Ricardo Fadic

Skeletal muscle cells express the profibrotic cytokine connective tissue growth factor (CTGF/CCN2), which induces their dedifferentiation

Fibrotic disorders are typified by excessive connective tissue and extracellular matrix (ECM) deposition that precludes normal healing processes of different tissues. Connective tissue growth factor (CTGF) seems to be involved in the fibrotic response. Several muscular dystrophies are characterized by a progressive weakness and wasting of the musculature, and by extensive fibrosis. However, the exact role of CTGF in skeletal muscle is unknown. Here we show that myoblasts and myotubes are able to synthesize CTGF in response to transforming growth factor type‐β (TGF‐β) and lysophosphatidic acid (LPA). CTGF induced several ECM constituents such as fibronectin, collagen type I and α4, 5, 6, and β1 integrin subunits in myoblasts and myotubes. CTGF had an important inhibitory effect on muscle differentiation evaluated by the decrease in the nuclear translocation of the early muscle regulatory factor myogenin and myosin. Remarkable, CTGF treatment of myoblasts induced their dedifferentiation, characterized by down regulating MyoD and desmin, two markers of committed myoblasts, together with a strong reorganization of cytoskeletal filaments. These results provide novel evidence for the underlying mechanisms and participation of skeletal muscle cells in the synthesis and role of CTGF inducing fibrosis, inhibiting myogenesis and dedifferentiating myoblasts. J. Cell. Physiol. 215: 410–421, 2008.

Increase in decorin and biglycan in Duchenne Muscular Dystrophy: role of fibroblasts as cell source of these proteoglycans in the disease

Fibrosis is a common pathological feature observed in muscles of patients with Duchenne muscular dystrophy (DMD). Biglycan and decorin are small chondroitin/dermatan sulfate proteoglycans in the muscle extracellular matrix (ECM) that belong to the family of structurally related proteoglycans called small leucine‐rich repeat proteins. Decorin is considered an anti‐fibrotic agent, preventing the process by blocking TGF‐β activity. There is no information about their expression in DMD patients. We found an increased amount of both proteoglycans in the ECM of skeletal muscle biopsies obtained from DMD patients. Both biglycan and decorin were augmented in the perimysium of muscle tissue, but only decorin increased in the endomysium as seen by immunohistochemical analyses. Fibroblasts were isolated from explants obtained from muscle of DMD patients and the incorporation of radioactive sulfate showed an increased synthesis of both decorin and biglycan in cultured fibroblasts compared to controls. The size of decorin and biglycan synthesized by DMD and control fibroblasts seems to be similar in size and anion charge. These findings show that decorin and biglycan are increased in DMD skeletal muscle and suggest that fibroblasts would be, at least, one source for these proteoglycans likely playing a role in the muscle response to dystrophic cell damage.

A consensus protocol for the management of medication-overuse headache: Evaluation in a multicentric, multinational study.

Introduction The management of medication-overuse headache (MOH) is often difficult and no specific guidelines are available as regards the most practical and effective approaches. In this study we defined and tested a consensus protocol for the management of MOH on a large population of patients distributed in different countries. Subjects and methods The protocol was based on evidence from the literature and on consolidated expertise of the members of the consensus group. The study was conducted according to a multicentric interventional design with the enrolment of 376 MOH subjects in four centres from Europe and two centres in Latin America. The majority of patients were treated according to an outpatient detoxification programme. The post-detoxification follow-up lasted six months. Results At the final evaluation, two-thirds of the subjects were no longer overusers and in 46.5% of subjects headache had reverted back to an episodic pattern of headache. When comparing the subjects who underwent out-patient detoxification vs those treated with in-patient detoxification, both regimens proved effective, although the drop-out rate was higher in the out-patient approach. Conclusions The present findings support the effectiveness and usability of the proposed consensus protocol in different countries with different health care modalities.

