Institute of Experimental Neurology INSpe

Milano, Italy

Institute of Experimental Neurology INSpe

Milano, Italy
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Rossi S.,NeuroLogica | Rossi S.,Cervello | Lo Giudice T.,NeuroLogica | Lo Giudice T.,Cervello | And 16 more authors.
British Journal of Pharmacology | Year: 2012

BACKGROUND AND PURPOSE Alterations of glutamate-mediated synaptic transmission occur early during neuroinflammatory insults, and lead to degenerative neuronal damage in multiple sclerosis (MS) and also in experimental autoimmune encephalomyelitis (EAE), which is a murine model of MS. Fingolimod is an effective orally active agent for the treatment of MS, affecting lymphocyte invasion of the brain. However, it is still unclear if fingolimod can be neuroprotective in this disorder. EXPERIMENTAL APPROACH Using neurophysiological recordings and morphological evaluation of dendritic integrity, we evaluated the effects of oral fingolimod on the clinical score of EAE mice in order to determine whether the compound was associated with preservation of synaptic transmission. KEY RESULTS Oral fingolimod prevented and reversed the pre- and postsynaptic alterations of glutamate transmission in EAE mice. These effects were associated with a clear amelioration of the clinical deterioration seen in EAE mice, and with a significant inhibition of neuronal dendritic pathology. Fingolimod did not alter the spontaneous excitatory postsynaptic currents in control animals, suggesting that only the pathological processes behind the inflammation-induced defects in glutamate transmission were modulated by this compound. CONCLUSIONS AND IMPLICATIONS The beneficial effects of fingolimod on the clinical, synaptic and dendritic abnormalities of murine EAE might correlate with the neuroprotective actions of this agent, as observed in MS patients. LINKED ARTICLE This article is commented on by Gillingwater, pp. 858-860 of this issue. © 2011 The British Pharmacological Society.

Marinaro C.,Institute of Experimental Neurology INSPE | Pannese M.,San Raffaele Scientific Institute | Weinandy F.,National Health Research Institute | Sessa A.,San Raffaele Scientific Institute | And 7 more authors.
Cerebral Cortex | Year: 2012

The canonical Wnt/Wingless pathway is implicated in regulating cell proliferation and cell differentiation of neural stem/progenitor cells. Depending on the context, β-Catenin, a key mediator of the Wnt signaling pathway, may regulate either cell proliferation or differentiation. Here, we show that β-Catenin signaling regulates the differentiation of neural stem/progenitor cells in the presence of the β-Catenin interactor Homeodomain interacting protein kinase-1 gene (Hipk1). On one hand, Hipk1 is expressed at low levels during the entire embryonic forebrain development, allowing β-Catenin to foster proliferation and to inhibit differentiation of neural stem/progenitor cells. On the other hand, Hipk1 expression dramatically increases in neural stem/progenitor cells, residing within the subventricular zone (SVZ), at the time when the canonical Wnt signaling induces cell differentiation. Analysis of mouse brains electroporated with Hipk1, and the active form of β-Catenin reveals that coexpression of both genes induces proliferating neural stem/progenitor cells to escape the cell cycle. Moreover, in SVZ derive neurospheres cultures, the overexpression of both genes increases the expression of the cell-cycle inhibitor P16Ink4. Therefore, our data confirm that the β-Catenin signaling plays a dual role in controlling cell proliferation/differentiation in the brain and indicate that Hipk1 is the crucial interactor able to revert the outcome of β-Catenin signaling in neural stem/progenitor cells of adult germinal niches. © The Author 2011. Published by Oxford University Press. All rights reserved.

Cambiaghi M.,San Raffaele Scientific Institute | Cambiaghi M.,Institute of Experimental Neurology INSPE | Cursi M.,San Raffaele Scientific Institute | Cursi M.,Institute of Experimental Neurology INSPE | And 10 more authors.
Epilepsy Research | Year: 2013

Deletion of one or more synapsin genes in mice results in a spontaneous epilepsy. In these animals, seizures can be evoked by opening or moving the cage. Aim of the present study was to characterize the evolution of the epileptic phenotype by neurophysiological examination and behavioral observation in synapsin triple knock-out (Syn-TKO) mice. Syn-TKO mice were studied from 20 postnatal days (PND) up to 6. months of age by video-EEG recording and behavioral observation. Background EEG spectral analysis was performed and data were compared to WT animals. Syn-TKO revealed rare spontaneous seizures and increased susceptibility to evoked seizures in mice from 60 to 100 PND. Spontaneous and evoked seizures presented similar duration and morphology. At times, seizures were followed by a post-ictal phase characterized by a 4. Hz rhythmic activity and immobility of the animal. Spectral analysis of background EEG evidenced a slowing of the theta-alpha peak in Syn-TKO mice compared to WT mice within the period from PND 40 to 100. These data indicate that Syn-TKO mice do not exhibit a linear progression of the epileptic phenotype, with the period corresponding to a higher susceptibility to evoked seizures characterized by background EEG slowing. This aspect might be connected to brain dysfunction often associated to epilepsy in the interictal period. © 2012 Elsevier B.V.

