PGC-1alpha modulates necrosis, inflammatory response, and fibrotic tissue formation in injured skeletal muscle

BACKGROUND: Skeletal muscle tissue has an enormous regenerative capacity that is instrumental for a successful defense against muscle injury and wasting. The peroxisome proliferator-activated receptor gamma coactivator 1alpha (PGC-1alpha) exerts therapeutic effects in several muscle pathologies, but its role in damage-induced muscle regeneration is unclear. METHODS: Using muscle-specific gain- and loss-of-function models for PGC-1alpha in combination with the myotoxic agent cardiotoxin (CTX), we explored the role of this transcriptional coactivator in muscle damage and inflammation. RESULTS: Interestingly, we observed PGC-1alpha-dependent effects at the early stages of regeneration, in particular regarding macrophage accumulation and polarization from the pro-inflammatory M1 to the anti-inflammatory M2 type, a faster resolution of necrosis and protection against the development of fibrosis after multiple CTX-induced injuries. CONCLUSIONS: PGC-1alpha exerts beneficial effects on muscle inflammation that might contribute to the therapeutic effects of elevated muscle PGC-1alpha in different models of muscle wasting

Dysferlin Interacts with Tubulin and Microtubules in Mouse Skeletal Muscle

Dysferlin is a type II transmembrane protein implicated in surface membrane repair in muscle. Mutations in dysferlin lead to limb girdle muscular dystrophy 2B, Miyoshi Myopathy and distal anterior compartment myopathy. Dysferlin's mode of action is not well understood and only a few protein binding partners have thus far been identified. Using affinity purification followed by liquid chromatography/mass spectrometry, we identified alpha-tubulin as a novel binding partner for dysferlin. The association between dysferlin and alpha-tubulin, as well as between dysferlin and microtubules, was confirmed in vitro by glutathione S-transferase pulldown and microtubule binding assays. These interactions were confirmed in vivo by co-immunoprecipitation. Confocal microscopy revealed that dysferlin and alpha-tubulin co-localized in the perinuclear region and in vesicular structures in myoblasts, and along thin longitudinal structures reminiscent of microtubules in myotubes. We mapped dysferlin's alpha-tubulin-binding region to its C2A and C2B domains. Modulation of calcium levels did not affect dysferlin binding to alpha-tubulin, suggesting that this interaction is calcium-independent. Our studies identified a new binding partner for dysferlin and suggest a role for microtubules in dysferlin trafficking to the sarcolemma

The Association between Influenza and Pneumococcal Vaccinations and SARS-Cov-2 Infection : Data from the EPICOVID19 Web-Based Survey

The present study aims to evaluate whether influenza and pneumococcal vaccinations are associated with positive nasopharyngeal swab (NPS) testing to detect SARS-CoV-2. Data from the Italian cross-sectional web-based survey (EPICOVID19), based on a self-selection sample of individuals aged 6518, were considered. The probability of a positive SARS-CoV-2 NPS test result as a function of influenza or anti-pneumococcal vaccination was evaluated using multivariable logistic regression, stratifying analysis by age (<65 years, 6565 years). From April 2020, 170,731 individuals aged <65 years and 28,097 6565 years filled out the EPICOVID19 questionnaire. Influenza and anti-pneumococcal vaccinations were received, respectively, by 16% and 2% of those <65 years, and by 53% and 13% of those 6565 years. SARS-CoV-2 NPS testing was reported by 6680 participants. Anti-pneumococcal and influenza vaccinations were associated with a decreased probability of a SARS-CoV-2 NPS positive test in the younger participants (OR = 0.61, 95% CI 0.41\u20130.91; OR = 0.85, 95%CI 0.74\u20130.98; respectively). A significantly lower probability of a positive test result was detected in the individuals 6565 years who received anti-pneumococcal vaccination (OR = 0.56, 95%CI 0.33\u20130.95). These results need to be confirmed by further investigations, but they are relevant given the probable coexistence of influenza, bacterial infections, and COVID-19 over the coming autumn\u2013winter season

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Characterization of the dysferlin protein and its binding partners reveals rational design for therapeutic strategies for the treatment of dysferlinopathies

Dysferlinopathies are incurable recessively inherited muscular dystrophies caused by loss of the dysferlin protein. Dysferlin is essential for the plasma membrane repair of skeletal muscle cells and is required for myotube formation. To design treatment strategies for dysferlinopathies, we studied dysferlinÕs molecular biology and characterized the functionality of dysferlinÕs seven C2 domains, its degradation pathway and its interaction with a novel protein, histone deacetylase 6. The results indicate that dysferlin and histone deacetylase 6 form a triad interaction with alpha-tubulin to modulate the acetylated alpha-tubulin levels of muscle cells, which may play a regulatory role during myotube formation. Furthermore, the characterization of dysferlinÕs C2 domains revealed that there is functional redundancy in their ability to localize dysferlin to, and effect repair of, the plasma membrane. Taking these results into consideration, we designed shorter, functional dysferlin molecules for usage in gene therapy. To find a novel pharmacological therapy for patients with dysferlin deficiency, we investigated the inhibition of dysferlinÕs degradation pathway. We demonstrated that when salvaged from proteasomal degradation, missense mutated dysferlin retained its biological activities for plasmalemmal localization, plasmalemmal repair and myotube formation. Further studies using recombinant missense mutated dysferlin constructs showed that certain missense mutants are intrinsically biologically active; whereas others lack functionality even when their levels are increased by transient transfection or by inhibiting their proteasomal degradation. Proteasomal inhibition represents a novel potential pharmacological treatment strategy for patients with dysferlin deficiency

