Ricci-Vitiani L.,Instituto Superiore Of Sanita |
Pallini R.,Catholic University of Rome |
Biffoni M.,Instituto Superiore Of Sanita |
Todaro M.,University of Palermo |
And 9 more authors.
Nature | Year: 2010
Glioblastoma is a highly angiogenetic malignancy, the neoformed vessels of which are thought to arise by sprouting of pre-existing brain capillaries. The recent demonstration that a population of glioblastoma stem-like cells (GSCs) maintains glioblastomas indicates that the progeny of these cells may not be confined to the neural lineage. Normal neural stem cells are able to differentiate into functional endothelial cells. The connection between neural stem cells and the endothelial compartment seems to be critical in glioblastoma, where cancer stem cells closely interact with the vascular niche and promote angiogenesis through the release of vascular endothelial growth factor (VEGF) and stromal-derived factor 1 (refs 5-9). Here we show that a variable number (range 20-90%, mean 60.7%) of endothelial cells in glioblastoma carry the same genomic alteration as tumour cells, indicating that a significant portion of the vascular endothelium has a neoplastic origin. The vascular endothelium contained a subset of tumorigenic cells that produced highly vascularized anaplastic tumours with areas of vasculogenic mimicry in immunocompromised mice. In vitro culture of GSCs in endothelial conditions generated progeny with phenotypic and functional features of endothelial cells. Likewise, orthotopic or subcutaneous injection of GSCs in immunocompromised mice produced tumour xenografts, the vessels of which were primarily composed of human endothelial cells. Selective targeting of endothelial cells generated by GSCs in mouse xenografts resulted in tumour reduction and degeneration, indicating the functional relevance of the GSC-derived endothelial vessels. These findings describe a new mechanism for tumour vasculogenesis and may explain the presence of cancer-derived endothelial-like cells in several malignancies. © 2010 Macmillan Publishers Limited. All rights reserved.
Haack T.B.,Helmholtz Center for Environmental Research |
Haack T.B.,TU Munich |
Danhauser K.,Helmholtz Center for Environmental Research |
Danhauser K.,TU Munich |
And 21 more authors.
Nature Genetics | Year: 2010
An isolated defect of respiratory chain complex I activity is a frequent biochemical abnormality in mitochondrial disorders. Despite intensive investigation in recent years, in most instances, the molecular basis underpinning complex I defects remains unknown. We report whole-exome sequencing of a single individual with severe, isolated complex I deficiency. This analysis, followed by filtering with a prioritization of mitochondrial proteins, led us to identify compound heterozygous mutations in ACAD9, which encodes a poorly understood member of the mitochondrial acyl-CoA dehydrogenase protein family. We demonstrated the pathogenic role of the ACAD9 variants by the correction of the complex I defect on expression of the wildtype ACAD9 protein in fibroblasts derived from affected individuals. ACAD9 screening of 120 additional complex Iĝ€"defective index cases led us to identify two additional unrelated cases and a total of five pathogenic ACAD9 alleles. © 2010 Nature America, Inc. All rights reserved.
Absinta M.,University of Milan |
Absinta M.,San Raffaele Scientific Institute |
Rocca M.A.,University of Milan |
Rocca M.A.,San Raffaele Scientific Institute |
And 7 more authors.
Neurology | Year: 2011
Objective: Double inversion recovery (DIR) sequences have improved the detection of cortical lesions (CLs) in adult patients with multiple sclerosis (MS). We evaluated the presence and frequency of CLs in pediatric patients with relapsing-remitting MS (RRMS) in comparison to adult patients with MS with the same clinical phenotype. Methods: Using a 3.0-T scanner, brain DIR, dual-echo, and 3-dimensional T1-weighted scans were acquired from 24 pediatric patients with RRMS, 15 adult patients with RRMS, and 10 pediatric healthy controls. CLs and white matter (WM) lesions were identified, and their volumes measured. Brain gray matter and WM volumes were also calculated. Between-group comparisons were performed using χ, Mann-Whitney, and analysis of variance tests. Poisson regressions for count data were used to model the number of lesions of the 2 groups of patients. Results: Compared to adults, pediatric patients had shorter disease duration and lower disability. WM lesion number and volume did not differ between pediatric and adult patients with MS. CLs were detected in 2 (8%) pediatric and 10 (66%) adult patients. Median CL volume was lower in pediatric than adult patients with RRMS (p = 0.0003). Regression analysis showed that pediatric patients had a lower number of CLs than adults (p = 0.0003), after adjusting for age, gender, Expanded Disability Status Scale score, and disease duration. Conclusion: CLs are rare in pediatric patients with MS. Since pediatric patients with MS have a clinical onset closer to the biological onset of the disease than adult patients with MS, our findings indicate that CL formation is likely not to be an initial event in this disease. © 2011 by AAN Enterprises, Inc. All rights reserved.