Laterza C.,Institute of Experimental Neurology INSpe | Merlini A.,Institute of Experimental Neurology INSpe | Merlini A.,San Raffaele Scientific Institute | De Feo D.,Institute of Experimental Neurology INSpe | And 13 more authors.
Nature Communications | Year: 2013

The possibility of generating neural stem/precursor cells (NPCs) from induced pluripotent stem cells (iPSCs) has opened a new avenue of research that might nurture bench-to-bedside translation of cell transplantation protocols in central nervous system myelin disorders. Here we show that mouse iPSC-derived NPCs (miPSC-NPCs) - when intrathecally transplanted after disease onset - ameliorate clinical and pathological features of experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis. Transplanted miPSC-NPCs exert the neuroprotective effect not through cell replacement, but through the secretion of leukaemia inhibitory factor that promotes survival, differentiation and the remyelination capacity of both endogenous oligodendrocyte precursors and mature oligodendrocytes. The early preservation of tissue integrity limits blood-brain barrier damage and central nervous system infiltration of blood-borne encephalitogenic leukocytes, ultimately responsible for demyelination and axonal damage. While proposing a novel mechanism of action, our results further expand the therapeutic potential of NPCs derived from iPSCs in myelin disorders. © 2009-2012 IEEE.

Esposito M.,Institute of Experimental Neurology INSPE | Ruffini F.,Institute of Experimental Neurology INSPE | Bellone M.,San Raffaele Scientific Institute | Gagliani N.,San Raffaele Scientific Institute | And 3 more authors.
Journal of Neuroimmunology | Year: 2010

Rapamycin is an oral immunosuppressant drug previously reported to efficiently induce naturally occurring CD4 +CD25 +FoxP3 + regulatory T ( nT reg) cells re-establishing long-term immune self-tolerance in autoimmune diseases. We investigated the effect of rapamycin administration to SJL/j mice affected by PLP 139-151-induced relapsing-remitting experimental autoimmune encephalomyelitis (RR-EAE). We found that oral or intraperitoneal treatment at the peak of disease or at the end of the first clinical attack, dramatically ameliorated the clinical course of RR-EAE. Treatment suspension resulted in early reappearance of disease. Clinical response was associated with reduced central nervous system demyelination and axonal loss. Rapamycin induced suppression of IFN-γ, and IL-17 release from antigen-specific T cells in peripheral lymphoid organs. While CD4 +FoxP3 + cells were unaffected, we observed disappearance of CD4 +CD45RB high effector T (T eff) cells and selective expansion of T reg cells bearing the CD4 +CD45RB lowFoxP3 +CD25 +CD10 3 + extended phenotype. Finally, the dual action of rapamycin on both T eff and T reg cells resulted in modulation of their ratio that closely paralleled disease course. Our data show that rapamycin inhibits RR-EAE, provide evidence for the immunological mechanisms, and indicate this compound as a potential candidate for the treatment of multiple sclerosis. © 2010 Elsevier B.V. All rights reserved.

Pluchino S.,San Raffaele Scientific Institute | Pluchino S.,University of Cambridge | Cusimano M.,San Raffaele Scientific Institute | Bacigaluppi M.,Institute of Experimental Neurology INSPE | Martino G.,Institute of Experimental Neurology INSPE
Archives Italiennes de Biologie | Year: 2010

Compelling evidence exists that somatic neural stem/precursor cell (NPC)-based therapies protect the central nervous system (CNS) from chronic inflammation-driven degeneration, such as that occurring in experimental autoimmune encephalomyelitis (EAE), multiple sclerosis (MS), cerebral ischemic/hemorrhagic stroke and spinal cord injury (SCI). However, while it was first assumed that NPC transplants may act through direct replacement of lost/damaged cells, it has now become clear that they are able to protect the damaged nervous system through a number of 'bystander' mechanisms other than the expected cell replacement. In immune-mediated experimental demyelination - both in rodents and non-human primates - others and we have shown that transplanted NPC possess a constitutive and inducible ability to mediate efficient 'bystander' myelin repair and axonal rescue. This novel mechanism(s), which may improve the success of transplantation procedures, is likely to be exerted by undifferentiated NPCs whose functional characteristics are regulated by both CNS-resident and blood-borne inflammatory cells releasing in situ major stem cell regulators. Here, we discuss some of these alternative 'bystander' mechanisms, while pointing at the formation of the atypical ectopic perivascular niches, as the most challenging example of reciprocal biologically sound cross talk between the inflamed microenvironment(s) and transplanted therapeutic NPCs.

