Biology subjects

Testa, G.

Publications and source records attributed to Testa, G..

At least 19 recordsLinked to original sources

bioRxiv2026

Co-regulatory changes in Homo sapiens prefrontal cortex shape RNA-chromatin interactions

Noncoding RNAs (ncRNAs) regulate gene expression through RNA-chromatin interactions, yet their role in human brain evolution remains unclear. To map these interactions, we integrated FANTOM6 neurogenic data with a comprehensive atlas of regulatory regions active during early cortical development. This integration effort linked ncRNAs and transcription factors (TFs) to their genomic targets, revealing functional interactions captured by RNA-DNA contact mapping, yet largely missed by chromatin conformation data. Overlaying these interactions with nearly fixed variants in Homo sapiens relative to extinct hominins uncovered widespread rewiring of TF binding, affecting genes implicated in progenitor proliferation and neuronal differentiation. Gene regulatory network reconstruction identified TEAD2 and ONECUT2 as key regulators of intermediate progenitors and migrating neurons. Functional perturbation followed by Cut&Tag and ATAC-seq linked the two TFs to disease- and evolutionarily- relevant pathways. Together, these results show how ncRNA-TF cooperation and selective cis-regulatory rewiring contributed to sapiens-specific features of cortical development.

molecular biology↗

bioRxiv2025

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↗

bioRxiv2025

Mapping and reprogramming microenvironment-induced cell states in human disease using generative AI

Tissue microenvironments reprogram local cellular states in disease, yet current computational spatial methods remain descriptive and do not simulate tissue perturbation. We present MintFlow, a generative AI algorithm that learns how the tissue microenvironment influences cell states and predicts how tissue perturbations can reprogram them. Applied to three human diseases, MintFlow uncovered distinct pathogenic spatial reprogramming in inflammatory and tumor microenvironments. In atopic dermatitis, MintFlow identified a novel, spatially-imprinted, type 2 (IL13+ITGAE+) epidermal T resident memory cell population (type 2 TRM), and decoded signaling pathways within the perivascular lymphoid niche. In melanoma, MintFlow identified fibrotic stroma resembling keloid scar tissue. In kidney cancer, MintFlow resolved immunosuppressed CD8+ T cell states within tertiary lymphoid structures. Furthermore, MintFlow enabled in silico perturbations of disease-relevant cell states and tissue environments. Regulatory T cell modulation in atopic dermatitis was predicted to suppress the pro-inflammatory tissue environment, supporting manipulation of these cells as a therapeutic target. In kidney cancer, in silico T cell replacement recapitulated immune checkpoint blockade, while spatially targeted macrophage depletion reverted immunosuppressed T cell states. The corresponding gene programs correlated with survival in large kidney cancer patient cohorts. Together, these findings position MintFlow as a tool for unbiased disease mechanism prediction and in silico perturbation, accelerating translational hypothesis generation and guiding therapeutic strategies.

genomics↗

bioRxiv2025

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↗

bioRxiv2025

Regulatory logic of human cortex evolution by combinatorial perturbations

Comparative genomic studies between contemporary and extinct hominins revealed key evolutionary modifications, but their number has hampered a system level investigation of their combined roles in scaffolding modern traits. Through multi-layered integration we selected 15 genes carrying nearly fixed sapiens-specific protein-coding mutations and developed a scalable design of combinatorial CRISPR-Cas9 bidirectional perturbations to uncover their regulatory hierarchy in cortical brain organoids. Interrogating the effects of overexpression and downregulation for all gene pairs in all possible combinations, we defined their impact on transcription and differentiation and reconstructed their regulatory architecture. We uncovered marked cell type-specific effects, including the promotion of alternative fates and the emergence of interneuron populations, alongside a core subnetwork comprising KIF15, NOVA1, RB1CC1 and SPAG5 acting as central regulator across cortical cell types.

systems biology↗

bioRxiv2025

Disruption of ADNP-KDM1A-GTF2I complex drives neural differentiation imbalance in Helsmoortel-Van der Aa syndrome