Merkwirth C.,University of Cologne |
Merkwirth C.,Salk Institute for Biological Studies |
Martinelli P.,University of Cologne |
Korwitz A.,University of Cologne |
And 6 more authors.
PLoS Genetics | Year: 2012
Fusion and fission of mitochondria maintain the functional integrity of mitochondria and protect against neurodegeneration, but how mitochondrial dysfunctions trigger neuronal loss remains ill-defined. Prohibitins form large ring complexes in the inner membrane that are composed of PHB1 and PHB2 subunits and are thought to function as membrane scaffolds. In Caenorhabditis elegans, prohibitin genes affect aging by moderating fat metabolism and energy production. Knockdown experiments in mammalian cells link the function of prohibitins to membrane fusion, as they were found to stabilize the dynamin-like GTPase OPA1 (optic atrophy 1), which mediates mitochondrial inner membrane fusion and cristae morphogenesis. Mutations in OPA1 are associated with dominant optic atrophy characterized by the progressive loss of retinal ganglion cells, highlighting the importance of OPA1 function in neurons. Here, we show that neuron-specific inactivation of Phb2 in the mouse forebrain causes extensive neurodegeneration associated with behavioral impairments and cognitive deficiencies. We observe early onset tau hyperphosphorylation and filament formation in the hippocampus, demonstrating a direct link between mitochondrial defects and tau pathology. Loss of PHB2 impairs the stability of OPA1, affects mitochondrial ultrastructure, and induces the perinuclear clustering of mitochondria in hippocampal neurons. A destabilization of the mitochondrial genome and respiratory deficiencies manifest in aged neurons only, while the appearance of mitochondrial morphology defects correlates with tau hyperphosphorylation in the absence of PHB2. These results establish an essential role of prohibitin complexes for neuronal survival in vivo and demonstrate that OPA1 stability, mitochondrial fusion, and the maintenance of the mitochondrial genome in neurons depend on these scaffolding proteins. Moreover, our findings establish prohibitin-deficient mice as a novel genetic model for tau pathologies caused by a dysfunction of mitochondria and raise the possibility that tau pathologies are associated with other neurodegenerative disorders caused by deficiencies in mitochondrial dynamics. © 2012 Merkwirth et al.
Cordiglieri C.,Neurological Institute Carlo Besta |
Marolda R.,Neurological Institute Carlo Besta |
Franzi S.,Neurological Institute Carlo Besta |
Cappelletti C.,Neurological Institute Carlo Besta |
And 6 more authors.
Journal of Autoimmunity | Year: 2014
The thymus is the main site of immune sensitization to AChR in myasthenia gravis (MG). In our previous studies we demonstrated that Toll-like receptor (TLR) 4 is over-expressed in MG thymuses, suggesting its involvement in altering the thymic microenvironment and favoring autosensitization and autoimmunity maintenance processes, via an effect on local chemokine/cytokine network. Here, we investigated whether TLR4 signaling may favor abnormal cell recruitment in MG thymus via CCL17 and CCL22, two chemokines known to dictate immune cell trafficking in inflamed organs by binding CCR4. We also investigated whether TLR4 activation may contribute to immunodysregulation, via the production of Th17-related cytokines, known to alter effector T cell (Teff)/regulatory T cell (Treg) balance. We found that CCL17, CCL22 and CCR4 were expressed at higher levels in MG compared to normal thymuses. The two chemokines were mainly detected around medullary Hassall's corpuscles (HCs), co-localizing with TLR4+ thymic epithelial cells (TECs) and CCR4+ dendritic cells (DCs), that were present in higher number in MG thymuses compared to controls. TLR4 stimulation in MG TECs increased CCL17 and CCL22 expression and induced the production of Th17-related cytokines. Then, to study the effect of TLR4-stimulated TECs on immune cell interactions and Teff activation, we generated an in-vitro imaging model by co-culturing CD4+ Th1/Th17 AChR-specific T cells, naïve CD4+CD25+ Tregs, DCs and TECs from Lewis rats. We observed that TLR4 stimulation led to a more pronounced Teff activatory status, suggesting that TLR4 signaling in MG thymic milieu may affect cell-to-cell interactions, favoring autoreactive T-cell activation. Altogether our findings suggest a role for TLR4 signaling in driving DC recruitment in MG thymus via CCL17 and CCL22, and in generating an inflammatory response that might compromise Treg function, favoring autoreactive T-cell pathogenic responses. © 2013 Elsevier Ltd.
