RESUMO
Duchenne muscular dystrophy (DMD) is an hereditary disease characterized by loss of muscle fibers and their progressive substitution by fat and fibrous tissue. Mesenchymal fibro-adipogenic progenitors (FAPs) expressing the platelet-derived growth factor receptor alpha (PDGFRα) are an important source of fibrosis and adipogenesis in dystrophic skeletal muscle. Among the therapies suggested for dystrophy are those based on nitric oxide (NO) donating drugs, the administration of which slows disease progression. NO has been shown to act by enhancing the regenerative potential of the diseased muscle. Whether it acts also by inhibiting fibrosis and adipogenesis was not known. Here, we show in vitro that NO regulates FAP fate through inhibition of their differentiation into adipocytes. In mdx mice, an animal model of DMD, treatment with the NO donating drug molsidomine reduced the number of PDGFRα(+) cells as well as the deposition of both skeletal muscle fat and connective tissues. Inhibition of adipogenesis was due to NO-induced increased expression of miR-27b leading to downregulation of peroxisome proliferator-activated receptors gamma (Pparγ1) expression in a pathway independent of cGMP generation. These findings reveal an additional effect of NO in dystrophic muscle that conceivably synergizes with its known effects on regeneration improvement and explain why NO-based therapies appear effective in the treatment of muscular dystrophy.
Assuntos
Adipócitos/metabolismo , Diferenciação Celular , Células-Tronco Mesenquimais/metabolismo , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/metabolismo , Óxido Nítrico/metabolismo , Adipócitos/patologia , Animais , GMP Cíclico , Células-Tronco Mesenquimais/patologia , Camundongos , Camundongos Endogâmicos mdx , Camundongos Knockout , MicroRNAs/genética , MicroRNAs/metabolismo , Músculo Esquelético/patologia , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/patologia , PPAR gama/genética , PPAR gama/metabolismoRESUMO
Satellite cells are myogenic precursors that proliferate, activate, and differentiate on muscle injury to sustain the regenerative capacity of adult skeletal muscle; in this process, they self-renew through the return to quiescence of the cycling progeny. This mechanism, while efficient in physiological conditions does not prevent exhaustion of satellite cells in pathologies such as muscular dystrophy where numerous rounds of damage occur. Here, we describe a key role of nitric oxide, an important signaling molecule in adult skeletal muscle, on satellite cells maintenance, studied ex vivo on isolated myofibers and in vivo using the α-sarcoglycan null mouse model of dystrophy and a cardiotoxin-induced model of repetitive damage. Nitric oxide stimulated satellite cells proliferation in a pathway dependent on cGMP generation. Furthermore, it increased the number of Pax7(+)/Myf5(-) cells in a cGMP-independent pathway requiring enhanced expression of Vangl2, a member of the planar cell polarity pathway involved in the Wnt noncanonical pathway. The enhanced self-renewal ability of satellite cells induced by nitric oxide is sufficient to delay the reduction of the satellite cell pool during repetitive acute and chronic damages, favoring muscle regeneration; in the α-sarcoglycan null dystrophic mouse, it also slowed disease progression persistently. These results identify nitric oxide as a key messenger in satellite cells maintenance, expand the significance of the Vangl2-dependent Wnt noncanonical pathway in myogenesis, and indicate novel strategies to optimize nitric oxide-based therapies for muscular dystrophy.
