Administration of adipose-derived stem cells extracellular vesicles in a murine model of spinal muscular atrophy: effects of a new potential therapeutic strategy

BACKGROUND

Spinal Muscular Atrophy (SMA) is an autosomal-recessive neuromuscular disease affecting children. It is caused by the mutation or deletion of the survival motor neuron 1 (SMN1) gene resulting in lower motor neuron (MN) degeneration followed by motor impairment, progressive skeletal muscle paralysis and respiratory failure. In addition to the already existing therapies, a possible combinatorial strategy could be represented by the use of adipose-derived mesenchymal stem cells (ASCs) that can be obtained easily and in large amounts from adipose tissue. Their efficacy seems to be correlated to their paracrine activity and the production of soluble factors released through extracellular vesicles (EVs). EVs are important mediators of intercellular communication with a diameter between 30 and 100 nm. Their use in other neurodegenerative disorders showed a neuroprotective effect thanks to the release of their content, especially proteins, miRNAs and mRNAs.

METHODS

In this study, we evaluated the effect of EVs isolated from ASCs (ASC-EVs) in the SMNΔ7 mice, a severe SMA model. With this purpose, we performed two administrations of ASC-EVs (0.5 µg) in SMA pups via intracerebroventricular injections at post-natal day 3 (P3) and P6. We then assessed the treatment efficacy by behavioural test from P2 to P10 and histological analyses at P10.

RESULTS

The results showed positive effects of ASC-EVs on the disease progression, with improved motor performance and a significant delay in spinal MN degeneration of treated animals. ASC-EVs could also reduce the apoptotic activation (cleaved Caspase-3) and modulate the neuroinflammation with an observed decreased glial activation in lumbar spinal cord, while at peripheral level ASC-EVs could only partially limit the muscular atrophy and fiber denervation.

CONCLUSIONS

Our results could encourage the use of ASC-EVs as a therapeutic combinatorial treatment for SMA, bypassing the controversial use of stem cells.

Extracellular vesicles from adipose mesenchymal stem cells target inflamed lymph nodes in experimental autoimmune encephalomyelitis

BACKGROUND AIMS

Adipose mesenchymal stem cells (ASCs) represent a promising therapeutic approach in inflammatory neurological disorders, including multiple sclerosis (MS). Recent lines of evidence indicate that most biological activities of ASCs are mediated by the delivery of soluble factors enclosed in extracellular vesicles (EVs). Indeed, we have previously demonstrated that small EVs derived from ASCs (ASC-EVs) ameliorate experimental autoimmune encephalomyelitis (EAE), a murine model of MS. The precise mechanisms and molecular/cellular target of EVs during EAE are still unknown.

METHODS

To investigate the homing of ASC-EVs, we intravenously injected small EVs loaded with ultra-small superparamagnetic iron oxide nanoparticles (USPIO) at disease onset in EAE-induced C57Bl/6J mice. Histochemical analysis and transmission electron microscopy were carried out 48 h after EV treatment. Moreover, to assess the cellular target of EVs, flow cytometry on cells extracted ex vivo from EAE mouse lymph nodes was performed.

RESULTS

Histochemical and ultrastructural analysis showed the presence of labeled EVs in lymph nodes but not in lungs and spinal cord of EAE injected mice. Moreover, we identified the cellular target of EVs in EAE lymph nodes by flow cytometry: ASC-EVs were preferentially located in macrophages, with a consistent amount also noted in dendritic cells and CD4+ T lymphocytes.

CONCLUSIONS

This represents the first direct evidence of the privileged localization of ASC-EVs in draining lymph nodes of EAE after systemic injection. These data provide prominent information on the distribution, uptake and retention of ASC-EVs, which may help in the development of EV-based therapy in MS.

CSF levels of Chitinase3like1 correlate with early response to cladribine in multiple sclerosis

Background

Cladribine has been introduced as a high-efficacy drug for treating relapsing-remitting multiple sclerosis (RRMS). Initial cohort studies showed early disease activity in the first year after drug initiation. Biomarkers that can predict early disease activity are needed.

Aim

To estimate cerebrospinal fluid (CSF) markers of clinical and radiological responses after initiation of cladribine.

Methods

Forty-two RRMS patients (30F/12M) treated with cladribine were included in a longitudinal prospective study. All patients underwent a CSF examination at treatment initiation, clinical follow-up including Expanded Disability Status Scale (EDSS) assessment, and a 3T MRI scan after 6,12 and 24 months, including the evaluation of white matter (WM) and cortical lesions (CLs). CSF levels of 67 inflammatory markers were assessed with immune-assay multiplex techniques. The 'no evidence of disease activity' (NEDA-3) status was assessed after two years and defined by no relapses, no disability worsening measured by EDSS and no MRI activity, including CLs.

Results

Three patients were lost at follow-up. At the end of follow-up, 19 (48%) patients remained free from disease activity. IFNgamma, Chitinase3like1, IL32, Osteopontin, IL12(p40), IL34, IL28A, sTNFR2, IL20 and CCL2 showed the best association with disease activity. When added in a multivariate regression model including age, sex, and baseline EDSS, Chitinase 3 like1 (p = 0.049) significantly increased in those patients with disease activity. Finally, ROC analysis with Chitinase3like1 added to a model with EDSS, sex, age previous relapses, WM lesion number, CLs, number of Gad enhancing lesions and spinal cord lesions provided an AUC of 0.76 (95%CI 0.60-0.91).

Conclusions

CSF Chitinase 3 like1 might provide prognostic information for predicting disease activity in the first years after initiation of cladribine. The drug's effect on chronic macrophage and microglia activation deserves further evaluation.

RNAseq analysis of olfactory neuroepithelium cytological samples in individuals with Down syndrome compared to euploid controls: a pilot study

Down syndrome is a common genetic disorder caused by partial or complete triplication of chromosome 21. This syndrome shows an overall and progressive impairment of olfactory function, detected early in adulthood. The olfactory neuronal cells are located in the nasal olfactory mucosa and represent the first sensory neurons of the olfactory pathway. Herein, we applied the olfactory swabbing procedure to allow a gentle collection of olfactory epithelial cells in seven individuals with Down syndrome and in ten euploid controls. The aim of this research was to investigate the peripheral gene expression pattern in olfactory epithelial cells through RNAseq analysis. Validated tests (Sniffin' Sticks Extended test) were used to assess olfactory function. Olfactory scores were correlated with RNAseq results and cognitive scores (Vineland II and Leiter scales). All Down syndrome individuals showed both olfactory deficit and intellectual disability. Down syndrome individuals and euploid controls exhibited clear expression differences in genes located in and outside the chromosome 21. In addition, a significant correlation was found between olfactory test scores and gene expression, while a non-significant correlation emerged between olfactory and cognitive scores. This first preliminary step gives new insights into the Down syndrome olfactory system research, starting from the olfactory neuroepithelium, the first cellular step on the olfactory way.

