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Coppola, G.

Publications and source records attributed to Coppola, G..

At least 19 recordsLinked to original sources

Built-in integrated living electronics: from biosynthesis tomodulation of neuronal function

Neuroelectronic interfaces hold great promise to restore functions in neurological disorders or motor dysfunctions, but current devices struggle to integrate seamlessly within living tissues. Here we report a transformative approach to create bionic neurons that autonomously build integrated fluorescent fibrils and demonstrate their role as neuromodulators. Using a combination of cell biology, ultrastructural, imaging and nanospectroscopical approaches, we deciphered the unique biosynthetic pathway employed by the cells to self-fabricate these nanoelectronics and uncover their hybrid structure. Importantly, patch clamp recordings revealed their neuromodulatory potential, through the perturbation of membrane electrical properties and the early rising phase of the action potential. Deciphering how basic molecular elements self-organize into complex architectures within biological environments could unlock the ability to engineer natural electroactive systems directly inside living organisms. This capability could be used to create conductive pathways between arbitrarily defined neurons, microcircuits, or nervous system regions, effectively writing connections into living brains.

synthetic biology↗

Optogenetic stimulation of nigral astrocytes is neuroprotective in a 6-OHDA model of neurodegeneration.

HighlightsO_LIOptogenetic stimulation of nigral astrocytes attenuates motor deficits & Th+ cell loss in a 6-OHDA model of neurodegeneration C_LIO_LIBulk RNA-seq analysis reveals optogenetic stimulation of nigral astrocytes induces early changes in microglia C_LIO_LIsnRNA-seq shows 6-OHDA alone induces extensive gene expression changes across all cell populations within the SN C_LIO_LIOligodendrocytes within the SNc express Th, which is upregulated with DA neuron loss C_LI Parkinsons disease is characterized by the loss of dopaminergic neurons in the substantia nigra. Glial-glial crosstalk is essential for maintaining the regional milieu, and appears to be particularly important in modulating neuroinflammation and many aspects of neurodegeneration. In particular, astrocytes are critical for maintaining dopamine neuronal integrity and survival, and astroglial dysfunction is prominent in Parkinsons disease. As such, astrocytes represent a potentially critical therapeutic target in neurodegeneration. In this study, in vivo optogenetics were used to selectively stimulate astrocytes in the substantia nigra following a striatal 6-OHDA lesion. Remarkably, a single bout of optogenetic stimulation was sufficient to attenuate motor deficits and dopamine neuron loss induced by the neurotoxin. Furthermore, bulk RNA-seq and snRNA-seq analysis of the substantia nigra revealed extensive changes in both microglia and oligodendrocytes, suggesting that the neuroprotective effects of stimulating astrocytes may be mediated through alterations in glia-glia crosstalk. Altogether, this work demonstrates the importance of understanding glia-glia interactions in neurodegeneration.

neuroscience↗

Genetic, transcriptomic, histological, and biochemical analysis of progressive supranuclear palsy implicates glial activation and novel risk genes

Progressive supranuclear palsy (PSP) is a rare Parkinsonian disorder characterized by problems with movement, balance, cognition, and other symptoms. PSP differs from Alzheimers disease (AD) and other neurodegenerative diseases displaying abnormal forms of the microtubule-associated protein tau ("tauopathies") by the presence of pathology not only in neurons, but also in astrocytes and oligodendrocytes. Genetic contributors may mediate these differences, however much of PSP genetics remains unexplained. Here we conducted the largest genome-wide association study (GWAS) of PSP to date including 2,779 cases (2,595 neuropathologically-confirmed) and 5,584 controls and identified six independent PSP susceptibility loci with genome-wide significant (p < 5x10-8) associations including five known (MAPT, MOBP, STX6, RUNX2, SLCO1A2) and one novel locus (C4A). Integration with cell type-specific epigenomic annotations revealed a unique oligodendrocytic signature that distinguishes PSP from AD and Parkinsons disease. Candidate PSP risk gene prioritization using expression quantitative trait loci (eQTLs) identified oligodendrocyte-specific effects on gene expression in half of the genome-wide significant loci, as well as an association with elevated C4A expression in bulk brain tissue which may be driven by increased C4A copy number in PSP cases. Finally, histological studies demonstrated abnormal tau aggregates in oligodendrocytes that colocalize with C4 (complement) deposition. Integrating GWAS with functional studies including epigenomic and eQTL analyses, we identified potential causal roles for variation in MOBP, STX6, RUNX2, SLCO1A2, and C4A in the pathogenesis of PSP.