Augmented synthesis and differential localization of heparan sulfate proteoglycans in duchenne Muscular dystrophy

Muscular dystrophies are characterized by continuous cycles of degeneration and regeneration that result in extensive fibrosis and a progressive diminution of muscle mass. Cell surface heparan sulfate proteoglycans are found almost ubiquitously on the surface and in the extracellular matrix (ECM) of mammalian cells. These macromolecules interact with a great variety of ligands, including ECM constituents, adhesion molecules, and growth factors. In this study, we evaluated the expression and localization of three heparan sulfate proteoglycans in the biopsies of Duchenne muscular dystrophy (DMD) patients. Through SDS–PAGE analyses followed by specific identification of heparitinase‐digested proteins with an anti‐Δ‐heparan sulfate specific monoclonal antibodies, we observed an increase of three forms of heparan sulfate proteoglycans, corresponding to perlecan, syndecan‐3, and glypican‐1. Immunohistochemistry analyses indicated a differential localization for these proteoglycans: glypican‐1 and perlecan were found mainly associated to ECM structures, while syndecan‐3 was associated to muscle fibers. These results suggest that the amount of specific heparan sulfate proteoglycans is augmented in skeletal muscle in DMD patients presenting a differential localization. J. Cell. Biochem. 85: 703–713, 2002.

Disability, anxiety and depression associated with medication-overuse headache can be considerably reduced by detoxification and prophylactic treatment. Results from a multicentre, multinational study (COMOESTAS project).

Objective The objective of this article is to investigate whether headache-related disability, depression and anxiety can be reduced by detoxification and prophylactic treatment in patients with medication-overuse headache (MOH). Methods Patients with MOH were included from six centres in Europe and Latin America in a seven-month cohort study. Before and six months after treatment, the degree of disability was measured by the Migraine Disability Assessment (MIDAS) questionnaire, while anxiety and depression were measured by the Hospital Anxiety and Depression Scale (HADS). Results A total of 694 patients with MOH were included, of whom 492 completed the study. Headache days were reduced by 58.4% from 23.6 to 9.8 days per month at six months (p < 0.001). The MIDAS score was reduced by 57.1% from baseline 59.9 to 25.7 (p < 0.001). Number of patients with depression was reduced by 50.7% from 195 to 96 and number of those with anxiety was reduced by 27.1% from 284 to 207 (both p < 0.001). Conclusions Disability, depression and anxiety were considerably reduced in patients with MOH by detoxification and prophylactic treatment. This emphasises the urgent need for increased awareness about avoiding overuse of headache medications and demonstrates that not only headache frequency but also disability are remarkably improved by adequate intervention.

Intracellular amyloid formation in muscle cells of Aβ-transgenic Caenorhabditis elegans: determinants and physiological role in copper detoxification

BackgroundThe amyloid β-peptide is a ubiquitous peptide, which is prone to aggregate forming soluble toxic oligomers and insoluble less-toxic aggregates. The intrinsic and external/environmental factors that determine Aβ aggregation in vivo are poorly understood, as well as the cellular meaning of this process itself. Genetic data as well as cell biological and biochemical evidence strongly support the hypothesis that Aβ is a major player in the onset and development of Alzheimers disease. In addition, it is also known that Aβ is involved in Inclusion Body Myositis, a common myopathy of the elderly in which the peptide accumulates intracellularly.ResultsIn the present work, we found that intracellular Aβ aggregation in muscle cells of Caenorhabditis elegans overexpressing Aβ peptide is affected by two single amino acid substitutions, E22G (Arctic) and V18A (NIC). Both variations show decrease intracellular amyloidogenesis compared to wild type Aβ. We show that intracellular amyloid aggregation of wild type Aβ is accelerated by Cu2+ and diminished by copper chelators. Moreover, we demonstrate through toxicity and behavioral assays that Aβ-transgenic worms display a higher tolerance to Cu2+ toxic effects and that this resistance may be linked to the formation of amyloid aggregates.ConclusionOur data show that intracellular Aβ amyloid aggregates may trap excess of free Cu2+ buffering its cytotoxic effects and that accelerated intracellular Aβ aggregation may be part of a cell protective mechanism.