Extracellular Vesicles from Mesenchymal Stem Cells: Towards Novel Therapeutic Strategies for Neurodegenerative Diseases

Neurodegenerative diseases are fatal disorders of the central nervous system (CNS) which currently lack effective treatments. The application of mesenchymal stem cells (MSCs) represents a new promising approach for treating these incurable disorders. Growing evidence suggest that the therapeutic effects of MSCs are due to the secretion of neurotrophic molecules through extracellular vesicles. The extracellular vesicles produced by MSCs (MSC-EVs) have valuable innate properties deriving from parental cells and could be exploited as cell-free treatments for many neurological diseases. In particular, thanks to their small size, they are able to overcome biological barriers and reach lesion sites inside the CNS. They have a considerable pharmacokinetic and safety profile, avoiding the critical issues related to the fate of cells following transplantation. This review discusses the therapeutic potential of MSC-EVs in the treatment of neurodegenerative diseases, focusing on the strategies to further enhance their beneficial effects such as tracking methods, bioengineering applications, with particular attention to intranasal delivery as a feasible strategy to deliver MSC-EVs directly to the CNS in an effective and minimally invasive way. Current progresses and limiting issues to the extent of the use of MSC-EVs treatment for human neurodegenerative diseases will be also revised.

Synergistic association of resveratrol and histone deacetylase inhibitors as treatment in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease associated with motor neuron degeneration, progressive paralysis and finally death. Despite the research efforts, currently there is no cure for ALS. In recent years, multiple epigenetic mechanisms have been associated with neurodegenerative diseases. A pathological role for histone hypoacetylation and the abnormal NF-κB/RelA activation involving deacetylation of lysines, with the exclusion of lysine 310, has been established in ALS. Recent findings indicate that the pathological acetylation state of NF-κB/RelA and histone 3 (H3) occurring in the SOD1(G93A) murine model of ALS can be corrected by the synergistic combination of low doses of the AMP-activated kinase (AMPK)-sirtuin 1 pathway activator resveratrol and the histone deacetylase (HDAC) inhibitors MS-275 (entinostat) or valproate. The combination of the epigenetic drugs, by rescuing RelA and the H3 acetylation state, promotes a beneficial and sexually dimorphic effect on disease onset, survival and motor neurons degeneration. In this mini review, we discuss the potential of the epigenetic combination of resveratrol with HDAC inhibitors in the ALS treatment.

Characterization and validation of olive FAD and SAD gene families: expression analysis in different tissues and during fruit development

Stearoyl-ACP desaturases (SADs) and fatty acid desaturases (FADs) play a critical role in plant lipid metabolism and also affect oil fatty acid composition introducing double bonds into the hydrocarbon chains to produce unsaturated fatty acids. In the present study, the genomic sequences of three SAD and three FAD candidate genes were characterized in olive and their expression was evaluated in different plant tissues. OeSAD genes corresponded to olive SAD1 and SAD2 and to a newly identified OeSAD4, sharing the conserved protein structure with other plant species. On the other hand, the full-length genomic sequences of two microsomal OeFAD genes (FAD2-1 and FAD2-2) and the plastidial FAD6, were released. When the level of expression was tested on different tissues of cv. Leccino, OeSAD1 and OeSAD2 were mainly expressed in the fruits, while OeFAD genes showed the lowest expression in this tissue. The mRNA profiling of all genes was directly studied in fruits of Leccino and Coratina cultivars during fruit development. In both genotypes, the expression level of OeSAD1 and OeSAD2 had the highest value during and after the pit-hardening period, when oil accumulation in fruit mesocarp is intensively increasing. Furthermore, the expression level of both OeFAD2 genes, which were the main candidates for oleic acid desaturation, were almost negligible during fruit ripening. These results have made possible to define candidate genes of the machinery regulation of fatty acid composition in olive oil, providing information on their sequence, gene structure and chromosomal location.

ASCs-Exosomes Recover Coupling Efficiency and Mitochondrial Membrane Potential in an in vitro Model of ALS

The amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by motoneurons death. Mutations in the superoxide dismutase 1 (SOD1) protein have been identified to be related to the disease. Beyond the different altered pathways, the mitochondrial dysfunction is one of the major features that leads to the selective death of motoneurons in ALS. The NSC-34 cell line, overexpressing human SOD1(G93A) mutant protein [NSC-34(G93A)], is considered an optimal in vitro model to study ALS. Here we investigated the energy metabolism in NSC-34(G93A) cells and in particular the effect of the mutated SOD1(G93A) protein on the mitochondrial respiratory capacity (complexes I-IV) by high resolution respirometry (HRR) and cytofluorimetry. We demonstrated that NSC-34(G93A) cells show a reduced mitochondrial oxidative capacity. In particular, we found significant impairment of the complex I-linked oxidative phosphorylation, reduced efficiency of the electron transfer system (ETS) associated with a higher rate of dissipative respiration, and a lower membrane potential. In order to rescue the effect of the mutated SOD1 gene on mitochondria impairment, we evaluated the efficacy of the exosomes, isolated from adipose-derived stem cells, administrated on the NSC-34(G93A) cells. These data show that ASCs-exosomes are able to restore complex I activity, coupling efficiency and mitochondrial membrane potential. Our results improve the knowledge about mitochondrial bioenergetic defects directly associated with the SOD1(G93A) mutation, and prove the efficacy of adipose-derived stem cells exosomes to rescue the function of mitochondria, indicating that these vesicles could represent a valuable approach to target mitochondrial dysfunction in ALS.

Biopsychosocial model of resilience in young adults with multiple sclerosis (BPS-ARMS): an observational study protocol exploring psychological reactions early after diagnosis

INTRODUCTION

Multiple sclerosis (MS), the most common neurological disease causing disability in young adults, is widely recognised as a major stress factor. Studies have shown that the first years after the diagnosis are distressing in terms of adjustment to the disease and that MS negatively affects patients' psychological well-being, quality of life (QoL) and social functioning. However, the links between disease-specific variables at diagnosis, resilience and psychological adjustment of patients with MS remain largely unexplored, especially in adolescents and young adults. This observational study aims to fill the gap of knowledge on biopsychosocial characteristics and resilience of young adults with MS to evaluate the relationship among these variables and to develop a biopsychosocial model of resilience.

METHODS AND ANALYSIS

Biological and clinical characteristics of young adults newly diagnosed with MS will be investigated by collecting clinical information, performing neurological examinations, MRI and analysing cerebrospinal fluid and blood biomarkers (eg, measures of inflammation), body composition, gut microbiota and movement/perceptual markers. Psychosocial characteristics (eg, psychological distress, coping strategies), QoL, psychological well-being and resilience will be assessed by self-report questionnaires. Comparative statistics (ie, analysis of variance or unpaired samples t-test, correlation and regression analyses) will be applied to evaluate the relationship among biological, psychological and social factors. The results are expected to allow a comprehensive understanding of the determinants of resilience in young patients with MS and to inform resilience interventions, tailored to young patients' specific needs, aiming to reduce the risk of maladaptive reactions to the disease and to improve psychological well-being and QoL.

ETHICS AND DISSEMINATION

The study has been approved by the Verona University Hospital Ethics Committee (approval number: 2029CESC). The findings will be disseminated through scientific publications in peer-reviewed journals, conference presentations, social media and specific websites.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT03825055).

