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Background and purpose: Amyotrophic lateral sclerosis (ALS), a neurodegenerative disease characterized by the degeneration of upper and lower motor neurons, progressive wasting and paralysis of voluntary muscles is currently incurable despite intense research and numerous unsuccessful clinical trials. Although considered as a pure motor neuron disease, increasing evidence indicates that the sole protection of motor neurons by a single target drug is not sufficient to improve the pathological phenotype. We therefore evaluated the therapeutic potential of the multi-target drug, trimetazidine, in SOD1G93A mice. Experimental approach: Trimetazidine is an anti-ischemic drug used for the treatment of coronary artery disease. As a metabolic modulator, Trimetazidine improves glucose metabolism. Furthermore, Trimetazidine enhances mitochondrial metabolism and promotes nerve regeneration, exerting an anti-inflammatory and antioxidant effect. Here, we orally treated SOD1G93A mice with Trimetazidine, solubilized in drinking water at a dose of 20 mg/kg, from disease onset. We assessed the impact of Trimetazidine on disease progression by studying metabolic parameters, grip strength, and histological alterations in skeletal muscle, peripheral nerve and spinal cord. Key results: Trimetazidine administration delays motor function decline, improves muscle performance and metabolism, and significantly extends overall survival of SOD1G93A mice (increased median survival of 16 days and 12.5 days for male and female respectively). Moreover, Trimetazidine prevents the dismantlement of neuromuscular junctions, attenuates motor neuron loss and reduces neuroinflammation in the spinal cord and in peripheral nerves. Conclusion and implications: In SOD1G93A mice, therapeutic effect of Trimetazidine is underpinned by its action on mitochondrial function in skeletal muscle and spinal cord. Keywords: Amyotrophic Lateral Sclerosis; Hypermetabolism; Mitochondria; Neurodegeneration; SOD1G93A mice; Trimetazidine.

Sarcopenia, a geriatric syndrome involving loss of muscle mass and strength, is often associated with the early phases of Alzheimer’s disease (AD). Pathological hallmarks of AD including amyloid β (Aβ) aggregates which can be found in peripheral tissues such as skeletal muscle. However, not much is currently known about their possible involvement in sarcopenia. We investigated neuronal innervation in skeletal muscle of Tg2576 mice, a genetic model for Aβ accumulation. We examined cholinergic innervation of skeletal muscle in adult Tg2576 and wild type mice by immunofluorescence labeling of tibialis anterior (TA) muscle sections using antibodies raised against neurofilament light chain (NFL) and acetylcholine (ACh) synthesizing enzyme choline acetyltransferase (ChAT). Combining this histological approach with real time quantification of mRNA levels of nicotinic acetylcholine receptors, we demonstrated that in the TA of Tg2576 mice, neuronal innervation is significantly reduced and synaptic area is smaller and displays less ChAT content when compared to wild type mice. Our study provides the first evidence of reduced cholinergic innervation of skeletal muscle in a mouse model of Aβ accumulation. This evidence sustains the possibility that sarcopenia in AD originates from Aβ-mediated cholinergic loss.

Neuroinflammation can severely affect brain homeostasis and adult hippocampal neurogenesis with detrimental effects on cognitive processes. Brain and gut are intimately connected via the “gut-brain axis”, a bidirectional communication system, and the administration of live bacteria (probiotics) has been shown to represent an intriguing approach for the prevention or even the cure of several diseases. In the present study we evaluated the putative neuroprotective effect of 15-days consumption of a multi-strain probiotic formulation based on food-associated strains and human gut bacteria at the dose of 109 CFU/mouse/day in a mouse model of acute inflammation, induced by an intraperitoneal single injection of LPS (0.1 mg/kg) at the end of probiotic administration. The results indicate that the prolonged administration of the multi-strain probiotic formulation not only prevents the LPS-dependent increase of pro-inflammatory cytokines in specific regions of the brain (hippocampus and cortex) and in the gastrointestinal district but also triggers a potent proneurogenic response capable of enhancing hippocampal neurogenesis. This effect is accompanied by a potentiation of intestinal barrier, as documented by the increased epithelial junction expression in the colon. Our hypothesis is that pre-treatment with the multi-strain probiotic formulation helps to create a systemic protection able to counteract or alleviate the effects of LPS-dependent acute pro-inflammatory responses.

Nuclear lamina components have long been regarded as scaffolding proteins, forming a dense fibrillar structure necessary for the maintenance of the nucleus shape in all the animal kingdom. More recently, mutations, aberrant localisation and deregulation of these proteins have been linked to several diseases, including cancer. Using publicly available data we found that the increased expression levels of the nuclear protein Lamin A/C correlate with a reduced overall survival in The Cancer Genome Atlas Research Network (TCGA) patients affected by glioblastoma multiforme (GBM). We show that the expression of the LMNA gene is linked to the enrichment of cancer-related pathways, particularly pathways related to cell adhesion and cell migration. Mimicking the modulation of LMNA in a GBM preclinical cancer model, we confirmed both in vitro and in vivo that the increased expression of LMNA is associated with an increased aggressiveness and tumorigenicity. In addition, delving into the possible mechanism behind LMNA-induced GBM aggressiveness and tumorigenicity, we found that the mTORC2 component, Rictor, plays a central role in mediating these effects.

