. Skeletal muscle regeneration typically occurs as a result of a trauma or disease, such as congenital or myopathies. To better understand the role of vessel plasticity in tissue remodeling, we took advantage of two muscular disorders that could be considered as paradigmatic situations of regenerating skeletal muscle in the child: Juvenile Dermatomyositis (JDM), the most frequent inflammatory myopathy and Duchenne Muscular Dystrophy (DMD), the most common type of muscular dystrophy. Although these two muscular disorders share, at the tissue level, similar mechanisms of necrosis-inflammation, they differ regarding the vessel domain. In JDM patients, microvascular changes consist in a destruction of endothelial cells assessed by focal capillary loss. This capillary bed destruction is transient. The tissue remodeling is efficient and muscle may progressively recover its function. By contrast, in DMD, despite an increase of vessels density in an attempt to improve the muscle perfusion, the muscle function progressively alters with age. We identified clinical and pathological markers of severity and predictive factors for poor clinical outcome in JDM by computing a comprehensive initial and follow-up clinical data set with deltoid muscle biopsy alterations controlled by age-based analysis of the deltoid muscle capillarization. We demonstrated that JDM can be divided into two distinctive clinical subgroups. The severe clinical presentation and outcome are linked to vasculopathy. Furthermore, a set of simple predictors (CMAS<34, gastrointestinal involvement, muscle endomysial fibrosis at disease onset) allow early recognition of patients needing rapid therapeutic escalation with more potent drugs. We studied in vitro the specific cell interactions between myogenic cells issued from JDM and DMD patients and normal endothelial cells to explore whether myogenic cells participate to the vessel remodeling observed in the two pathologies. We demonstrated that MPCs possessed angiogenic properties depending on the pathological environment. In DMD, MPCs promoted the development of establishment of an anarchic, although strong, EC stimulation, leading to the formation of weakly functional vessels. In JDM, MPCs enhanced the vessel reconstruction via the secretion of proangiogenic factors. This functional analysis was supported by the transcriptomic analysis consistent with a central vasculopathy in JDM including a strong and specific response to an inflammatory environment. On the contrary, DMD cells presented an unbalanced homeostasis with deregulation of several processes including muscle and vessel development with attempts to recover neuromuscular system by MPCs. To summarize, our data should allow the definition of new functions of vessel cells in skeletal muscle remodelling during muscle pathologies of the child that will open the way to explore new therapeutic options and to gain further insights in the pathogenesis of these diseases.

Des études précédentes ont montré qu’une carence en vitamine E prédispose à la myopathie du poulet de chair. L’effet d’un ajout de vitamine E dans la diète commerciale sur la dégénérescence des fibres musculaires de la poitrine et de la cuisse a été étudié chez les poulets de chair. Des poulets mâles ROSS 308 (n = 1100) ont été assignés de façon aléatoire à deux traitements alimentaires (aliment commercial + 25 à 50 mg de vitamine E surajouté par kg vs aliment commercial + 0 mg de vitamine E supplémentaire). Les poulets ont été répartis sur 10 parquets (cinq répétitions par traitement). Le poids corporel et la consommation d’aliment ont été mesurés hebdomadairement. Aux jours j28, j35, j42 et j49, du sang a été prélevé pour mesurer le niveau de vitamine E et l’activité de la créatine kinase (CK). Les muscles Pectoralis superficialis et Adductor magnus ont été prélevés pour des analyses histologiques aux jours j28, j42 et j49; les fibres dégénérées ont été dénombrées sur chaque muscle prélevé. La concentration plasmatique de vitamine E était plus élevée dans le groupe supplémenté (P = 0.001). L’activité de la CK n’était pas différente dans les deux groupes (P = 0.20) mais très élevée, et n’était pas toujours en relation avec les dommages musculaires, à cause de grandes fluctuations de la CK entre les individus du même groupe. Le nombre de fibres endommagées était plus élevé dans le muscle Pectoralis superficialis (poitrine) que dans le muscle Adductor magnus (cuisse) dans les deux groupes; il y avait aussi moins de fibres dégénérées à j28 dans la poitrine des poulets qui ont reçus la diète supplémentée. Ces résultats suggèrent que l’ajout de vitamine E à la diète conventionnelle augmente le niveau de vitamine E dans le plasma et dans les tissus, diminue le nombre de fibres dégénérées dans la poitrine des jeunes poulets sans pour autant modifier la conversion alimentaire. La mesure de l’activité plasmatique de la CK ne saurait suffire à elle seule pour détecter précocement la myopathie nutritionnelle dans les élevages de poulets de chair. / Previous studies have shown that vitamin E deficiency could lead to nutritional myopathy in broiler chickens. Vitamin E was added to a conventional commercial diet to evaluate its effect on breast and thigh muscle fibers degeneration in broiler chickens. Male chickens ROSS 308 (n = 1100) were randomly assigned to two dietary treatments (a commercial diet with 25 to 50 mg of extra vitamin E per kg of commercial diet and a commercial diet without extra vitamin E). Chickens were randomly divided into 10 pens (five replicates per treatment). Body weight and feed intake were monitored weekly. At d28, d35, d42 and d49 blood from chickens were sampled and assayed for level of vitamin E and creatine kinase (CK) activity. Both Pectoralis superficialis and Adductor magnus muscles from chickens were sampled for histological examination at d28, d42 and d49, and degenerated fibers were numbered. Plasma levels of vitamin E were higher in the supplemented group (P = 0.001), whereas activity of CK was high in both groups, but not significantly different (P = 0.20) due to strong fluctuations in CK activities within groups of these fast growing chickens. Pectoralis superficialis muscle had more damaged fibers than adductor’s in both groups. There were less degenerated fibers in pectoral muscle from d28 chickens receiving the supplemented diet. These results suggested that adding vitamin E into conventional diet increases plasma vitamin E and decreases the number of degenerated muscle fibers within pectoral muscle of young chickens. Measuring the CK activity in plasma is not sufficient for early detection of nutritional myopathy in broiler chicken’s farms.