Andrographolide attenuates skeletal muscle dystrophy in mdx mice and increases efficiency of cell therapy by reducing fibrosis

BackgroundDuchenne muscular dystrophy (DMD) is characterized by the absence of the cytoskeletal protein dystrophin, muscle wasting, increased transforming growth factor type beta (TGF-β) signaling, and fibrosis. At the present time, the only clinically validated treatments for DMD are glucocorticoids. These drugs prolong muscle strength and ambulation of patients for a short term only and have severe adverse effects. Andrographolide, a bicyclic diterpenoid lactone, has traditionally been used for the treatment of colds, fever, laryngitis, and other infections with no or minimal side effects. We determined whether andrographolide treatment of mdx mice, an animal model for DMD, affects muscle damage, physiology, fibrosis, and efficiency of cell therapy.Methodsmdx mice were treated with andrographolide for three months and skeletal muscle histology, creatine kinase activity, and permeability of muscle fibers were evaluated. Fibrosis and TGF-β signaling were evaluated by indirect immunofluorescence and Western blot analyses. Muscle strength was determined in isolated skeletal muscles and by a running test. Efficiency of cell therapy was determined by grafting isolated skeletal muscle satellite cells onto the tibialis anterior of mdx mice.Resultsmdx mice treated with andrographolide exhibited less severe muscular dystrophy than untreated dystrophic mice. They performed better in an exercise endurance test and had improved muscle strength in isolated muscles, reduced skeletal muscle impairment, diminished fibrosis and a significant reduction in TGF-β signaling. Moreover, andrographolide treatment of mdx mice improved grafting efficiency upon intramuscular injection of dystrophin-positive satellite cells.ConclusionsThese results suggest that andrographolide could be used to improve quality of life in individuals with DMD.

Effects of body temperature on chemosensory activity of the cat carotid body in situ

The effects of changes in body core temperature (TB) upon the frequency of chemosensory discharges (fx) from one carotid nerve were studied in pentobarbitone anesthetized cats. Raising TB from 35 to 40 degrees C increased fx in some cats, an effect more commonly seen after contralateral carotid neurotomy. In other animals, the simultaneously increased alveolar ventilation counteracted the above effect. A multiple correlation analysis of global data showed predicted increases in fx in response to raising TB at different CO2 levels.

The added value of an electronic monitoring and alerting system in the management of medication-overuse headache: A controlled multicentre study

Background Medication-overuse headache (MOH) is a chronic disabling condition associated with a high rate of relapse. Methods We evaluated whether the adoption of electronic-assisted monitoring, advice and communication would improve the outcome over a follow-up of 6 months in a controlled, multicentre, multinational study conducted in six headache centres located in Europe and Latin America. A total of 663 MOH subjects were enrolled and divided into two groups: the Comoestas group was monitored with an electronic diary associated with an alert system and a facilitated communication option, and the Classic group with a paper headache diary. Results We observed a significantly higher percentage of overuse-free subjects in the Comoestas group compared with the Classic group: 73.1 vs 64.1% (odds ratio 1.45, 95% confidence interval 1.07–2.09, p = 0.046). The Comoestas group performed better also regarding the number of days/month with intake of acute drugs and the level of disability [Migraine Disability Assessment Score: Comoestas group – 42.5 ± 53.6 (35.5–49.3) and Classic group – 27.5 ± 56.1 (20.6–34.3) (p < 0.003)]. Conclusion The adoption of the electronic tool improved the outcome of patients suffering from MOH after withdrawal from overused drugs. Information and communication technology represents a valid aid for optimizing the management of chronic conditions at risk of worsening or of relapsing. Trial registration The trial was registered at ClinicalTrials.gov (no. NCT02435056).

Calibers and microtubules of sympathetic axons are not subject to trophic control by the preganglionic nerve

The caliber and microtubular content of the fibers emerging from the superior cervical ganglion of the cat were studied up to 60 days following preganglionic nerve transection. No significant difference was observed between normal and treated animals. This suggests that the caliber and microtubular content of the sympathetic axon are not subject to trophic control by the preganglionic nerve and that the normal firing rate of the pathway seems insufficient to affect the microtubular content of the fiber.