Assuntos
GMP Cíclico/metabolismo , Músculo Esquelético/fisiologia , Proteínas do Tecido Nervoso/metabolismo , Óxido Nítrico/fisiologia , Regeneração , Células Satélites de Músculo Esquelético/fisiologia , Animais , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Camundongos , Camundongos da Linhagem 129 , Molsidomina/farmacologia , Molsidomina/uso terapêutico , Desenvolvimento Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/embriologia , Distrofias Musculares/tratamento farmacológico , Distrofias Musculares/patologia , Proteínas do Tecido Nervoso/genética , Óxido Nítrico/farmacologia , Doadores de Óxido Nítrico/farmacologia , Doadores de Óxido Nítrico/uso terapêutico , Células Satélites de Músculo Esquelético/efeitos dos fármacos , Células Satélites de Músculo Esquelético/metabolismo , Transdução de SinaisRESUMO
CONTEXT: Osteopathic tradition in the cranial field (OCF) stated that the primary respiratory mechanism (PRM) relies on the anatomical links between the occiput and sacrum. Few studies investigated this relationship with inconsistent results. No studies investigated the occiput-sacrum connection from a neurophysiological perspective. OBJECTIVES: This study aims to determine whether the sacral technique (ST), compared to the compression of the fourth ventricle (CV4) technique, can affect brain alpha-band power (AABP) as an indicator of a neurophysiological connection between the occiput and sacrum. METHODS: Healthy students, 22-30 years old for men and 20-30 years old for women, were enrolled in the study and randomized into eight interventions groups. Each group received a combination of active techniques (CV4 or ST) and the corresponding sham techniques (sham compression of the fourth ventricle [sCV4] or sham sacral technique [sST] ), organized in two experimental sessions divided by a 4 h washout period. AABP was continuously recorded by electroencephalogram (EEG) of the occipital area in the first 10 min of resting state, during each intervention (active technique time) and after 10 min (post-active technique time), for a total of approximately 50 min per session. Analysis was carried out utilizing a repeated-measure ANOVA within the linear general model framework, consisting of a within-subject factor of time and a within-subject factor of treatment (CV4/ST). RESULTS: Forty healthy volunteers (mean age ± SD, 23.73±1.43 years; range, 21-26 years; 16 male and 24 female) were enrolled in the study and completed the study protocol. ANOVA revealed a time × treatment interaction effect statistically significant (F=791.4; p<0.001). A particularly high increase in mean AABP magnitude was recorded during the 10 min post-CV4, compared to both the CV4 and post-sCV4 application (p<0.001). During all the times analyzed for ST and sST application, no statistically significant differences were registered with respect to the resting state. CONCLUSIONS: The ST does not produce immediate changes on occipital AABP brain activity. CV4, as previous evidence supported, generates immediate effects, suggesting that a different biological basis for OCF therapy's connection between the head and sacrum should be explored.
Assuntos
Osteopatia , Medicina Osteopática , Adulto , Estudos Cross-Over , Eletroencefalografia , Feminino , Quarto Ventrículo , Humanos , Masculino , Osteopatia/métodos , Adulto JovemRESUMO
A resolutive therapy for muscular dystrophies, a heterogeneous group of genetic diseases leading to muscular degeneration and in the severe forms to death, is still lacking. Since inflammation and defects in nitric oxide generation are recognized key pathogenic events in muscular dystrophy, we have analysed the effects of a derivative of ibuprofen, NCX 320, belonging to the class of cyclooxygenase inhibiting nitric oxide donator (CINOD), in the α-sarcoglycan null mice, a severe mouse model of dystrophy. NCX 320 was administered daily in the diet for 8months starting 1month from weaning. Muscle functional recovery was evaluated by free wheel and treadmill tests at 8months. Serum creatine kinase activity, as well as the number of diaphragm inflammatory infiltrates and necrotic fibres, was measured as indexes of skeletal muscle damage. Muscle regeneration was evaluated in diaphragm and tibialis anterior muscles, measuring the numbers of centronucleated fibres and of myogenic precursor cells. NCX 320 mitigated muscle damage, reducing significantly serum creatine kinase activity, the number of necrotic fibres and inflammatory infiltrates. Moreover, NCX 320 stimulated muscle regeneration increasing significantly the number of myogenic precursor cells and regenerating fibres. All these effects concurred in inducing a significant improvement of muscle function, as assessed by both free wheel and treadmill tests. These results describe the properties of a new compound incorporating nitric oxide donation together with anti-inflammatory properties, showing that it is effective in slowing muscle dystrophy progression long term. Of importance, this new compound deserves specific attention for its potential in the therapy of muscular dystrophy given that ibuprofen is well tolerated in paediatric patients and with a profile of safety that makes it suitable for chronic treatment such as the one required in muscular dystrophies.