L’objectif central de cette thèse de Doctorat était d’investiguer les dysfonctions mitochondriales qui surviennent précocement au cours de la phase compensée du remodelage ventriculaire pathologique et qui pourraient jouer un rôle causal dans la progression vers l’insuffisance cardiaque. Nos travaux antérieurs, réalisés à l’aide d’un modèle de surcharge volumique chronique induite par une fistule aorto-cavale (ACF) chez le Rat WKHA, ont montré qu’au cours du remodelage ventriculaire, les mitochondries développaient une vulnérabilité à l’ouverture du pore de perméabilité transitionnelle (PTP : un élément clé de la signalisation de la mort cellulaire) [1]. Ceci était observable au stade compensé du remodelage en absence des dysfonctions mitochondriales majeures typiquement observées dans le cœur insuffisant. Ces résultats nous ont amenés à suggérer que la vulnérabilité à l’ouverture du PTP pourrait constituer un mécanisme précoce favorisant la progression de la cardiopathie. Dans l’étude 1 de cette thèse, nous avons tenté de tester cette hypothèse en induisant une ACF chez deux souches de rats affichant de très nettes différences au niveau de la propension à développer l’insuffisance cardiaque : les souches WKHA et Sprague Dawley (SD). Nos études in vitro sur organelles isolées et in situ sur l’organe entier ont permis de confirmer que, dans le cœur ACF, les mitochondries développent une vulnérabilité à l’ouverture du PTP et à l’activation de la voie mitochondriale de la mort cellulaire lorsqu’exposées à des stress pertinents à la pathologie (surcharge calcique, ischémie-reperfusion [I-R]). Cependant, bien que comparativement aux animaux WKHA, les animaux SD démontraient un remodelage ventriculaire plus rapide et prononcé et une progression précoce vers l’insuffisance cardiaque, aucune différence n’était observable entre les deux groupes au niveau des dysfonctions mitochondriales, suggérant quelles ne sont pas à l’origine de la progression plus rapide de la pathologie chez la souche SD, à tout le moins en réponse à la surcharge volumique. Nous avons par la suite déterminé, à l’aide des mêmes approches expérimentales, si cette vulnérabilité mitochondriale était observable dans une cardiopathie d’étiologie différente, plus spécifiquement celle qui est associée à la dystrophie musculaire de Duchenne (DMD), une maladie génétique causée par une mutation de la protéine dystrophine. Nos études menées (études 2-4) sur de jeunes souris mdx (le modèle murin de la DMD) exemptes de tout signe clinique de cardiopathie n’ont révélé aucune différence au niveau des fonctions mitochondriales de base. Cependant, tout comme dans le modèle d’ACF, les mitochondries dans le cœur de souris mdx étaient significativement plus vulnérables à l’ouverture du PTP lorsque soumises à une I-R (étude 2). Par ailleurs, nous avons démontré que l’administration aiguë de sildénafil aux souris mdx induisait une abolition de l’ouverture du PTP et de ses conséquences signalétiques, une diminution marquée du dommage tissulaire et une meilleure récupération fonctionnelle à la suite de l’I-R (étude 3). Nous avons ensuite testé chez la souris mdx l’administration aiguë de SS31, un peptide anti-oxydant ciblé aux mitochondries, cependant aucun effet protecteur n’a été observé, suggérant que le tamponnement des radicaux libres est d’une utilité limitée si les perturbations de l’homéostasie calcique typiques à cette pathologie ne sont pas traitées simultanément (étude 4). Globalement, les travaux effectués au cours de cette thèse démontrent que la vulnérabilité à l’ouverture du PTP constitue une dysfonction précoce et commune qui survient au cours de remodelages ventriculaires pathologiques d’étiologies différentes. Par ailleurs, ces travaux suggèrent des stratégies d’intervention pharmacologiques ciblant ce processus, dont l’efficacité pour la prévention de l’insuffisance cardiaque demande à être établie. / The central objective of this doctoral thesis was to investigate the mitochondrial dysfunction that occurs early during the compensated phase of pathological ventricular remodeling and which may play a causal role in the progression to heart failure. Our previous work using a model of chronic volume overload induced by aorto-caval fistula (ACF) in rats WKHA showed that during the ventricular remodeling, mitochondria developed a vulnerability to permeability transition pore opening (PTP: a key component of cell death signaling) [1]. This was observed at the stage of compensated remodeling in the absence of major mitochondrial dysfunction typically observed in the failing heart. These results led us to suggest that the vulnerability to PTP opening could be a mechanism facilitating the progression of the cardiomyopathy. In our first study of this thesis we have attempted to test this hypothesis by inducing ACF in two strains of rats displaying sharp