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Cheroni, C.

Publications and source records attributed to Cheroni, C..

13 recordsLinked to original sources

COG5-mediated Golgi organization coordinates neural progenitor fate during human brain development

Apical radial glial cells (aRGs) are highly polarized epithelial cells that drive human cortical development through tightly regulated lineage progression. A distinctive feature of aRGs is their non-canonical Golgi organization, raising the possibility that specialized intracellular trafficking and secretory processes contribute to progenitor behaviour. However, how Golgi architecture contributes to human corticogenesis remains poorly understood. Here, we investigate this question in the context of COG5 deficiency, a rare congenital disorder of glycosylation associated with neurodevelopmental defects, using patient-derived fibroblasts and brain organoids, N-glycomics, glycolipidomics, and single-cell transcriptomics. We show that COG5 deficiency disrupts Golgi organization and impairs Golgi-to-ER retrograde trafficking. At the neurodevelopmental level, COG5-deficient organoids display altered ventricular organization and reduced basal progenitor abundance. Single-cell transcriptomic analysis reveals rewired developmental trajectories characterized by premature differentiation from apical progenitors with activation of neuronal pathways. Despite the absence of major abnormalities in plasma glycoproteins glycosylation, glycolipidomic analysis identified marked defects in glycosphingolipid maturation within patient-derived brain organoids, indicating selective impairment of neural lipid glycosylation. Transcriptomic and biochemical analyses further revealed dysregulation of developmental pathways, including reduced Notch signalling and altered localization of both cleaved Notch1 and the Golgi-associated protein ACBD3. Consistent with impaired progenitor maintenance, COG5-deficient organoids displayed altered cleavage plane orientation in apical progenitors. Together, our findings suggest a link between Golgi organization, intracellular trafficking, membrane glycosylation, and lineage progression in human neural progenitors, identifying Golgi architecture as an important regulator of apical radial glial cell biology and cortical development.

cell biology↗

A molecular cell atlas of endocrine signalling in human neural organoids

Hormonal signalling shapes the development of the human brain and its disruption is implicated in various neuropsychiatric conditions. However, a comprehensive and mechanistic understanding of how hormonal pathways orchestrate human neurodevelopment remains elusive. Here we present a multi-scale high resolution atlas of endocrine signalling in human neural organoids through systematic perturbations with agonists and inhibitors of seven key hormonal pathways: androgen (AND), estrogen (EST), glucocorticoid (GC), thyroid (THY), retinoic acid (RA), liver X (LX), and aryl hydrocarbon (AH). By integrating bulk and single-cell transcriptomics, high-throughput imaging and targeted steroidomics, we mapped the molecular and cellular consequences of their physiologically relevant perturbations. Retinoic acid exerted the most profound effect, promoting neuronal differentiation and maturation, consistent with its established role as a patterning factor. Our analysis further benchmarked neural organoids for in vitro endocrinology and neurotoxicology by confirming previously reported in vivo effects, such as induction of mTOR signalling by AND, alteration of disease relevant genes by GC and enhanced differentiation by TH. Furthermore, we observed that LX activation upregulates genes involved in cholesterol metabolism while AH inhibition promotes neuronal differentiation. We next uncovered extensive crosstalks between these endocrine pathways, as in the paradigmatic convergence induced by AND agonist and inhibitors of GC, TH, and LX, affecting genes related to protein folding and metabolic regulation, as also highlighted by weighted gene co-expression network analysis. Single-cell analyses pinpointed cell-type-specific responses to hormonal challenges, such as the caudalization of progenitors and neurons upon RA activation and the depletion of specific neurodevelopmental states upon AH activation. Finally, we dissected the cytoarchitectural and morphometric impact of hormonal perturbations and demonstrated that neural organoids possess active steroidogenic pathways that are functionally modulated by the tested compounds. This atlas provides a systematic quantification of the hormonal impact on human neurodevelopment, enabling the investigation of uncharted aspects in the developmental origins of neuropsychiatric traits. Through the empowering architecture of its knowledge base for iterative adoption by the community, this resource will thus be key to probe how environmental factors and genetic endocrine vulnerabilities contribute to neurodevelopmental outcomes, as well as to train advanced generative models for improving their predictive power on gene environment interactions in human neurodevelopment.

