Biology subjects

Cappello, S.

Publications and source records attributed to Cappello, S..

16 recordsLinked to original sources

bioRxiv2026

Evolution Shapes Cortical Interneuron Migration

The cerebral cortex comprises excitatory neurons and inhibitory interneurons originating from distinct forebrain regions. During migration, cortical interneurons (cINs) interact dynamically with neighbouring cells and their microenvironment, contributing to cortical architecture. However, how evolutionary changes in cIN migration shape species-specific cortical development remains unclear. Comparative analyses in mouse, ferret, and human models revealed a conserved migratory sequence but distinct behaviours: human cINs migrate slower, display increased leading-process branching, and exhibit more frequent homotypic repulsive interactions than their mouse and ferret counterparts. These features promote dispersed cortical invasion of cINs in humans and ferrets, contrasting with the stream-like migration observed in mice. Mechanistically, elevated expression of the cytosolic carboxypeptidase CCP1 in human cINs reduces microtubule glutamylation and doublecortin recruitment, thereby facilitating leading-process branching. These findings identify a CCP1-dependent mechanism regulating cIN dispersion and suggest that evolutionary changes in cIN migration contribute to divergent patterns of cortical morphogenesis across mammals.

neuroscience↗

bioRxiv2026

Human cerebral assembloids as a model to study the interaction of glioblastoma with resident glial cells

Glioblastoma (GB) is a highly invasive brain cancer characterized by extensive peritumoral glial reactivity. Although GB infiltration and recurrence remain major therapeutic challenges, the contribution of GB-induced gliosis to tumor progression is poorly understood. To investigate glia-GB interactions, we developed human iPSC-derived cerebral forebrain assembloids containing innate microglia and macroglia and transplanted them with GB cells. The model recapitulates key tumor features observed in patients, including distinct tumor regions, reactive gliosis, and altered tissue stiffness. Single-cell RNA sequencing revealed an unexpected enrichment of extracellular vesicles (EVs) in peritumoral reactive glia, which we validated in patient samples. EV inhibition impaired formation of the peritumoral niche, whereas EVs from GB-containing assembloids induced glial reactivity in GB-free assembloids. Furthermore, the modularity of our system enables incorporation of additional niche components, such as monocytes, allowing investigation of the monocyte-glia-tumor axis and providing a powerful platform to dissect mechanisms regulating the GB microenvironment.

neuroscience↗

bioRxiv2026

A reproducible human brain tissue model to study physiological and disease-associated microglia phenotypes

Stem-cell-based in vitro models offer promising potential to elucidate human brain cell functions and interactions under physiological and pathological conditions. However, harnessing this potential is impaired by low reproducibility, maturity, or cell-type diversity of existing models. Especially, prolonged incorporation of mature microglia and studies of neuroinflammation have proven challenging. Here, we developed a 3D cortical brain tissue model (3BTM) containing neurons, astrocytes, and microglia with high reproducibility, maturity, and viability. 3BTMs show morphological, functional, and proteomic maturation of all cell types, leading to high similarity to their in vivo counterparts. Incorporated microglia survive for over 6 months and display mature morphology, functions, and gene expression. Importantly, when engineered to model Alzheimers disease pathology, 3BTMs recapitulate key disease hallmarks including amyloid deposition, increased phospho-Tau levels, and neuroinflammation, with microglia shifting their transcriptional landscape to disease-relevant signatures. Together, our model offers unprecedented possibilities for studying physiological and pathological states of human brain tissue and translational applications.

neuroscience↗

bioRxiv2025

DCHS1 Modulates Forebrain Proportions in Modern Humans via a Glycosylation Change