The Paradox of Self-Fertile Varieties in the Context of Self-Incompatible Genotypes in Olive

Olive, representing one of the most important fruit crops of the Mediterranean area, is characterized by a general low fruit yield, due to numerous constraints, including alternate bearing, low flower viability, male-sterility, inter-incompatibility, and self-incompatibility (SI). Early efforts to clarify the genetic control of SI in olive gave conflicting results, and only recently, the genetic control of SI has been disclosed, revealing that olive possesses an unconventional homomorphic sporophytic diallelic system of SI, dissimilar from other described plants. This system, characterized by the presence of two SI groups, prevents self-fertilization and regulates inter-compatibility between cultivars, such that cultivars bearing the same incompatibility group are incompatible. Despite the presence of a functional SI, some varieties, in particular conditions, are able to set seeds following self-fertilization, a mechanism known as pseudo-self-compatibility (PSC), as widely reported in previous literature. Here, we summarize the results of previous works on SI in olive, particularly focusing on the occurrence of self-fertility, and offer a new perspective in view of the recent elucidation of the genetic architecture of the SI system in olive. Recent advances in research aimed at unraveling the molecular bases of SI and its breakdown in olive are also presented. The clarification of these mechanisms may have a huge impact on orchard management and will provide fundamental information for the future of olive breeding programs.

Acetylation state of RelA modulated by epigenetic drugs prolongs survival and induces a neuroprotective effect on ALS murine model

Dysregulation in acetylation homeostasis has been implicated in the pathogenesis of the amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disorder. It is known that the acetylation of transcriptional factors regulates their activity. The acetylation state of NF-kB RelA has been found to dictate the neuroprotective versus the neurotoxic effect of p50/RelA. Here we showed that the pro-apoptotic acetylation mode of RelA, involving a general lysine deacetylation of the subunit with the exclusion of the lysine 310, is evident in the lumbar spinal cord of SOD1(G93A) mice, a murine model of ALS. The administration of the HDAC inhibitor MS-275 and the AMPK/sirtuin 1 activator resveratrol restored the normal RelA acetylation in SOD1(G93A) mice. The SOD1(G93A) mice displayed a 3 weeks delay of the disease onset, associated with improvement of motor performance, and 2 weeks increase of lifespan. The epigenetic treatment rescued the lumbar motor neurons affected in SOD1(G93A) mice, accompanied by increased levels of protein products of NF-kB-target genes, Bcl-xL and brain-derived neurotrophic factor. In conclusion, we here demonstrate that MS-275 and resveratrol restore the acetylation state of RelA in the spinal cord, delaying the onset and increasing the lifespan of SOD1(G93A) mice.

The role of mutated SOD1 gene in synaptic stripping and MHC class I expression following nerve axotomy in ALS murine model

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by motoneuron death. Several cellular pathways have been described to be involved in ALS pathogenesis; however, the involvement of presynaptic stripping and the related MHC class I molecules in mutant SOD1 motoneurons remains to be clarified. To this purpose, we here investigated, for the first time, the motoneurons behavior, di per se and after facial axonal injury, in terms of synaptic stripping and MHC class I expression in wild-type (Wt) mice and in a murine model of ALS, the SOD1(G93A) mice, at the presymptomatic and symptomatic stage of the disease. Concerning Wt animals, we found a reduction in synaptophysin immunoreactivity and an increase of MHC class I molecules in facial motoneurons after axotomy. In uninjured motoneurons of SOD1(G93A) mice, an altered presynaptic framework was evident, and this phenomenon increased during the disease course. The alteration in the presynaptic input is related to excitatory fibers. Moreover, after injury, a further decrease of excitatory input was not associated to an upregulation of MHC class I molecules in motoneuron soma. This study demonstrates, for the first time, that the presence of mutated SOD1 protein affects the MHC class I molecules expression, altering the presynaptic input in motoneurons. Nevertheless, a positive MHC class I immunolabeling was evident in glial cells around facial injured motoneurons, underlying an involvement of these cells in synaptic stripping. This study contributes to better understand the involvement of the mutated SOD1 protein in the vulnerability of motoneurons after damage.

Labeling and Magnetic Resonance Imaging of Exosomes Isolated from Adipose Stem Cells

Adipose stem cells (ASC) represent a promising therapeutic approach for neurodegenerative diseases. Most biological effects of ASC are probably mediated by extracellular vesicles, such as exosomes, which influence the surrounding cells. Current development of exosome therapies requires efficient and noninvasive methods to localize, monitor, and track the exosomes. Among imaging methods used for this purpose, magnetic resonance imaging (MRI) has advantages: high spatial resolution, rapid in vivo acquisition, and radiation-free operation. To be detectable with MRI, exosomes must be labeled with MR contrast agents, such as ultra-small superparamagnetic iron oxide nanoparticles (USPIO). Here, we set up an innovative approach for exosome labeling that preserves their morphology and physiological characteristics. We show that by labeling ASC with USPIO before extraction of nanovesicles, the isolated exosomes retain nanoparticles and can be visualized by MRI. The current work aims at validating this novel USPIO-based exosome labeling method by monitoring the efficiency of the labeling with MRI both in ASC and in exosomes. © 2017 by John Wiley & Sons, Inc.

MRI reveals therapeutical efficacy of stem cells: An experimental study on the SOD1(G93A) animal model

PURPOSE

The first part of the experiment identifies and validates MRI biomarkers distinctive of the disease progression in the transgenic superoxide dismutase gene (SOD1(G93A)) animal model. The second part assesses the efficacy of a mesenchymal stem cell-based therapy through the MRI biomarkers previously defined.

METHODS

The first part identifies MRI differences between SOD1(G93A) and healthy mice. The second part of the experiment follows the disease evolution of stem cell-treated and non-stem-cell treated SOD1(G93A) mice. The analysis focused on voxel-based morphometry and T2 mapping on the brain tissues, and T2-weighted imaging and diffusion tensor imaging (DTI) on the hind limbs.

RESULTS

Comparing diseased mice to healthy control revealed gray matter alterations in the brainstem area, accompanied by increased T2 relaxation time. Differences in muscle volume, muscle signal intensity, fractional anisotropy, axial diffusivity, and radial diffusivity were measured in the hind limbs. In the comparison between stem cell-treated mice and nontreated ones, differences in muscle volume, muscle signal intensity, and DTI-derived maps were found.

CONCLUSION

MRI-derived biomarkers can be used to identify differences between stem cell-treated and nontreated SOD1(G93A) mice. Magn Reson Med 79:459-469, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

ALS Pathogenesis and Therapeutic Approaches: The Role of Mesenchymal Stem Cells and Extracellular Vesicles

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive muscle paralysis determined by the degeneration of motoneurons in the motor cortex brainstem and spinal cord. The ALS pathogenetic mechanisms are still unclear, despite the wealth of studies demonstrating the involvement of several altered signaling pathways, such as mitochondrial dysfunction, glutamate excitotoxicity, oxidative stress and neuroinflammation. To date, the proposed therapeutic strategies are targeted to one or a few of these alterations, resulting in only a minimal effect on disease course and survival of ALS patients. The involvement of different mechanisms in ALS pathogenesis underlines the need for a therapeutic approach targeted to multiple aspects. Mesenchymal stem cells (MSC) can support motoneurons and surrounding cells, reduce inflammation, stimulate tissue regeneration and release growth factors. On this basis, MSC have been proposed as promising candidates to treat ALS. However, due to the drawbacks of cell therapy, the possible therapeutic use of extracellular vesicles (EVs) released by stem cells is raising increasing interest. The present review summarizes the main pathological mechanisms involved in ALS and the related therapeutic approaches proposed to date, focusing on MSC therapy and their preclinical and clinical applications. Moreover, the nature and characteristics of EVs and their role in recapitulating the effect of stem cells are discussed, elucidating how and why these vesicles could provide novel opportunities for ALS treatment.