neuroscience↗

Aging Differentially Alters the Transcriptome and Landscape of Chromatin Accessibility in the Male and Female Mouse Hippocampus

Aging-related memory impairment and pathological memory disorders such as Alzheimers disease differ between males and females, and yet little is known about how aging-related changes in the transcriptome and chromatin environment differ between sexes in the hippocampus. To investigate this question, we compared the chromatin accessibility landscape and gene expression/alternative splicing pattern of young adult and aged mouse hippocampus in both males and females using ATAC-seq and RNA-seq. We detected significant aging-dependent changes in the expression of genes involved in immune response and synaptic function, and aging-dependent changes in the alternative splicing of myelin sheath genes. We found significant sex-bias in the expression and alternative splicing of hundreds of genes, including aging-dependent female-biased expression of myelin sheath genes and aging-dependent male-biased expression of genes involved in synaptic function. Aging was associated with increased chromatin accessibility in both male and female hippocampus, especially in repetitive elements, and with an increase in LINE-1 transcription. We detected significant sex-bias in chromatin accessibility in both autosomes and the X chromosome, with male-biased accessibility enriched at promoters and CpG-rich regions. Sex differences in gene expression and chromatin accessibility were amplified with aging, findings that may shed light on sex differences in aging-related and pathological memory loss. HighlightsO_LIAging amplifies sex differences in the transcriptome and chromatin accessibility of mouse hippocampus C_LIO_LIAging is associated with widespread changes in the transcriptome of mouse hippocampus, including in genes involved in immune response and synaptic function C_LIO_LIMyelin sheath-related genes in aged hippocampus show female-biased expression C_LIO_LIAlternative splicing of myelin sheath-related genes changes with aging in the hippocampus C_LIO_LISex-bias is evident in alternative splicing of nuclear and primary cilia genes C_LIO_LIAging in the hippocampus is associated with increased chromatin accessibility in both males and females C_LIO_LILINE-1 derived sequences are more accessible and LINE-1 transcripts are upregulated in the aged hippocampus of both males and females C_LIO_LIPromoter and CpG-rich regions show male-biased accessibility C_LI

neuroscience↗

Astroglial Hmgb1 regulates postnatal astrocyte morphogenesis and cerebrovascular maturation.

Astrocytes are intimately linked with brain vessels, a relationship that is critical for neuronal health and function. However, astroglial factors driving these physical and functional associations during postnatal brain development have yet to be identified. We characterized structural and transcriptional changes in mouse cortical astrocytes and microvessels during the first two postnatal weeks and found that high-mobility group box 1 (Hmgb1), normally upregulated with injury and involved in adult cerebrovascular repair, was highly expressed in astrocytes at birth and then decreased rapidly. Astrocyte-selective ablation of Hmgb1 at birth affected astrocyte morphology and endfoot placement, altered distribution of endfoot proteins connexin43 and aquaporin-4, induced transcriptional changes in astrocytes related to cytoskeleton remodeling, and profoundly disrupted endothelial ultrastructure. While lack of astroglial Hmgb1 did not affect the blood-brain barrier or angiogenesis postnatally, it impaired neurovascular coupling and behavior in adult mice. These findings identify astroglial Hmgb1 as a key player in postnatal gliovascular maturation.