differences in the propensity to develop heart failure: WKHA strains and Sprague Dawley (SD). Our studies in vitro on isolated organelles and in situ on the whole organ have confirmed that, in the ACF heart, mitochondria develop a vulnerability to PTP opening and activation of mitochondrial cell death when exposed to stresses relevant to the pathology (calcium overload, ischemia-reperfusion [I-R]). However, SD animals compared to WKHA showed a more rapid and pronounced ventricular remodeling and early progression to heart failure, no difference was found between the two groups in terms of mitochondrial dysfunction, suggesting that this is not behind the more rapid progression of the disease in the SD strain, at least in response to volume overload. We subsequently determined, using the same experimental approaches, if this vulnerability was observed in mitochondria of heart disease from other etiology more specifically that associated with Duchenne muscular dystrophy (DMD), a genetic disease caused by a mutation of the protein dystrophin. Our studies (studies 2-4) on young mdx mice (the mouse model of DMD) free of clinical signs of heart disease showed no difference in basal mitochondrial functions. However, as in the model of ACF, the mitochondria of mdx mice heart were significantly more vulnerable to PTP opening when subjected to I-R (study 2). Furthermore, we demonstrated that acute administration of sildenafil to mdx mice abolished the PTP opening and its signaling consequences, markedly reduced of tissue damage and improved functional recovery following I-R (Study 3). We then tested in mdx mice acute administration of SS31, an antioxidant peptide that targets and accumulates in mitochondria. However, no protective effect was observed, suggesting that the buffering of free radicals have a limited utility if the typical perturbations of the calcium homeostasis in this disease are not treated simultaneously (Study 4). Overall, the work done during this thesis show that the vulnerability to PTP opening is a common and early dysfunction that occurs during pathological ventricular remodeling of different etiologies. Moreover, these studies suggest pharmacological intervention strategies targeting this process, whose effectiveness in preventing heart failure needs to be established.

Pas de résumé français / Pas de résumé anglais

La jonction myotendineuse (JMT) est une interface spécialisée dans la transmission des forces entre le muscle et le tendon. Le collagène XXII (COLXXII) est un nouveau composant de cette jonction (Koch et al., 2004). COLXXII fait partie de la sous-famille des FACITs (Fibrils Associated Collagen with Interrupted Triple helix) qui se caractérisent par leur capacité à s’associer aux collagènes fibrillaires pour former des réseaux protéiques. La fonction de ce nouveau composant de la JMT n’est pas connue. C’est pourquoi nous avons décidé de réaliser une perte de fonction chez le poisson zèbre en utilisant la stratégie anti-sens morpholinos et d’en étudier le phénotype par différentes techniques. Chez l’embryon, le COLXXII est exprimé aux extrémités des fibres musculaires au niveau de leur ancrage sur le myosepte (structure équivalente au tendon des mammifères) pour être déposé à la JMT. Son expression est régulée par des membres de la famille des FGF, probablement FGF8. L’absence de COLXXII conduit à une perte des capacités contractiles du muscle et au détachement et à la rétractation progressive des fibres musculaires, causés par une rupture de la JMT qui s’opère entre la lame basale des fibres musculaires et la matrice tendineuse. Le morphotype induit par l’injection de morpholino COLXXII phénocopie les mutants sapje (mutant dystrophine) et candyfloss (mutation de la chaîne α2 des laminines) indiquant que COLXXII permet un lien structural entre le muscle et le tendon. Nos résultats montrent que COLXXII joue un rôle crucial dans le développement et la fonction de la JMT et représente un nouveau gène candidat pour les dystrophies musculaires. / The myotendinous junction (MTJ) is a specialized structure that transmits muscle contractile forces to tendon. Collagen XXII (COLXXII) is a novel component of MTJ (Koch et al., 2004). It belongs to the FACITs (Fibrils Associated Collagen with Interrupted Triple helix) subset of the collagen superfamily that is characterized by their capacity to mediate protein-protein interactions. The in vivo role of COLXXII has not been elucidated. Therefore, we decided to analyze its function in developing zebrafish using the morpholino-based knock-down strategy. We showed that its transcripts are exclusively expressed at the extremities of muscle fibers close to myoseptal tendons and the protein is deposited at the MTJ. The onset of COLXXII expression depends on FGF signaling, probably FGF8. Using different methods, we showed that loss of COLXXII induces morphofunctional alterations of muscle/tendon development and muscle weakness. Progressive muscle fiber detachment and retraction are observed in morphants that result from MTJ failure occuring at the muscle basement membrane/myosepta extracellular matrix side. The morphotype of the MO22-injected embryos is reminiscent to the sapje (dystrophin mutant) and candyfloss (laminin α2 chain mutation) mutant phenotypes indicating that COLXXII provides a molecular link between muscle and tendons. Our results suggest that COLXXII plays a crucial role in MTJ development and function and represents a novel candidate gene for muscular dystrophies.

