Increased circulating levels of interleukin-6 induce perturbation in redox-regulated signaling cascades in muscle of dystrophic mice

Duchenne muscular dystrophy (DMD) is an X-linked genetic disease in which dystrophin gene is mutated, resulting in dysfunctional or absent dystrophin protein. The pathology of dystrophic muscle includes degeneration, necrosis with inflammatory cell invasion, regeneration, and fibrous and fatty changes. Nevertheless, the mechanisms by which the absence of dystrophin leads to muscle degeneration remain to be fully elucidated. An imbalance between oxidant and antioxidant systems has been proposed as a secondary effect of DMD. However, the significance and precise extent of the perturbation in redox signaling cascades is poorly understood. We report that mdx dystrophic mice are able to activate a compensatory antioxidant response at the presymptomatic stage of the disease. In contrast, increased circulating levels of IL-6 perturb the redox signaling cascade, even prior to the necrotic stage, leading to severe features and progressive nature of muscular dystrophy

Increased levels of interleukin-6 exacerbate the dystrophic phenotype in mdx mice

Duchenne muscular dystrophy (DMD) is characterized by progressive lethal muscle degeneration and chronic inflammatory response. The mdx mouse strain has served as the animal model for human DMD. However, while DMD patients undergo extensive necrosis, the affected muscles of adult mdx mice rapidly regenerates and regains structural and functional integrity. The basis for the mild effects observed in mice compared with the lethal consequences in humans remains unknown. In this study, we provide evidence that interleukin-6 (IL-6) is causally linked to the pathogenesis of muscular dystrophy. We report that forced expression of IL-6, in the adult mdx mice, recapitulates the severe phenotypic characteristics of DMD in humans. Increased levels of IL-6 exacerbate the dystrophic muscle phenotype, sustaining inflammatory response and repeated cycles of muscle degeneration and regeneration, leading to exhaustion of satellite cells. The mdx/IL6 mouse closely approximates the human disease and more faithfully recapitulates the disease progression in humans. This study promises to significantly advance our understanding of the pathogenic mechanisms that lead to DMD

Skeletal muscle myopenia in mice model of bile duct ligation and carbon tetrachloride-induced liver cirrhosis

Skeletal muscle myopathy is universal in cirrhotic patients, however, little is known about the main mechanisms involved. The study aims to investigate skeletal muscle morphological, histological, and functional modifications in experimental models of cirrhosis and the principal molecular pathways responsible for skeletal muscle myopathy. Cirrhosis was induced by bile duct ligation (BDL) and carbon tetrachloride (CCl4) administration in mice. Control animals (CTR) underwent bile duct exposure or vehicle administration only. At sacrifice, peripheral muscles were dissected and weighed. Contractile properties of extensor digitorum longus (EDL) were studied in vitro. Muscle samples were used for histological and molecular analysis. Quadriceps muscle histology revealed a significant reduction in cross-sectional area of muscle and muscle fibers in cirrhotic mice with respect to CTR. Kinetic properties of EDL in both BDL and CCl4 were reduced with respect to CTR; BDL mice also showed a reduction in muscle force and a decrease in the resistance to fatigue. Increase in myostatin expression associated with a decrease in AKT-mTOR expressions was observed in BDL mice, together with an increase in LC3 protein levels. Upregulation of the proinflammatory citochines TNF-a and IL6 and an increased expression of NF-kB and MuRF-1 were observed in CCl4 mice. In conclusion, skeletal muscle myopenia was present in experimental models of BDL and CCl4-induced cirrhosis. Moreover, reduction in protein synthesis and activation of protein degradation were the main mechanisms responsible for myopenia in BDL mice, while activation of ubiquitin-pathway through inflammatory cytokines seems to be the main potential mechanism involved in CCl4 mice

Muscle expression of a local Igf-1 isoform protects motor neurons in an ALS mouse model

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by a selective degeneration of motor neurons, atrophy, and paralysis of skeletal muscle. Although a significant proportion of familial ALS results from a toxic gain of function associated with dominant SOD1 mutations, the etiology of the disease and its specific cellular origins have remained difficult to define. Here, we show that muscle-restricted expression of a localized insulin-like growth factor (Igf) -1 isoform maintained muscle integrity and enhanced satellite cell activity in SOD1G93A transgenic mice, inducing calcineurin-mediated regenerative pathways. Muscle-specific expression of local Igf-1 (mIgf-1) isoform also stabilized neuromuscular junctions, reduced inflammation in the spinal cord, and enhanced motor neuronal survival in SOD1G93A mice, delaying the onset and progression of the disease. These studies establish skeletal muscle as a primary target for the dominant action of inherited SOD1 mutation and suggest that muscle fibers provide appropriate factors, such as mIgf-1, for neuron survival

Sviluppo di una micro CT con sorgente Quasi-Monocromatica Multi-Energy per lo studio in vivo della crescita e della metastasi tumorale

