NeuroWebinar & Seminar
1 appointment per week, on Friday at 2.00 pm
**Hybrid seminar : both in presence (max 25 people in Seminar room) and on webex
Friday 23/2/2024 h. 2.00 pm -
Helena L. A. Vieira
, UCIBIO, Applied Molecular Biosciences Unit, Department of Chemistry, NOVA School of Science and Technology, Universidade Nova de Lisboa, Portugal
Carbon monoxide promotes mitochondrial homeostasis in brain cells:
Cell energy and fate control in stroke context
Carbon monoxide (CO) is a gasotransmitter endogenously produced by the activity of heme oxygenase, which is a stress-response enzyme. Endogenous CO or low concentrations of exogenous CO have been described to present several cytoprotective functions: anti-apoptosis, anti-inflammatory, vasomodulation, maintenance of homeostasis, stimulation of preconditioning and modulation of cell differentiation.
The seminar will present and discuss how CO is cytoprotective in glial cells and how CO improves neuronal differentiation. In fact, COprevents oxidative stress-induced astrocytic cell death by improving oxidative metabolism  and mitochondrial quality control . The anti-neuroinflammatory effect of CO is also dependent on microglial metabolism control regulated by neuroglobin . Finally, neuronal differentiation is facilitated by CO modulation of metabolism: oxidative phosphorylation  and pentose phosphate pathway .
 A.S. Almeida, C.S.F. Queiroga, M.F.Q. Sousa, P.M. Alves, H.L.A. Vieira, Carbon monoxide modulates apoptosis by reinforcing oxidative metabolism in astrocytes: Role of Bcl-2, J. Biol. Chem. 287 (2012) 10761–10770. doi:10.1074/jbc.M111.306738.
 C. Figueiredo-Pereira, B. Villarejo-Zori, P.C. Cipriano, D. Tavares, I. Ramírez-Pardo, P. Boya, H.L.A. Vieira, Carbon Monoxide Stimulates Both Mitophagy And Mitochondrial Biogenesis to Mediate Protection Against Oxidative Stress in Astrocytes, Mol. Neurobiol. 60 (2023) 851–863. doi:10.1007/s12035-022-03108-7.
 D. Dias-Pedroso, J.S. Ramalho, V.A. Sardão, J.G. Jones, C.C. Romão, P.J. Oliveira, H.L.A. Vieira, Carbon Monoxide-Neuroglobin Axis Targeting Metabolism Against Inflammation in BV-2 Microglial Cells, Mol. Neurobiol. 59 (2022) 916–931. doi:10.1007/s12035-021-02630-4.
 A.S. Almeida, U. Sonnewald, P.M. Alves, H.L.A. Vieira, Carbon monoxide improves neuronal differentiation and yield by increasing the functioning and number of mitochondria, J. Neurochem. 138 (2016) 423–435. doi:10.1111/jnc.13653.
 A.S. Almeida, N.L. Soares, C.O. Sequeira, S.A. Pereira, U. Sonnewald, H.L.A. Vieira, Improvement of neuronal differentiation by carbon monoxide: Role of pentose phosphate pathway, Redox Biol. 17 (2018) 338–347. doi:10.1016/j.redox.2018.05.004.
Host: Alessandro Vercelli | webex link
Friday 16/2/2024 h. 2.00 pm -
Vasco Meneghini , San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
Targeting astrocytes with editing technologies to treat Alexander Disease
Alexander disease (AxD) is a rare, lethal leukodystrophy caused by gain-of-function mutations in the gene encoding for glial fibrillary acidic protein (GFAP), the main intermediate filament of astrocytes. Accumulation of GFAP aggregates in Rosenthal fibers leads to central nervous system (CNS)dysfunction with typical pathological traits such as astrogliosis, loss of myelin, seizures, and spasticity. No cure is currently available for this neurodegenerative disorder.
