Symptomatic sinus node dysfunction (SND) is the most common bradyarrhythmia and the leading cause for over 500,000 electric pacemaker devices implanted yearly in Europe and U.S. In recent years, an increasing number of mutations affecting ion channels involved in sino?atrial automaticity, including RyR2, HCN4 and CaV1.3, have been reported to underlie inheritable primary SND. Using murin model, we have demonstrated that silencing or inhibiting the G protein gated K+ channel (Girk4) normalizes heart rate and prevents bradyarrhythmia in mouse models of primary SND. Therefore, targeting Girk4 may drastically reduce SND symptoms in patients and significantly improve the quality of life. To further appreciate the patient-specific context and penetrate the genotype/phenotype relationship of SND, FENICE offers to exploit cutting-edge technologies including iPSC, CRISPR/Cas9, siRNA, patient cohort and single cell genomics to generate iPSC-derived pacemaker-like cardiomyocytes and model SND using patient-derived cardiomyocytes harbouring mutations on RyR2, HCN4 and CaV1.3. Primary results indicate our capability to obtain more than 50% of iPSC-derived atrial- and pacemaker-like cardiomyocytes. FENICE will employ adenoviral vectors to silence IKACh current and evaluate whether it normalizes automaticity in SND patient-derived pacemaker-like cardiomyocytes. Finally, to reach pathophysiological evidences, FENICE will tailor therapeutic strategy in available mouse models of primary SND using adenoviral vectors. Overall FENICE explores fundamental, clinical and therapeutic aspects of SND in patient-specific cellular and molecular context using cutting-edge technologies. At the interface between basic research and clinical research, FENICE also aims at bringing new personalized medicine tools for cardiovascular diseases. The scientific synergy and physical proximity among the 2 partners are a guarantee for effectiveness and successful outcomes of the project.

Emerging evidence indicates that unconventional protein secretion (UPS) is critical for the dissemination of aggregate-prone proteins that cause neurodegenerative diseases (NDs), such as Tau and a-synuclein (aSNC) in Alzheimer’s (AD) and Parkinson’s (PD) diseases, respectively. Hence to uncover mechanisms underlying UPS, a process poorly characterized, is of utmost importance. Recently, we demonstrated that lysosomes represent a critical sorting station for UPS, and more specifically for Tau and aSNC propagation via the exocytosis of lysosomes and their transport through tunnelling nanotubes (TNTs). A fundamental challenge now is to understand how lysosomes acquire secretory and transport carrier properties, promoting Tau and aSNC dissemination. Toward this objective, our project aims at: 1- Uncovering molecular determinants activated or recruited on lysosomes to divert those organelles toward compartments competent for fusion with the plasma membrane or transport trough TNTs, and to identify potential factors involved at every step of Tau and aSNC trafficking. For this, functional assays on lysosome, pooled genome-wide CRISPR screen and proteomic approaches will be performed. 2- Investigating the role of identified factors in iPSCs-derived neurons and in Zebrafish models. This will validate their pathophysiological relevance, and reveal their therapeutic potential. 3- Testing the role of lysosome as main sorting station in patients with NDs. The levels of multiple lysosomal enzymes will be assessed in cerebrospinal fluid (CSF) from patients. In addition, Tau profile from purified secretory lysosomes will be established and compared to the specific Tau forms detected in CSF of AD patients. At the crossroad of critical challenges, we believe that this project can shed light on fundamental mechanisms governing lysosome biology that will ultimately contribute to novel biomedical applications in NDs.

Disorders affecting social behaviors, such as autism spectrum disorders (ASD), are complex neurodevelopmental disorders involving deficits in social interaction and communication. To date, no pharmacological treatment that improve social symptoms exists for ASD, and the only therapeutic options rely on costly behavioral intervention programs with limited beneficial effects. Oxytocin and its receptor are key determinant players of social behaviors with therapeutic potential for social interaction deficits. Oxytocin receptor is expressed in specific brain structures and cell types in the central nervous system. Here, we propose i) to dissect the role of oxytocin receptor in these structures, spanning from olfactory neurons to glial cells and neurons in interconnected central brain areas, and ii) establish a therapeutic framework of exogenous intranasal oxytocin administration in a mouse model of autism. We will identify how oxytocin receptor in the mouse olfactory system modulates social interactions, determine the modulatory role of oxytocin receptor centrally, in both neurons and astrocytes and use administration of exogenous oxytocin in a well-established and mouse model of ASD and Fragile X syndrome. Overall, our project will provide essential novel information on how oxytocin modulate social signals and brain activity to enable social interactions, providing therapeutic levers in the context of sociability disorders.

Addictions to psychoactive substances generate a growing public health concern and represent a significant financial burden. Efforts should thus be made to understand how addictive behavior settles in order to ultimately define strategies to prevent such pathological process. Despite identified brain structures and synaptic circuit underlying addictive behavior, our understanding of the cellular substrate underlying changes in the treatment of information that lead to addiction remain incomplete. Neuroglial interactions have recently been showed to markedly partake in brain information processing and cognitive functions. However, how they participate to the rewiring leading to addiction is unresolved. Our recent dataset show that the astroglial protein Cx30 is strongly involved in the response to cocaine exposure. Interestingly, Cx30 bears multiple functions that may all influence the plastic changes associated with addiction. Namely, its channel function that can regulate levels of small molecules such as dopamine as well as its role in shaping extracellular matrix proteins or coverage of glutamatergic synapses. The current project therefore aims at understanding how astroglial Cx30 takes part in the development of addictive behavior toward cocaine. To this end, the objectives of the current project are threefold: 1- Ascertain the implication of Cx30 in the development, persistence and relapse to addictive behavior 2- Decipher the physiopathological processes at play and controlled by astrocytes in cocaine addiction 3- Identify the astroglial pathway(s) underlying Cx30 control of addiction. Unraveling how neuroglial interactions influence cerebral functions will provide a more comprehensive framework for identifying dysfunctions underlying brain disorders as well as novel therapeutic targets.

The nucleoporin RanBP2 is a component of the cytoplasmic filaments of the nuclear pore complex known to regulate the nuclear export of RNA molecules, and the post-translational modification of proteins during nucleocytoplasmic trafficking. Mutations in the N-terminal domain of RanBP2 are associated with a rare genetic predisposition in otherwise healthy individuals to deleterious inflammation and Acute Necrotizing Encephalopathy (ANE) following viral infection, frequently by Influenza A virus (IAV). We found that loss of RanBP2 leads to increased expression of some pro-inflammatory cytokines in cell lines and primary immune cells, suggesting that some inflammatory pathways are regulated by RanBP2 and that this control is lost with mutant ANE-associated RanBP2. To uncover the mechanisms linking RanBP2 to deleterious inflammation following IAV infection, we will study both cells lacking RanBP2, and ANE cells that contain the prevalent RanBP2 mutation T585M (c. 1880C/T). Our project aims to establish how RanBP2 regulates the inflammatory response to infection in genetically edited cell lines and mouse models, as well as samples from ANE patients, focusing on (i) the Impact of viral infection, cell type and mutations on RanBP2 localisation and dynamics, (ii) the effect of RanBP2 on cytokine production, and (iii) the CNS-specific role of RanBP2 and brain susceptibility of ANE. The project leverages our diverse expertise in virus/host cell interaction and neuroinflammation. Thus, this collaboration will foster exchange of knowledge, and will help understand how alterations in the nuclear pore complex contribute to disease development following viral infection.