molecular biology↗

Benchmarking cerebellar organoids to model autism spectrum disorder and human brain evolution

While cortical organoids have been used to model different facets of neurodevelopmental conditions and human brain evolution, cerebellar organoids have not yet featured so prominently in the same context, despite increasing evidence of this brain regions importance for cognition and behavior. Here, we provide a longitudinal characterization of cerebellar organoids benchmarked against human fetal data and identify at very early stages of development a significant number of dynamically expressed genes relevant for neurodevelopmental conditions such as autism and attention deficit hyperactivity disorders. Then, we model an ASD mutation impacting CHD8, showing both granule cell and oligodendrocyte lineages prominently affected, resulting in altered network activity in more mature organoids. Lastly, using CRISPR/Cas9 editing, we also model an evolution-relevant mutation in a regulatory region of the CADPS2 gene. We investigate the effect of the derived allele exclusive to Homo sapiens, identifying a rerouting of the CADPS2-expression in rhombic lip cells, coupled with a different sensitivity to hypoxia which in turn lead to a differential timing of granule cell differentiation. HIGHLIGHTSO_LILongitudinal characterization of cerebellar organoids uncovers disorder related genes especially at early stages of development C_LIO_LIMutation in CHD8 alter rhombic lip and oligodendrocytes differentiation via WNT pathway C_LIO_LIRerouting of CADPS2 expression, delaying differentiation and migration, in recent human evolution C_LI IN BRIEFAprile and colleagues longitudinally profiled cerebellar organoids, benchmarking them against a fetal human atlas and identified a highly dynamic expression of genes related to cognitive and behavioral disorders especially at early stages of differentiation. Organoids were used to model the impact of a high-penetrance mutation associated with autism spectrum disorder and a high-frequency derived allele in Homo sapiens predicted to have played a role in recent brain evolution.

neuroscience↗

A mixture of endocrine disrupting chemicals linked to lower birth weight induces adipogenesis and transcriptional changes related to birth weight alterations and diabetes

There is increasing evidence that endocrine disrupting chemicals (EDCs) are contributing to the rise in metabolic disorders and obesity. Humans are constantly exposed to numerous EDCs, thus human exposure entails complex EDC mixtures. In this study, we examined the effects of an EDC mixture, mixture G, composed of four phthalate esters, triclosan, and three poly- och perfluorinated alkyl substances. Mixture G had previously been defined based on its association with lower birth weight in a pregnancy cohort, where low birth weight is an early risk factor for metabolic morbidities later in life. Here, we studied its effects on adipogenesis and uncovered their underlying transcriptional changes. Human mesenchymal stem cells (hMSCs) were exposed to mixture G in concentrations and mixing ratios that reflect those measured in human serum. Mixture G induced adipogenesis in hMSCs, as evidenced by a dose-dependent increase in lipid droplet accumulation after 14-21 days. Notably, significant adipogenic effects were observed at concentrations comparable to those detected in humans. RNA-sequencing upon exposure for 48 h revealed dose-dependent transcriptional changes in over 1000 genes. Mixture G-induced differentially expressed genes (DEGs) showed significant overlap with genes involved in osteogenesis, with glucocorticoid-regulated genes, and with genes associated with birth weight alterations and diabetes type II. These results indicate that exposure to an environmentally relevant EDC mixture induces adipogenesis and leads to transcriptional alterations that might change the balance between adipogenic and osteogenic differentiation as well as the functionality of MSCs, possibly via interference with glucocorticoid signalling. Thus our findings underscore the role of EDCs as metabolic disruptors and shed light on the molecular mechanisms underlying their potential contribution to the development of metabolic disorders. HighlightsO_LIAn endocrine disruptor mixture linked to lower birth weight increases adipogenesis C_LIO_LIThe mixture induced transcriptomic changes at low doses C_LIO_LIAffected genes are associated with birth weight and diabetes type II C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=78 SRC="FIGDIR/small/638050v1_ufig1.gif" ALT="Figure 1"> View larger version (17K): org.highwire.dtl.DTLVardef@12428bforg.highwire.dtl.DTLVardef@ef28b3org.highwire.dtl.DTLVardef@159024corg.highwire.dtl.DTLVardef@a605b7_HPS_FORMAT_FIGEXP M_FIG C_FIG

pharmacology and toxicology↗

High resolution multi-scale profiling of embryonic germ cell-like cells derivation reveals pluripotent state transitions in humans