Reactive oxygen species (ROS) play a pivotal role in different pathologic conditions, including ischemia, diabetes, and aging. We previously showed that ROS enhance miR-200c expression, causing endothelial cell (EC) apoptosis and senescence. Herein, we dissect the interaction among miR-200c and three strictly related proteins that modulate EC function and ROS production: sirtuin 1 (SIRT1), endothelial nitric oxide synthase (eNOS), and forkhead box O1 (FOXO1). Moreover, the role of miR-200c on ROS modulation was also investigated.We demonstrated that miR-200c directly targets SIRT1, eNOS, and FOXO1; via this mechanism, miR-200c decreased NO and increased the acetylation of SIRT1 targets, that is, FOXO1 and p53. FOXO1 acetylation inhibited its transcriptional activity on target genes, that is, SIRT1 and the ROS scavengers, catalase and manganese superoxide dismutase. In keeping, miR-200c increased ROS production and induced p66Shc protein phosphorylation in Ser-36; this mechanism upregulated ROS and inhibited FOXO1 transcription, reinforcing this molecular circuitry. These in vitro results were validated in three in vivo models of oxidative stress, that is, human skin fibroblasts from old donors, femoral arteries from old mice, and a murine model of hindlimb ischemia. In all cases, miR-200c was higher versus control and its targets, that is, SIRT1, eNOS, and FOXO1, were downmodulated. In the mouse hindlimb ischemia model, anti-miR-200c treatment rescued these targets and improved limb perfusion. Innovation and Conclusion: miR-200c disrupts SIRT1/FOXO1/eNOS regulatory loop. This event promotes ROS production and decreases NO, contributing to endothelial dysfunction under conditions of increased oxidative stress such as aging and ischemia. Antioxid. Redox Signal. 27, 328-344.

Satellite cells (SCs) are muscle stem cells that remain quiescent during homeostasis and are activated in response to acute muscle damage or in chronic degenerative conditions such as Duchenne Muscular Dystrophy. The activity of SCs is supported by specialized cells which either reside in the muscle or are recruited in regenerating skeletal muscles, such as for instance macrophages (MΦs). By using a dystrophic mouse model of transient MΦ depletion, we describe a shift in identity of muscle stem cells dependent on the crosstalk between MΦs and SCs. Indeed MΦ depletion determines adipogenic conversion of SCs and exhaustion of the SC pool leading to an exacerbated dystrophic phenotype. The reported data could also provide new insights into therapeutic approaches targeting inflammation in dystrophic muscles., Author summary Muscular dystrophies are a heterogenous group of genetic disorders characterized by muscle wasting, leading to loss of mobility and eventually to death due to respiratory or cardiac failure. Duchenne Muscular Dystrophy (DMD) is one of the most severe dystrophies and is caused by the loss of functional dystrophin protein owing to genetic mutations, consequently, the sarcolemma becomes fragile and susceptible to muscle damage induced by contraction. Satellite cells (SCs) are skeletal muscle stem cells that mediate the repair process leading to muscle regeneration. Dystrophic muscles undergo continuous cycles of degeneration and regeneration eventually culminating in myofiber loss and deposition of fibrous and fatty connective tissue. Inflammation is always associated with the muscle regeneration process. Among different types of inflammatory cells, mainly macrophages (MΦs) are present in regenerating skeletal muscles and are involved in the regenerative process both after an acute injury and during pathological conditions such as DMD. We focused on the cross-talk between MΦs and SCs in a mouse model of DMD and highlighted a role of MΦs in preserving the SC identity.

Fibro-adipogenic progenitors (FAPs) are currently defined by their anatomical position, expression of non-specific membrane-associated proteins, and ability to adopt multiple lineages in vitro. Gene expression analysis at single-cell level reveals that FAPs undergo dynamic transitions through a spectrum of cell states that can be identified by differential expression levels of Tie2 and Vcam1. Different patterns of Vcam1-negative Tie2high or Tie2low and Tie2low/Vcam1-expressing FAPs are detected during neonatal myogenesis, response to acute injury and Duchenne Muscular Dystrophy (DMD). RNA sequencing analysis identified cell state-specific transcriptional profiles that predict functional interactions with satellite and inflammatory cells. In particular, Vcam1-expressing FAPs, which exhibit a pro-fibrotic expression profile, are transiently activated by acute injury in concomitance with the inflammatory response. Aberrant persistence of Vcam1-expressing FAPs is detected in DMD muscles or upon macrophage depletion, and is associated with muscle fibrosis, thereby revealing how disruption of inflammation-regulated FAPs dynamics leads to a pathogenic outcome., Fibro-adipogenic progenitors (FAPs) resident in skeletal muscle are involved in both regeneration and maladaptive processes. Here, the authors identify subpopulations of FAPs with biological activities implicated in physiological muscle repair that are altered in pathological conditions such as muscular dystrophies.

