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Mutations or deletions in the SHANK3 gene have been identified in up to 1% of autism spectrum disorder cases and are considered the main cause of neuropsychiatric symptoms of Phelan McDermid syndrome (PMS). While in the absence of Shank3, synaptic dysfunctions have been extensively described, other mechanisms through which Shank3 could regulate neuronal functions have not been clearly elucidated. Here, we reported that the ribosomal protein Rpl3 was downregulated in cortex and striatum of Shank3 KO mice and in neurons differentiated from hiPSCs derived from a PMS patient. Rpl3 is essential for ribosomal biogenesis and function and its reduced expression resulted in impaired protein synthesis in Shank3 KO mice that can be rescued by restoring its expression. Furthermore, we showed that chronic treatment with VU0409551, a potent and selective mGlu5 positive allosteric modulator, rescued Rpl3 expression and the resulting reduced protein synthesis, leading to a long-lasting improvement of behavioral deficits in Shank3 KO mice. Altogether, we suggest a new role for Shank3 in modulating ribosomal function and protein synthesis, and that restoring protein synthesis could be a strategy to correct Shank3 KO related behavioral phenotypes.

Ageing is the greatest global healthcare challenge, as it underlies age-related functional decline and is the primary risk factor for a range of common diseases, including neurodegenerative conditions such as Alzheimer’s disease (AD). However, the molecular mechanisms defining chronological age versus biological age, and how these underlie AD pathogenesis, are not well understood. The objective of this study was to integrate common human genetic variation associated with human lifespan or AD from Genome-Wide Association Studies (GWAS) with co-expression networks altered with age in the central nervous system, to gain insights into the biological processes which connect ageing with AD and lifespan. Initially, we identified common genetic variation in the human population associated with lifespan and AD by performing a gene-based association study using GWAS data. We also identified preserved co-expression networks associated with age in the brains of C57BL/6J mice from bulk and single-cell RNA-sequencing (RNA-seq) data, and in the brains of humans from bulk RNA-seq data. We then intersected the human gene-level common variation with these co-expression networks, representing the different cell types and processes of the brain. We found that genetic variation associated with AD was enriched in both microglial and oligodendrocytic bulk RNA-seq gene networks, which show increased expression with ageing in the human hippocampus, in contrast to synaptic networks which decreased with age. Further, longevity-associated genetic variation was modestly enriched in a single-cell gene network expressed by homeostatic microglia. Finally, we performed a transcriptome-wide association study (TWAS), to identify and confirm new risk genes associated with ageing that show variant-dependent changes in gene expression. In addition to validating known ageing-related genes such as APOE and FOXO3, we found that Caspase 8 (CASP8) and APOC1 show genetic variation associated with longevity. We observed that variants contributing to ageing and AD balance different aspects of microglial function suggesting that ageing-related processes affect multiple cell types in the brain. Specifically, changes in homeostatic microglia are associated with lifespan, and allele-dependent expression changes in age-related genes control microglial activation and myelination influencing the risk of developing AD. We identified putative molecular drivers of these genetic networks, as well as module genes whose expression in relevant human tissues are significantly associated with AD-risk or longevity, and may drive “inflammageing.” Our study also shows allele-dependent expression changes with ageing for genes classically involved in neurodegeneration, including MAPT and HTT, and demonstrates that PSEN1 is a prominent member/hub of an age-dependent expression network. In conclusion, this work provides new insights into cellular processes associated with ageing in the brain, and how these may contribute to the resilience of the brain against ageing or AD-risk. Our findings have important implications for developing markers indicating the physiological age and pre-pathological state of the brain, and provide new targets for therapeutic intervention.

International audience; Phelan-McDermid syndrome (PMS) is a 22q13.3 deletion syndrome that presents with a disturbed development, neurological and psychiatric characteristics, and sometimes other comorbidities like seizures. The epilepsy manifests itself in a variety of seizure semiologies. Further diagnostics using electroencephalogram (EEG) and brain magnetic resonance imaging (MRI) are important in conjunction with the clinical picture of the seizures to decide whether anticonvulsant therapy is necessary. As part of the development of European consensus guidelines we focussed on the prevalence and semiology of epileptic seizures in PMS associated with a pathogenic variant in the SHANK3 gene or the 22q13 deletion involving SHANK3, in order to then be able to make recommendations regarding diagnosis and therapy.

Alzheimer’s disease (AD) is characterized by synaptic loss, which can result from dysfunctional microglial phagocytosis and complement activation. However, what signals drive aberrant microglia-mediated engulfment of synapses in AD is unclear. Here we report that secreted phosphoprotein 1 (SPP1/osteopontin) is upregulated predominantly by perivascular macrophages and, to a lesser extent, by perivascular fibroblasts. Perivascular SPP1 is required for microglia to engulf synapses and upregulate phagocytic markers including C1qa, Grn and Ctsb in presence of amyloid-β oligomers. Absence of Spp1 expression in AD mouse models results in prevention of synaptic loss. Furthermore, single-cell RNA sequencing and putative cell–cell interaction analyses reveal that perivascular SPP1 induces microglial phagocytic states in the hippocampus of a mouse model of AD. Altogether, we suggest a functional role for SPP1 in perivascular cells-to-microglia crosstalk, whereby SPP1 modulates microglia-mediated synaptic engulfment in mouse models of AD.