Un innovativo micro scanner CT per piccolo animali – basato su di una sorgente che genera una coppia di fasci X Quasi-Monocromatici paralleli con diverse energie selezionabili – è in corso di installazione e caratterizzazione al Dipartimento di Fisica dell’Università di Bologna. Lo scopo della ricerca è quello di effettuare l’imaging radiologico in vivo del tessuto tumorale e/o dei pattern di neo-angiogenesi in una fase diagnostica precoce realizzando la separazione del tessuto patologico da quello sano per mezzo della tecnica multi-energy che consiste nell’utilizzo di due o più fasci di raggi X quasi-monocromatici in sostituzione dell’unico fascio policromatico utilizzato nella radiologia convenzionale. Lo strumento consentirà inoltre lo studio, sui topi, della crescita tumorale e della formazione delle metastasi per differenti tipologie di tumore. Per la diagnosi precoce del tumore è essenziale essere in grado di rivelare i cambiamenti tissutali precancerosi, come la neo-angiogenesi. Si tratta di un meccanismo che si verifica in una fase iniziale dello sviluppo della patologia ed è dovuto alla produzione di molecole che stimolano la creazione di nuovi vasi sanguigni per alimentare la crescita delle cellule cancerose. Come dimostrato in precedenti studi di fattibilità [1], un sistema di imaging basato su due fasci di raggi X quasi-monocromatici di differenti energie fornisce maggiore sensibilità nella rivelazione di basse concentrazioni di mezzo di contrasto iodato rispetto ai tradizionali apparati RX con fascio policromatico. La K-edge dual energy radiology è una tecnologia potenzialmente in grado di rivelare il processo di neo-angiogenesi tumorale in uno stadio precoce quando la strumentazione convenzionale non dispone di sufficiente sensibilità. Inoltre, la possibilità di selezionare le energie dei fasci quasi-monocromatici consente l’applicazione della Multi-Energy Quasi-MonochromaticRadiology: selezionando opportunamente le energie è possibile esaltare le differenze fra i coefficienti di attenuazione lineare del tessuto patologico rispetto a quello sano aumentando il contrasto della patologia. Infatti, la tecnica multi-energy consente di ricostruire il numero atomico efficace e persino la composizione chimica del tessuto irradiato. Tuttavia, per ottenere questo risultato, si dovrebbero conoscere le bande di energia in cui l’assorbimento dei raggi X da parte del tessuto tumorale eventualmente differisce significativamente da quello dei tessuti sani. Per questo motivo è stata iniziata una sistematica caratterizzazione radiologica di molti tipi di tessuti sani e neoplastici, murini e umani allo scopo di costituire un catalogo delle finestre di energia in cui sarà possibile applicare la metodica multi-energy

Phenotypical Characterization and Clinical Outcome of Canine Burkitt-Like Lymphoma

In dogs, Burkitt-like lymphoma (B-LL) is rare tumor and it is classified as a high-grade B-cell malignancy. The diagnosis is challenging because of the similar histologic appearance with other histotypes, no defined phenotypical criteria and poorly described clinical aspects. The aim of the study was to provide a detailed description of clinical and morphological features, as well as immunophenotypical profile of B-LL in comparison with the human counterpart. Thirteen dogs with histologically proven B-LL, for which a complete staging and follow-up were available, were retrospectively selected. Immunohistochemical expression of CD20, PAX5, CD3, CD10, BCL2, BCL6, MYC, and caspase-3 was evaluated. Histologically, all B-LLs showed a diffuse architecture with medium to large-sized cells, high mitotic rate and diffuse starry sky appearance. B-phenotype of neoplastic cells was confirmed both by flow-cytometry and immunohistochemistry. Conversely, B-LLs were negative for BCL2 and MYC, whereas some cases co-expressed BCL6 and CD10, suggesting a germinal center B-cell origin. Disease stage was advanced in the majority of cases. All dogs received CHOP-based chemotherapy with or without immunotherapy. Despite treatment, prognosis was poor, with a median time to progression and survival of 130 and 228 days, respectively. Nevertheless, ~30% of dogs survived more than 1 year. An increased apoptotic index, a high turnover index and caspase-3 index correlated with shorter survival. In conclusion, canine B-LL shows phenotypical differences with the human counterpart along with features that might help to differentiate this entity from diffuse large B-cell lymphoma

Transcriptional regulation of metabotropic glutamate receptor 2/3 expression by the NF-κB pathway in primary dorsal root ganglia neurons: a possible mechanism for the analgesic effect of L-acetylcarnitine