Effect of physical exercise and anabolic steroid treatment on spinal motoneurons and surrounding glia of wild-type and ALS mice

Motoneuron degeneration is the hallmark of amyotrophic lateral sclerosis (ALS). The cause and predisposing factors for sporadic ALS are still unknown. Exposure to a specific environmental risk factors in subjects with a susceptibility genotype may increase the risk of the disease. The role of physical activity and the use of anabolic steroids are still debated in epidemiological studies on patients and murine models of ALS. To assess at the cellular level the role (beneficial or detrimental) of physical exercise and the use of anabolic steroid, we here investigated, in SOD1(G93A) (mSOD1) mice and wild-type littermates, changes in the ventral horn after regular exercise, treatment with the anabolic androgenic steroid 19-nortestosterone (nandrolone), and their combination, compared with matched control sedentary mice. The experiments were pursued for several weeks until symptom onset in mSOD1 mice. Lumbar motoneurons, astrocytes and microglia were analyzed. In wild-type mice, cytological alterations of motoneurons were observed especially after nandrolone treatment. The following main findings were observed in treated mSOD1 mice versus untreated ones: i) nandrolone treatment markedly enhanced motoneuron loss; this detrimental effect was reverted by the combination with exercise, resulting in increased motoneuron survival; ii) astrocytic activation was most marked after nandrolone treatment when motoneuron damage was most severe; iii) microglia activation was most marked after physical exercise when motoneuron damage was less severe. The results indicate a vulnerability of mSOD1 motoneurons to nandrolone treatment, a potential neuroprotective effect of physical exercise, and a modulation by glial cells in the ALS murine model in the examined paradigms.

Citrate-stabilized lanthanide-doped nanoparticles: brain penetration and interaction with immune cells and neurons

Aim: To unravel key aspects of the use of lanthanide-doped nanoparticles (NPs) in biomedicine, the interaction with immune and brain cells. Materials & methods: Effects of citrate-stabilized CaF2 and SrF2: Yb, Er NPs (13–15 nm) on human dendritic cells and neurons were assessed in vitro. In vivo distribution was analyzed in mice at tissue and ultrastructural levels, and with glia immunophenotyping. Results: The NPs did not elicit dendritic cell activation and were internalized by cultured neurons, without viability changes. After intravenous injection, NPs were found in the brain parenchyma, without features of glial neuroinflammatory response. Conclusion: Lanthanide-doped NPs do not activate cells protagonists of systemic and brain immune responses, are endocytosed by neurons and can cross an intact blood–brain barrier.

Magnetic resonance imaging of ultrasmall superparamagnetic iron oxide-labeled exosomes from stem cells: a new method to obtain labeled exosomes

PURPOSE

Recent findings indicate that the beneficial effects of adipose stem cells (ASCs), reported in several neurodegenerative experimental models, could be due to their paracrine activity mediated by the release of exosomes. The aim of this study was the development and validation of an innovative exosome-labeling protocol that allows to visualize them with magnetic resonance imaging (MRI).

MATERIALS AND METHODS

At first, ASCs were labeled using ultrasmall superparamagnetic iron oxide nanoparticles (USPIO, 4-6 nm), and optimal parameters to label ASCs in terms of cell viability, labeling efficiency, iron content, and magnetic resonance (MR) image contrast were investigated. Exosomes were then isolated from labeled ASCs using a standard isolation protocol. The efficiency of exosome labeling was assessed by acquiring MR images in vitro and in vivo as well as by determining their iron content. Transmission electron microscopy images and histological analysis were performed to validate the results obtained.

RESULTS

By using optimized experimental parameters for ASC labeling (200 µg Fe/mL of USPIO and 72 hours of incubation), it was possible to label 100% of the cells, while their viability remained comparable to unlabeled cells; the detection limit of MR images was of 10(2) and 2.5×10(3) ASCs in vitro and in vivo, respectively. Exosomes isolated from previously labeled ASCs retain nanoparticles, as demonstrated by transmission electron microscopy images. The detection limit by MRI was 3 µg and 5 µg of exosomes in vitro and in vivo, respectively.

CONCLUSION

We report a new approach for labeling of exosomes by USPIO that allows detection by MRI while preserving their morphology and physiological characteristics.

Exosome derived from murine adipose-derived stromal cells: Neuroprotective effect on in vitro model of amyotrophic lateral sclerosis

Therapeutic strategies for the fatal neurodegenerative disease amyotrophic lateral sclerosis (ALS) have not yet provided satisfactory results. Interest in stem cells for the treatment of neurodegenerative diseases is increasing and their beneficial action seems to be due to a paracrine effect via the release of exosomes, main mediators of cell-cell communication. Here we wished to assess, in vitro, the efficacy of a novel non-cell therapeutic approach based on the use of exosomes derived from murine adipose-derived stromal cells on motoneuron-like NSC-34 cells expressing ALS mutations, and used as in vitro models of disease. In particular, we set out to investigate the effect of exosomes on NSC-34 naïve cells and NSC-34 cells overexpressing human SOD1(G93A) or SOD1(G37R) or SOD1(A4V) mutants, exposed to oxidative stress. The data presented here indicate for the first time that exosomes (0.2 µg/ml) are able to protect NSC-34 cells from oxidative damage, which is one of the main mechanism of damage in ALS, increasing cell viability. These data highlight a promising role of exosomes derived from stem cells for potential therapeutic applications in motoneuron disease.

Imidazole-stabilized gold nanoparticles induce neuronal apoptosis: an in vitro and in vivo study

Gold nanoparticles are increasingly being employed in innovative biological applications thanks to their advantages of material- and size-dependent physics and chemical interactions with the cellular systems. On the other hand, growing concern has emerged on the toxicity which would render gold-based nanoparticles harmful to cell cultures, animals, and humans. Emerging attention is focused on the interaction of gold nanoparticles with nervous system, especially regarding the ability to overcome the blood-brain barrier (BBB) which represents the major impediment to the delivery of therapeutics into the brain. We synthesized highly stable 2-mercapto-1-methylimidazole-stabilized gold-nanoparticles (AuNPs)-mmi to investigate their entry, accumulation, and toxicity in vitro (SH-SY5Y human neuroblastoma cells) and in vivo (brain of C57BL/6 mice) through optical and electron microscopy. After incubation in the cell culture medium at the lowest dose of 0.1 mg/mL the (AuNPs)-mmi nanoparticles were found compacted and recruited into endosome/lysosomes (1 h) before their fusion (2 h) and the onset of neuronal death by apoptosis (4 h) as proved by terminal-transferase-mediated dUTP nick end labeling assay and caspase-3 immunoreactivity. The ability of (AuNPs)-mmi to cross the BBB was assessed by injection in the caudal vein of C57BL/6 mice. Among different brain regions, the nanoparticles were found in the CaudatoPutamen area, mainly in the striatal neurons 4 h after injection. These neurons showed the typical hallmarks of apoptosis. Our findings provide, for the first time, the dynamic of 2-mercapto-1-methylimidazole nanogold uptake. The molecular mechanism which underlies the nanogold-driven apoptotic event is analyzed and discussed in order to take into account when designing nanomaterials to interface with biological structures.