Astrocytes coordinate several homeostatic processes of the central nervous system and play essential roles for normal brain development and response to disease conditions. Protocols for the conversion of human induced pluripotent stem cells (hiPSCs) into mature astrocytes have opened to the generation of in vitro systems to explore astrocytes’ functions in living human cell contexts and patient-specific settings. In this study, we present an optimized monolayer procedure to commit hiPSC-derived cortical progenitors into enriched populations of cortical astrocyte progenitor cells (CX APCs) that can be further amplified and efficiently differentiated into mature astrocytes. Our optimized system provides a valid tool to explore the role of these cells in neurodevelopmental and neuropsychiatric diseases, opening it up to applications in drug development and biomarkers discovery/validation.

Epilepsy is one of the most prevalent serious brain disorders worldwide. Accumulating evidence has suggested that inflammation participates in the progression and pathogenesis of epilepsy. During inflammation, a cytosolic multimolecular complex called the "inflammasome" is activated, driving the innate immune response. This inflammatory pathway by sensing various pathogens and molecules from damaged cells and then activation of caspase-1 enzyme initiates inflammatory responses. Activated caspase-1 leads to the proteolytic cleavage of the pro-inflammatory cytokines, interleukin-1β (IL-1β) and interleukin-18 (IL-18), and also induction of an inflammatory programmed cell death termed pyroptosis. NLR family pyrin domain-containing 1 (NLRP1) and NLRP3 are the two best-characterized inflammasome members, and both basic and clinical research has reported their activation during epilepsy. This overview is intended to summarize the current literature concerning NLRP1 and NLRP3 inflammasome activation and epilepsy.

We compute nonparametric and forward-looking option-implied quantile and expectile curves, and we study their properties on a 5-year dataset of weekly options written on the S&P 500 Index. After studying the dynamics of the single curves and their joint behaviour, we investigate the potentiality of these quantities for risk management and forecasting purposes. As an alternative form of variability mesaures, we compute option-implied interquantile and interexpectile differences, that are compared with a weekly VIX-like index. In terms of forecasting power we investigate how different quantities related to the implicit quantile and expectile curves predict future logreturns and future realized variances.

About a third of patients with major depressive disorder (MDD) do not have an adequate response to first-line antidepressant treatment, i.e., develop a treatment-resistant depression (TRD). The partial understanding of MDD pathophysiology currently constitutes the major barrier to clinical and research progress on this topic. However, recent advances in genome editing techniques as well as in induced pluripotent stem cells (iPSC) technology are offering unprecedented opportunities in both human disease modelling and drug discovery. These technology progresses have been enabling to set up disease-relevant patient-specific in vitro disease modeling for various mental disorders. The resulting models have the potential to significantly improve pathophysiologic understanding of MDD and then overcome some limitations inherent to animal and post-mortem models. More recently, psychiatry started to deal with the fast acting antidepressant ketamine and its derivates. Although ketamine appears to have the potential to transform the treatment of depression, its specific mechanisms of action are only partially known. Such knowledge is necessary to develop a model to understand the mechanisms behind fast-acting antidepressants, which may enable the discovery of novel glutamatergic compounds for the treatment of MDD. After discussing both the current understanding of ketamine's mechanisms of action, and the state of the art of human iPSC technology, the authors will introduce the implementation of a TRD model based on iPSC human technology and aimed at studying the ketamine's fast acting antidepressant mechanisms of action.

SummaryMicroglia are phagocytes of the brain parenchyma, where they interact with neurons to engulf synapses in a context-dependent manner. Genetic studies in Alzheimer’s disease (AD) highlight dysfunctional phagocytic signaling in myeloid cells as disease-associated pathway. In AD models, there is a region-specific reactivation of microglia-synapse phagocytosis involving complement; however, what drives microglia-synapse engulfment remains unknown. Here, we show that SPP1 (Osteopontin), a glycoprotein associated with inflammation, is regionally upregulated and modulates microglial synaptic engulfment in AD mouse models. Ultrastructural examination revealed SPP1 expression predominantly by perivascular macrophages, a subtype of border-associated macrophages, in the hippocampus of mice and patient tissues. Cell-cell interaction networks of single-cell transcriptomics data suggested that perivascular SPP1 drives microglial functional states in the hippocampal microenvironment of AD mice. Absence of Spp1 expression resulted in failure of microglia to mediate synaptic phagocytosis. This study suggests a critical role for perivascular SPP1 in neuroimmune crosstalk in AD-relevant context.

Genetic mosaicism, a condition in which an organ includes cells with different genotypes, is frequently present in monogenic diseases of the central nervous system caused by the random inactivation of the X-chromosome, in the case of X-linked pathologies, or by somatic mutations affecting a subset of neurons. The comprehension of the mechanisms of these diseases and of the cell-autonomous effects of specific mutations requires the generation of sparse mosaic models, in which the genotype of each neuron is univocally identified by the expression of a fluorescent protein in vivo. Here, we show a dual-color reporter system that, when expressed in a floxed mouse line for a target gene, leads to the creation of mosaics with tunable degree. We demonstrate the generation of a knockout mosaic of the autism/epilepsy related gene PTEN in which the genotype of each neuron is reliably identified, and the neuronal phenotype is accurately characterized by two-photon microscopy., Genetic mosaicism is frequently present in monogenic diseases of the central nervous system. Here the authors design a dual-colour reporter system that can be used to tune the degree of mosaicism in mouse models.