L-acetylcarnitine (LAC), a drug utilized for the treatment of neuropathic pain in humans, has been shown to induce analgesia in rodents by up-regulating the expression of metabotropic glutamate receptor 2 (mGlu2) in dorsal root ganglia (DRG). We now report that LAC-induced upregulation of mGlu2 expression in DRG cultures involves transcriptional activation mediated by nuclear factor-kappaB (NF-κB). A single application of LAC (250 μM) to DRG cultures induced a transient increase in mGlu2 mRNA, which was observable after 1 hour and was no longer detectable after 1 to 4 days. In contrast, LAC treatment had no effect on mGlu3 mRNA expression. Pharmacological inhibition of NF-κB binding to DNA by caffeic acid phenethyl ester (CAPE) (2.5 μg/ml for 30 minutes) reduced the constitutive expression of mGlu2 and mGlu3 mRNA after 1–4 days and reduced the constitutive expression of mGlu2/3 protein at 4 days. This evidence combined with the expression of p65/RelA and c-Rel in DRG neurons indicated that expression of mGlu2 and mGlu3 is endogenously regulated by the NF-κB family of transcription factors. Consistent with this idea, the transient increase in mGlu2 mRNA induced by LAC after 1 hour was completely suppressed by CAPE. Furthermore, LAC induced an increase in the acetylation of p65/RelA, a process that enhances the transcriptional activity of p65/RelA. These results are consistent with the hypothesis that LAC selectively induces the expression of mGlu2 by acting as a donor of acetyl groups, thus enhancing the activity of the NF-κB family of transcription factors. Accordingly, we show that carnitine, which has no effect on pain thresholds, had no effect on p65/RelA acetylation and did not enhance mGlu2 expression. Taken together, these results demonstrate that expression of mGlu2 and mGlu3 mRNA is regulated by the NF-κB transcriptional machinery, and that agents that increase acetylation and activation of NF-κB transcription factors might induce analgesia via upregulation of mGlu2 in DRG neurons

Continued high prevalence of HIV, HBV and HCV among injecting and noninjecting drug users in Italy

We estimated the prevalence of HIV, HBV and HCV infections among injecting and non-injecting drug users treated within public drug-treatment centres in Italy to determine the correlates of infection. In the sample of 1330 drug users, the prevalence of HIV was 14.4% among drug injectors and 1.6% among non-injectors; the prevalence of HBV was 70.4% among injecting drug users and 22.8% among non-injectors and of HCV was 83.2% among injecting drug users and 22.0% among non-injectors. Old age, unemployment, and intravenous drug use were significantly correlated with each of the infections, as well as a longer history of injecting drug use. The results indicate that these infections continue to circulate among drug users, highlighting the need for monitoring of this group in Italy

Platelet Rich Plasma Enhancement of Skin Regeneration in an ex-vivo Human Experimental Model

An original ex vivo wounded skin culture protocol using autologous Platelet Rich Plasma (PRP) and enriched Dulbecco's Modified Eagle's Medium demonstrated a favourable modulation of the epithelial cells and fibroblasts proliferation, a relevant antiinflammatory action and a favourable modulation of the re-organization of collagen and elastic fibres. The step by step regenerative effects of PRP on human skin wound repair and regeneration process was observed over a period of 10 days

Subcutaneous Ticks in Wild Carnivores: Any Host-Related Differences?

SIMPLE SUMMARY: Ticks are obligate parasites living part of their life attached on the skin surface of different mammal species. In the last decades, there have been several reports of ticks found dead underneath the skin of foxes, raccoon dogs, golden jackals, domestic dogs, and a human being. The biological reasons behind this phenomenon are still unclear, although most of the reports are in canid species, suggesting that the immunological response of canids might favor it. The aim of this study was to investigate the presence of ticks under the skin of different wild carnivore species in Northwestern Italy, where they have never been described before. Out of 63 wild carnivores, 11 foxes were found infested with 51 dead ticks under the skin of the animals. All the preserved ticks collected underneath the skin of the foxes were identified as Ixodes spp., meaning that this tick species might be more frequently involved in the phenomenon, as already suggested by the scientific community. By contrast, no subcutaneous ticks were found in wolves, the other most prevalent wild canid species in Northwestern Italy, supporting the idea that the immune reaction of wolves may not favor the embedment of ticks underneath the skin. ABSTRACT: Ticks under the skin have been shown in different canid species such as red fox, domestic dog, and raccoon dog. Despite being increasingly reported in Europe in the last decade, the biological mechanisms associated to subcutaneous ticks (SCT), as well as the predisposing factors, are not yet clear. The main goal of this study was to investigate the presence of SCT in wild carnivores in Northwestern Italy. Sixty-three wild carnivores were examined, and SCT were submitted to histological examination or stored in ethanol for morphological and molecular identification. A portion of the cox1 gene and 16S rDNA were amplified, and positive PCR products were sequenced. Fifty-one small brown-coloured nodules of about 2 × 3 mm containing ticks in different decomposition stages were observed in 11 out of 30 foxes. Seven ticks were classified as Ixodes ricinus, while 14 ticks were determined only at the genus level (Ixodes spp.), and in two ticks no morphological key was applicable due to the advanced degradation status. By PCR, the rDNA fragment of six ticks (26.1%, 95% CI: 12.6–46.5%) was amplified, and BLAST analysis revealed a 99–100% nucleotide similarity to I. ricinus. At the histological examination, the inflammatory response varied from a mild to a moderate mixed infiltrate, primarily composed by neutrophils and lymphocytes. The results of this study confirm foxes as the main wild reservoir for SCT. The absence of SCT in other carnivores (badgers and martens) is in accordance with other studies. Ixodes ricinus is the most frequently reported tick species, corroborating the idea that longirostral ticks might be more frequently associated to SC embedment than brevirostral ticks