Primordial germ cells (PGCs) are the embryonic precursors of the gametes. In mice and rats, PGCs can readily acquire pluripotency in vitro by forming embryonic germ cells (EGCs). To date, a comparable in vitro system has not been established in humans, despite the fact that human PGCs (hPGCs) readily undergo pluripotent conversion in the context of germ cell tumorigenesis. Here we report that hPGC-like cells (hPGCLCs) undergo conversion to human embryonic germ-like cells (hEGCLCs) upon exposure to the same inductive signals previously used to derive mouse EGCs. This defined, feeder-free culture system allows efficient derivation of human EGCLCs which can be expanded and maintained in standard human pluripotent stem cell medium. hEGCLCs are transcriptionally similar to human pluripotent stem cells (hPSCs) and can differentiate into all three germ layers, as well as giving rise to PGCLCs once more - demonstrating the interconvertibility of pluripotent states. This is also evident at the epigenetic level, as the initial DNA demethylation that occurs in hPGCLCs is largely reversed in hEGCLCs, restoring DNA methylation to the level observed in hPSCs. This new in vitro model captures the transition from the pluripotent stem cell state to a germ cell identity and back again, and therefore represents a highly tractable system to study pluripotent and epigenetic transitions, including those which occur during human germ cell tumorigenesis. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=195 HEIGHT=200 SRC="FIGDIR/small/632914v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@14572bcorg.highwire.dtl.DTLVardef@6fa7c1org.highwire.dtl.DTLVardef@6eaa99org.highwire.dtl.DTLVardef@1822307_HPS_FORMAT_FIGEXP M_FIG C_FIG In briefWe report the first fully defined system to efficiently convert hPGCLCs to a pluripotent stem cell (PSC) state. We tracked pluripotent state transitions by multi-omic analysis and provided a high-resolution map of the transcriptional and epigenomic transitions upon entry to and exit from the human germline. HighlightsO_LIEfficient derivation of hEGCLC in fully defined feeder-free conditions C_LIO_LISingle-cell transcriptomic profiling of transitions from the hPSC state to hPGCLCs and back. C_LIO_LILongitudinal DNA methylation profiling highlights the overall reversibility of epigenetic states C_LIO_LIMulti-omic gene regulatory network analysis identifies key regulators of pluripotent transitions C_LI

developmental biology↗

Multiplexing cortical brain organoids for the longitudinal dissection of developmental traits at single cell resolution

The combination of brain organoid and single cell omic technologies holds transformative potential to dissect human neurobiology at high resolution and with mechanistic precision. Delivering this promise in the context of human neurodiversity, physiological and pathological alike, requires however a major leap in scalability, given the need for experimental designs that include multiple individuals and, prospectively, population cohorts. To lay the foundation for this, we implemented and benchmarked complementary strategies to multiplex brain organoids. Following an extended longitudinal design with a uniquely informative set of timepoints, we pooled cells from different induced pluripotent stem cell lines either during organoids generation (upstream multiplexing in mosaic models) or before single cell-RNAseq library preparation (downstream multiplexing). We developed a new method, SCanSNP, and an aggregated call to deconvolve organoids cell identities, overcoming current criticalities in doublets prediction and low quality cells identification and improving accuracy over state of the art algorithms. Integrating single cell transcriptomes and analysing cell types across neurodevelopmental stages and multiplexing modalities, we validated the feasibility of both multiplexing methods in charting neurodevelopmental trajectories at high resolution, linking their specificity to genetic variation between individual lines. Together, this multiplexing suite of experimental and computational methods provides an enabling resource for disease modelling at scale and paves the way towards an in vitro epidemiology paradigm.

neuroscience↗

Curation of causal interactions mediated by genes associated to autism accelerates the understanding of gene-phenotype relationships underlying neurodevelopmental disorders