Comparative anatomical studies of primates and extinct hominins, including Neanderthals, show that the modern human brain is characterised by a disproportionately enlarged neocortex relative to the striatum. To explore the molecular basis of this difference, we screened for missense mutations that are unique to modern humans and occur at high frequency and that alter post-translational sites. One such mutation was identified in DCHS1, a protocadherin family gene, and it was found to disrupt an N-glycosylation site in modern humans. Using CRISPR/Cas9-editing we introduced into human-induced pluripotent stem cells (hiPSCs) this ancestral DCHS1 variant present in Neanderthals and other primates, representing the ancestral state before the modern human-specific substitution. Leveraging hiPSCs-derived neural organoids, we observed an expansion of striatal progenitors at the expense of the neocortex, mirroring the anatomical distribution seen in non-human primates. We further identify the ephrin receptor EPHA4 as a binding partner of DCHS1 and show that modern human-specific alterations in DCHS1 modulate EPHA4-ephrin signalling, contributing to a gradual shift in the neocortex-to-striatum ratio - a hallmark of brain organisation in our species.

neuroscience↗

bioRxiv2025

Developmental gene expression patterns driving species-specific cortical features

The cerebral cortex shows species-specific variations in size and organization, likely accounting for distinct behavioral abilities. These structural differences may reflect evolutionary changes in the developmental expression of shared genes. To investigate this possibility, we compared cell-type-specific gene expression across species in the developing mouse and human neocortex, and human cortical organoids, by generating a shared transcriptional reference framework. This identified genes with conserved/divergent expression patterns, providing a molecular foundation to interrogate species-specific cellular properties. Using this resource, we discovered that the transcription factor JUNB is expressed in human but not mouse progenitors. Through cell-type-specific gain- and loss-of-function experiments in mice and human organoids, we demonstrate that JUNB bidirectionally controls human cortical features, including progenitor proliferation rates, neuronal production timing, and total neuronal output. This reveals how cell-type-specific regulation of shared genes during development can drive species-specific cortical features, providing a framework for understanding the molecular basis of cortical evolution.

neuroscience↗

bioRxiv2024

Intrinsic and extrinsic mechanisms alter neural cell fate specification in EPM1 Epilepsy

The extracellular milieu, including extracellular vesicles (EVs), plays a pivotal role in brain development by regulating neural processes such as proliferation, differentiation, and migration. In this study, we sought to elucidate the pathogenesis of progressive myoclonus epilepsy type 1 (EPM1), a disease caused by mutations in the CSTB gene, using cerebral organoids (COs) derived from EPM1 patient cells. The results demonstrate that EPM1 COs display increased electrophysiological activity and a disrupted excitatory/inhibitory balance. Single-cell RNA sequencing (scRNA-seq) analysis of ventral EPM1-Cos revealed an abnormal specification of progenitor fate, with a shift toward dorsal neuron identities at the expense of inhibitory interneurons. In addition, pathological alterations in EV biogenesis and cargo were identified, including aberrant Sonic Hedgehog (SHH) signaling, which may disrupt cortical patterning. These findings suggest that both intrinsic progenitor identity shifts and extrinsic EV-mediated signaling contribute to EPM1 pathology. Our study highlights potential therapeutic strategies mediated by EVs as a novel approach to mitigate disease progression.

neuroscience↗

bioRxiv2024

Neuronal Hyperactivity in Neurons Derived from Individuals with Grey Matter Heterotopia

Periventricular heterotopia (PH), a common form of grey matter heterotopia associated with developmental delay and drug-resistant seizures, poses a challenge in understanding its neurophysiological basis. Human cerebral organoids (hCOs) derived from patients with causative mutations in FAT4 or DCHS1 mimic PH features. However, neuronal activity in these 3D models has not yet been invetigated. Here, silicon probe recordings revealed exaggerated spontaneous spike activity in FAT4 and DCHS1 hCOs, suggesting functional changes in neuronal networks. Transcriptome and proteome analyses identified changes in gene ontology terms associated with neuronal morphology and synaptic function. Furthermore, patch-clamp recordings revealed a decreased spike threshold specifically in DCHS1 neurons, likely due to increased somatic voltage-gated sodium channels. Morphological reconstructions and immunostainings revealed greater morphological complexity of PH neurons and synaptic alterations contributing to hyperactivity, with morphological rescue observed in DCHS1 neurons by wild-type DCHS1 expression. Overall, we provide new comprehensive insights into the cellular changes underlying symptoms of grey matter heterotopia.