Two major processes tightly regulate protein synthesis, the initiation of mRNA translation and elongation phase that mediates the movement of ribosomes along the mRNA. The elongation phase is a high energy-consuming process, and is mainly regulated by the eukaryotic elongation factor 2 kinase (eEF2K) activity that phosphorylates and inhibits eEF2, the only known substrate of the kinase. eEF2K activity is closely regulated by several signaling pathways because the translation elongation phase strongly influences the cellular energy demand and can change the expression of specific proteins in different tissues. An increasing number of recent findings link eEF2k over activation to an array of human diseases, such as atherosclerosis, pulmonary arterial hypertension, progression of solid tumors, and some major neurological disorders. Several neurological studies suggest that eEF2K is a valuable target in treating epilepsy, depression and major neurodegenerative diseases. Despite eEF2k is an ubiquitous and conserved protein, it has been proved that its deletion does not affect development in animal models and in general cell viability. Therefore, it is possible to postulate that inhibiting its function may not cause serious side effects. In addition, eEF2K is a peculiar kinase molecularly different from most of other mammalian kinases and new compounds that inhibit eEF2K should not necessarily interfere with other important protein kinases. In this review we will critically summarize the evidence supporting the role of the altered eEF2K/eEF2 pathway in defined neurological diseases and its implications in curing these diseases in animal models, and possibly in humans, by targeting eEF2K activity.

Background Dravet Syndrome is a severe childhood pharmaco-resistant epileptic disorder mainly caused by mutations in the SCN1A gene, which encodes for the α1 subunit of the type I voltage-gated sodium channel (NaV1.1), that causes imbalance between excitation and inhibition in the brain. We recently found that eEF2K knock out mice displayed enhanced GABAergic transmission and tonic inhibition and were less susceptible to epileptic seizures. Thus, we investigated the effect of inhibition of eEF2K on the epileptic and behavioral phenotype of Scn1a ± mice, a murine model of Dravet Syndrome. Methods To elucidate the role of eEF2K pathway in the etiopathology of Dravet syndrome we generated a new mouse model deleting the eEF2K gene in Scn1a ± mice. By crossing Scn1a ± mice with eEF2K−/− mice we obtained the three main genotypes needed for our studies, Scn1a+/+ eEF2K+/+ (WT mice), Scn1a ± eEF2K+/+ mice (Scn1a ± mice) and Scn1a ± eEF2K−/− mice, that were fully characterized for EEG and behavioral phenotype. Furthermore, we tested the ability of a pharmacological inhibitor of eEF2K in rescuing EEG alterations of the Scn1a ± mice. Results We showed that the activity of eEF2K/eEF2 pathway was enhanced in Scn1a ± mice. Then, we demonstrated that both genetic deletion and pharmacological inhibition of eEF2K were sufficient to ameliorate the epileptic phenotype of Scn1a ± mice. Interestingly we also found that motor coordination defect, memory impairments, and stereotyped behavior of the Scn1a ± mice were reverted by eEF2K deletion. The analysis of spontaneous inhibitory postsynaptic currents (sIPSCs) suggested that the rescue of the pathological phenotype was driven by the potentiation of GABAergic synapses. Limitations Even if we found that eEF2K deletion was able to increase inhibitory synapses function, the molecular mechanism underlining the inhibition of eEF2K/eEF2 pathway in rescuing epileptic and behavioral alterations in the Scn1a ± needs further investigations. Conclusions Our data indicate that pharmacological inhibition of eEF2K could represent a novel therapeutic intervention for treating epilepsy and related comorbidities in the Dravet syndrome.

Members of the Shank protein family are master scaffolds of the postsynaptic architecture and mutations within the SHANK genes are causally associated with autism spectrum disorders (ASDs). We generated a Shank2-Shank3 double knockout mouse that is showing severe autism related core symptoms, as well as a broad spectrum of comorbidities. We exploited this animal model to identify cortical brain areas linked to specific autistic traits by locally deleting Shank2 and Shank3 simultaneously. Our screening of 10 cortical subregions revealed that a Shank2/3 deletion within the retrosplenial area severely impairs social memory, a core symptom of ASD. Notably, DREADD-mediated neuronal activation could rescue the social impairment triggered by Shank2/3 depletion. Data indicate that the retrosplenial area has to be added to the list of defined brain regions that contribute to the spectrum of behavioural alterations seen in ASDs., publishedVersion

Phelan-McDermid syndrome (PMS) was initially called the 22q13 deletion syndrome based on its etiology as a deletion of the distal long arm of chromosome 22. These included terminal and interstitial deletions, as well as other structural rearrangements. Later, pathogenetic variants and deletions of the SHANK3 gene were found to result in a phenotype consistent with PMS. The association between SHANK3 and PMS led investigators to consider disruption/deletion of SHANK3 to be a prerequisite for diagnosing PMS. This narrow definition of PMS based on the involvement of SHANK3 has the adverse effect of causing patients with interstitial deletions of chromosome 22 to “lose” their diagnosis. It also results in underreporting of individuals with interstitial deletions of 22q13 that preserve SHANK3. To reduce the confusion for families, clinicians, researchers, and pharma, a simple classification for PMS has been devised. PMS and will be further classified as PMS-SHANK3 related or PMS-SHANK3 unrelated. PMS can still be used as a general term, but this classification system is inclusive. It allows researchers, regulatory agencies, and other stakeholders to define SHANK3 alterations or interstitial deletions not affecting the SHANK3 coding region.