We developed a novel, single-dose gene editing strategy for the lifetime treatment of AxD. We selected a single guide RNA (gRNA) targeting the murineGfapgenein3T3 cells transduced with a lentiviral vector (LV) harboring the R76H-mutant GFAP protein fused to mCherry. FACS analysis of mCherry expression showed that the best gRNA candidate induced a robust knock-down ofGFAP-mCherry, while nogene editing at top off-target loci was evident. To optimize the in vivo brain-directed delivery of theGfap-targeting CRISPR system, pilot experiments defined the optimal injection protocol, AAV serotype and promoter, resulting in high astrocytic tropism and transduction rates of AxD-affected brain regions. Selected AAV carrying the Gfap-targetinggRNA and the Cas9 nuclease was administered by intracerebroventricular injections in neonatal AxD mice. AVV-mediated Cas9/sgRNAdelivery resulted in on-target editingin GFAP+ astrocytes, decreased astrogliosis and reduced accumulation of Rosenthal fibers - a hallmark of AxD pathology - in white matter regions. These data provide in vivo proof-of-concept of the efficacy of a CRISPR/Cas9 editing approach in ameliorating disease-associated phenotypes.
To expand on the potential of gene editing as a mutation-specific treatment for AxD, we are currently developing allele-specific gene therapies targeting the murine R76H mutation, homolog of the human mutation hotspot detected in AxD patients. Among them, we identified adenine base editors that efficiently correct the Gfap mutation in vitro and we are currently validating this approach in vivo. Overall, our study provides initial proof-of-concept data on the efficacy of a CRISPR/Cas9 editing approach in ameliorating disease-associated phenotypes. Our results pave the way for pre-clinical studies aimed at improving the editing tolls targeting the mutated Gfap allele in the CNS using AAV vectors or, prospectively, non-viral delivery systems.
Host: Martina Lorenzati
Friday 9/2/2024 h. 2.00 pm -
Alessandro Usiello , Dept. Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania L. Vanvitelli
D-amino acids metabolism abnormalities in neurological and psychiatric disorders
D-aspartate (D-Asp) has a transient emergence in the mammalian brain. It is abundant in the embryonic phase and the first post-natal days before significantly decreasing thereafter. Interestingly, during prenatal phases, the intracellular localization of D-Asp seems to be developmentally regulated, according to the functional activity of neuroblasts. It has long been established that D-aspartate oxidase (DDO) is the enzyme responsible for D-Asp catabolism. Accordingly, the post-natal decrease of D-Asp content is associated with the concomitant, progressive increase in Ddo gene expression and DDO activity in the rodent brain. D-Asp is present at extracellular level, where it acts as an agonist at NMDA and mGlu5 receptors. In line with its pharmacological role, we found that adult mice with abnormally high cerebral D-Asp levels showed increased NMDA receptor-dependent functional and structural plasticity, and improved spatial memory.
Although these findings highlight the influence of non-physiologically high D-Asp levels on several cerebral processes at adulthood, it is so far unknown the significance of embryonic D-Asp in the mammalian brain and its involvement on brain functions and behaviors at adulthood. To clarify this issue, we have recently generated a novel knockin mouse model in which the expression of DDO is anticipated starting from the zygotic stage to enable the removal of the embryonic storage of cerebral D-Asp. To this aim, we targeted a Ddo cDNA cassette in the genomic Rosa26 locus to allow the ectopic transcription of Ddo under the regulatory control of the constitutive Rosa26 promoter. We found that knockin strategy resulted in a strong, allele-dependent increase of both Ddo expression and DDO enzymatic activity in heterozygous ( R26 Ddo/+ ) and homozygous ( R26 Ddo/Ddo ) Ddo knockin brains, compared to wild-type controls ( R26 +/+ ). These molecular alterations resulted in a corresponding strong ontogenetic depletion of cerebral D-Asp, from embryonic to adult phase. However, deregulated Ddo gene expression did not affect the cerebral levels of L-Asp, the precursor of D-Asp biosynthesis, as well as the metabolism of D-serine and L-glutamate, the two main neuroactive molecules involved in NMDA receptor-dependent transmission. Surprisingly, despite the removal of embryonic cerebral D-Asp, Ddo knockin mice were viable, fertile and did not show any evident abnormalities at adulthood. Moreover, histological and immunohistochemical analysis revealed no gross differences in brain size or structural organization and no variations in neuronal density and distribution in adult Ddo knockin mice. Conversely, we found that early D-Asp depletion was associated with increased number of cortical parvalbumin-positive interneurons and improved cognitive abilities of adult Ddo knockin mice in spatial memory e recognition tasks. Overall, the molecular, morphological and behavioral characterization of Ddo knockin mice revealed unexpected phenotypes that deserve further investigations not only in adult but also in juvenile and embryonic phases of mouse brain development.