Mutations in ADNP (Activity-Dependent Neuroprotective Protein) are among the most frequent monogenic causes of autism spectrum disorder (ASD) and lead to Helsmoortel-Van der Aa syndrome (HVDAS). Yet how ADNP dysfunction leads to HVDAS is unclear. We employed patient-derived induced pluripotent stem cells, cortical organoids and ADNP KO human neural stem cells (hNSCs) to clarify the cellular and molecular mechanism of HVDAS onset. We purified an ADNP-KDM1A-GTF2I (AKG) protein complex from hNSCs and show that it targets transposable elements (TEs) to repress nearby gene transcription. Upon ADNP KO, KDM1A binding is lost at promoters targeted by AKG, pointing to ADNP as the anchoring subunit of the AKG complex. HVDAS cortical organoids show impaired progenitor proliferation and accelerated neuronal differentiation, coupled with a sustained upregulation of neurogenesis transcriptional programs, including key transcription factors normally repressed by AKG. This work suggests that the AKG complex acts as the relevant ADNP unit in the molecular onset of HVDAS.

neuroscience↗

bioRxiv2025

Donor-Specific Digital Twin for Living Donor Liver Transplant Recovery

Liver resection initiates a meticulously coordinated hyperplasia process characterized by regulated cell proliferation that drives liver regeneration. This process concludes with the complete restoration of liver mass, showcasing the precision and robustness of this homeostasis. The remarkable capacity of the liver to regenerate rapidly into a fully functional organ has been crucial to the success of living donor liver transplantation (LDLT). In healthy livers, hepatocytes typically remain in a quiescent state (G0). However, following partial hepatectomy, these cells transition to the G1 phase to re-enter the cell cycle. Surgical resection induces various stresses, including physical injury, altered blood flow, and increased metabolic demands. These all trigger the activation and suppression of numerous genes involved in tissue repair, regeneration, and functional recovery. Both coding and noncoding RNAs detectable in the bloodstream during this process provide valuable insights into the gene responses driving liver recovery. This study integrates clinical gene expression data into a previously developed mathematical model of liver regeneration, which tracks transitions among quiescent, primed, and proliferating hepatocytes to construct virtual, patient-specific liver models. Using whole transcriptome RNA sequencing data from 12 healthy LDLT donors, collected at 14 time points over a year, we identified liver resection-specific gene expression patterns through Weighted Gene Co-expression Network Analysis (WGCNA). These patterns were organized into distinct clusters with unique transcriptional dynamics and mapped to model variables using deep learning techniques. Consequently, we developed a Personalized Progressive Mechanistic Digital Twin (PePMDT) for the livers of LDLT donors. The resulting PePMDT predicts individual patient recovery trajectories by leveraging blood-derived gene expression data to simulate regenerative responses. By transforming gene expression profiles into dynamic model variables, this approach bridges clinical data and mathematical modeling, providing a robust platform for personalized medicine. This study highlights the transformative potential of data-driven frameworks like PePMDT in advancing precision medicine and optimizing recovery outcomes for LDLT donors.

systems biology↗

bioRxiv2025

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↗

bioRxiv2025

A harmonized ovarian cancer scRNA-seq atlas to dissect disease heterogeneity underlying metastatization and chemoresistance