Autism spectrum disorder (ASD) comprises a large group of neurodevelopmental conditions featuring, over a wide range of severity and combinations, a core set of manifestations (restricted sociality, stereotyped behavior and language impairment) alongside various comorbidities. Common and rare variants in several hundreds of genes and regulatory regions have been implicated in the molecular pathogenesis of ASD along a range of causation evidence strength. Despite significant progress in elucidating the impact of few paradigmatic individual loci, such sheer complexity in the genetic architecture underlying ASD as a whole has hampered the identification of convergent actionable hubs hypothesized to relay between the vastness of risk alleles and the core phenotypes. In turn this has limited the development of strategies that can revert or ameliorate this condition, calling for a systems-level approach to probe the cross-talk of cooperating genes in terms of causal interaction networks in order to make convergences experimentally tractable and reveal their clinical actionability. As a first step in this direction, we have captured from the scientific literature information on the causal links between the genes whose variants have been associated with ASD and the whole human proteome. This information has been annotated in a computer readable format in the SIGNOR database and is made freely available in the resource website. To link this information to cell functions and phenotypes, we have developed graph algorithms that estimate the functional distance of any protein in the SIGNOR causal interactome to phenotypes and pathways. The main novelty of our approach resides in the possibility to explore the mechanistic links connecting the suggested gene-phenotype relations.

systems biology↗

GTF2I dosage regulates neuronal differentiation and social behavior in 7q11.23 neurodevelopmental disorders

Copy number variations at 7q11.23 cause neurodevelopmental disorders with shared and opposite manifestations. Deletion causes Williams-Beuren syndrome (WBS), while duplication causes 7q11.23 microduplication syndrome (7Dup). Converging evidence indicates GTF2I, from the 7q11.23 locus, is a key mediator of the cognitive-behavioral phenotypes associated with WBS and 7Dup. Here we integrate molecular profiling of patient-derived cortical organoids (COs) and transgenic mouse models to dissect 7q11.23 disease mechanisms. Proteomic and transcriptomic profiling of COs revealed opposite dynamics of neural progenitor proliferation and transcriptional imbalances, leading to precocious excitatory neuron production in 7Dup. The accelerated excitatory neuron production in 7Dup COs could be rescued by GTF2I knockdown. Transgenic mice with Gtf2i duplication recapitulated early neuronal differentiation defects and ASD-like behaviors. Remarkably, inhibition of LSD1, a downstream effector of GTF2I, was sufficient to rescue ASD-like phenotypes. We propose that the GTF2I-LSD1 axis constitutes a molecular pathway amenable to therapeutic intervention.

neuroscience↗

Benchmarking brain organoid recapitulation of fetal corticogenesis

Brain organoids are becoming increasingly relevant to dissect the molecular mechanisms underlying psychiatric and neurological conditions. The in vitro recapitulation of key features of human brain development affords the unique opportunity of investigating the developmental antecedents of neuropsychiatric conditions in the context of the actual patients genetic backgrounds. Specifically, multiple strategies of brain organoid (BO) differentiation have enabled the investigation of human cerebral corticogenesis in vitro with increasing accuracy. However, the field lacks a systematic investigation of how closely the gene co-expression patterns seen in cultured BO from different protocols match those observed in fetal cortex, a paramount information for ensuring the sensitivity and accuracy of modeling disease trajectories. Here we benchmark BO against fetal corticogenesis by integrating transcriptomes from in-house differentiated cortical BO (CBO), other BO systems, human fetal brain samples processed in-house, and prenatal cortices from the BrainSpan Atlas. We identified co-expression patterns and prioritized hubs of human corticogenesis and CBO differentiation, highlighting both well-preserved and discordant trends across BO protocols, including different degrees of heterochronicity in differentiation across BO models compared to fetal cortex. Our approach provides a framework to directly compare the extent of in vivo/in vitro alignment of neurodevelopmentally relevant processes and their attending temporalities, structured as an accessible resource to query for modelling human corticogenesis and the neuropsychiatric outcomes of its alterations.

developmental biology↗

Novel antiviral interferon sensitive genes unveiled by correlation-driven gene selection and integrated systems biology approaches.