Characterization of dysferlin's C2 domains reveals novel binding specificities to phospholipids and alpha-tubulin

Mutations in the dysferlin gene lead to a form of limb girdle muscular dystrophy (LGMD2B). Dysferlin is a transmembrane protein consisting of seven C2 domains and two DysF domains. Dysferlin is implicated in skeletal muscle membrane repair but its mechanisms in this process are poorly defined. To better understand dysferlin's function, this thesis sought to characterize the binding specificities of dysferlin's seven C2 domains to three phospholipids that compose mammalian lipid membranes, as well as to alpha-tubulin, which was identified by liquid chromatography-mass spectrometry as a novel dysferlin interacting protein. The following body of work showed that dysferlin's C2A domain binds to phosphatidylserine (PS), phosphatidylinositol 4-phosphate (PIP) and phosphatidylinositol 4,5-bisphosphate (PIP2) in a calcium-dependent manner. Dysferlin's other C2 domains each bound to PS in a weaker, calcium-independent manner. This study also revealed that dysferlin's C2A and C2B domains bound to alpha-tubulin in a calcium-independent manner. The possible implications of these interactions in patch membrane repair and dysferlin trafficking are discussed.La présence de mutations dans le gène de la dysferline est responsable du développement d'une forme de dystrophie musculaire des ceintures (LGMD2B). La dysferline est une protéine transmembranaire composée de sept domaines C2 et de deux domaines DysF. Pour mieux comprendre le fonctionnement de la dysferline, nous avons entrepris des études pour déterminer la spécificité d'interaction des domaines C2 avec des lipides trouvés dans les membranes des cellules eukaryotes. De plus, nous avons entrepris des études pour caractériser et valider l'interaction entre la dysferline et l'alpha-tubuline qui a été, préalablement, identifiée comme un ligand de la dysferline par chromatographie en phase liquide et spectrométrie de masse. Les résultats ont démontré que le domaine C2A de la dysferline se lie à la phosphatidylsérine (PS), le phosphatidylinositol-4-phosphate (PIP) et le phosphatidylinositol 4,5-biphosphate (PIP2) en présence de calcium. Quant aux autres domaines C2, ils se lient faiblement à la PS indépendamment de la présence de calcium. Ce travail a également révélé que les domaines C2A and C2B de la dysferline peuvent se lier à l'alpha-tubuline indépendamment de la présence de calcium. Les implications possibles de ces interactions sur la réparation de la membrane plasmique des muscles squelettiques et sur la ségrégation de la dysferline dans la cellule musculaire sont discutées

Characterization of lipid binding specificities of dysferlin C2 domains reveals novel interactions with phosphoinositides

Dysferlin is a type II transmembrane protein implicated in Ca(2+)-dependent sarcolemmal membrane repair. Dysferlin has seven C2 domains, which are lipid and protein binding modules. In this study, we sought to characterize the lipid binding specificity of dysferlin's seven C2 domains. Dysferlin's C2A domain was able to bind to phosphatidylserine (PS), phosphatidylinositol 4-phosphate [PtdIns(4)P], and phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P(2)] in a Ca(2+)-dependent fashion. The remainder of the C2 domains exhibited weaker and Ca(2+)-independent binding to PS and no significant binding to phosphoinositides

Immagini e modelli, riflessi di una architettura perduta: il Complesso Termale di Agnano

The paper presents the results of research carried out on the thermal spa complex of Agnano in Naples, designed at the beginning of the last century by the architect Giulio Ulisse Arata and significantly transformed over time. Starting from the study of archival documents, along with the analysis and three-dimensional survey of the state of the places, a model has been obtained capable of reflecting the original project of the architect from Piacenza. The aim of the research was to recall its memory by rereading the original configuration through the remains, going beyond the degradation and representing the original magnificence of the places through digital documents, videos and 3D models

Immagini e modelli, riflessi di una architettura perduta: il Complesso Termale di Agnano

The paper presents the results of research carried out on the thermal spa complex of Agnano in Naples, designed at the beginning of the last century by the architect Giulio Ulisse Arata and significantly transformed over time. Starting from the study of archival documents, along with the analysis and three-dimensional survey of the state of the places, a model has been obtained capable of reflecting the original project of the architect from Piacenza. The aim of the research was to recall its memory by rereading the original configuration through the remains, going beyond the degradation and representing the original magnificence of the places through digital documents, videos and 3D models

Dysferlin binds to microtubules.

<p>His-myc-dysferlin purified on Ni-NTA beads was incubated with polymerized microtubules. Reactions were resolved by SDS-PAGE stained with SimplyBlue SafeStain. Arrows point to His-myc-dysferlin, tubulin, BSA, and to MAP1&MAP2 of the microtubule-associated protein fraction (MAPF), which includes MAP2A, MAP2B, MAP1 and tau. S: Soluble phase, P: Pellet. Lane 1: Microtubules alone, lane 2: Microtubules incubated with MAPF, lane 3: Microtubules incubated with BSA, lane 4: MAPF alone, lane 5: BSA alone, lane 6: Purified His-myc-dysferlin alone, lane 7: Microtubules incubated with purified His-myc-dysferlin.</p