INTRODUÇÃO: As distrofias musculares de cinturas (DMC) representam um grupo heterogêneo de desordens hereditárias e degenerativas da musculatura esquelética, com evolução progressiva, caracterizadas pelo acometimento predominante das cinturas escapular e/ou pélvica. São classificadas de acordo com o padrão de herança e o gene envolvido, podendo ser autossômicas dominantes ou autossômicas recessivas. No presente estudo, foi feita a análise de pacientes com diagnóstico de distrofia muscular de cinturas 2B (DMC2B). Trata-se de condição autossômica recessiva, cujo gene envolvido na sua fisiopatologia é o DYSF; sua mutação pode associar-se a alterações na proteína disferlina. OBJETIVOS: Avaliar a distribuição da fraqueza muscular na distrofia muscular de cinturas 2B com ênfase no acometimento dos membros superiores; realizar avaliação objetiva da força muscular para preensão palmar e pinças; correlacionar a força muscular dos diferentes movimentos com a idade de início dos sintomas, idade na ocasião da avaliação, tempo de evolução da doença e capacidade funcional. METODOLOGIA: Estudo prospectivo, observacional, corte transversal, caso-controle. Foi feita avaliação clínica da força muscular de membros superiores e superiores dos pacientes, através de instrumentos clínicos específicos e dinamômetro de pinça e de preensão palmar; adicionalmente, foram aplicadas escalas de capacidade funcional (Escala de Vignos e Escala de Brooke). RESULTADOS: Foram avaliados 12 pacientes com diagnóstico molecular confirmado de DMC2B e recrutados 41 pacientes para o grupo controle. Os grupos não diferiram por gênero nem nas médias etárias. A média da idade de início dos sintomas dos pacientes foi de 26,9 anos (DP 10,05); a idade média na ocasião da avaliação foi de 43,6 anos (DP 9,34). A avaliação clínica da força muscular evidenciou maior acometimento de membros inferiores em relação aos membros superiores. A dinamometria de pinça (bidigital e trigidital) e de preensão palmar evidenciou diferença significativa entre os pacientes e o grupo controle para todos os movimentos citados. Os valores de CK apresentaram média de 2769 U/L (cerca de quinze vezes o limite superior de normalidade). As escalas de avaliação de capacidade funcional evidenciaram uma correlação significativa entre a idade do paciente na ocasião da avaliação e o escore na escala de Brooke. CONCLUSÃO: A análise do padrão de fraqueza dos pacientes com DMC2B evidenciou acometimento de membros inferiores e também de membros superiores. A análise objetiva com dinamometria demonstrou acometimento em todos os movimentos avaliados, evidenciando o envolvimento distal de membros superiores. A análise da capacidade funcional de membros superiores apresentou correlação com idade na avaliação (quanto maior a idade do paciente, maior o grau de incapacidade para membros superiores). Os valores de CK e de força muscular correlacionaram-se com a idade do início dos sintomas e idade na avaliação, ou seja, o início mais precoce da doença correlacionou-se com quadros mais graves (maiores valores de CK e maior envolvimento de força muscular - principalmente distal de membros superiores) / INTRODUCTION: Limb-girdle muscular dystrophies (LGMD) are a heterogeneous group of hereditary and degenerative disorders of the skeletal muscle, with progressive evolution, characterized by the predominant involvement of the scapular and / or pelvic girdles. They are classified according to the inheritance pattern and the involved gene, being autosomal dominant or autosomal recessive. In the present study, we evaluated patients with a diagnosis of 2D (LGMD2B). The LGMD2B is an autosomal recessive condition whose gene involved in its pathophysiology is DYSF; its mutation may be associated with changes in protein dysferlin. OBJECTIVES: To assess the distribution of muscle weakness in 2D womb muscular dystrophy with emphasis on upper limb involvement; perform objective evaluation of muscle strength for palmar grip and forceps; to correlate the muscular strength of the different movements with the age of onset of symptoms, age at the time of evaluation, duration of disease and functional capacity. METHODS: Prospective, observational, cross-sectional, case-control study. Clinical evaluation