developmental biology↗

Precision localization of cellular proteins with fluorescent Fab-based probes

Currently, a major technical limitation of microscopy based image analysis is linkage error - a visualization error that is measured by the distance between the cellular protein to be detected and the fluorescence emitter used for detection. With continuously improving resolution of todays (super-resolution) microscopes, the linkage errors can severely hamper the correct interpretation of images and is usually introduced in experiments by the use of standard intracellular staining reagents such as fluorescently labelled antibodies. The linkage error of standard labelled antibodies is caused by the size of the antibody and the random distribution of fluorescent emitters on the antibody surface. Together, these two factors account for a fluorescence displacement of ~40nm when staining proteins by indirect immunofluorescence; and ~20nm when staining with fluorescently coupled primary antibodies. In this study, we describe a class of staining reagents that effectively reduce the linkage error by more than five-fold when compared to conventional staining techniques. These reagents, called Fluo-N-Fabs, consist of an antigen binding fragment of a full-length antibody (Fab/ fragment antigen binding) that is selectively conjugated at the N-terminal amino group with fluorescent organic molecules, thereby reducing the distance between the fluorescent emitter and the protein target of the analysis. Fluo-N-Fabs also exhibit the capability to penetrate tissues and highly crowded cell compartments, thus allowing for the efficient detection of cellular epitopes of interest in a wide range of fixed samples. We believe this class of reagents realize an unmet need in cell biological super resolution imaging studies where the precise localization of the target of interest is crucial for the understanding of complex biological phenomena.

cell biology↗

Generation of a molecular interactome of the glioblastoma perivascular niche reveals Integrin Binding Sialoprotein as a key mediator of tumor cell migration

Glioblastoma (GBM) is characterized by extensive microvascular hyperproliferation. In addition to supplying blood to the tumor, GBM vessels also provide trophic support to glioma cells and serve as conduits for migration into the surrounding brain promoting recurrence. Here, we enriched CD31-expressing glioma vascular cells (GVC) and A2B5-expressing glioma tumor cells (GTC) from primary GBM and utilized RNA sequencing to create a comprehensive interaction map of the secreted and extracellular factors elaborated by GVC that can interact with receptors and membrane molecules on GTC. To validate our findings, we utilized functional assays, including a novel hydrogel-based migration assay and in vivo mouse models to demonstrate that one identified factor, the little-studied integrin binding sialoprotein (IBSP) enhances tumor growth and promotes the migration of GTC along the vasculature. This perivascular niche interactome will serve a resource to the research community in defining the potential functions of the GBM vasculature.

cancer biology↗

Tau interactome mapping reveals dynamic processes in synapses and mitochondria associated with neurodegenerative disease

Tau (MAPT) drives neuronal dysfunction in Alzheimers disease (AD) and other tauopathies. To dissect the underlying mechanisms, we combined an engineered ascorbic acid peroxidase (APEX) approach with quantitative affinity purification mass spectrometry (AP-MS) followed by proximity ligation assay (PLA) to characterize Tau interactomes modified by neuronal activity and mutations that cause frontotemporal dementia (FTD) in human induced pluripotent stem cell (iPSC)-derived neurons. We established activity-dependent interactions of Tau with presynaptic vesicle proteins during Tau secretion and mapped the exact APEX-tau-induced biotinylated tyrosines to the cytosolic domains of the interacting vesicular proteins. We showed that FTD mutations impair bioenergetics and markedly diminished Taus interaction with mitochondria proteins, which were downregulated in AD brains of multiple cohorts and correlated with disease severity. These multi-modal and dynamic Tau interactomes with unprecedented spatiotemporal resolution shed novel insights into Taus role in neuronal function and disease-related processes with potential therapeutic targets to block Tau-mediated pathogenesis.

neuroscience↗

Functional regulatory variants implicate distinct transcriptional networks in dementia

Predicting functionality of noncoding variation is one of the major challenges in modern genetics. We employed massively parallel reporter assays to screen 5,706 variants from genome-wide association studies for both Alzheimers disease (AD) and Progressive Supranuclear Palsy (PSP). We identified 320 functional regulatory polymorphisms (SigVars) comprising 27 of 34 unique tested loci, including multiple independent signals across the complex 17q21.31 region. We identify novel risk genes including PLEKHM1 in PSP and APOC1 in AD, and perform gene-editing to validate four distinct causal loci, confirming complement 4 (C4A) as a novel genetic risk factor for AD. Moreover, functional variants preferentially disrupt transcription factor binding sites that converge on enhancers with differential cell-type specific activity in PSP and AD, implicating a neuronal SP1-driven regulatory network in PSP pathogenesis. These analyses support a novel mechanism underlying noncoding genetic risk, whereby common genetic variants drive disease risk via their aggregate activity on specific transcriptional programs. One Sentence SummaryHigh-throughput functional analysis of GWAS loci reveals cell-type specific regulatory networks that mediate genetic risk for dementia.