neuroscience↗

bioRxiv2024

Chronic exposure to glucocorticoids amplifies inhibitory neuron cell fate during human neurodevelopment in organoids

Disruptions in the tightly regulated process of human brain development have been linked to increased risk for brain and mental illnesses. While the genetic contribution to these diseases is well established, important environmental factors have been less studied at molecular and cellular levels. In this study, we used single-cell and cell-type-specific techniques to investigate the effect of glucocorticoid (GC) exposure, a mediator of antenatal environmental risk, on gene regulation and lineage specification in unguided human neural organoids. We characterized the transcriptional response to chronic GC exposure during neural differentiation and studied the underlying gene regulatory networks by integrating single-cell transcriptomics-with chromatin accessibility data. We found lasting cell type-specific changes that included autism risk genes and several transcription factors associated with neurodevelopment. Chronic GCs influenced lineage specification primarily by priming the inhibitory neuron lineage through key transcription factors like PBX3. We provide evidence for convergence of genetic and environmental risk factors through a common mechanism of altering lineage specification.

neuroscience↗

bioRxiv2023

Extracellular vesicle-mediated trafficking of developmental cues is altered during human brain disease

Cellular crosstalk is an essential process influenced by numerous factors including secreted vesicles that transfer nucleic acids, lipids, and proteins between cells. Extracellular vesicles (EVs) have been the center of many studies focusing on neuron-to-neuron communication, but the role of EVs in progenitor-to-neuron and -astrocyte communication and whether EVs display cell-type-specific features for cellular crosstalk during neurogenesis is unknown. Here, using human-derived cerebral organoids, neural progenitors, neurons, and astrocytes, we found that many proteins coded by genes associated with neurodevelopmental disorders are transported via EVs. Thus, we characterized the protein content of EVs and showed their cell type-specific dynamics and function during brain development. Changes in the physiological crosstalk between cells can lead to neurodevelopmental disorders. EVs from patients with epilepsy were found altered in composition and function. Alterations in the intracellular and extracellular compartments highlighted a clear dysregulation of protein trafficking. This study sheds new light on the biology of EVs during brain development and neurodevelopmental disorders. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=185 SRC="FIGDIR/small/546646v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@1dad15aorg.highwire.dtl.DTLVardef@e699ccorg.highwire.dtl.DTLVardef@17b371borg.highwire.dtl.DTLVardef@5efa7b_HPS_FORMAT_FIGEXP M_FIG C_FIG Graphical abstract(left) EV uptake mechanism varies depending on the receiving cell type; NPCs transport neuron EVs (nEVs) and astrocyte EVs (aEVs) to the nucleus, astrocytes localize progenitor EVs (pEVs) to the cytoplasm, and neurons retain pEVs and aEVs along the plasma membrane. (right) Cerebral organoids (COs) from progressive Myoclonus Epilepsy Type I (EPM1) patients release EVs lacking key proteins in neurodevelopment and proteins necessary for EV biogenesis and release. Illustration created using BioRender.

developmental biology↗

bioRxiv2023

Distinct subtypes of grey matter heterotopia show subtype-specific morpho-electric neuronal properties and dynamics of epileptiform activity in mice

Grey matter heterotopia (GMH) are neurodevelopmental disorders associated with abnormal cortical function and epilepsy. Subcortical band heterotopia (SBH) and periventricular nodular heterotopia (PVNH) are two well-recognized GMH subtypes in which neurons are misplaced, either forming nodules lining the ventricles in PVNH, or forming bands in the white matter in SBH. Although both PVNH and SBH are commonly associated with epilepsy, it is unclear whether these two GMH subtypes differ in terms of pathological consequences or, on the contrary, share common altered mechanisms. Here, we studied two robust preclinical models of SBH and PVNH, and performed a systematic comparative assessment of the physiological and morphological diversity of heterotopia neurons, as well as the dynamics of epileptiform activity and input connectivity. We uncovered a complex set of altered properties, including both common and distinct physiological and morphological features across heterotopia subtypes, and associated with specific dynamics of epileptiform activity. Taken together, these results suggest that pro-epileptic circuits in GMH are, at least in part, composed of neurons with distinct, subtype-specific, physiological and morphological properties depending on the heterotopia subtype. Our work supports the notion that GMH represent a complex set of disorders, associating both shared and diverging pathological consequences, and contributing to forming epileptogenic networks with specific properties. A deeper understanding of these properties may help to refine current GMH classification schemes by identifying morpho-electric signatures of GMH subtypes, to potentially inform new treatment strategies.