The advent of single cell technology has enabled researchers with the ability to achieve unprecedented resolution in the characterization of biological systems. The consequent increasing availability of single cell dataset brought about the possibility to obtain comprehensive reference atlases, to shed light on the molecular and cellular foundations of healthy and diseased tissues. This process has highlighted the need to integrate datasets from different sources while being able to distinguish true biological signal from technical confounders. While this issue is widespread to most biological settings, it holds especially true for cancer samples, which are characterized by a diffused inter- and intra-patient phenotypic heterogeneity. To address this issue, here we developed a novel integration method tailored to highly heterogeneous single cell transcriptomic data and applied it to one of the quintessential heterogeneous cancer type, namely high-grade serous ovarian cancer, to generate the first reference atlas for this disease. By identifying patient-specific cell populations and deriving metacells, we were able to preserve inter-patient biological variability. Using a variational autoencoder, we integrated metacell data, revealing an evolving landscape of cell states along disease progression and treatment for each of the main cell types constituting the dataset. Also, we showed the potential of this resource by identifying diffused and tissue/treatment-specific cell-to-cell interactions. Finally, the generated integration model allowed to expand the atlas with additional data, granting iterative refinement over time of this disease reference. Our strategy now provides a valuable resource for the cancer research community, facilitating the investigation of tumor heterogeneity towards the development of novel therapeutic strategies.

cancer biology↗

bioRxiv2025

CHD2 Dosage Ties Autolysosomal Pathway to Cortical Maturation in Disease and Evolution

The mechanisms linking evolutionary changes in gene regulation to brain development and neurodevelopmental disease susceptibility remain poorly understood. Here, we identify a human-specific variant in an enhancer region that reduces expression of the chromatin remodeler CHD2. We investigate the variant's functional consequences using genome editing, cross-primate induced pluripotent stem cell models, cortical organoids, single-cell transcriptomics, patient-derived cells, and neuronal network analyses. We demonstrate that CHD2 dosage bidirectionally regulates lysosomal function and autophagosome flux to set the tempo of neuronal maturation. Higher CHD2 expression, as found in ancestralized and non-human primate models, enhances lysosomal degradative capacity and accelerates dendritic and synaptic maturation. Conversely, CHD2 haploinsufficiency yields reciprocal defects and disrupts broader neurodevelopmental transcriptional programs. Restoring lysosomal function genetically or pharmacologically rescues neuronal maturation in CHD2-haploinsufficient neurons, establishing lysosomal dysfunction as a causal and therapeutically tractable mechanism. These findings reveal that CHD2 and lysosomal homeostasis constitute a critical molecular axis regulating the pace of cortical development across evolution and disease.

neuroscience↗

bioRxiv2025

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↗

bioRxiv2024

YY1 mutations disrupt corticogenesis and cytoarchitecture through a cell-type specific rewiring of cell-autonomous and non-cell-autonomous transcriptional programs

Germline mutations of YY1 cause Gabriele-de Vries syndrome (GADEVS), a neurodevelopmental disorder featuring intellectual disability and a wide range of systemic manifestations. To dissect the cellular and molecular mechanisms underlying GADEVS, we combined large-scale imaging, single-cell multiomics and gene regulatory network reconstruction in 2D and 3D patient-derived physiopathologically relevant cell lineages. YY1 haploinsufficiency causes a pervasive alteration of cell type specific transcriptional networks, disrupting corticogenesis at the level of neural progenitors and terminally differentiated neurons, including cytoarchitectural defects reminiscent of GADEVS clinical features. Transcriptional alterations in neurons propagated to neighboring astrocytes through a major non-cell autonomous pro-inflammatory effect that grounds the rationale for modulatory interventions. Together, neurodevelopmental trajectories, synaptic formation and neuronal-astrocyte cross talk emerged as salient domains of YY1 dosage-dependent vulnerability. Mechanistically, cell-type resolved reconstruction of gene regulatory networks uncovered the regulatory interplay between YY1, NEUROG2 and ETV5 and its aberrant rewiring in GADEVS. Our findings underscore the reach of advanced in vitro models in capturing developmental antecedents of clinical features and exposing their underlying mechanisms to guide the search for targeted interventions.

neuroscience↗

bioRxiv2023

Single nucleus RNA sequencing reveals glial cell type-specific responses to ischemic stroke