Duchenne muscular dystrophy (DMD) is a genetic disease associated with mutations of Dystrophin gene that regulate myofiber integrity and muscle degeneration, characterized by oxidative stress increase. We previously published that reactive oxygen species (ROS) induce miR-200c that is responsible for apoptosis and senescence. Moreover, we demonstrated that miR-200c increases ROS production and phosphorylates p66Shc in Ser-36. p66Shc plays an important role in muscle differentiation; we previously showed that p66Shc−/− muscle satellite cells display lower oxidative stress levels and higher proliferation rate and differentiated faster than wild-type (wt) cells. Moreover, myogenic conversion, induced by MyoD overexpression, is more efficient in p66Shc−/− fibroblasts compared to wt cells. Herein, we report that miR-200c overexpression in cultured myoblasts impairs skeletal muscle differentiation. Further, its overexpression in differentiated myotubes decreases differentiation indexes. Moreover, anti-miR-200c treatment ameliorates myogenic differentiation. In keeping, we found that miR-200c and p66Shc Ser-36 phosphorylation increase in mdx muscles. In conclusion, miR-200c inhibits muscle differentiation, whereas its inhibition ameliorates differentiation and its expression levels are increased in mdx mice and in differentiated human myoblasts of DMD. Therefore, miR-200c might be responsible for muscle wasting and myotube loss, most probably via a p66Shc-dependent mechanism in a pathological disease such as DMD.

AIM Young patients with operated complex congenital heart defects (CHD) often develop sinus node dysfunction (SND) requiring permanent pacing with rate-responsive function. Activity-driven sensors cannot account for nonmovement stress and cannot modulate heart rate physiologically. Closed Loop Stimulation (CLS, Biotronik, Berlin, Germany) is a physiological rate-responsive pacemaker based on the indirect measure of ventricular contractility. No data are available on the effects of such pacing strategy in young patients. METHODS We report a series of nine patients with CHD and SND who underwent single-chamber CLS-atrial pacing with endocardial or epicardial lead. During the first 30 days, the pacemaker was programmed in AAI pacing mode and then was switched to CLS-atrial pacing mode. An in-hospital control was scheduled 1-2 months later to evaluate the CLS response to neurovegetative stresses (i.e., nonmovement stress [Stroop color test, handgrip] and exercise stress test) and Holter monitor. CLS pacing was compared with rate-responsive accelerometer-driven pacing (AAIR). RESULTS At telemetric interrogation, CLS pacing showed a more physiological pattern of 24-h heart rate trends than accelerometer sensors. The data obtained during nonmovement/exercise stress demonstrated a physiological increase in the pacing rate with CLS, in synergy with spontaneous events. The accelerometer sensor histogram, during nonmovement stress, showed a "nonresponse" behavior (only lower rate events), and during exercise test showed most events in lower rate range. Holter monitoring showed increase of average and maximum heart rate compared with AAIR. CONCLUSION In young CHD patients, endocardial/epicardial CLS-atrial pacing demonstrated a physiological response of heart rate to neurovegetative and physical stresses.

Energy demand of remote monitoring in cardiac implantable electronic devices has never been investigated. Biotronik Home Monitoring (HM) is characterized by daily transmissions that may affect longevity.The aim of the study was to retrospectively compare longevity of a specific dual-chamber pacemaker model in patients with HM on and patients with HM off.Hospital files of 201 patients (mean age 87 ± 10 years, 78 men) who had received a Biotronik Cylos DR-T pacemaker between April 2006 and May 2010 for standard indication were reviewed. In 134 patients (67%), HM was activated. The primary end point was device replacement due to battery depletion.The median follow-up period was 56.4 months (interquartile range 41.8-65.2 months). The estimated device longevity was 71.1 months (95% confidence interval [CI] 69.1-72.3 months) in the HM-on group and 60.4 months (CI 55.9-65.1 months) in the HM-off group (P.0001). The frequency of inhospital visits with significant device reprogramming was higher in the HM-on group than in the HM-off group (33.3% vs 25.0%, respectively; P = .03). Lower ventricular pulse amplitude (2.3 ± 0.4 V vs 2.7 ± 0.5 V; P.0001) and pacing percentage (49% ± 38% vs 64% ± 38%; P = .02), both calculated as time-weighted averages, were observed with HM on as compared with HM off. Patient attrition was significantly lower in the HM-on group (9.7%; 95% CI 3.0%-28.7%) than in the HM-off group (45.6%; 95% CI 30.3%-64.3%) (P.0001).In normal practice, energy demand of HM, if present, was overshadowed by programming optimization likely favored by continuous monitoring. Pacemakers controlled remotely with HM showed an 11-month longer longevity. Patient retention was superior.