We propose a nonparametric Bayesian approach for the estimation of the pricing kernel. Historical stock returns and option market data are combined through the Dirichlet Process (DP) to construct an option-adjusted physical measure. The precision parameter of the DP process is calibrated to the amount of trading activity in deep-out-of-the-money options. We use the option-adjusted physical measure to construct an option-adjusted pricing kernel. An empirical investigation on the S&P 500 Index from 2002 to 2015 shows that the option-adjusted pricing kernel is consistently monotonically decreasing, regardless of the level of volatility, thus providing an explanation to the well known U-shaped pricing kernel puzzle.

This paper provides a theoretical analysis on the impacts of using a suboptimal information set for the estimation of the pricing kernel and, more in general, for the validity of the fundamental th...

Recently, we reported oligoadenylate synthetase 1 (OAS1) contributed to the risk of Alzheimer’s disease, by its enrichment in transcriptional networks expressed by microglia. However, the function of OAS1 within microglia was not known. Using genotyping from 1313 individuals with sporadic Alzheimer’s disease and 1234 control individuals, we confirm the OAS1 variant, rs1131454, is associated with increased risk for Alzheimer’s disease. The same OAS1 locus has been recently associated with severe coronavirus disease 2019 (COVID-19) outcomes, linking risk for both diseases. The single nucleotide polymorphisms rs1131454(A) and rs4766676(T) are associated with Alzheimer’s disease, and rs10735079(A) and rs6489867(T) are associated with severe COVID-19, where the risk alleles are linked with decreased OAS1 expression. Analysing single-cell RNA-sequencing data of myeloid cells from Alzheimer’s disease and COVID-19 patients, we identify co-expression networks containing interferon (IFN)-responsive genes, including OAS1, which are significantly upregulated with age and both diseases. In human induced pluripotent stem cell-derived microglia with lowered OAS1 expression, we show exaggerated production of TNF-α with IFN-γ stimulation, indicating OAS1 is required to limit the pro-inflammatory response of myeloid cells. Collectively, our data support a link between genetic risk for Alzheimer’s disease and susceptibility to critical illness with COVID-19 centred on OAS1, a finding with potential implications for future treatments of Alzheimer’s disease and COVID-19, and development of biomarkers to track disease progression.

The development of new therapeutic avenues that target the early stages of Alzheimer's disease (AD) is urgently necessary. A disintegrin and metalloproteinase domain 10 (ADAM10) is a sheddase that is involved in dendritic spine shaping and limits the generation of amyloid-β. ADAM10 endocytosis increases in the hippocampus of AD patients, resulting in the decreased postsynaptic localization of the enzyme. To restore this altered pathway, we developed a cell-permeable peptide (PEP3) with a strong safety profile that is able to interfere with ADAM10 endocytosis, upregulating the postsynaptic localization and activity of ADAM10. After extensive validation, experiments in a relevant animal model clarified the optimal timing of the treatment window. PEP3 administration was effective for the rescue of cognitive defects in APP/PS1 mice only if administered at an early disease stage. Increased ADAM10 activity promoted synaptic plasticity, as revealed by changes in the molecular compositions of synapses and the spine morphology. Even though further studies are required to evaluate efficacy and safety issues of long-term administration of PEP3, these results provide preclinical evidence to support the therapeutic potential of PEP3 in AD.

Dravet Syndrome is a severe childhood pharmacoresistant epileptic disorder caused mainly by mutations in the SCN1A gene, which encodes for the α1 subunit of the type I voltage-gated sodium channel (NaV1.1), that cause imbalance between excitation and inhibition in the brain. We recently found that eEF2K knock out mice displayed enhanced GABAergic transmission and tonic inhibition and were less susceptible to epileptic seizures. In Scn1a+/- mice, a mouse model of the Dravet syndrome, we found that the activity of eEF2K/eEF2 pathway was enhanced. Then, we demonstrated that both genetic deletion and pharmacological inhibition of eEF2K were able to reduce the epileptic phenotype of Scn1a+/- mice. Interestingly we also found that motor coordination defect, memory impairments, and stereotyped behavior of the Scn1a+/- mice were reverted by eEF2K deletion. The analysis of spontaneous inhibitory postsynaptic currents (sIPSCs) suggested that the rescue of the pathological phenotype was driven by the potentiation of GABAergic synapses. Our data indicate that pharmacological inhibition of eEF2K could represent a novel therapeutic intervention for treating epilepsy and related comorbidities in the Dravet syndrome.

The advent of intra-nasal esketamine (ESK), one of the first so called fast-acting antidepressant, promises to revolutionize the management of treatment resistant depression (TRD). This NMDA receptor antagonist has proven to be rapidly effective in the short- and medium-term course of the illness, revealing its potential in targeting response in TRD. Although many TRD ESK responders are able to achieve remission, a considerable portion of them undergo a metamorphosis of their depression into different clinical presentations, characterized by instable responses and high recurrence rates that can be considered closer to the concept of Difficult to Treat Depression (DTD) than to TRD. The management of these DTD patients usually requires a further complex multidisciplinary approach and can benefit from the valuable contribution of new personalized medicine tools such as therapeutic drug monitoring and pharmacogenetics. Despite this, these patients usually come with long and complex previous treatments history and, often, advanced and sophisticated ongoing pharmacological schemes that can make the finding of new alternative options to face the current recurrences extremely challenging. In this paper, we describe two DTD patients—already receiving intranasal ESK but showing an instable course—who were clinically stabilized by the association with minocycline, a semisynthetic second-generation tetracycline with known and promising antidepressant properties.