of the muscular strength of the upper and upper limbs of the patients was made through specific clinical instruments and pinch dynamometer and palmar grip; In addition, functional capacity scales were applied (Vignos Scale and Brooke Scale). RESULTS: Twelve patients with confirmed molecular diagnosis of DMC2B were evaluated and 41 patients were recruited for the control group. The groups did not differ by gender nor in the age groups. The mean age of onset of the patients\' symptoms was 26.9 years (SD 10.05); the mean age at the time of the evaluation was 43.6 years (SD 9.34). The clinical evaluation of muscle strength showed a greater involvement of the lower limbs in relation to the upper limbs. Pinch dynamometry (bidigital and trigidital) and handgrip dynamometry showed a significant difference between the patients and the control group for all the mentioned movements. CK values presented a mean of 2769 U / L (about eight times the upper limit of normality); there was a significant negative correlation (p <0.01) between the age of the patient at the time of the evaluation and the maximum value of CK. The functional capacity evaluation scales showed a significant correlation between the age of the patient at the time of the evaluation and the score on the Brooke scale. The correlation values between the muscular strength between the different movements evaluated and the age of onset of symptoms, age at the time of evaluation and time of evaluation of the disease presented values of significance close to 0.05 for the upper limb distal muscles and age of onset and age at the time of evaluation. CONCLUSION: The analysis of the weakness pattern of patients with LGMD2B showed involvement of lower limbs as well as upper limbs. Objective analysis with dynamometry showed involvement in all the movements evaluated, showing the distal involvement in the upper limbs. The analysis of functional capacity of upper limbs showed correlation with age in the evaluation (the higher the patient\'s age, the greater the degree of incapacity for upper limbs). The values of CK and muscle strength correlated with the age of onset of symptoms and age at the assessment, ie the earlier onset of the disease was correlated with more severe conditions (higher CK values and greater involvement of muscle strength - mainly distal upper limbs)

Introdução: As disferlinopatias são doenças genéticas causadas por alterações no gene da disferlina (DYSF), também denominadas distrofia muscular de cinturas (DMC) do tipo 2B, sendo a segunda em frequência em diversos países. A determinação de biomarcadores de função muscular desta doença se faz necessária. Objetivo: Estudo de caracterização da força e da função muscular nas disferlinopatias para estabelecer biomarcadores de habilidades motoras. Método: Amostra de 40 pacientes com dados de prontuário de força muscular (Medical Research Council - MRC), índice MRC, tempo de deambulação de 10 metros e, escalas de Vignos, Egen Klassifikation, Avaliação Funcional para distrofia muscular de Duchenne (FES-DMD) e North Star Ambulatory Assessment adaptada (a-NSAA). Resultados: Prevalência da disferlinopatia de 25,5% no Centro de Pesquisa sobre o Genoma Humano e Células Tronco, idade média de 36,5 anos, 52,5% do sexo masculino e 75% deambuladores. Músculos mais acometidos: abdominal, glúteo, íliopsoas, isquiotibial, quadríceps femoral, tibial anterior e deltoide médio. Correlação forte entre MRC e tempo de deambulação de 10 metros (média r=0,77) e, muito forte da MRC distal dos MMII com a-NSAA (r=0,90). Interação da MRC dos membros superiores (MMSS) e membros inferiores (MMII) entre os segmentos proximal e distal (p < 0,001), sendo mais evidente em MMSS do que em MMII. Taxa variável de progressão da doença, com 60% dos pacientes moderadamente ou gravemente afetados com menos de 12 anos de doença. Conclusão: Os achados caracterizam o padrão de fraqueza muscular dos brasileiros com disferlinopatia como proximal e distal dos MMII, com comprometimento associado da região proximal dos MMSS, além de elucidar as habilidades motoras em relação ao processo de locomoção. A forte correlação encontrada entre a força muscular, o tempo de deambulação de 10 metros e a escala a-NSAA, associada ao acompanhamento da evolução do desempenho de alguns grupos músculos podem fornecer um biomarcador adequado para o estudo da doençaCharacterization of muscle strength and function in Brazilian subjects with dysferlinopathy / Introduction: Dysferlinopathies are genetic diseases, caused to changes in the disferlina gene (DYSF), also named limb-girdle dystrophy type 2B, that is the second one in frequency in several countries. The small number of biomarkers of functional performance researches brings the need for studies in this area. Objective: This study characterizes muscle strength and function in subjects with dysferlinopathy to