Forced mild physical training improves blood volume in the motor and hippocampal cortex of old mice

OBJECTIVES

To assess the effect of mild forced physical training on cerebral blood volume (CBV) and other brain parameters in old mice.

SETTING

Treadmill in the animal house.

PARTICIPANTS

Thirty old (>25 mo) male mice were randomly assigned to one of three groups, exercise (E), exercise plus testosterone (T) (ET), and rest (C).

INTERVENTION

Mild physical training on treadmill (30 min a day at belt speed = 8 m/min, five days a week) with or without one weekly injection of testosterone.

MEASUREMENTS

CBV, quantitative transverse relaxation time (T2) maps, and cortical thickness were measured by magnetic resonance imaging.

RESULTS

A significant increase of CBV was found in the motor and hippocampal cortex of E and ET mice; cortical thickness was not affected. T2 maps analysis suggested that water distribution did not change. T administration did not add to the effect of physical training.

CONCLUSION

This work provides first quantitative evidence that exercise initiated at old age is able to improve the hemodynamic status of the brain cortex in key regions for movement and cognition without inducing edema.

Analysis of neuromuscular junctions and effects of anabolic steroid administration in the SOD1G93A mouse model of ALS

Several lines of evidence indicate that neuromuscular junction (NMJ) destruction and disassembly is an early phenomenon in amyotrophic lateral sclerosis (ALS). Here we analyzed by confocal and electron microscopy the NMJ structure in the diaphragm of SOD1G93A mice at symptom onset. In these mice, which provide a model for familial ALS, diaphragm denervation (~50%) as well as gastrocnemius denervation (~40%) was found. In addition, the size of the synaptic vesicle pool was reduced and alterations of mitochondria were observed in approximately 40% of the remaining presynaptic terminals. Chronic treatment of SOD1G93A mice with the anabolic steroid nandrolone during the presymptomatic stage preserved the diaphragm muscle mass and features indicative of synaptic activity. These features were represented by the number of vesicles docked within 200 nm from the presynaptic membrane and area of acetylcholine receptor clusters. Structural preservation of mitochondria was documented in presynaptic terminals. However, innervation of diaphragm muscle fibers was only slightly increased in nandrolone-treated SOD1-mutant mice. Altogether the results point out and define fine structural alterations of diaphragm NMJs in the murine model of familial ALS at symptom onset, and indicate that nandrolone may prevent or delay structural alterations in NMJ mitochondria and stimulate presynaptic activity but does not prevent muscle denervation during the disease.

The anabolic/androgenic steroid nandrolone exacerbates gene expression modifications induced by mutant SOD1 in muscles of mice models of amyotrophic lateral sclerosis

Anabolic/androgenic steroids (AAS) are drugs that enhance muscle mass, and are often illegally utilized in athletes to improve their performances. Recent data suggest that the increased risk for amyotrophic lateral sclerosis (ALS) in male soccer and football players could be linked to AAS abuse. ALS is a motor neuron disease mainly occurring in sporadic (sALS) forms, but some familial forms (fALS) exist and have been linked to mutations in different genes. Some of these, in their wild type (wt) form, have been proposed as risk factors for sALS, i.e. superoxide dismutase 1 (SOD1) gene, whose mutations are causative of about 20% of fALS. Notably, SOD1 toxicity might occur both in motor neurons and in muscle cells. Using gastrocnemius muscles of mice overexpressing human mutant SOD1 (mutSOD1) at different disease stages, we found that the expression of a selected set of genes associated to muscle atrophy, MyoD, myogenin, atrogin-1, and transforming growth factor (TGF)β1, is up-regulated already at the presymptomatic stage. Atrogin-1 gene expression was increased also in mice overexpressing human wtSOD1. Similar alterations were found in axotomized mouse muscles and in cultured ALS myoblast models. In these ALS models, we then evaluated the pharmacological effects of the synthetic AAS nandrolone on the expression of the genes modified in ALS muscle. Nandrolone administration had no effects on MyoD, myogenin, and atrogin-1 expression, but it significantly increased TGFβ1 expression at disease onset. Altogether, these data suggest that, in fALS, muscle gene expression is altered at early stages, and AAS may exacerbate some of the alterations induced by SOD1 possibly acting as a contributing factor also in sALS.

Aldosterone receptor antagonism and heart failure: insights from an outpatient clinic

OBJECTIVE

In randomized clinical trials, aldosterone antagonists have been shown to reduce mortality and morbidity in heart failure (HF). The aim of the present study was to examine the risk-benefit profile of aldosterone antagonists in routine clinical practice.

METHODS

A retrospective analysis, extending over a 1-year period, of the clinical, instrumental and laboratory data of 264 HF outpatients was performed. All patients were on a beta-blocker and an ACE-inhibitor (or angiotensin-II receptor-blocker) and 151 were taking an aldosterone antagonist.

RESULTS

At baseline, subjects treated with aldosterone antagonists had a higher NYHA class, a larger left-ventricular end-diastolic volume, a worse ejection fraction and a higher systolic pulmonary arterial pressure (sPAP). During follow-up, a greater reduction in sPAP and a tendency towards improved systolic and diastolic function were observed in subjects treated with aldosterone antagonists. Moreover, clinical and laboratory parameters did not deteriorate in patients taking aldosterone antagonists. Mortality rates were similar in the two groups (8.6% vs. 8.8%, P = NS).

CONCLUSIONS

The use of aldosterone antagonists in HF is associated with an improvement in cardiac function and is well tolerated. In the present study, patients administered these agents had a comparable clinical outcome to that of the control group, despite important differences in baseline risk.

Forced mild physical training-induced effects on cognitive and locomotory behavior in old mice

OBJECTIVES

To assess the effect of mild forced physical training on cognitive and locomotory behavior in old (26 mo.) mice.

DESIGN

Randomized, controlled study.

SETTING

Open-field in the behavioral laboratory.

PARTICIPANTS

Sixteen old sedentary male mice randomly assigned to one of two groups, exercise (E) or rest (R).

INTERVENTION

group E underwent treadmill running for one month at moderate intensity (belt speed=8 m/min, 45 min, five days a week), group R was only allowed spontaneous locomotor activity.

MEASUREMENTS

exploratory and locomotor behavior were evaluated in an enriched environment (Ethovision recording).

RESULTS

motor patterns were significantly reduced (chi2 test, p<0.05) in the E vs R group after one month of training; exploratory patterns were not different, both groups showing modest exploratory activity.

CONCLUSIONS

mild forced physical training initiated at old age may have detrimental effect on motor behavior in male mice without improving cognitive parameters.

Physical training is associated with changes in nuclear magnetic resonance and morphometrical parameters of the skeletal muscle in senescent mice

The effect of a three-month training period on T2 relaxation time as well as on myofibre size and type was investigated in the lower limbs of senescent mice. After training, T2 (which is a magnetic resonance imaging parameter known to increase during acute exercise) was significantly higher in trained mice (36.37+/-1.27 vs 37.76+/-2.06 ms, p=0.003, n=8), whereas no change was found in non-trained animals (36.35+/-1.02 vs 36.24+/-1.15 ms, p=0.278, n=8). The percentage of muscle limb area evaluated in vivo on magnetic resonance images before and after the experimental period was unchanged in trained mice (69.84+/-2.50 vs 70.29+/-2.29, p=0.896, n=3) and decreased in non-trained animals (72.98+/-1.68 vs 64.62+/-2.34, p=0.006, n=3). Cross-sectional area of fast and slow myofibres, evaluated on paraffin-embedded samples after immunolabelling for skeletal fast fibre myosin, was lower in non-trained than in trained mice in both gastrocnemius and quadriceps muscle, but no change in slow/fast fibre ratio nor in apoptotic rate was found. These data show that training can prevent sarcopenia in senescent mice by affecting muscle status and inducing myofibre hypertrophy in the absence of significant muscle damage.