Various neuroimaging approaches have reported alterations in brain connectivity in patients with autism spectrum disorder (ASD). Nevertheless, specific cellular and molecular mechanisms underlying these alterations remain to be elucidated. In the present Editorial, we highlight an article in the current issue of the Journal of Neurochemistry that provides first evidence for the structural and cellular basis of an atypical corpus callosum long-distance connectivity impairments observed in ASD patients. The authors used a juvenile valproic acid (VPA) rat model of ASD that presents with reduced myelin level, specifically in the corpus callosum, and with an altered myelin sheet structure that is closely associated with the behavioral alteration found in these rats. This hypomyelination occurs primarily during infancy prior to oligodendroglial alterations, implicating that axonal-oligodendroglial connections are compromised in this model. Concomitant with the hypomyelination, the ASD rat model showed an atypical brain metabolic pattern, with hypometabolic activity across the whole brain, and hypermetabolism in brain areas related to autistic-like behavior. These findings contribute to unravel the neurobiological basis underlying white matter alteration and altered long-distance brain connectivity as described in ASD, paving the way to the development of new early diagnostic markers and toward developing future specific therapies for ASD.

The forward‐looking nature of option market data allows one to derive economically based and model‐free risk measures. This article proposes an extensive analysis of the performances of option‐implied value at risk and conditional value at risk and compares them with classical risk measures for the S&P 500 index. Delivering good results both at short and long time horizons, the proposed option‐implied risk metrics emerge as a convenient alternative to the existing risk measures.

RNA analysis at the cellular resolution in the human brain is challenging. Here, we describe an optimised approach for detecting single RNA transcripts in a cell-type specific manner in frozen human brain tissue using multiplexed fluorescent RNAscope probes. We developed a new robust analytical approach for RNAscope quantification. Our method shows that low RNA integrity does not significantly affect RNAscope signal, recapitulates bulk RNA analysis and provides spatial context to transcriptomic analysis of human post-mortem brain at single-cell resolution. In summary, our optimised method allows the usage of frozen human samples from brain banks to perform quantitative RNAscope analysis. ispartof: SCIENTIFIC REPORTS vol:9 issue:1 ispartof: location:England status: published

Market efficiency and the pricing kernel are closely related. A non-monotonic decreasing pricing kernel implies the existence of a trading strategy in contingent claims that stochastically ...

Impairments in social relationships and awareness are features observed in autism spectrum disorders (ASDs). However, the underlying mechanisms remain poorly understood. Shank2 is a high���confidence ASD candidate gene and localizes primarily to postsynaptic densities (PSDs) of excitatory synapses in the central nervous system (CNS). We show here that loss of Shank2 in mice leads to a lack of social attachment and bonding behavior towards pubs independent of hormonal, cognitive, or sensitive deficits. Shank2���/��� mice display functional changes in nuclei of the social attachment circuit that were most prominent in the medial preoptic area (MPOA) of the hypothalamus. Selective enhancement of MPOA activity by DREADD technology re���established social bonding behavior in Shank2���/��� mice, providing evidence that the identified circuit might be crucial for explaining how social deficits in ASD can arise., publishedVersion

Human mutations and haploinsufficiency of the SHANK family genes are associated with autism spectrum disorders (ASD) and intellectual disability (ID). Complex phenotypes have been also described in all mouse models of Shank mutations and deletions, consistent with the heterogeneity of the human phenotypes. However, the specific role of Shank proteins in synapse and neuronal functions remain to be elucidated. Here, we generated a new mouse model to investigate how simultaneously deletion of Shank1 and Shank3 affects brain development and behavior in mice. Shank1–Shank3 DKO mice showed a low survival rate, a developmental strong reduction in the activation of intracellular signaling pathways involving Akt, S6, ERK1/2, and eEF2 during development and a severe behavioral impairments. Our study suggests that Shank1 and Shank3 proteins are essential to developmentally regulate the activation of Akt and correlated intracellular pathways crucial for mammalian postnatal brain development and synaptic plasticity. Therefore, Akt function might represent a new therapeutic target for enhancing cognitive abilities of syndromic ASD patients.

