RESUMEN
BACKGROUND/OBJECTIVES: The primary objective of this study was to explore physicians' adherence to the dietary pattern known as the Mediterranean diet (MD). As a secondary objective we assessed physicians' awareness on the benefits of the MD and of the possibility of prescribing it. SUBJECTS/METHODS: Physicians' adherence to the MD was evaluated through the Spanish associations SEMERGEN and CAMFIC, who sent the validated PREDIMED screener to their affiliates. The results reflected a high, medium, low or very low level of adherence depending on total score. The sample was drawn between 2014 and 2016. The second questionnaire evaluated the physicians' knowledge of the MD and their opinion about recommending it. RESULTS: The PREDIMED test was answered by 422 Spanish physicians. In 8 out of 14 questions, more than 50% of the individuals scored only 1 point. However, 3 questions resulted in 1 point being scored by almost all physicians. Thus, on average, 55% of questions obtained 1-point scoring. The second questionnaire was answered by 212 physicians; 70% of them considered themselves to be aware of the benefits of the MD. More than 60% said they could invest 5 min of their time to recommend the MD. CONCLUSIONS: Primary care physicians do not show a high level of adherence to the MD and emphasize the need for creating tools to evaluate it in their patients. This research can be useful as both a database and a justification for the creation of a new protocol to help physicians increase their own and their patients' MD adherence.
Asunto(s)
Dieta Mediterránea , Médicos de Atención Primaria , Cumplimiento y Adherencia al Tratamiento , Humanos , España , Encuestas y CuestionariosRESUMEN
In Duchenne muscular dystrophy (DMD), a persistently altered and reorganizing extracellular matrix (ECM) within inflamed muscle promotes damage and dysfunction. However, the molecular determinants of the ECM that mediate inflammatory changes and faulty tissue reorganization remain poorly defined. Here, we show that fibrin deposition is a conspicuous consequence of muscle-vascular damage in dystrophic muscles of DMD patients and mdx mice and that elimination of fibrin(ogen) attenuated dystrophy progression in mdx mice. These benefits appear to be tied to: (i) a decrease in leukocyte integrin α(M)ß(2)-mediated proinflammatory programs, thereby attenuating counterproductive inflammation and muscle degeneration; and (ii) a release of satellite cells from persistent inhibitory signals, thereby promoting regeneration. Remarkably, Fib-gamma(390-396A) (Fibγ(390-396A)) mice expressing a mutant form of fibrinogen with normal clotting function, but lacking the α(M)ß(2) binding motif, ameliorated dystrophic pathology. Delivery of a fibrinogen/α(M)ß(2) blocking peptide was similarly beneficial. Conversely, intramuscular fibrinogen delivery sufficed to induce inflammation and degeneration in fibrinogen-null mice. Thus, local fibrin(ogen) deposition drives dystrophic muscle inflammation and dysfunction, and disruption of fibrin(ogen)-α(M)ß(2) interactions may provide a novel strategy for DMD treatment.
Asunto(s)
Fibrina/metabolismo , Antígeno de Macrófago-1/metabolismo , Distrofia Muscular Animal/terapia , Distrofia Muscular de Duchenne/terapia , Animales , Matriz Extracelular/metabolismo , Fibrinógeno/antagonistas & inhibidores , Fibrinógeno/genética , Fibrinógeno/metabolismo , Fibrinógeno/farmacología , Humanos , Inflamación/genética , Inflamación/metabolismo , Inflamación/patología , Inflamación/terapia , Leucocitos/metabolismo , Activación de Macrófagos/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos mdx , Ratones Noqueados , Ratones Mutantes , Modelos Biológicos , Distrofia Muscular Animal/genética , Distrofia Muscular Animal/metabolismo , Distrofia Muscular Animal/patología , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/metabolismo , Distrofia Muscular de Duchenne/patología , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/metabolismo , Fragmentos de Péptidos/farmacología , Regeneración/fisiología , Células Satélite del Músculo Esquelético/patología , Células Satélite del Músculo Esquelético/fisiologíaRESUMEN
Disruption of skeletal muscle homeostasis by substitution with fibrotic tissue constitutes the principal cause of death in Duchenne muscular dystrophy (DMD) patients, yet the implicated fibrogenic mechanisms remain poorly understood. This study identifies the extracellular PAI-1/urokinase-type plasminogen activator (uPA) balance as an important regulator of microribonucleic acid (miR)-21 biogenesis, controlling age-associated muscle fibrosis and dystrophy progression. Genetic loss of PAI-1 in mdx dystrophic mice anticipated muscle fibrosis through these sequential mechanisms: the alteration of collagen metabolism by uPA-mediated proteolytic processing of transforming growth factor (TGF)-ß in muscle fibroblasts and the activation of miR-21 expression, which inhibited phosphatase and tensin homologue and enhanced AKT signaling, thus endowing TGF-ß with a remarkable cell proliferation-promoting potential. Age-associated fibrogenesis and muscle deterioration in mdx mice, as well as exacerbated dystrophy in young PAI-1(-/-) mdx mice, could be reversed by miR-21 or uPA-selective interference, whereas forced miR-21 overexpression aggravated disease severity. The PAI-1-miR-21 fibrogenic axis also appeared dysregulated in muscle of DMD patients, providing a basis for effectively targeting fibrosis and muscular dystrophies in currently untreatable individuals.