neuroscience↗

bioRxiv2022

Temporal regulation of ZBTB16 expression by glucocorticoids alters human cortical neurogenesis

Glucocorticoids are important for proper organ maturation and their levels are tightly regulated during development. Here we use human cerebral organoids and mice to study cell-type specific effects of glucocorticoids on neurogenesis. We show that glucocorticoids increase a specific type of basal progenitors (co-expressing PAX6 and EOMES) that has been shown to drive cortical expansion in gyrified species. This effect is mediated via the transcription factor ZBTB16 and leads to increased production of neurons. A phenome-wide mendelian randomization analysis of an enhancer variant that moderates glucocorticoid-induced ZBTB16 levels, reveals causal relationships with higher educational attainment and altered brain structure. The relationship with postnatal cognition is supported by data from a prospective pregnancy cohort. This study provides a novel cellular and molecular pathway for the effects of glucocorticoids on human neurogenesis that relates to lasting postnatal phenotypes.

neuroscience↗

bioRxiv2022

Extrinsic regulation of interneuron specification and migration

The imbalance between excitatory and inhibitory neurons in the human brain might lead to neurodevelopmental and neuropsychiatric disorders including cortical malformations, epilepsy, and autism spectrum disorders. We propose that the extracellular environment regulates interneuron differentiation and migration during development, ultimately affecting the excitatory/inhibitory balance. Using ventral cerebral organoids and dorso-ventral cerebral assembloids with mutations in the extracellular matrix gene LGALS3BP, we show that the composition of the extracellular environment regulates the molecular differentiation of neurons, resulting in alterations in migratory dynamics. To investigate how the extracellular environment affects neuronal specification and migration, we characterized the protein content of extracellular vesicles from cerebral organoids carrying a mutation in LGALS3BP, previously identified in individuals with cortical malformations and neuropsychiatric disorders. These results revealed differences in protein composition. Interestingly, proteins associated with cell-fate decision, neuronal migration and extracellular matrix composition were altered in mutant extracellular vesicles. Moreover, we show that treatment with extracellular vesicles changes the transcriptomic profile in neural progenitor cells. Our results indicate that neuronal molecular differentiation is regulated by factors released into the extracellular environment.

developmental biology↗

bioRxiv2021

AMPylation is a specific lysosomal protein posttranslational modification in neuronal maturation.

Protein AMPylation is a pervasive posttranslational modification with an emerging role in neurodevelopment. In metazoans the two highly conserved protein AMP-transferases together with a diverse group of AMPylated proteins have been identified using chemical proteomics and biochemical techniques. However, the function of this modification remains largely unknown. Particularly problematic is the localization of thus far identified AMPylated proteins and putative AMP-transferases. Here, we uncover protein AMPylation as a novel posttranslational modification of luminal lysosomal proteins characteristic in differentiating neurons. Through a combination of chemical proteomics, advanced gel-based separation of modified and unmodified proteins and activity assay, we show that an AMPylated, lysosomal soluble form of exonuclease PLD3 increases dramatically during neuronal maturation and that AMPylation inhibits its catalytic activity. Together, our findings unveil so far unknown lysosomal posttranslational modification, its connection to neuronal differentiation and putatively provide a novel molecular rationale to design of therapeutics for lysosomal storage diseases.