International audience; Shank3 monogenic mutations lead to autism spectrum disorders (ASD). Shank3 is part of the glutamate receptosome that physically links ionotropic NMDA receptors to metabotropic mGlu5 receptors through interactions with scaffolding proteins PSD95-GKAP-Shank3-Homer. A main physiological function of the glutamate receptosome is to control NMDA synaptic function that is required for plasticity induction. Intact glutamate receptosome supports glutamate receptors activation and plasticity induction, while glutamate receptosome disruption blocks receptors activity, preventing the induction of subsequent plasticity. Despite possible impact on metaplasticity and cognitive behaviors, scaffold interaction dynamics and their consequences are poorly defined. Here, we used mGlu5-Homer interaction as a biosensor of glutamate receptosome integrity to report changes in synapse availability for plasticity induction. Combining BRET imaging and electrophysiology, we show that a transient neuronal depolarization inducing NMDA-dependent plasticity disrupts glutamate receptosome in a long-lasting manner at synapses and activates signaling pathways required for the expression of the initiated neuronal plasticity, such as ERK and mTOR pathways. Glutamate receptosome disruption also decreases the NMDA/AMPA ratio, freezing the sensitivity of the synapse to subsequent changes of neuronal activity. These data show the importance of a fine-tuning of protein-protein interactions within glutamate receptosome, driven by changes of neuronal activity, to control plasticity. In a mouse model of ASD, a truncated mutant form of Shank3 prevents the integrity of the glutamate receptosome. These mice display altered plasticity, anxiety-like, and stereotyped behaviors. Interestingly, repairing the integrity of glutamate receptosome and its sensitivity to the neuronal activity rescued synaptic transmission, plasticity, and some behavioral traits of Shank3∆C mice. Altogether, our findings characterize mechanisms by which Shank3 mutations cause ASD and highlight scaffold dynamics as new therapeutic target.

Although complex inflammatory-like alterations are observed around the amyloid plaques of Alzheimer's disease (AD), little is known about the molecular changes and cellular interactions that characterize this response. We investigate here, in an AD mouse model, the transcriptional changes occurring in tissue domains in a 100-μm diameter around amyloid plaques using spatial transcriptomics. We demonstrate early alterations in a gene co-expression network enriched for myelin and oligodendrocyte genes (OLIGs), whereas a multicellular gene co-expression network of plaque-induced genes (PIGs) involving the complement system, oxidative stress, lysosomes, and inflammation is prominent in the later phase of the disease. We confirm the majority of the observed alterations at the cellular level using in situ sequencing on mouse and human brain sections. Genome-wide spatial transcriptomics analysis provides an unprecedented approach to untangle the dysregulated cellular network in the vicinity of pathogenic hallmarks of AD and other brain diseases. ispartof: CELL vol:182 issue:4 pages:976-+ ispartof: location:United States status: published

Calcineurin (CaN), acting downstream of intracellular calcium signals, orchestrates cellular remodeling in many cellular types. In astrocytes, major homeostatic players in the central nervous system (CNS), CaN is involved in neuroinflammation and gliosis, while its role in healthy CNS or in early neuro-pathogenesis is poorly understood. Here we report that in mice with conditional deletion of CaN in GFAP-expressing astrocytes (astroglial calcineurin KO, ACN-KO), at 1 month of age, transcription was largely unchanged, while the proteome was deranged in the hippocampus and cerebellum. Gene ontology analysis revealed overrepresentation of annotations related to myelin sheath, mitochondria, ribosome and cytoskeleton. Over-represented pathways were related to protein synthesis, oxidative phosphorylation, mTOR and neurological disorders, including Alzheimer's disease (AD) and seizure disorder. Comparison with published proteomic datasets showed significant overlap with the proteome of a familial AD mouse model and of human subjects with drug-resistant seizures. ACN-KO mice showed no alterations of motor activity, equilibrium, anxiety or depressive state. However, in Barnes maze ACN-KO mice learned the task but adopted serial search strategy. Strikingly, beginning from about 5 months of age ACN-KO mice developed spontaneous tonic-clonic seizures with an inflammatory signature of epileptic brains. Altogether, our data suggest that the deletion of astroglial CaN produces features of neurological disorders and predisposes mice to seizures. We suggest that calcineurin in astrocytes may serve as a novel Ca2+-sensitive switch which regulates protein expression and homeostasis in the central nervous system.

SummaryAdult hippocampal neurogenesis (AHN) plays a crucial role in memory processes and is impeded in the brains of Alzheimer’s disease (AD) patients. However, the molecular mechanisms impacting AHN in AD brain are unknown. Here we identify miR-132, one of the most consistently downregulated microRNAs in AD, as a novel mediator of the AHN deficits in AD. The effects of miR-132 are cell-autonomous and its overexpression is proneurogenic in the adult neurogenic niche in vivo and in human neural stem cells in vitro. miR-132 knockdown in wild-type mice mimics neurogenic deficits in AD mouse brain. Restoring miR-132 levels in mouse models of AD significantly restores AHN and relevant memory deficits. Our findings provide mechanistic insight into the hitherto elusive functional significance of AHN in AD and designate miR-132 replacement as a novel therapeutic strategy to rejuvenate the AD brain and thereby alleviate aspects of memory decline.

Approximately 30% of Major Depressive Disorder (MDD) patients develop treatment-resistant depression (TRD). Among the different causes that make TRD so challenging in both clinical and research contexts, major roles are played by the inadequate understanding of MDD pathophysiology and the limitations of current pharmacological treatments. Nevertheless, the field of psychiatry is facing exciting times. Combined with recent advances in genome editing techniques, human induced pluripotent stem cell (hiPSC) technology is offering novel and unique opportunities in both disease modelling and drug discovery. This technology has allowed innovative disease-relevant patient-specific in vitro models to be set up for many psychiatric disorders. Such models hold great potential in enhancing our understanding of MDD pathophysiology and overcoming many of the well-known practical limitations inherent to animal and post-mortem models. Moreover, the field is approaching the advent of (es)ketamine, a glutamate N-methyl-d-aspartate (NMDA) receptor antagonist, claimed as one of the first and exemplary agents with rapid (in hours) antidepressant effects, even in TRD patients. Although ketamine seems poised to transform the treatment of depression, its exact mechanisms of action are still unclear but greatly demanded, as the resulting knowledge may provide a model to understand the mechanisms behind rapid-acting antidepressants, which may lead to the discovery of novel compounds for the treatment of depression. After reviewing insights into ketamine’s mechanisms of action (derived from preclinical animal studies) and depicting the current state of the art of hiPSC technology below, we will consider the implementation of an hiPSC technology-based TRD model for the study of ketamine’s fast acting antidepressant mechanisms of action.