establish biomarkers of motor skills. Method: Data were available from 40 patients and included muscle strength assessment using the Medical Research Council (MRC) power scale, MRC index, timed motor performances for walking and data from the Vignos, Egen Klassifikation, Functional Assessment for Duchenne muscular dystrophy (FES-DMD) and the adapted North Star Ambulatory Assessment (a-NSAA) scales. Results: The prevalence of dysferlinopathy was 25.5% in the Centre for the Study of the Human Genome and Stem Cells (CEGH-CEL), the mean cohort age was 36.5 years, 52.5% were males and 75% were walkers. The weaker muscle found were the abdominal, gluteus, iliopsoas, hamstrings, quadriceps femoris, tibialis anterior and medial deltoid. Strong correlations were observed between the MRC power score and walking time (r = 0.77) and very strong between the MRC distal lower limb power score and a-NSAA (r = 0.90). Interactions of MRC scores were observed between the upper and lower limbs and the proximal and distal regions (p < 0.001) but were more evident in the upper limbs. The disease progression rates were variable with 60% of patients moderately or severely affected after more than 12 years since diagnosis. Conclusion: These findings suggest the pattern of muscular weakness in Brazilians with dysferlinopathy is predominantly in the lower limbs (proximal and distal) with associated involvement of the proximal upper limbs and elucidates the motor abilities in relation to locomotion. Due to the strong correlation with muscle strength, the walking time and the a-NSAA scale, in association with monitoring the evolution of the performance of some specific muscles can provide a suitable biomarker for the study of the disease

Introdução: A Distrofia Muscular de Duchenne (DMD) é caracterizada como uma fraqueza muscular progressiva que leva à incapacidade. Devido às dificuldades funcionais enfrentadas pelos indivíduos com DMD, o uso da tecnologia assistiva é essencial para proporcionar ou promover habilidades funcionais. Na DMD, além do comprometimento musculoesquelético, uma disfunção autonômica cardíaca também tem sido relatada. Assim, visamos investigar as respostas autonômicas agudas de indivíduos com DMD durante a realização de uma tarefa no computador. Método: A variabilidade da frequência cardíaca foi avaliada através de métodos lineares e não lineares, utilizando uma cinta torácica com equipamento de monitoramento de eletrocardiograma (ECG). Assim, 45 indivíduos foram incluídos no grupo com DMD e 45 no grupo de desenvolvimento típico (controle), avaliados for 20 minutos em repouso sentado e 5 minutos com a realização de uma tarefa no computador. Resultados: Os indivíduos com DMD apresentaram menor modulação cardíaca parassimpática durante o repouso, que diminuiu ainda mais durante a tarefa no computador. Conclusão: Indivíduos com DMD exibiram respostas autonômicas cardíacas mais intensas durante a tarefa no computador / Introduction: Duchenne muscular dystrophy (DMD) is characterized by progressive muscle weakness that leads to disability. Due to functional difficulties faced by individuals with DMD, the use of assistive technology is essential to provide or expand functional abilities. In DMD, as well as musculoskeletal impairment, cardiac autonomic dysfunction has also been reported. Thus, we aimed to investigate acute cardiac autonomic responses in a computer task of DMD subjects. Method: Heart rate variability was evaluated through linear and nonlinear methods, using a breast strap electrocardiogram (ECG) measuring device. Thus, 45 subjects were included in the group with DMD and 45 in the typical development (control) group, assessed for 20 minutes sitting at rest and five minutes with a task on the computer. Results: Individuals with DMD had lower parasympathetic cardiac modulation at rest, which decreased further during the task on the computer. Conclusion: Individuals with DMD exhibited more intense cardiac autonomic responses during computer tasks

A evolução da Distrofia Muscular de Duchenne (DMD) culmina na morte dos pacientes por problemas respiratórios, que aparentemente estão relacionados com a fraqueza de sua musculatura. O propósito deste estudo foi avaliar o efeito de três exercícios respiratórios de ioga na função respiratória em pacientes com DMD. A escolha dos exercícios foi motivada pelo fato de não se encontrar similares nos procedimentos fisioterápicos atuais no ocidente e por poderem ser praticados sem a necessidade de aparatos ou ajuda externa, facilitando sua execução diária. Os exercícios foram ensinados individualmente no ambulatório do Hospital das Clínicas da Universidade de São Paulo em dias regulares de consultas dos pacientes. As séries, bem como a sua progressão, levaram em consideração as limitações individuais. Foi realizada uma avaliação inicial das condições respiratórias (função