Changes in the expression of P2X1 and P2X2 purinergic receptors in facial motoneurons after nerve lesions in rodents and correlation with motoneuron degeneration

Involvement of P2X1 and P2X2 purinergic receptors in motoneuron response to injury was investigated with Western blotting and immunohistochemistry and correlated with motoneuron loss, Bcl-2 expression, nitric oxide synthase induction and glial activation. P2X1 was highly induced in rat facial motoneurons after nerve resection, which causes slowly occurring neurodegeneration. P2X1 induction was lower and less persistent after nerve crush, permissive for fiber regeneration. P2X2 expression was found in nuclei of rat facial motoneurons, with nuclear export in the cytoplasm after nerve resection. P2X1 induction in axotomized facial motoneurons was impaired in superoxide dismutase (SOD)1-G93A-mutant mice, a model of motoneuron disease. The data in rats point to a correlation of P2X1 induction with motoneuron degeneration, which also involves P2X2 intracellular changes, rather than with axon regeneration effort. The data in mice show that the SOD1 mutation interferes with injury-elicited P2X1 induction, suggesting alterations of ATP release from mutant motoneurons after damage.

Ninety-Five Percent Insulin Independence Rate 3 Years After Pancreas Transplantation Alone With Portal-Enteric Drainage

AIMS

Portal-enteric drainage (PED) might be particularly suitable for pancreas transplantation alone (PTA), since it has been associated with an immunologic advantage and achieves excellent metabolic results. We describe our experience with a consecutive series of 40 PTAs with PED.

METHODS

Between April 2001 and March 2004, 40 consecutive PTAs were performed with PED. Recipients were selected according to the American Diabetic Association recommendations. Donors were selected according to standard criteria irrespective of HLA match, although matching for A and B loci was considered at the time of graft allocation. Immunosuppression consisted of induction treatment with basiliximab (n = 34) or thymoglobulin (n = 6), and maintenance therapy with steroids, mycophenolate mofetil, and tacrolimus.

RESULTS

After a mean cold ischemia time of 690 minutes (range, 517-965 min) all pancreases functioned immediately. Three grafts were lost due to hyperacute or accelerated rejection. No graft was lost to vascular thrombosis, although 5 (12.5%) nonocclusive thromboses were identified and the grafts were rescued with intravenous heparin infusion. A repeat laparotomy was required in 7 recipients (17.5%) No patient required multiple repeat laparotomies, and none died. After a mean follow-up of 16.4 months (range, 1-36 mo), 2 recipients were diagnosed with rejection episodes, which were reversed with steroid boluses. Actuarial 3-year patient, and graft survival rates were 100% and 94.9%, respectively. The following parameters showed significant improvement compared with pretransplantation evaluation: hemoglobin A1C concentration, total and high-density lipoprotein cholesterol levels, arterial blood pressure, cardiac performance, retinopathy, proteinuria, and neuropathy.

CONCLUSIONS

Pancreas transplantation alone with PED provides high rates of long-term insulin-independence.

Cardiac evaluation for simultaneous pancreas-kidney transplantation and incidence of cardiac perioperative complications: preliminary study

Type I diabetes mellitus (IDDM) is associated with an increased cardiovascular risk, and eligibility protocols for simultaneous pancreas-kidney transplantation (SPKT) are consequently accurate for preoperative cardiovascular assessment. According to our algorithm, coronary angiography in SPKT candidates is indicated for patients not only experiencing previous cardiac events or symptoms, but also those with long-standing diabetes (more than 25 years) and/or age over 45 years. Furthermore, a basal transthoracic echocardiographic exam (TTE) is performed to assess cardiac volumes, left ventricular mass, systolic function, and kinesis. The aims of this study were to evaluate perioperative cardiac morbidity and mortality in 18 SPKT-eligible patients, divided into two groups on the basis of the presence/absence of angiographically evident coronary artery disease (CAD), as well as to assess the impact of left ventricular hypertrophy (LVH) on cardiac complications. Cardiac intraoperative morbidity and mortality and postoperative mortality and major morbidity were absent; minor cardiac morbidity consisted only of silent ischemic ECG alterations, without significant differences between groups, although the incidence seemed to be higher in the CAD-positive population. LVH detected preoperatively by TTE exam also failed to correlate with the incidence of such complications. Selection of SPKT candidates by coronary angiography may have positive effects on perioperative cardiac morbidity and mortality. A larger sample size is needed to give the study statistical power. Medium- and long-term follow-up studies are warranted to evaluate the effects of preoperative selection on survival rates.

Echocardiographic evaluation in type 1 diabetic patients on waiting list for isolated pancreas or kidney-pancreas transplantation

Type 1 diabetic patients may display abnormalities of left ventricular geometry and systolic and diastolic function. Patients on the waiting list for solitary pancreas or kidney-pancreas transplantation were evaluated by Doppler echocardiography to assess left ventricular geometry and systolic and diastolic function, and correlate these parameters with clinical characteristics. We evaluated 78 patients including 45 men with an overall mean age of 39.5 +/- 7.2 years and a disease duration of 24 +/- 9.8 years. Among these 78 patients, 13 showed isolated retinopathy, 9 isolated arterial hypertension, 45 concomitant retinopathy and hypertension and overt nephropathy, while 11 were free of complications. The results of our study showed an increased left ventricular mass and abnormal diastolic function among patients with simultaneous target organ complications and with hypertension, as has been reported in many previous studies. In contrast study patients with no complications showed normal left ventricular structure and function. This finding conflicts with data from several reports in the medical literature in which diastolic impairment was present in type 1 diabetic patients at an early stage of disease and with no evident microvascular and macrovascular complications.

Altered reaction of facial motoneurons to axonal damage in the presymptomatic phase of a murine model of familial amyotrophic lateral sclerosis

In transgenic mice carrying the G93A human mutation of Cu/Zn superoxide dismutase (SOD1), which provide a model of familial amyotrophic lateral sclerosis, we investigated, before the onset of symptoms, two parameters of the response of facial motoneurons to nerve transection, i.e. nitric oxide synthase induction and motoneuron loss. Axotomy elicited after 2 and 3 weeks high nitric oxide synthase expression in facial motoneurons of wild-type mice, whereas the induction was very weak or absent in transgenic mice. At 1 month post-axotomy, loss of facial motoneurons was significantly higher in mutant mice than in wild-type littermates. Thus, SOD1 mutation interferes with the oxidative cascade elicited by axonal injury in cranial motoneurons. The results also indicate that the adverse gain of function of the mutant SOD1 enhances the vulnerability of motoneurons to peripheral stressful conditions.