Assuntos
Inibidores de Ciclo-Oxigenase/uso terapêutico , Ibuprofeno/análogos & derivados , Distrofia Muscular Animal/tratamento farmacológico , Óxido Nítrico/metabolismo , Animais , Linhagem Celular , Inibidores de Ciclo-Oxigenase/farmacologia , Deleção de Genes , Ibuprofeno/farmacologia , Ibuprofeno/uso terapêutico , Camundongos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Distrofia Muscular Animal/patologia , Prostaglandina-Endoperóxido Sintases/metabolismo , Sarcoglicanas/genéticaRESUMO
In Drosophila melanogaster, Cup acts as a translational regulator during oocyte maturation and early embryogenesis. In this report, we show that Cup associates with Miranda, an adaptor protein involved in localization of specific mRNA complexes in both neuroblasts and oocytes. miranda and cup also interact genetically, since reducing miranda activity worsens the oogenesis defects associated with different cup mutant alleles. miranda mRNA is first detected within the cytoplasm of egg chambers during early oogenesis, coincidentally with very low levels of Miranda protein. We furthermore show that Cup interacts with Staufen, a protein involved in mRNA localization during oogenesis and nervous system development, and the two proteins co-localize within the posterior cytoplasm of late oocytes. Our results substantiate the idea that Cup is a multi-functional protein cooperating with different protein partners to direct egg chamber development at multiple time-points.
Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Regulação da Expressão Gênica no Desenvolvimento , Oogênese/fisiologia , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/metabolismo , Animais , Proteínas de Ciclo Celular/genética , Cruzamentos Genéticos , Citoplasma/metabolismo , Proteínas de Drosophila/genética , Drosophila melanogaster/metabolismo , Feminino , Imunofluorescência , Imunoprecipitação , Hibridização In Situ , Oócitos/citologia , Oócitos/metabolismo , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/metabolismo , Biossíntese de Proteínas , RNA Mensageiro/genética , Proteínas de Ligação a RNA/genética , Técnicas do Sistema de Duplo-HíbridoRESUMO
Pitt-Hopkins Syndrome (PTHS) is a rare genetic disorder caused by insufficient expression of the TCF4 gene. Children with PTHS typically present with gastrointestinal disorders and early severe chronic constipation is frequently found (75%). Here we describe the case of a PTHS male 10-year-old patient with chronic constipation in whom Osteopathic Manipulative Treatment (OMT) resulted in improved bowel functions, as assessed by the diary, the QPGS-Form A Section C questionnaire, and the Paediatric Bristol Stool Form Scale. The authors suggested that OMT may be a valid tool to improve the defecation frequency and reduce enema administration in PTHS patients.
RESUMO
The urinary-type plasminogen activator, or uPA, controls matrix degradation through the conversion of plasminogen into plasmin and is regarded as the critical trigger for plasmin generation during cell migration and invasion, under physiological and pathological conditions (such as cancer metastasis). The proteolytic activity of uPA is responsible for the activation or release of several growth factors and modulates the cell survival/apoptosis ratio through the dynamic control of cell-matrix contacts. The urokinase receptor (uPAR), binding to the EGF-like domain of uPA, directs membrane-associated extracellular proteolysis and signals through transmembrane proteins, thus regulating cell migration, adhesion and cytoskeletal status. However, recent evidence highlights an intricate relationship linking the uPA/uPAR system to cell growth and apoptosis.