Interferons (IFNs) are key cytokines involved in alerting the immune system to viral infection. After IFN stimulation, cellular transcriptional profile critically changes, leading to the expression of several IFN stimulated genes (ISGs) that exert a wide variety of antiviral activities. Despite many ISGs have been already identified, a comprehensive network of coding and non-coding genes with a central role in IFN-response still needs to be elucidated. We performed a global RNA-Seq transcriptome profile of the HCV permissive human hepatoma cell line Huh7.5 and its parental cell line Huh7, upon IFN treatment, to define a network of genes whose coordinated modulation plays a central role in IFN-response. Our study adds molecular actors, coding and non-coding genes, to the complex molecular network underlying IFN-response and shows how systems biology approaches, such as correlation networks, networks topology and gene ontology analyses can be leveraged to this aim.

systems biology↗

CHD8 haploinsufficiency alters the developmental trajectories of human excitatory and inhibitory neurons linking autism phenotypes with transient cellular defects

Chromodomain helicase DNA-binding 8 (CHD8) is one of the most frequently mutated genes causative of autism spectrum disorder (ASD). While its phenotypic spectrum often encompasses macrocephaly and hence implicates cortical abnormalities in this form of ASD, the neurodevelopmental impact of human CHD8 haploinsufficiency remains unexplored. Here we combined human cerebral organoids and single cell transcriptomics to define the effect of ASD-linked CHD8 mutations on human cortical development. We found that CHD8 haploinsufficiency causes a major disruption of neurodevelopmental trajectories with an accelerated generation of inhibitory neurons and a delayed production of excitatory neurons alongside the ensuing protraction of the proliferation phase. This imbalance leads to a significant enlargement of cerebral organoids aligned to the macrocephaly observed in patients with CHD8 mutations. By adopting an isogenic design of patient-specific mutations and mosaic cerebral organoids, we define genotype-phenotype relationships and uncover their cell-autonomous nature. Finally, our results assign different CHD8-dependent molecular defects to particular cell types, pointing to an abnormal and extended program of proliferation and alternative splicing specifically affected in, respectively, the radial glial and immature neuronal compartments. By identifying temporally restricted cell-type specific effects of human CHD8 mutations, our study uncovers developmental alterations as reproducible endophenotypes for neurodevelopmental disease modelling.

neuroscience↗

Longitudinal dissection in brain organoids at single cell resolution uncovers the developmental role of GSK3 in human corticogenesis

The regulation of proliferation and polarity of neural progenitors is crucial for the development of the brain cortex, with modes and timings of cell division intimately related to the stereotypical acquisition of layer-specific neuronal identities. Animal studies have implicated glycogen synthase kinase 3 (GSK3) as a pivotal regulator of both proliferation and polarity, yet the functional relevance of its signaling for the unique features of human corticogenesis remain to be elucidated. Here we harness human cortical brain organoids to probe, at single cell resolution, the longitudinal impact of GSK3 inhibition through multiple developmental stages. Our results indicate that chronic GSK3 inhibition increases the proliferation of neural progenitors and causes massive derangement of cortical tissue architecture. Surprisingly, single cell transcriptome profiling revealed only a discrete impact on early neurogenesis and uncovered the outer radial glia and the astrogenic lineage as the main GSK3-dependent developmental domains. Through this first single cell-level dissection of the GSK3 regulatory network in human corticogenesis, our work uncovers a remarkably specific conduit between the architecture of progenitor niches and lineage specification.

developmental biology↗

The Drosophila Eukaryotic Initiation Factor eIF6 affects development by regulating apoptosis via the ecdysone pathway

During development, ribosome biogenesis and translation reach peak activities, due to impetuous cell proliferation. Current models predict that protein synthesis elevation is controlled by transcription factors and signalling pathways. Developmental models addressing translation factors overexpression effects are lacking. Eukaryotic Initiation Factor (eIF6) is necessary for ribosome biogenesis and efficient translation. eIF6 is a single gene, conserved from yeasts to mammals, suggesting a tight regulation need. We generated a Drosophila melanogaster in vivo model of eIF6 upregulation, demonstrating a boost in general translation and the shut off of the ecdysone biosynthetic pathway. Translation modulation in S2 cells showed that translational rate and ecdysone biosynthesis are inversely correlated. In vivo, eIF6-driven alterations delayed programmed cell death (PCD), resulting in aberrant phenotypes, partially rescued by ecdysone administration. Our data show that eIF6 triggers a translation program with far-reaching effects on metabolism and development, stressing the driving and central role of translation.

developmental biology↗