genetics↗

Molecular and functional properties of PFC astrocytes during neuroinflammation-induced anhedonia

Astrocytes are widely implicated in CNS diseases, but their contributions to disease related phenotypes remain incompletely explored. Anhedonia accompanies several neurological and psychiatric diseases, including major depressive disorder (MDD) and Alzheimers disease (AD), both of which are associated with neuroinflammation. In order to explore how neuroinflammation affects astrocytes, we assessed medial prefrontal cortex (PFC) and visual cortex (VCX) astrocytic gene expression using a neuroinflammation mouse model that displayed anhedonia as a phenotype. In this model, anhedonia was reversed by the fast acting antidepressant ketamine. Astrocyte specific gene expression alterations included those related to immune cell signaling, intracellular Ca2+ signaling, cholesterol biosynthesis, and metabolic pathways. Such changes peaked when anhedonia was greatest, and reversed to normal when anhedonia subsided. However, region-specific molecular identities between PFC and VCX astrocytes were maintained throughout, implying that astrocyte identities do not converge during neuroinflammation. We also mapped anhedonia-related astrocyte and bulk tissue gene expression changes onto published PFC single cell RNA sequencing data, and compared them to MDD and AD post-mortem human tissue samples to identify shared mechanisms. Finally, we assessed how neuroinflammation affected mPFC neuronal properties and detected no alterations at a time point when there was strong astrocyte reactivity. Our data show that neuroinflammation can cause significant and reversible changes in astrocyte gene expression and mouse behaviour without obvious neurotoxicity or loss of essential homeostatic functions. Furthermore, gene expression signatures accompanying neuroinflammation reveal pathways shared with MDD and AD, which display neuroinflammation as a comorbidity in humans. Significance statementAstrocytes are widely implicated in brain diseases, but their contributions to disease-related phenotypes remain incompletely explored. To make inroads into this problem, we assessed medial prefrontal cortex (PFC) and visual cortex (VCX) astrocyte gene expression using a peripherally induced neuroinflammation mouse model that produced anhedonia - a phenotype associated with several brain disorders. Neuroinflammation caused reversible changes in mouse behaviour and astrocyte-specific gene expression changes, some of which were related to human post mortem data for major depressive disorder (MDD) and Alzheimers disease (AD), but without any clear evidence of neurotoxicity in PFC of mice. The astrocyte molecular alterations accompanying neuroinflammation-induced anhedonia will be informative to explore diverse brain disorders and the effects of neuroinflammation on the CNS more broadly.

neuroscience↗

PTBP1 Regulates Injury Responses and Sensory Pathways in Adult Peripheral Neurons

Polypyrimidine Tract Binding Protein 1 (PTBP1) is expressed only at embryonic stages in central neurons. Its downregulation triggers neuronal differentiation in precursor and non-neuronal cells, an approach recently used to generate neurons de novo for amelioration of neurodegenerative disorders. Moreover, PTBP1 is replaced by its paralog PTBP2 in mature central neurons. Surprisingly, we found both proteins co-expressed in adult sensory and motor neurons, with PTBP2 restricted mainly to the nucleus, while PTBP1 shows strong axonal localization. Levels of axonal PTBP1 increased markedly after peripheral nerve injury, and its cargos include mRNAs involved in axonal growth and regeneration, such as importin {beta}1 and RhoA. Perturbation of PTBP1 affects neuronal injury responses, axon outgrowth and sensation in vivo. Thus, PTBP1 has roles in sensory function and regenerative capacity of adult sensory neurons. These findings suggest that caution may be required before considering targeting PTBP1 for therapeutic purposes.