Natural killer cell-mediated lysis of dorsal root ganglia neurons via RAE1/NKG2D interactions

Natural killer cells have been reported to be able to kill various transformed and virus-infected target cells. It was recently observed that NK cells also could kill syngeneic dorsal root ganglia (DRG) neurons by a perforin-dependent mechanism. We demonstrate here that this phenomenon does not reflect a general ability of NK cells to kill neurons in culture. While DRG neurons of the peripheral nervous system were readily killed, ventral spinal cord neurons and hippocampal neurons of the central nervous system (CNS) were resistant to lysis. The resistance to NK cell-mediated lysis of the latter neurons was not related to protection by MHC class I molecules, since similar beta(2)-microglobulin(-/-) neurons were equally resistant to lysis. While exploring other possible molecular mechanisms for the selective triggering of lysis of DRG neurons, we observed that the retinoic acid early inducible gene-1 (RAE-1), the product of which is a ligand for the NK cell-activating receptor NKG2D, was expressed at high levels in the DRG neurons. In contrast, RAE-1 was expressed only at very low levels in the resistant CNS-derived neurons. Blocking NK cells withanti-NKG2D antibodies inhibited NK cell-mediated killing of the DRG neurons. Thus, we demonstrate that NK cell-mediated lysis of DRG neurons correlates with the expression of RAE-1 and that this lysis is dependent on activation of NK cells via NKG2D. This observation demonstrates that NK cells can kill non-pathogen-infected or non-transformed syngeneic cells through activation of the NKG2D receptor.

Priming by muscle inflammation alters the response and vulnerability to axotomy-induced damage of the rat facial motor nucleus

To ascertain whether signaling due to peripheral inflammation affects motoneuron vulnerability, we examined in adult rats the reaction to axonal injury of facial motoneurons primed by muscle inflammation. In this double-hit paradigm, preconditioning was achieved by injections into the facial muscles of the T cell mitogen phytohemagglutinin, which was found in a previous study ( 11 ) to elicit a retrograde response in motoneurons. Facial nerve transection was used as test lesion. Intramuscular injections of saline prior to axotomy were used as control for lectin pretreatment. In rats pretreated with phytohemagglutinin injection, upregulation of the expression of the antiapoptotic bcl-2 gene, examined with in situ hybridization, was significantly higher in facial motoneurons at 2 days postaxotomy compared with saline-injected control cases. After repeated phytohemagglutinin injections followed by nerve transection, induction in facial motoneurons of nitric oxide synthase, revealed by histochemistry and immunohistochemistry, as well as activation of the surrounding microglia, was enhanced at 14 days postaxotomy with respect to the saline-treated control cases. At the same time point, no significant intergroup difference was detected in the intensity of astrocytic activation. At 1 month postaxotomy, stereological cell counts revealed that motoneuron loss was significantly greater in the cases pretreated with phytohemagglutinin than in the saline-treated cases. The data point out that the response of the facial motor nucleus to axonal damage is altered by previous exposure to peripheral inflammation and that such preconditioning stimulus enhances motoneuron vulnerability to nerve injury.

Cardiopulmonary exercise test in young women affected by anorexia nervosa

BACKGROUND

The aim of this study was to evaluate exercise performance in patients affected by anorexia nervosa.

METHODS

We studied 19 patients (all females, mean age 23.1 +/- 5.2 years) affected by anorexia nervosa (mean weight 37.3 kg, body mass index 14.04 +/- 1.4 kg/m2) and 20 constitutionally thin women, matched for age, height and physical activity, with a body mass index < 19 kg/m2. All these women underwent clinical examination, standard ECG and a cardiopulmonary stress test.

RESULTS

Patients affected by anorexia nervosa showed a lower heart rate and systolic blood pressure at peak exercise (148.8 +/- 13.8 vs 171 +/- 9.2 b/min, p < 0.001, and 130 +/- 9.5 vs 152 +/- 11.2 mmHg, p < 0.001), work load (85.5 +/- 15.1 vs 117.2 +/- 20.3 W, p < 0.001), rate-pressure product (19 371 +/- 2391 vs 25,986 +/- 2218 b/min/mmHg, p < 0.001), oxygen uptake (VO2) at rest and maximum VO2 (5.4 +/- 1.7 vs 7.1 +/- 1.1 ml/kg/min, p < 0.001, and 28.08 +/- 6.3 vs 40.2 +/- 7.1 ml/kg/min, p < 0.001), anaerobic threshold (15.7 +/- 1.9 vs 20.4 +/- 2.1 ml/kg/min, p < 0.001), VO2 during exercise (9.5 +/- 1.2 vs 12.8 +/- 1.3 ml/min/W, p < 0.001), maximum minute ventilation (34.5 +/- 9.9 vs 48.4 +/- 10.3 /min, p < 0.001), and oxygen pulse (7.2 +/- 2 vs 10.9 +/- 2.4 ml/b, p < 0.001).

CONCLUSIONS

These data show an abnormal working capacity and cardiovascular responses to exercise in patients affected by anorexia nervosa. The low VO2, both at rest and during exercise, allows them to maintain a relatively high level of physical activity, which contributes to increase the energy expenditure needed for weight loss.

Retrograde response of the rat facial motor nucleus to muscle inflammation elicited by phytohaemagglutinin

To investigate whether motoneurons react to signals deriving from target inflammation, we studied the facial motor nucleus after injections of phytohaemagglutinin in the snout of adult rats. This plant lectin is a tool widely used to induce proliferation and activation of T lymphocytes, and we observed marked lymphocyte infiltration in the injected facial muscles. Retrograde labelling of motoneurons was not detected after peripheral injections of fluorochrome-conjugated phytohaemagglutinin. Nitric oxide synthase, revealed by NADPH-diaphorase histochemistry, OX-42-immunoreactive microglia, and expression of the cell death repressor gene bcl-2, investigated with nonradioactive in situ hybridization and immunohistochemistry, were evaluated in the facial nucleus. Daily phytohaemagglutinin injections for 4 days, mimicking repeated muscle exposure to inflammatory stimuli, resulted after 2-day survival in NADPH-diaphorase induction in motoneurons and marked activation of the surrounding microglia. Quantitative image analysis of NADPH-diaphorase staining, and OX-42 immunoreactivity and microglial cell counts indicated highly significant increases with respect to saline-injected control cases. The occurrence of a neuroprotective retrograde response was evaluated monitoring bcl-2 expression. Following single phytohaemagglutinin administration, bcl-2 mRNA was significantly upregulated at 6 h in facial motoneurons and returned to basal levels at 24 h. Bcl-2 immunoreactivity was markedly upregulated at 24 h and was still significantly higher than in controls at 7 days, when concomitant NADPH-diaphorase induction in motoneurons and microglia activation was also observed. No degenerative features were observed in motoneurons after phytohaemagglutinin injections at the examined time-points. The data point out that local muscle inflammation retrogradely elicits gene activation in motoneurons and their microenvironment.

Acute-phase reactants in acute myocardial infarction: impact on 5-year prognosis

BACKGROUND

Acute-phase reactants have recently been shown to have a short-term and possibly long-term prognostic value in acute coronary syndromes. The aim of the present study was to retrospectively verify whether serum levels of inflammation markers can predict the occurrence of early and late cardiac events after myocardial infarction.