pulmonar e pressões respiratórias) em 85 pacientes com idade entre 6 e 14 anos. Estas avaliações foram repetidas a cada 5 meses (em média) ao longo do treinamento. Os dados foram analisados de diferentes maneiras: pacientes que fizeram todas as avaliações ao longo de 10 meses (N=39); ao longo de 20 meses (N=18) e com os resultados dos pacientes que fizeram pelo menos uma avaliação além da inicial ao longo de 10 meses (N=70). Os grupos foram divididos por faixa etária em dois subgrupos (6 a 9 anos e 10 a 14 anos de idade). Constatou-se na análise com N=39 e N=70 que os pacientes mais novos que executaram os exercícios aplicados, apresentaram depois de 10 meses de treinamento, elevação nos valores absolutos e relativos da capacidade vital forçada (CVF), volume expiratório forçado em 1 segundo (VEF1) e pressão expiratória máxima (PEmax) e que os pacientes mais velhos, depois de 10 meses de treinamento, apresentaram melhora nos índices de pressão expiratória máxima (PEmax) em valores absolutos e relativos. Na análise com N=18 observou-se que os pacientes obtiveram melhora nos valores absolutos da função pulmonar (CVF e VEF1) até os 20 meses de treinamento quando comparamos com os valores do início e para a PEmax em valores absolutos, os resultados aumentam até 10 meses de treinamento e depois se mantém estáveis. Observou-se diminuição no declínio dos índices de função pulmonar dos pacientes quando comparados com crianças normais (porcentagem do predito). Constatou-se na análise determinada pela curva dos resultados da PEmax por faixa etária em valores relativos, que após 10 meses de prática dos exercícios de ioga, o declínio de seus valores foi retardado. O grande fator de melhora destes pacientes foi o aumento da força muscular expiratória forçada conseguido especialmente com a prática da técnica denominada kapalabhati. Recomendamos que estes exercícios sejam incorporados à prática clínica dos pacientes com DMD com a intenção de minimizar os danos causados pela perda da capacidade respiratória. / Duchenne Muscular Dystrophy (DMD) has a progression that culminates in the death of the patients for respiratory problems, which are apparently related to the weakness of the respiratory muscles. The objective of this study was to investigate the effects of three respiratory techniques of yoga in the respiratory function of patients with DMD. The selection of the exercises was conducted taking into account that there are no similar ones in the actual western physiotherapeutic procedures, and due to the fact that all of them may be practiced without the need of any apparatus or external help, making their daily practice easy. The exercises were taught individually in the Ambulatory of the General Hospital of the University of São Paulo during the regular appointments of the patients. The series of exercises, as well as their progressions, took into consideration the individual limitations. In order to establish the respiratory conditions (FVC, FEV1, PImax, and PEmax) of the group, an initial evaluation was conducted with 85 patients between 6 and 14 years old. The follow-up evaluations were carried out on an average 5-month interval, during the training period. Data were analyzed in different ways: subjects which had all the evaluations during 10 months of training (N=39); during 20 months of training (N=18) and with the results of patients that had at lest one evaluation besides the initial in the first 10 months (N=70). Furthermore, the total group was divided by age into 2 subgroups: (from 6 to 9 years old, and from 10 to 14 years old). The analysis of the groups with N=39, and N=70 revealed that, after 10 months of training, the younger subjects had increased their absolute and relative values of forced vital capacity (FVC), expiratory forced volume in 1 sec (FEV1), and maximal expiratory pressure (PEmax) , and that the older subjects, after the same period, had their absolute and relative PEmax also increased. In the analysis of the subgroup with N=18, there was an increase in the absolute values for pulmonary function (FVC and FEV1) until 20 months of training, while for PEmax this increase was seen only until 10 months, and afterwards there was a maintenance of its values. There was a reduction in the decline of the pulmonary function indexes of the patients when compared with healthy subjects (percentage of the predicted). The curve results of relative PEmax according to age revealed that after 10 months of practicing the prescribed exercises, the decline of its values was postponed. The greatest improvement in these children was found in the expiratory muscle power, attained through the practice of the technique called kapalabhati. We recommend the inclusion of these exercises to the clinical treatment of the DMD patients with the intention of minimizing the damage caused by the loss of respiratory capacity.