neuroscience↗

Epigenetic clock and methylation studies in vervet monkeys

DNA methylation-based biomarkers of aging have been developed for many mammals but not yet for the vervet monkey (Chlorocebus sabaeus), which is a valuable non-human primate model for biomedical studies. We generated novel DNA methylation data from vervet cerebral cortex, blood, and liver using highly conserved mammalian CpGs represented on a custom array (HorvathMammalMethylChip40). We present six DNA methylation-based estimators of age: vervet multi-tissue epigenetic clock and tissue-specific clocks for brain cortex, blood, and liver. In addition, two dual species clocks (human-vervet clocks) for measuring chronological age and relative age, respectively. Relative age was defined as ratio of chronological age to maximum lifespan to address the species differences in maximum lifespan. The high accuracy of the human-vervet clocks demonstrates that epigenetic aging processes are evolutionary conserved in primates. When applying these vervet clocks to tissue samples from another primate species, rhesus macaque, we observed high age correlations but strong offsets. We characterized CpGs that correlate significantly with age in the vervet. CpG probes hypermethylated with age across tissues were located near the targets of Polycomb proteins SUZ12 and EED, and genes possessing the trimethylated H3K27 mark in their promoters. The epigenetic clocks are expected to be useful for age estimation of wild-born animals and anti-aging studies in vervets.

developmental biology↗

AD-linked R47H-TREM2 mutation induces disease-enhancing proinflammatory microglial states in mice and humans

The hemizygous R47H variant of TREM2, a microglia-specific gene in the brain, increases risk for late-onset Alzheimers disease (AD). In this study, we identified a subpopulation of microglia with disease-enhancing proinflammatory signatures associated with the R47H mutation in human AD brains and tauopathy mouse brains. Using transcriptomic analysis at the single-nuclei level from AD patients with the R47H or the common variant (CV)-TREM2 with matched sex, pathology and APOE status, we found that the R47H mutation was associated with cell type- and sex-specific transcriptional changes in human AD brains, with microglia exhibiting the most robust alterations. Further characterization revealed that R47H-associated microglial subpopulations had enhanced inflammatory signatures including hyperactivation of Akt, one of the signaling pathways downstream of TREM2. In a newly-generated tauopathy knock-in mouse model expressing one allele of human TREM2 (hTREM2) with either the R47H mutation or CV, R47H induced and exacerbated tau-mediated spatial memory deficits in female mice. Single-cell transcriptomic analysis of microglia from these mice also revealed transcriptomic changes induced by R47H that had significant overlaps with R47H microglia in human AD brains, including robust increases in proinflammatory cytokines, activation of Syk-Akt-signaling, and elevation of a subset of disease-associated microglial signatures. Strikingly, pharmacological Akt inhibition largely reversed the enhanced inflammatory signatures induced by R47H in primary microglia treated with tau fibrils. By unraveling the disease-enhancing properties of the R47H mutation in mouse and human, our findings shed light on an immune-linked AD subtype and provide new directions for modulating microglial immune responses to treat AD.

neuroscience↗

Establishment of a Human Induced Pluripotent Stem Cell-Derived Neuromuscular Co-Culture Under Optogenetic Control

The failure of the neuromuscular junction (NMJ) is a key component of degenerative neuromuscular disease, yet how NMJs degenerate in disease is unclear. Human induced pluripotent stem cells (hiPSCs) offer the ability to model disease via differentiation toward affected cell types, however, the re-creation of an in vitro neuromuscular system has proven challenging. Here we present a scalable, all-hiPSC-derived co-culture system composed of independently derived spinal motor neurons (MNs) and skeletal myotubes (sKM). In a model of C9orf72-associated disease, co-cultures form functional NMJs that can be manipulated through optical stimulation, eliciting muscle contraction and measurable calcium flux in innervated sKM. Furthermore, co-cultures grown on multi-electrode arrays (MEAs) permit the pharmacological interrogation of neuromuscular physiology. Utilization of this co-culture model as a tunable, patient-derived system may offer significant insights into NMJ formation, maturation, repair, or pathogenic mechanisms that underlie NMJ dysfunction in disease.

neuroscience↗

Systems analysis of blood transcriptomes in dementia patients reveals an innate immune response shared across disorders

The role of peripheral inflammation in dementia is an important but complex topic. We present here the largest cohort of peripheral blood gene expression data ever assembled from patients with dementia and matching controls. Importantly, this cohort includes individuals from a diverse set of dementia disorders, including Alzheimers Disease (AD), mild cognitive impairment (MCI), and multiple disorders within the frontotemporal dementia (FTD) spectrum. We found strong transcriptional evidence of an innate immune inflammatory response, mediated by monocytes and neutrophils, in AD, MCI, and two FTD subtypes, PSP and nfvPPA. This transcriptional inflammatory response is enriched for genetic risk for AD, in part because it is also enriched for microglial genes, which have previously been implicated in AD risk. Finally, we show that this transcriptional response is strongly enriched for binding of the transcription factors PU.1 and RELA, which have previously been linked to AD risk and progression.