METHODS

We reevaluated 58 consecutive patients (43 men and 15 women, mean age 66 +/- 12 years) admitted to our Center during 1993 with a first myocardial infarction. Patients with non-cardiac causes of inflammation were excluded, as well as patients with a left ventricular ejection fraction <40%. From the first blood sample obtained at admission, we evaluated C-reactive protein (CRP) and alpha1-acid glycoprotein (alpha1-AGP) serum levels, the erythrocyte sedimentation rate (ESR), fibrinogen levels, and the white blood cell (WBC) count. We also evaluated the highest level of serum cardiac markers. Follow-up data were collected for 55 patients in June 1999.

RESULTS

Five in-hospital and 13 delayed cardiac deaths occurred. The mean follow-up of current survivors was 5.9 +/- 0.4 years. Patients in whom cardiac death occurred had significantly higher CRP (7.4 +/- 4.1 vs 3.0 +/- 2.4 mg/dl, p < 0.001) and alpha1-AGP levels (160 +/- 38 vs 113 +/- 24 mg/dl, p < 0.001), ESR (63 +/- 30 vs 37 +/- 25 mm/hour, p < 0.001), and WBC count (13,727 +/- 3,853 vs 10,936 +/- 3,358/mm3, p = 0.004). At multivariate analysis, higher alpha1-AGP (p < 0.001) and CRP serum levels (p = 0.02) were independent predictors of cardiac death. Patients in whom cardiac events occurred during follow-up showed higher CRP (5.7 +/- 3.7 vs 1.6 +/- 1.5 mg/dl, p < 0.001) and alpha1-AGP levels (140 +/- 36 vs 101 +/- 23 mg/dl, p < 0.001) and ESR (50 +/- 30 vs 34 +/- 26 mm/hour, p = 0.06). Higher alpha1-AGP (p < 0.001) and CRP serum levels (p = 0.03) were independent predictors of the occurrence of cardiac events.

CONCLUSIONS

The present study shows that CRP and alpha1-AGP have an independent prognostic value in patients presenting with a first, uncomplicated myocardial infarction. Assays of these markers may help to better stratify patients hospitalized for acute coronary syndromes.

Symptomatic improvement after transmyocardial laser revascularization: how long does it last?

BACKGROUND

The aim of this study was to determine whether short-term clinical improvement after isolated transmyocardial holmium laser revascularization (TMLR) in patients with coronary artery disease not amenable to traditional treatment is maintained through a longer follow-up.

METHODS

Between November 1995 and June 1999 34 patients underwent TMLR (mean age, 67+/-7 years); previous revascularization procedures had been performed in 76%. Preoperatively, mean angina class was 3.6+/-0.5 in 12 patients with unstable angina; mean left ventricular ejection fraction was 47%+/-9%.

RESULTS

There was 1 early death due to low cardiac output. Mean duration of TMLR and of the entire operation was 25+/-12 minutes and 125+/-43 minutes, respectively. There were no major postoperative complications; mean hospital stay was 8+/-4 days. There were 8 late deaths caused by stroke (2 patients), cardiac failure (1 patient), and myocardial infarction (5 patients). Follow-up of current survivors ranges from 4 to 48 months (mean, 32+/-12 months). At 1-year follow-up mean angina class was 1.8+/-0.8; but at a later follow-up (mean, 35+/-10 months) it significantly increased to 2.2+/-0.7 (p = 0.005). Three-year actuarial survival was 76%+/-8% and freedom from cardiac events 44%+/-10%.

CONCLUSIONS

Our results show that after initial clinical improvement many patients experience return of angina or cardiac events; this questions the long-term symptomatic benefit of TMLR.

Activation and response to axotomy of microglia in the facial motor nuclei of G93A superoxide dismutase transgenic mice

Mice over-expressing a human mutation of Cu(2+)/Zn(2+) superoxide dismutase (SOD1) provide a model of amyotrophic lateral sclerosis. Using tomato lectin histochemistry, we analyzed microglia in the facial nuclei of SOD1(G93A) transgenic mice in the late stage of disease. In these animals, microglia was markedly activated, and ensheathed facial motoneurons as observed in wild-type mice 1 week after nerve transection. In the axotomized facial nucleus of transgenic mice at the same time point, microglia activation was enhanced and exhibited phagocytic features. The findings show that in the facial nucleus microglial cells react to motoneuron disease caused by the SOD1 mutation and to axotomy-induced damage of facial motoneurons.

Usefulness of carotid intima-media thickness measurement and peripheral B-mode ultrasound scan in the clinical screening of patients with coronary artery disease

Previous observational studies have shown a relationship between carotid intima-media thickness (IMT) and coronary artery disease (CAD). In this study the authors evaluated the accuracy of the common carotid IMT measurement in predicting the presence and severity of CAD and the additional information offered by the detection of carotid, iliac, and lower limb plaques. One hundred and fifty consecutive patients were subjected to coronary angiography and carotid, iliac, and lower limb ultrasound scan. The mean value of six IMT measurements of the far wall of the common carotid artery was calculated in each patient. The mean IMT was significantly correlated to the number of stenosed coronary vessels (r = 0.43, p<0.001), although the positive and negative predictive value of mean IMT in identifying patients with CAD was low (81% and 46%, respectively). The combined information offered by IMT measurements and peripheral (carotid, iliac, and lower limb) plaque detection was then used to obtain the best multivariate regression model able to predict CAD status. The multivariate model showed a highly significant multiple correlation coefficient (r = 0.60, p<0.0001) and a sharp improvement in the negative predictive value (92%) with respect to the univariable model. B-mode ultrasound scan including common carotid IMT measurement and peripheral plaque detection may be of clinical value in the screening of patients with CAD.

The impact of coronary artery disease on the coronary vasomotor response to nonionic contrast media

BACKGROUND

Coronary artery disease (CAD) alters the vasomotor response to a variety of pharmacological agents. We tested the hypothesis that CAD also has an impact on the coronary vasomotor response to radiologic contrast media.

METHODS AND RESULTS

We performed quantitative coronary angiography in 42 patients without angiographic evidence of CAD and 38 patients with CAD in the left coronary artery. Angiographically smooth coronary segments (n=235) were analyzed for changes on luminal diameters and coronary venous oxygen saturation in response to 3 media: the nonionic dimer iodixanol, the nonionic monomer iopromide, and the ionic agent ioxaglate. In subjects without CAD, we assessed the effects of intracoronary administration of the nitric oxide synthase inhibitor N(G)-monomethyl-L-arginine and of the cyclooxygenase inhibitor indomethacin on such changes. Iodixanol induced coronary vasodilation in subjects without CAD (8.8+/-8.6%, P<0.001). Patients with CAD exhibited no significant diameter changes in segments >/=20 mm apart from a stenosis (4.7+/-9.4%, P=NS) and significant constriction in segments <20 mm from a stenosis (-3.8+/-4.6%, P<0. 05). Similar results were obtained with iopromide, but no changes were found with ioxaglate. All contrast media induced transient (<35 seconds) increases in coronary venous oxygen saturation in all subjects. Indomethacin, but not N(G)-monomethyl-L-arginine, blunted the vasodilating effect of iodixanol and iopromide (by 80% and 76%, respectively; P<0.001).

CONCLUSIONS

Nonionic contrast media induce a vasodilatory response in normal vessels not by a mechanism involving increased flow or endothelial nitric oxide synthesis, but rather by depending on preserved vascular cyclooxygenase activity. CAD changes normal epicardial vasodilatory response into vasoconstriction.