Asunto(s)
MicroARNs/fisiología , Distrofias Musculares/genética , Serpina E2/fisiología , Adolescente , Factores de Edad , Animales , Proliferación Celular , Niño , Colágeno/metabolismo , Femenino , Fibrosis/genética , Humanos , Masculino , Ratones , Ratones Noqueados , Proteínas Proto-Oncogénicas c-akt/metabolismo , Serpina E2/genética , Serpina E2/metabolismo , Transducción de Señal , Factor de Crecimiento Transformador beta/metabolismo , Factor de Crecimiento Transformador beta/fisiologíaRESUMEN
The repair of an injured tissue is a complex biological process involving the coordinated activities of tissue-resident and infiltrating cells in response to local and systemic signals. Following acute tissue injury, inflammatory cell infiltration and activation/proliferation of resident stem cells is the first line of defense to restore tissue homeostasis. However, in the setting of chronic tissue damage, such as in Duchenne Muscular Dystrophy, inflammatory infiltrates persist, the ability of stem cells (satellite cells) is blocked and fibrogenic cells are continuously activated, eventually leading to the conversion of muscle into nonfunctional fibrotic tissue. This review explores our current understanding of the cellular and molecular mechanisms underlying efficient muscle repair that are dysregulated in muscular dystrophy-associated fibrosis and in aging-related muscle dysfunction.
Asunto(s)
Músculo Esquelético/fisiología , Envejecimiento , Animales , Matriz Extracelular/metabolismo , Fibrosis/metabolismo , Humanos , Músculo Esquelético/lesiones , Músculo Esquelético/patología , Distrofias Musculares/metabolismo , Distrofias Musculares/patología , RegeneraciónRESUMEN
In the fatal degenerative Duchenne muscular dystrophy (DMD), skeletal muscle is progressively replaced by fibrotic tissue. Here, we show that fibrinogen accumulates in dystrophic muscles of DMD patients and mdx mice. Genetic loss or pharmacological depletion of fibrinogen in these mice reduced fibrosis and dystrophy progression. Our results demonstrate that fibrinogen-Mac-1 receptor binding, through induction of IL-1beta, drives the synthesis of transforming growth factor-beta (TGFbeta) by mdx macrophages, which in turn induces collagen production in mdx fibroblasts. Fibrinogen-produced TGFbeta further amplifies collagen accumulation through activation of profibrotic alternatively activated macrophages. Fibrinogen, by engaging its alphavbeta3 receptor on fibroblasts, also directly promotes collagen synthesis. These data unveil a profibrotic role of fibrinogen deposition in muscle dystrophy.
Asunto(s)
Fibrinógeno/fisiología , Activación de Macrófagos/fisiología , Distrofia Muscular de Duchenne/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Animales , Células Cultivadas , Niño , Preescolar , Colágeno/metabolismo , Fibroblastos/metabolismo , Fibrosis , Humanos , Integrina alfaVbeta3/metabolismo , Interleucina-1beta/metabolismo , Antígeno de Macrófago-1/metabolismo , Macrófagos/fisiología , Ratones , Ratones Endogámicos mdx , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Distrofia Muscular Animal/inmunología , Distrofia Muscular Animal/metabolismo , Distrofia Muscular Animal/patología , Distrofia Muscular de Duchenne/inmunología , Distrofia Muscular de Duchenne/patología , Unión ProteicaRESUMEN
BACKGROUND: A physiological increase in muscle glutathione after training is not seen in patients with chronic obstructive pulmonary disease (COPD), indicating abnormal peripheral muscle adaptations to exercise. OBJECTIVE: We hypothesized that oxidative stress is primarily associated with low body mass index (BMI). METHODS: Eleven patients with preserved BMI (BMI(N): 28.2 +/- 1.2 kg.m(-2)), 9 patients with low BMI (BMI(L): 19.7 +/- 0.60 kg.m(-2)) and 5 age-matched controls (26.5 +/- 0.9 kg.m(-2)) were studied before and after 8 weeks of high-intensity endurance training. Reduced glutathione (GSH) and gamma-glutamyl cysteine synthase heavy-subunit chain mRNA expression (gammaGCS-HS mRNA) were measured in the vastus lateralis. RESULTS: After training, exercise capacity increased (DeltaVO(2)PEAK, 13 +/- 5.2%; 10 +/- 5.6% and 15 +/- 4.3% in BMI(L), BMI(N) and controls, respectively; p < 0.05 each). GSH levels decreased in BMI(L) (from 5.2 +/- 0.7 to 3.7 +/- 0.8 nmol/mg protein, DeltaGSH -1.5 +/- 0.7 nmol/mg protein, p < 0.05); no changes were seen in BMI(N) (from 5.4 +/- 0.7 to 6.7 +/- 0.9 nmol/mg protein, DeltaGSH 1.3 +/- 0.9 nmol/mg protein), whereas GSH markedly increased in controls (from 4.6 +/- 1 to 8.7 +/- 0.4 nmol/mg protein, DeltaGSH 4.1 +/- 1 nmol/mg protein, p < 0.01). DeltaGSH in BMI(L) was different from DeltaGSH in BMI(N) and controls (p < 0.05, each). Consistent changes were observed in gammaGCS-HS mRNA expression. CONCLUSIONS: GSH depletion after training in BMI(L) may suggest that oxidative stress plays a key role in muscle wasting in COPD patients.