Assuntos
Receptores de Superfície Celular/fisiologia , Ativador de Plasminogênio Tipo Uroquinase/fisiologia , Apoptose , Proliferação de Células , Humanos , Receptores de Ativador de Plasminogênio Tipo Uroquinase , Transdução de SinaisRESUMO
BACKGROUND: In dystrophin-deficient muscles of Duchenne Muscular Dystrophy (DMD) patients and the mdx mouse model, nitric oxide (NO) signalling is impaired. Previous studies have shown that NO-donating drugs are beneficial in dystrophic mouse models. Recently, a long-term treatment (9 months) of mdx mice with naproxcinod, an NO-donating naproxen, has shown a significant improvement of the dystrophic phenotype with beneficial effects present throughout the disease progression. It remains however to be clearly dissected out which specific effects are due to the NO component compared with the anti-inflammatory activity associated with naproxen. Understanding the contribution of NO vs the anti-inflammatory effect is important, in view of the potential therapeutic perspective, and this is the final aim of this study. METHODS: Five-week-old mdx mice received either naproxcinod (30 mg/kg) or the equimolar dose of naproxen (20 mg/kg) in the diet for 6 months. Control mdx mice were used as reference. Treatments (or vehicle for control groups) were administered daily in the diet. For the first 3 months the study was performed in sedentary animals, then all mice were subjected to exercise until the sixth month. Skeletal muscle force was assessed by measuring whole body tension in sedentary animals as well as in exercised mice and resistance to fatigue was measured after 3 months of running exercise. At the end of 6 months of treatment, animals were sacrificed for histological analysis and measurement of naproxen levels in blood and skeletal muscle. RESULTS: Naproxcinod significantly ameliorated skeletal muscle force and resistance to fatigue in sedentary as well as in exercised mice, reduced inflammatory infiltrates and fibrosis deposition in both cardiac and diaphragm muscles. Conversely, the equimolar dose of naproxen showed no effects on fibrosis and improved muscle function only in sedentary mice, while the beneficial effects in exercised mice were lost demonstrating a limited and short-term effect. CONCLUSION: In conclusion, this study shows that NO donation may have an important role, in addition to anti-inflammatory activity, in slowing down the progression of the disease in the mdx mouse model therefore positioning naproxcinod as a promising candidate for treatment of DMD.
Assuntos
Distrofia Muscular de Duchenne/tratamento farmacológico , Naproxeno/análogos & derivados , Naproxeno/uso terapêutico , Doadores de Óxido Nítrico/uso terapêutico , Animais , Disponibilidade Biológica , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos mdx , Distrofia Muscular de Duchenne/fisiopatologia , Naproxeno/farmacocinética , Doadores de Óxido Nítrico/farmacocinéticaRESUMO
Mutations in the human parkin (PARK2) gene cause autosomal recessive-juvenile Parkinson's disease (AR-JP). In Drosophila melanogaster, mutant parkin alleles display a broad range of phenotypic alterations, including female infertility. Here we report that reducing the level of eukaryotic translation initiation factor 4E (eIF4E) activity specifically rescues the female sterile phenotypes associated with the parkin(P23) mutant allele. Additional defects, including reduction of pupal viability and body size, are also entirely recovered in both male and female flies of the abovementioned genotype. We further show that a null eIF4E-binding protein (4E-BP) allele counteracts the in vivo effects produced, in a parkin(P23) mutant background, by the reduction of functional eIF4E copy number. Moreover, Parkin and eIF4E interact in vitro and co-localize at the posterior end of developing oocytes. Finally, we show that eIF4E is over-expressed in parkin(P23) mutant ovaries as compared to wild-types. Taken together, our data are consistent with the idea that Parkin and eIF4E act in a common pathway, likely modulating cap-dependent translation initiation events.
Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Fator de Iniciação 4E em Eucariotos/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Tamanho Corporal/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/crescimento & desenvolvimento , Fator de Iniciação 4E em Eucariotos/genética , Feminino , Genes Letais , Masculino , Mutação , Ovário/metabolismo , Pupa/metabolismo , Ubiquitina-Proteína Ligases/genéticaRESUMO
In metazoa, the spatio-temporal translation of diverse mRNAs is essential to guarantee proper oocyte maturation and early embryogenesis. The eukaryotic translation initiation factor 4E (eIF4E), which binds the 5' cap structure of eukaryotic mRNAs, associates with either stimulatory or inhibitory factors to modulate protein synthesis. In order to identify novel factors that might act at the translational level during Drosophila oogenesis, we have undertaken a functional proteomic approach and isolated the product of the Hsp83 gene, the evolutionarily conserved chaperone Hsp90, as a specific component of the cap-binding complex. Here we report that Hsp90 interacts in vitro with the translational repressor Cup. In addition, we show that Hsp83 and cup interact genetically, since lowering Hsp90 activity enhances the oogenesis alterations linked to diverse cup mutant alleles. Hsp90 and Cup co-localize in the cytoplasm of the developing germ-line cells within the germarium, thus suggesting a common function from the earliest stages of oogenesis. Taken together, our data start elucidating the role of Hsp90 during Drosophila female germ-line development and strengthen the idea that Cup has multiple essential functions during egg chamber development.