Is it possible to achieve almost riskless, nonfluctuating investment payoffs in the long run, at a fraction of the traditional funding requirement, using equity investments? The persistence of low interest rates is spurring research on this question because of the need to increase yields, while limiting the variability of investment results. Payouts of savings account units aim to achieve an almost riskless outcome over a long horizon. We show that they can be managed as contingent claims and, when denominated in units of a stock index, less expensively than under classical risk-neutral assumptions. To assess the robustness of the proposed hedge portfolios, we introduce a simple overfunded scheme and show its reliability using bootstrapping. The results show that by applying an overfunding of 6%, the probability of not achieving the target is less than 1%. At the heart of this result are the mean-reversion and the leverage effect of the minimal market model, together with the supermartingale property of the benchmarked savings account.

We forecast monthly Value at Risk (VaR) and Conditional Value at Risk (CVaR) using option market data and four different econometric techniques. Independently from the econometric approach used, all models produce quick to estimate forward-looking risk measures that do not depend from the amount of historical data used and that, through the implied moments of options, better reflect the ever-changing market scenario. All proposed option-based approaches outperform or are equally good to different “traditional” forecasts that use historical returns as input. The extensive robustness of our results shows that the real driver of the better forecasts is the use of option market data as inputs for the analysis, more than the type of econometric approach implemented.

Summary Single-nucleus RNA sequencing (snRNA-seq) is used as an alternative to single-cell RNA-seq, as it allows transcriptomic profiling of frozen tissue. However, it is unclear whether snRNA-seq is able to detect cellular state in human tissue. Indeed, snRNA-seq analyses of human brain samples have failed to detect a consistent microglial activation signature in Alzheimer’s disease. Our comparison of microglia from single cells and single nuclei of four human subjects reveals that, although most genes show similar relative abundances in cells and nuclei, a small population of genes (∼1%) is depleted in nuclei compared to whole cells. This population is enriched for genes previously implicated in microglial activation, including APOE, CST3, SPP1, and CD74, comprising 18% of previously identified microglial-disease-associated genes. Given the low sensitivity of snRNA-seq to detect many activation genes, we conclude that snRNA-seq is not suited for detecting cellular activation in microglia in human disease., Graphical Abstract, Highlights • A small set of genes is depleted in microglial nuclei relative to single cells • This set is enriched for microglial activation genes, including APOE and SPP1 • This depletion is confirmed in publicly available datasets • Single-nucleus sequencing is not suited for the detection of human microglial activation, Thrupp et al. demonstrate the depletion of a small population of genes in nuclei relative to cells in human microglia by using single-nucleus and single-cell sequencing. This population is enriched for microglial activation genes, suggesting that single-nucleus sequencing is not suited for the detection of microglial activation in humans.

We propose option-implied measures of conditional asymmetry based upon quantiles and expectiles inferred from weekly options. All quantities are by construction forward looking and estimated non-parametrically through a novel arbitrage-free natural smoothing spline technique that produces quick to estimate volatility smiles. We find that option implied asymmetry indicators exhibit short, medium and long-term predictive ability for the U.S. equity risk premium and market volatility, both in- and out-of-sample, and outperform equal indicators inferred from historical returns.

We here investigated the effects of overexpressed superoxide dismutase (SOD)1 and amyotrophic lateral sclerosis (ALS)-linked SOD1 mutants G93A and G147S in Neuro 2A (N2A) cell lines, and found a three-fold increase in lamellipodia either in cells cultured under differentiated or undifferentiated growth conditions. In undifferentiated N2A cells, SOD1 constructs promoted lamellipodial protrusions to similar extent as the overexpression of Rac1, and SOD1-mediated lamellipodia were prevented by coexpression of the N17 dominant-negative form of Rac1, or shRNA for a downstream effector of Rac1, the insulin receptor tyrosine kinase substrate p53 (IRSp53) or its binding partner LIN7. Moreover, no additive effect was measured by coexpression of the SOD1 constructs with Rac1, IRSp53 or LIN7. Collectively these data support a role for SOD1 in the regulation of Rac1-mediated lamellipodia pathway, a property fully retained by the two SOD1 mutants.

The term “Shankopathies” identifies neurodevelopmental diseases, such as autism Spectrum Disorders (ASD), Intellectual Disability (ID), and schizophrenia (SCZ) caused by deletion or mutations of SHANK/ProSAP genes. The three SHANK genes code for a postsynaptic scaffold protein which has a main function of regulating synaptic formation, development and plasticity. The review summarizes the major genetic, molecular and electrophysiological studies that provide new information about the function of Shanks proteins and are prodromic in identifying therapeutic approaches, pharmacological targets for treating patients with SHANK deletions and mutations and eventually for other patients affected by neuropsychiatric and neurodevelopmental disorders.