Liautard C.,University of Nice Sophia Antipolis |
Scalmani P.,Neurological Institute Carlo Besta |
Carriero G.,IRCCS Foundation Neurological Institute Carlo Besta |
De Curtis M.,IRCCS Foundation Neurological Institute Carlo Besta |
And 2 more authors.
Epilepsia | Year: 2013
Purpose Dravet syndrome (DS) is caused by dominant mutations of the SCN1A gene, encoding the NaV1.1 sodium channel α subunit. Gene targeted mouse models of DS mutations replicate patients' phenotype and show reduced γ-aminobutyric acid (GABA)ergic inhibition. However, little is known on the properties of network hyperexcitability and on properties of seizure generation in these models. In fact, seizures have been studied thus far with surface electroencephalography (EEG), which did not show if specific brain regions are particularly involved. We have investigated hyperexcitability and epileptiform activities generated in neuronal networks of a mouse model of DS. Methods We have studied heterozygous NaV1.1 knock-out mice performing field potential recordings in combined hippocampal/cortical slices in vitro and video/depth electrode intracerebral recordings in vivo during hyperthermia-induced seizures. Key Findings In slices, we have disclosed specific signs of hyperexcitability of hippocampal circuits in both the pre-epileptic and epileptic periods, and a specific epileptiform activity was generated in the hippocampus upon application of the convulsant 4-aminopyridine in the epileptic period. During in vivo hyperthermia-induced seizures, we have observed selective hippocampal activity in early preictal phases and pronounced hippocampal activity in the ictal phase. Significance We have identified specific epileptiform activities and signs of network hyperexcitability, and disclosed the important role of the hippocampus in seizure generation in this model. These activities may be potentially used as targets for screenings of antiepileptic approaches. © 2013 Wiley Periodicals, Inc.
Using social capital to construct a conceptual International Classification of Functioning, Disability, and Health Children and Youth Version-based framework for stronger inclusive education policies in Europe
Maxwell G.,Jönköping University College |
Koutsogeorgou E.,Neurological Institute Carlo Besta
American Journal of Physical Medicine and Rehabilitation | Year: 2012
Inclusive education is part of social inclusion; therefore, social capital can be linked to an inclusive education policy and practice. This association is explored in this article, and a practical measure is proposed. Specifically, the World Health Organization's International Classification of Functioning, Disability and Health Children and Youth Version (ICF-CY) is proposed as the link between social capital and inclusive education. By mapping participation and trust indicators of social capital to the ICF-CY and by using the Matrix to Analyse Functioning in Education Systems (MAFES) to analyze the functioning of inclusive education policies and systems, a measure for stronger inclusive education policies is proposed. Such a tool can be used for policy planning and monitoring to ensure better inclusive education environments. In conclusion, combining enhanced social capital linked to stronger inclusive education policies, by using the ICF-CY, can lead to better health and well-being for all. Copyright © 2011 by Lippincott Williams & Wilkins.