Host: Alessandro Vercelli
Friday 2/2/2024 h. 2.00 pm - Webinar
Ariel Di Nardo , CNRS Research Scientist and Co-director, Development & Neuropharmacology Team, CIRB, Collège de France
Anxiety-like behavior regulated by non-cell autonomous transcription factor activity
Our laboratory investigates the role of non-cell autonomous homeoprotein transcription factors in regulating cerebral cortex physiology. We discovered that OTX2 homeoprotein is expressed in the choroid plexus, secreted into cerebrospinal fluid, and transferred into parvalbumin (PV)-expressing interneurons in mice. OTX2 participates in PV cell maturation and regulates the timing of plasticity critical periods throughout the brain. These juvenile periods allow for remodeling of circuitry in response to the environmental and genetic contexts, and are associated with disease outcomes. Although our initial OTX2 studies were primarily focused on mouse visual system critical periods, we have also investigated higher order circuits involved in anxiety-like behavior shaped by early-life stress. Our recent findings revealed OTX2 target genes in cortical PV cells with epigenetic outcomes and showed that choroid plexus OTX2 affects animal behavior.
Host: Serena Stanga
22/1/2024 h. 2.00 pm -
Elia Di Schiavi , Institute of Biosciences and BioResources, IBBR; Dept. Biology, Agriculture and Food Science, CNR Naples, Italy
Splicing regulation of Reticulon is involved in preventing neurodegeneration in a C. elegans model of SMA
An efficient splicing of mRNA is required in all cells, but neurons seem to be more vulnerable to splicing perturbations. In fact, numerous neurodegenerative diseases are caused by splicing defects, including Spinal Muscular Atrophy (SMA). However, why neurons are more affected to splicing alterations and which step of the RNA processing is impaired in this disease is still debated. SMA is caused by mutations in the Survival Motor Neuron (Smn) gene, which is involved in RNA metabolism and splicing. We have demonstrated that genes differentially expressed or spliced in induced pluripotent cell-derived motor neurons (iPS-MNs) from SMA patients are enriched in the RNA motif 7. This motif is specifically recognized by hnRNPQ, a spliceosomal component physically interacting with SMN. We demonstrated that hrpr-1, the hnRNPQ homolog in C. elegans, is involved in motoneurons (MNs) survival similarly to smn-1, the Smn homolog. We demonstrated that they genetically interact and exert a neuroprotective function specifically in MNs. Comparing hrpr-1 known targets in C. elegans and the alternatively spliced genes identified in SMA patients, we identified a new possible downstream target of the pathway: ret-1, the only homolog in C. elegans of Reticulon genes, a family of transmembrane proteins involved in vesicle recycling and formation, and in neurite outgrowth. We confirmed a possible involvement of ret-1 in SMA by observing alteration in its transcript levels in C. elegans, SMA mice and patients. Moreover, we demonstrated that ret-1 splicing pattern is altered when smn-1 is depleted and that hrpr-1 and smn-1 work together to guarantee the correct splicing of exon 5 of ret-1 gene. Thus, we identified for the first time a neuroprotective role of hrpr-1 and the involvement of ret-1 in neurodegeneration.
Center of Research in Myology, Sorbonne University, Paris, France
Deciphering key molecular players in skeletal muscle affected by SMA
Spinal Muscular Atrophy (SMA) is traditionally considered a disease of the motor neurons, however, increasingly the systemic role of the SMN protein is being underscored. In particular, the role of the muscle as both an axis of pathology and driver of overall disease, is being appreciated. After an initial characterization of the phenotypic and molecular features of the skeletal muscle tissue in a severe SMA mouse model, we sought to investigate the response of the muscle upon administration of the approved therapies. Therefore, we collected paravertebral muscle from SMA Type II patients (n=8) after treatment with Nusinersen and age matched controls (n=7) and performed RNA-sequencing. This analysis revealed a heterogeneous response of the skeletal muscle tissue to the therapy with most of the patients having a persistent DNA damage and P53 pathways activation despite the restoration of SMN levels. This study provides a molecular roadmap of the state of SMA muscle after treatment. Work is ongoing to determine that molecular reasons – be they genetic, epigenetic, or clinical for the heterogeneous response to Nusinersen injection, and to test drug candidates to improve mitochondrial function and decrease DNA damage in skeletal muscle.