bioinformatics↗

The burden of deleterious variants in a non-human primate biomedical model

Genome sequencing studies of nonhuman primate (NHP) pedigree and population samples are discovering variants on a large and rapidly growing scale. These studies are increasing the utility of several NHP species as model systems for human disease. In particular, by identifying homozygous protein truncating variants (hPTVs) in genes hypothesized to play a role in causing human diseases, it may be possible to elucidate mechanisms for the phenotypic impact of such variants through investigations that are infeasible in humans. The Caribbean vervet (Chlorocebus aethiops sabaeus) is uniquely valuable for this purpose, as the dramatic expansion of its population following severe bottlenecks has enabled PTVs that passed through the bottleneck to attain a relatively high frequency. Using whole genome sequence (WGS) data from 719 monkeys of the Vervet Research Colony (VRC) extended pedigree, we found 2,802 protein-truncating alleles in 1,747 protein-coding genes present in homozygous state in at least one monkey. Polymorphic sites for 923 SNV hPTVs were also observed in natural Caribbean populations from which the VRC descends. The vervet genome browser (VGB) includes information on these PTVs, together with a catalog of phenotypes and biological samples available for monkeys who carry them. We describe initial explorations of the possible impact of vervet PTVs on early infant mortality.

genetics↗

DYNLRB1 is Essential for Dynein Mediated Transport and Neuronal Survival

The cytoplasmic dynein motor complex transports essential signals and organelles from the cell periphery to perinuclear region, hence is critical for the survival and function of highly polarized cells such as neurons. Dynein Light Chain Roadblock-Type 1 (DYNLRB1) is thought to be an accessory subunit required for specific cargos, but here we show that it is essential for general dynein-mediated transport and sensory neuron survival. Homozygous Dynlrb1 null mice are not viable and die during early embryonic development. Furthermore, heterozygous or adult knockdown animals display reduced neuronal growth, and selective depletion of Dynlrb1 in proprioceptive neurons compromises their survival. Conditional depletion of Dynlrb1 in sensory neurons causes deficits in several signaling pathways, including {beta}-catenin subcellular localization, and a severe impairment in the axonal transport of both lysosomes and retrograde signaling endosomes. Hence, DYNLRB1 is an essential component of the dynein complex.

neuroscience↗

Translatomic database of cortical astroglia across male and female mouse development reveals two distinct developmental phenotypes

Astroglial cells are emerging as key players in the development and homeostatic maintenance of neurons and neuronal networks. Astroglial cell functions are critical to neuronal migration and maturation, myelination, and synapse dynamics, however little is known about astroglial phenotypic changes over development. Furthermore, astroglial cells express steroid hormone receptors and show rapid responses to hormonal manipulations, however, despite important sex differences in telencephalic regions such as the cortex and hippocampus few studies have examined sex differences in astroglial cells in development and outside of the hypothalamus and amygdala. To phenotype cortical astroglial cells across postnatal development while considering potential sex differences, we used translating ribosome affinity purification together with RNA sequencing (TRAPseq) and immunohistochemistry to phenotype the entire astroglial translatome in males and females at key developmental time points: P1, P4, P7, P14, P35 and in adulthood. Overall, we found two distinct astroglial phenotypes between early (P1-P7) and late development (P14-Adult). We also noted that although astroglia show few basal sex differences in adulthood, they show significant sex differences in developmental gene expression patterns, with peak sex differences observed at P7. At least part of the sex differences observed at P7 appear to be due to males reaching a more mature astroglial phenotype earlier than females. Together, these data clearly delineate and phenotype astroglia across development and identify sex differences in astroglial developmental programs. Importantly, these developmental sex differences could have an impact on the construction and maintenance of neuronal networks and potential developmental windows of vulnerability to neurologic and psychiatric disease.

neuroscience↗