Cerovic M.,University of Cardiff | Cerovic M.,Institute of Experimental Neurology INSPE | Bagetta V.,Fondazione Santa Lucia | Pendolino V.,Fondazione Santa Lucia | And 12 more authors.
Biological Psychiatry | Year: 2015

Background Bidirectional long-term plasticity at the corticostriatal synapse has been proposed as a central cellular mechanism governing dopamine-mediated behavioral adaptations in the basal ganglia system. Balanced activity of medium spiny neurons (MSNs) in the direct and the indirect pathways is essential for normal striatal function. This balance is disrupted in Parkinson's disease and in l-3,4-dihydroxyphenylalanine (l-DOPA)-induced dyskinesia (LID), a common motor complication of current pharmacotherapy of Parkinson's disease.Methods Electrophysiological recordings were performed in mouse cortico-striatal slice preparation. Synaptic plasticity, such as long-term potentiation (LTP) and depotentiation, was investigated. Specific pharmacological inhibitors or genetic manipulations were used to modulate the Ras-extracellular signal-regulated kinase (Ras-ERK) pathway, a signal transduction cascade implicated in behavioral plasticity, and synaptic activity in different subpopulations of striatal neurons was measured.Results We found that the Ras-ERK pathway, is not only essential for long-term potentiation induced with a high frequency stimulation protocol (HFS-LTP) in the dorsal striatum, but also for its reversal, synaptic depotentiation. Ablation of Ras-guanine nucleotide-releasing factor 1 (Ras-GRF1), a neuronal activator of Ras proteins, causes a specific loss of HFS-LTP in the medium spiny neurons in the direct pathway without affecting LTP in the indirect pathway. Analysis of LTP in animals with unilateral 6-hydroxydopamine lesions (6-OHDA) rendered dyskinetic with chronic L-DOPA treatment reveals a complex, Ras-GRF1 and pathway-independent, apparently stochastic involvement of ERK.Conclusions These data not only demonstrate a central role for Ras-ERK signaling in striatal LTP, depotentiation, and LTP restored after L-DOPA treatment but also disclose multifaceted synaptic adaptations occurring in response to dopaminergic denervation and pulsatile administration of L-DOPA.

Mori F.,NeuroLogica | Nicoletti C.G.,NeuroLogica | Rossi S.,NeuroLogica | Motta C.,NeuroLogica | And 11 more authors.
NeuroMolecular Medicine | Year: 2014

During multiple sclerosis (MS) inflammatory attacks, and in subsequent clinical recovery phases, immune cells contribute to neuronal and oligodendroglial cell survival and tissue repair by secreting growth factors. Animal studies showed that growth factors also play a substantial role in regulating synaptic plasticity, and namely in long-term potentiation (LTP). LTP could drive clinical recovery in relapsing patients by restoring the excitability of denervated neurons. We recently reported that maintenance of synaptic plasticity reserve is crucial to contrast clinical deterioration in MS and that the platelet-derived growth factor (PDGF) may play a key role in its regulation. We also reported that a Hebbian form of LTP-like cortical plasticity, explored by paired associative stimulation (PAS), correlates with clinical recovery from a relapse in MS. Here, we explored the role of PDGF in clinical recovery and in adaptive neuroplasticity in relapsing-remitting MS (RR-MS) patients. We found a correlation between the cerebrospinal fluid (CSF) PDGF concentrations and the extent of clinical recovery after a relapse, as full recovery was more likely observed in patients with high PDGF concentrations and poor recovery in subjects with low PDGF levels. Consistently with the idea that PDGF-driven synaptic plasticity contributes to attenuate the clinical consequences of tissue damage in RR-MS, we also found a striking correlation between CSF levels of PDGF and the amplitude of LTP-like cortical plasticity explored by PAS. CSF levels of fibroblast growth factor, granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor did not correlate with clinical recovery nor with measures of synaptic transmission and plasticity. © 2014 Springer Science+Business Media New York.

Muzio L.,Institute of Experimental Neurology INSPE | Cavasinni F.,Institute of Experimental Neurology INSPE | Marinaro C.,Institute of Experimental Neurology INSPE | Bergamaschi A.,Institute of Experimental Neurology INSPE | And 8 more authors.
Molecular and Cellular Neuroscience | Year: 2010

The peri-ventricular area of the forebrain constitutes a preferential site of inflammation in multiple sclerosis, and the sub-ventricular zone (SvZ) is functionally altered in its animal model experimental autoimmune encephalomyelitis (EAE). The reasons for this preferential localization are still poorly understood. We show here that, in EAE mice, blood-derived macrophages, T and B cells and microglia (Mg) from the surrounding parenchyma preferentially accumulate within the SvZ, deranging its cytoarchitecture. We found that the chemokine Cxcl10 is constitutively expressed by a subset of cells within the SvZ, constituting a primary chemo-attractant signal for activated T cells. During EAE, T cells and macrophages infiltrating the SvZ in turn secrete pro-inflammatory cytokines such as TNFα and IFNγ capable to induce Mg cells accumulation and SvZ derangement. Accordingly, lentiviral-mediated over-expression of IFNγ or TNFα in the healthy SvZ mimics Mg/microglia recruitment occurring during EAE, while Cxcl10 over-expression in the SvZ is able to increase the frequency of peri-ventricular inflammatory lesions only in EAE mice. Finally, we show, by RT-PCR and in situ hybridization, that Cxcl10 is expressed also in the healthy human SvZ, suggesting a possible molecular parallelism between multiple sclerosis and EAE. © 2009 Elsevier Inc. All rights reserved.

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