Asunto(s)
Índice de Masa Corporal , Ejercicio Físico/fisiología , Glutatión/metabolismo , Músculo Esquelético/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Anciano , Cromatografía Líquida de Alta Presión , Humanos , Masculino , Persona de Mediana Edad , Oxidación-Reducción , Estrés Oxidativo/fisiología , Enfermedad Pulmonar Obstructiva Crónica/fisiopatologíaRESUMEN
Chronic obstructive pulmonary disease is associated with systemic effects including reduced body weight, oxidative stress and altered circulating TNFalpha levels. The present study was aimed to investigate whether chronic exposure to cigarette smoke induces these systemic changes in a guinea pig model. Seven animals/group were exposed to the smoke of seven cigarettes/day, 5 days/week, during 2, 4 and 6 months (chronic exposure). Three animals/group were sacrificed immediately, 3 h or 24 h after exposure to seven cigarettes (acute exposure). Chronically smoke-exposed animals exhibited lower body weight gain, starting at 5th week, and goblet cell metaplasia in small bronchioles. At 6 months there was a trend for increased plasma and lung tissue TNFalpha levels. No changes, neither in skeletal muscle glutathione (GSH) nor in plasma lipid peroxidation, were observed at any time point after chronic exposure. However, skeletal muscle GSH decreased and plasma lipid peroxidation increased immediately after acute smoke exposure, equaling control levels thereafter. We conclude that cigarette smoke exposure in the guinea pig induces a transient and repeated oxidative effect, which might result in impaired systemic metabolism and consequent failure of smoke-exposed animals to gain weight. The effects of cigarette smoke on body weight antecede and appear to be independent from the alterations produced in small airways.
Asunto(s)
Contaminación por Humo de Tabaco/efectos adversos , Animales , Bronquios/patología , Glutatión/metabolismo , Células Caliciformes/patología , Cobayas , Exposición por Inhalación/efectos adversos , Peroxidación de Lípido , Pulmón/metabolismo , Masculino , Metaplasia , Músculo Esquelético/metabolismo , Estrés Oxidativo , Factor de Necrosis Tumoral alfa/biosíntesis , Aumento de PesoRESUMEN
Skeletal muscle differentation is a complex process regulated at multiple levels. This study addressed the effect of glutathione (GSH) depletion on the transition of murine skeletal muscle C2C12 myoblasts into myocytes induced by growth factor inactivation. Cellular GSH levels increased within 24 hours on myogenic stimulation of myoblasts due to enhanced GSH synthetic rate accounted for by stimulated glutamate-L-cysteine ligase (also known as gamma-glutamylcysteine synthetase) activity. In contrast, the synthesis rate of GSH using gamma-glutamylcysteine and glutamate as precursors, which reflects the activity of the GSH synthetase, did not change during differentiation. The stimulation of GSH stores preceded the myogenic differentiation of C2C12 myoblasts monitored by expression of muscle-specific genes, creatine kinase (CK), myosin heavy chain (MyHC), and MyoD. The pattern of DNA binding activity of NF-kappaB and AP-1 in differentiating cells was similar both displaying an activation peak at 24 hours after myogenic stimulation. Depletion of cellular GSH levels 24 hours after stimulation of differentiation abrogated myogenesis as reflected by lower CK activity, MyHC levels, MyoD expression, and myotubes formation, effects that were reversible on GSH replenishment by GSH ethyl ester (GHSEE). Moreover, GSH depletion led to sustained activation of NF-kappaB, while GSHEE prevented it. Furthermore, inhibition of NF-kappaB activation restored myogenesis despite GSH depletion. Thus, GSH contributes to the formation of myotubes from satellite myoblasts by ensuring inactivation of NF-kappaB, and hence maintaining optimal GSH levels may be beneficial in restoring muscle mass in chronic inflammatory disorders.