Leo N L.,Hospital Comarcal del Baix Llobregat Moises Broggi |
Casanova-Molla J.,University of Barcelona |
Lauria G.,Neurological Institute Carlo Besta |
Valls-Sole J.,University of Barcelona
Muscle and Nerve | Year: 2011
The brainstem pathways that mediate the somatosensory blink reflex (SBR) are not completely understood. We hypothesized that the circuits of the SBR might be affected separately from those of the trigeminal blink reflex (TBR). We examined 7 patients with mesencephalic lesions and 8 patients with medullary lesions. The SBR was elicited by median nerve stimulation. The TBR was elicited by supraorbital nerve stimulation. In patients with upper brainstem lesions, the TBR was normal, whereas the SBR was generally abnormal. The SBR was either absent or small and was significantly delayed with respect to control subjects. The opposite was the rule in patients with lower brainstem lesions who had delayed or absent TBR and no abnormal findings in the SBR. The SBR is mediated through circuits in the upper brainstem. Study of the SBR can be helpful in the neurophysiological assessment of patients with mesencephalic lesions. © 2011 Wiley Periodicals, Inc.
Panuccio G.,Montreal Neurological Institute |
Sanchez G.,Montreal Neurological Institute |
Levesque M.,Montreal Neurological Institute |
Salami P.,Montreal Neurological Institute |
And 2 more authors.
Epilepsia | Year: 2012
Purpose: The piriform cortex (PC) is known to be epileptic-prone and it may be involved in the manifestation of limbic seizures. Herein, we have characterized some electrophysiologic and pharmacologic properties of the spontaneous epileptiform activity generated by PC networks maintained in vitro. Methods: We performed field potential recordings from the PC in coronal or sagittal rat brain slices along with pharmacologic manipulations of γ-aminobutyric acid (GABA)ergic and glutamatergic signaling during application of the convulsant drug 4-aminopyridine (4AP, 50 μm). Key Findings: Coronal and sagittal preparations generated interictal-like and ictal-like epileptiform discharges with similar duration and frequency. Ictal-like discharges in sagittal slices were initiated mostly in the PC anterior subregion, whereas interictal activity did not have any preferential site of origin. In sagittal slices, high frequency oscillations (HFOs) at 80-200 Hz were detected mainly at the beginning of the ictal discharge in both posterior and anterior subregions. N-Methyl-d-aspartate (NMDA) receptor antagonism abolished ictal discharges, but failed to influence interictal activity. In the absence of ionotropic glutamatergic transmission, PC networks generated slow, GABA receptor-dependent events. Finally, GABA A receptor antagonism during application of 4AP only, abolished ictal discharges and disclosed recurrent interictal activity. Significance: Our findings demonstrate that PC networks can sustain in vitro epileptiform activity induced by 4AP. HFOs, which emerge at the onset of ictal activity, may be involved in PC ictogenesis. As reported in several cortical structures, ionotropic glutamatergic neurotransmission is necessary but not sufficient for ictal discharge generation, a process that also requires operative GABA A receptor-mediated signaling. © 2012 International League Against Epilepsy.
Maggi L.,Neurological Institute Carlo Besta |
Mantegazza R.,Neurological Institute Carlo Besta
Clinical Drug Investigation | Year: 2011
Acquired myasthenia gravis (MG) is a chronic autoimmune disorder of the neuromuscular junction, characterized clinically by muscle weakness and abnormal fatigability on exertion. Current guidelines and recommendations for MG treatment are based largely on clinical experience, retrospective analyses and expert consensus. Available therapies include oral acetylcholinesterase (AChE) inhibitors for symptomatic treatment, and short- and long-term disease-modifying treatments. This review focuses on treatment of MG, mainly on the use of the AChE inhibitor pyridostigmine. Despite a lack of data from well controlled clinical trials to support their use, AChE inhibitors, of which pyridostigmine is the most commonly used, are recommended as first-line therapy for MG. Pyridostigmine has been used as a treatment for MG for over 50 years and is generally considered safe. It is suitable as a long-term treatment in patients with generalized non-progressive milder disease, and as an adjunctive therapy in patients with severe disease who are also receiving immunotherapy. Novel AChE inhibitors with oral antisense oligonucleotides have been developed and preliminary results appear to be promising. In general, however, AChE inhibitors provide only partial benefit and most patients eventually switch to long-term immunosuppressive therapies, most frequently corticosteroids andor azathioprine. Although AChE inhibitors are known to be well tolerated and effective in relieving the symptoms of MG, further efforts are required to improve treatment options for the management of this disorder. © 2011 Adis Data Information BV. All rights reserved.