Host: Marina Boido
h. 9.00 am
Makoto Sato , Department of Anatomy and Neuroscience, Graduate School of Medicine; Division of Child Development, United Graduate School of Child Development (UGSCD) - Osaka University, JAPAN
Cytoskeletons and cortical development: How does the neocortex develop to establish the prototype of neuronal circuits by neuronal migration and collateral formation?
To understand the complex neuronal circuits for higher functioning of the neocortex from a compositional perspective, I have studied cortical development, in particular cytoskeletal regulatory mechanisms underlying migration and collateral formation. Periventricular nodular heterotopia gave me the first hint to study cortical development focusing on the regulation of cytoskeletons. Periventricular heterotopia is a hereditary disease in which the brain has a second cortex (cluster of nerve cells) around the ventricle, a so-called double cortex, and one of its characteristics is intractable epilepsy.
The cause of the disease is believed to be a mutation in the actin-binding protein filamin A on the X chromosome, suggesting that filamin A is important for neurons to migrate out of the cortical ventricular zone to form the neocortex. We have identified and studied a novel molecule, FILIP (filamin A interacting protein), which promotes the degradation of filamin A. Very recently, it was reported that mutations in FILIP (FILIP1 in human) cause congenital arthrogryposis multiplex, intellectual disability, holoprosencephaly, and encephalocele in human (FILIP disease). In my talk, I will introduce a series of FILIP-related studies to and its regulatory factors, including some unpublished data.
It is generally believed that mutation of molecules involved in neuronal migration increases susceptibility to various neuropsychiatric diseases, but the relationship between these mutations has not been fully elucidated. Therefore, to examine changes in neural networks due to variations in neuronal arrangement, we first constructed a system to visualize single-cell level neural networks for individual cerebral cortical neurons. Sequential collateral formation to apparently predetermined targets is critical to establish the prototype of neuronal circuits. I will also present our latest results that underlie such collateral formation in my talk.
Host: Alessandro Vercelli
Friday 12/1/2024 h. 2.00 pm -
Filippo Sean Giorgi , Dept. Translational Research and of New Surgical and Medical Technologies, University of Pisa
The central noradrenergic system and neurodegeneration occurring along the Alzheimer’s Disease continuum and ageing
Understanding Alzheimer’s Disease (AD) pathophysiology represents a major challenge of neuroscience research, and effective disease-modifying therapies are still far to be developed. In recent years, growing attention has been focused on the possible role of the noradrenergic nucleus Locus Coeruleus (LC) in AD pathogenesis and physiopathology. Experimental findings and human post-mortem data all converge in underscoring the impact of early LC degeneration in AD-related degenerative phenomena and AD natural history. A better shaping of the features and role of LC in AD might be crucial in detailing its role as a research biomarker, as well as a potential therapeutic target of AD.
In this seminar, an overview of the current research on the role of the LC in AD will be provided, including some pieces of data I have been collecting in recent years. In particular, we, in parallel with other groups, have been able to confirm in vivo in humans the significant involvement of LC in the AD continuum by profiting of advanced Magnetic Resonance Imaging (MRI) tools (LC-MRI) which have been developed ad-hoc. Recently, we have also shown its involvement in the conversion from Mild Cognitive Impairment to dementia and the association between the degeneration of different parts of LC with the cortical metabolism of AD patients. Moreover, we explored the relationship between LC structural integrity and neuroinflammation, by assessing the association of LC-MRI with plasma interleukins in patients and healthy controls. Finally, I will illustrate and discuss experimental studies currently ongoing on the relationship between LC and normal ageing, and between LC degeneration and late-onset epilepsy; these might offer additional perspectives for dissecting the complex pathophysiology of AD and the role of LC.
Host: Alessandro Vercelli