Frontotemporal Dementia (FTD) is a neurodegenerative disorder mainly characterised by Tau or TDP43 inclusions. A co-autoimmune aetiology has been hypothesised. In this study, we aimed at defining the pathogenetic role of anti-AMPA GluA3 antibodies in FTD. Serum and cerebrospinal fluid (CSF) anti-GluA3 antibody dosage was carried out and the effect of CSF with and without anti-GluA3 antibodies was tested in rat hippocampal neuronal primary cultures and in differentiated neurons from human induced pluripotent stem cells (hiPSCs). TDP43 and Tau expression in hiPSCs exposed to CSF was assayed. Forty-one out of 175 screened FTD sera were positive for the presence of anti-GluA3 antibodies (23.4%). FTD patients with anti-GluA3 antibodies more often presented presenile onset, behavioural variant FTD with bitemporal atrophy. Incubation of rat hippocampal neuronal primary cultures with CSF with anti-GluA3 antibodies led to a decrease of GluA3 subunit synaptic localization of the AMPA receptor (AMPAR) and loss of dendritic spines. These results were confirmed in differentiated neurons from hiPSCs, with a significant reduction of the GluA3 subunit in the postsynaptic fraction along with increased levels of neuronal Tau. In conclusion, autoimmune mechanism might represent a new potentially treatable target in FTD and might open new lights in the disease underpinnings.

SummaryThe linear cause-consequence relationship linking amyloid-β peptide (Aβ) accumulation to neuronal dysfunction in Alzheimer disease (AD) is gradually replaced by the concept that Aβ initiates complex inflammatory-like cellular alterations that progressively become Aβ independent and lead to brain dyshomeostasis. Little is known about the pathophysiology of this cellular phase of AD. We use here two orthogonal technologies, Spatial Transcriptomics and in situ sequencing, to analyse the transcriptome changes in cells in the amyloid-β plaque niche in a knock-in mouse model for AD. We identify a multicellular co-expressed gene network of 57 Plaque-Induced Genes (PIGs) that define a series of co-ordinated and spatially restricted microglia, astroglia and oligodendrocyte responses to progressing amyloid plaques encompassing complement, oxidative stress and inflammation. A separate oligodendrocyte network suggests abnormal myelination. Spatial Transcriptomics provides an unprecedented approach to untangle the dysregulated cellular network in the vicinity of pathogenic hallmarks of AD and other brain diseases.

Hybrid interfaces between living cells and nano/microstructured scaffolds have huge application potential in biotechnology, spanning from regenerative medicine and stem cell therapies to localized drug delivery and from biosensing and tissue engineering to neural computing. However, 3D architectures based on semiconducting polymers, endowed with responsivity to visible light, have never been considered. Here, we apply for the first time a push-coating technique to realize high aspect ratio polymeric pillars, based on polythiophene, showing optimal biocompatibility and allowing for the realization of soft, 3D cell cultures of both primary neurons and cell line models. HEK-293 cells cultured on top of polymer pillars display a remarkable change in the cell morphology and a sizable enhancement of the membrane capacitance due to the cell membrane thinning in correspondence to the pillars' top surface, without negatively affecting cell proliferation. Electrophysiology properties and synapse number of primary neurons are also very well preserved. In perspective, high aspect ratio semiconducting polymer pillars may find interesting applications as soft, photoactive elements for cell activity sensing and modulation. Hybrid interfaces between living cells and nano/microstructured scaffolds have huge application potential in biotechnology, spanning from regenerative medicine and stem cell therapies to localized drug delivery and from biosensing and tissue engineering to neural computing. However, 3D architectures based on semiconducting polymers, endowed with responsivity to visible light, have never been considered. Here, we apply for the first time a push-coating technique to realize high aspect ratio polymeric pillars, based on polythiophene, showing optimal biocompatibility and allowing for the realization of soft, 3D cell cultures of both primary neurons and cell line models. HEK-293 cells cultured on top of polymer pillars display a remarkable change in the cell morphology and a sizable enhancement of the membrane capacitance due to the cell membrane thinning in correspondence to the pillars' top surface, without negatively affecting cell proliferation. Electrophysiology properties and synapse number of primary neurons are also very well preserved. In perspective, high aspect ratio semiconducting polymer pillars may find interesting applications as soft, photoactive elements for cell activity sensing and modulation.

© 2019 Elsevier Inc. Synapses are fundamental information-processing units of the brain, and synaptic dysregulation is central to many brain disorders (“synaptopathies”). However, systematic annotation of synaptic genes and ontology of synaptic processes are currently lacking. We established SynGO, an interactive knowledge base that accumulates available research about synapse biology using Gene Ontology (GO) annotations to novel ontology terms: 87 synaptic locations and 179 synaptic processes. SynGO annotations are exclusively based on published, expert-curated evidence. Using 2,922 annotations for 1,112 genes, we show that synaptic genes are exceptionally well conserved and less tolerant to mutations than other genes. Many SynGO terms are significantly overrepresented among gene variations associated with intelligence, educational attainment, ADHD, autism, and bipolar disorder and among de novo variants associated with neurodevelopmental disorders, including schizophrenia. SynGO is a public, universal reference for synapse research and an online analysis platform for interpretation of large-scale -omics data (https://syngoportal.org and http://geneontology.org). The SynGO consortium presents a framework to annotate synaptic protein locations and functions and annotations for 1,112 synaptic genes based on published experimental evidence. SynGO reports exceptional features and disease associations for synaptic genes and provides an online data analysis platform.