Reactive neuroglia critically shape the brains response to ischemic stroke. However, their phenotypic heterogeneity impedes a holistic understanding of the cellular composition and microenvironment of the early ischemic lesion. Here we generated a single cell resolution transcriptomics dataset of the injured brain during the acute recovery from permanent middle cerebral artery occlusion. This approach unveiled infarction and subtype specific molecular signatures in oligodendrocyte lineage cells and astrocytes, which ranged among the most transcriptionally perturbed cell types in our dataset. Specifically, we characterized and compared infarction restricted proliferating oligodendrocyte precursor cells (OPCs), mature oligodendrocytes and heterogeneous reactive astrocyte populations. Our analyses unveiled unexpected commonalities in the transcriptional response of oligodendrocyte lineage cells and astrocytes to ischemic injury. Moreover, OPCs and reactive astrocytes were involved in a shared immuno-glial cross talk with stroke specific myeloid cells. In situ, osteopontin positive myeloid cells accumulated in close proximity to proliferating OPCs and reactive astrocytes, which expressed the osteopontin receptor CD44, within the perilesional zone specifically. In vitro, osteopontin increased the migratory capacity of OPCs. Collectively, our study highlights molecular cross talk events which might govern the cellular composition and microenvironment of infarcted brain tissue in the early stages of recovery.

neuroscience↗

bioRxiv2023

miRNA-mediated inhibition of an actomyosin network in hippocampal pyramidal neurons restricts sociability in adult male mice

Social deficits are frequently observed in patients suffering from neurodevelopmental disorders, but the molecular mechanisms regulating sociability are still poorly understood. We recently reported that the loss of the microRNA cluster miR-379-410 leads to hypersocial behavior and anxiety in mice. Here, we show that ablating miR-379-410 in excitatory neurons of the postnatal mouse hippocampus recapitulates hypersociability, but not anxiety. At the cellular level, miR-379-410 loss in excitatory neurons leads to increased excitatory synaptic transmission and upregulation of an actomyosin gene network. Re-expression of three cluster miRNAs, as well as pharmacological inhibition of the actomyosin activator ROCK, was sufficient to reinstate normal sociability in miR-379-410 knockout mice. Several actomyosin genes and miR-379-410 family members were reciprocally dysregulated in isogenic human iPSC-derived neurons harboring a deletion present in Williams-Beuren-Syndrome patients, which are characterized by hypersocial behavior. Together, our results unveil a novel microRNA-actomyosin pathway involved in the control of sociability.

neuroscience↗

bioRxiv2023

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↗

bioRxiv2023

A multi-layered integrative analysis reveals a cholesterol metabolic program in outer radial glia with implications for human brain evolution

The definition of molecular and cellular mechanisms contributing to evolutionary divergences in brain ontogenetic trajectories is essential to formulate hypotheses about the emergence of our species. Yet the functional dissection of evolutionary modifications derived in the Homo sapiens lineage at an appropriate level of granularity remains particularly challenging. Capitalizing on recent single-cell sequencing efforts that have massively profiled neural stem cells from the developing human cortex, we develop an integrative computational framework in which we perform (i) trajectory inference and gene regulatory network reconstruction, (ii) (pseudo)time-informed non-negative matrix factorization for learning the dynamics of gene expression programs, and (iii) paleogenomic analysis for a higher-resolution mapping of the regulatory landscape where our species acquired derived mutations in comparison to our closest relatives. We provide evidence for cell type-specific activation and regulation of gene expression programs during indirect neurogenesis. In particular, our analysis uncovers a zinc-finger transcription factor, KLF6, as a key regulator of a cholesterol metabolic program specifically in outer radial glia. Our strategy allows us to further probe whether the (semi)discrete gene expression programs identified have been under selective pressures in our species lineage. A cartography of the regulatory landscape impacted by Homo sapiens-derived transcription factor binding site disruptions reveals signals of selection clustering around regulatory regions associated with GLI3, a well-known regulator of the radial glial cell cycle. As a whole, our study contributes to the evidence of significant changes impacting metabolic pathways in recent human brain evolution.

evolutionary biology↗

bioRxiv2023

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↗

bioRxiv2022

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↗