Introdução: A Retinose Pigmentar (RP) é uma doença hereditária da retina, caracterizada por perda da função visual, principalmente devido à degeneração dos fotorreceptores (bastonetes e cones). Objetivo: Avaliar os efeitos de uma única injeção intravítrea de fração mononuclear de células da medula óssea (FMMO) CD34+ em pacientes portadores de RP. Métodos: Ensaio clínico aberto, não randomizado, prospectivo, observador mascarado, no qual 20 pacientes, portadores de RP, com boa fixação ao exame de campo visual, foram incluídos. Única injeção intravítrea (IIV) de FMMO foi aplicada em apenas um dos olhos de cada paciente, enquanto que os olhos contralaterais serviram como controle e foram submetidos à injeção simulada. As avaliações incluíram: melhor acuidade visual corrigida (MAVC); campo visual estático - estratégia 30-2 (Octopus 900); microperimetria (MAIA - Center Vue) para avaliar estabilidade de fixação e sensibilidade macular; eletrorretinografia de campo total (ERG) e multifocal (mfERG) - padrão da ISCEV usando aparelho Espion E2 (Diagnosys LLC) e tomografia de coerência óptica (OCT). Os exames foram realizados antes da injeção e 4, 16, 32 e 48 semanas após. Resultados: Não houve diferença significativa na MAVC durante o seguimento. A diferença entre MAVC medida após 48 semanas e a basal foi de -0,04 ? 0,02 logMAR nos olhos tratados frente a -0,03 ? 0,01 logMAR nos controles (p=0,3898). A melhora da sensibilidade macular foi discretamente maior nos olhos com FMMO: 1,0 ? 0,5 dB do que nos olhos contralaterais: 0,2 ? 0,5 dB, mas sem significância estatística (p=0,0569). Não se observou mudança na estabilidade de fixação. A perda de desvio médio (MD) do campo visual dos olhos tratados (0,33 ? 0,70 dB) foi discretamente menor do que nos olhos controle (1,12 ? 0,58 dB) (p=0,0761). Nenhuma diferença significativa foi observada nas amplitudes e latências das respostas eletrorretinográficas durante o período avaliado. Não se verificou nenhuma complicação e nem efeito colateral após a injeção. Conclusão: A aplicação intravítrea de FMMO contendo células CD34+ mostrou-se segura em pacientes com RP. Observou-se, ainda, discreta melhora na sensibilidade macular, mas esta não foi significativa estatisticamente. Estudos futuros são necessários para esclarecer o potencial uso dessas células em distrofias retinianas. / Introduction: Retinitis pigmentosa (RP) is a hereditary disease of the retina, characterized by loss of visual function, mainly due to degeneration of the photoreceptors (rods and cones). Objective: To evaluate the effects of a single intravitreal injection of bone marrow mononuclear fraction (BMMF) containing CD34+ cells in patients with RP. Methods: Open trial, non-randomized, prospective, masked observer, in which 20 patients with RP with good fixation in visual field examination were included. Single intravitreal injection of BMMF was performed in only one eye of each patient, while the contralateral eyes served as control and underwent shaw injection. Evaluations included: best corrected visual acuity (BCVA); static visual field - strategy 30-2 (Octopus 900); microperimetry (MAIA - Center Vue) to evaluate fixation stability and macular sensitivity; full-field (ERG) and multifocal (mfERG) electroretinograms according to the ISCEV using Espion E2 (Diagnosys LLC) and optical coherence tomography (OCT). The exams were performed before the injection and 4, 16, 32 and 48 weeks after. Results: There was no significant difference in BCVA during follow-up. The difference measured in BCVA between 48 weeks and baseline was 0.04 ? 0.02 logMAR in treated eyes versus -0.03 ? 0.01 logMAR in controls (p=0.3898). The improvement in macular sensitivity was slightly higher in BMMF eyes: 1.0 ? 0.5 dB than in contralateral eyes: 0.2 ? 0.5 dB, but without statistical significance (p=0.0569). No change in fixation stability was observed. The mean deviation loss (MD) of the visual field in treated eyes (0.33 ? 0.70 dB) was slightly lower than in the control eyes (1.12 ? 0.58 dB) (p=0.0761). No significant difference was observed evaluating amplitudes and latencies of ERG and mfERG responses during the follow-up. No complications or side effects were observed after the injection. Conclusion: The intravitreal injection of BMMF containing CD34 + cells was shown to be safe in patients with RP. There was still a slight improvement in macular sensitivity, but this was not statistically significant. Future studies are needed to clarify the potential use of these cells in retinal dystrophies.