biochemistry↗

bioRxiv2020

Combined CTL and NK cell cytotoxicity against cancer cells

CTL and NK cells recognize and eliminate cancer cells. However, immune evasion, down regulation of immune function by the tumor microenvironment, or resistance of cancer cells are a major problem. While CTL and NK cells are both important to eliminate cancer, most studies address them individually. In a new experimental human model, we analysed combined primary human CTL and NK cell cytotoxicity against the melanoma cell line SK-Mel-5. At high effector-to-target ratios, MART-1-specific CTL or NK cells eliminated SK-Mel-5 cells within 24 hours indicating that SK-Mel-5 cells are initially not resistant. However, at lower effector-to-target ratios, which resemble conditions of the immune contexture in human cancer, a significant number of SK-Mel-5 cells survived. Whereas CTL pre-exposure induced resistance in surviving SK-Mel-5 cells to subsequent CTL or NK cell cytotoxicity, NK cell pre-exposure induced resistance in surviving SK-Mel-5 cells to NK cells but not to MART-1 specific CTL. In contrast, there was even a slight enhancement of CTL cytotoxicity against SK-Mel-5 cells following NK cell pre-exposure. In all other combinations, resistance to subsequent cytotoxicity was higher, if melanoma cells were pre-exposed to larger numbers of CTL or NK cells. Increases in human leukocyte antigen class I expression correlated with resistance to NK cells, while reduction in MART-1 antigen expression correlated with reduced CTL cytotoxicity. CTL cytotoxicity was rescued beyond control levels by exogenous MART-1 antigen. This study quantifies the interdependence of CTL and NK cell cytotoxicity and may guide strategies for efficient CTL-NK cell anti-melanoma therapies. Key points summaryO_LICytotoxic T lymphocytes (CTL) and natural killer (NK) cells eliminate cancer cells. CTL and NK work in parallel, but most studies address them individually. C_LIO_LIIn a new human experimental model, antigen-specific CTL and NK cell cytotoxicity interdependence against melanoma is shown. C_LIO_LIWhereas high numbers of antigen-specific CTL and NK cells eliminate all melanoma cells, lower, more physiological numbers induce resistance, in case secondary CTL or NK cell exposure follow initial CTL cell exposure or if secondary NK cell exposure follows initial NK cell exposure; only if secondary CTL exposure follows initial NK cell exposure no resistance of melanoma but even a slight enhancement of cytotoxicity was observed. C_LIO_LIAlterations in HLA-I expression correlated with resistance to NK cells, while reduction in antigen expression correlated with reduced CTL cytotoxicity. CTL cytotoxicity was rescued beyond control levels by exogenous antigen. C_LIO_LIThe results should help to better understand and optimize immune therapies against cancer. C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=97 SRC="FIGDIR/small/150672v2_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@19fef9eorg.highwire.dtl.DTLVardef@12cae81org.highwire.dtl.DTLVardef@749eeforg.highwire.dtl.DTLVardef@6e7cf1_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2020

Cell-type specific impact of glucocorticoid receptor activation on the developing brain

A fine-tuned balance of glucocorticoid receptor (GR) activation is essential for organ formation, with disturbances influencing health outcomes. Excess GR-activation in utero has been linked to brain-related negative outcomes, with unclear underlying mechanisms, especially regarding cell-type specific effects. To address this, we used an in vitro model of fetal human brain, induced pluripotent-stem-cell-derived cerebral organoids, and mapped GR-activation effects using single-cell transcriptomics across development. Interestingly, neurons showed targeted regulation of differentiation- and maturation-related transcripts, suggesting a delay of these processes upon GR-activation. Uniquely in neurons, differentially-expressed transcripts were significantly enriched for genes associated with behavior-related phenotypes and disorders. This suggests that aberrant GR-activation could impact proper neuronal maturation, leading to increased disease susceptibility, through neurodevelopmental processes at the interface of genetic susceptibility and environmental exposure.

neuroscience↗

bioRxiv2019

FICD activity and AMPylation remodelling modulate human neurogenesis.

Posttranslational modification (PTM) of proteins represents an important cellular mechanism for controlling diverse functions such as signalling, localisation or protein-protein interactions1. AMPylation (also termed adenylylation) has recently been discovered as a prevalent PTM for regulating protein activity2. In human cells AMPylation has been exclusively studied with the FICD protein3-6. Here we investigate the role of AMPylation in human neurogenesis by introducing a cell-permeable propargyl adenosine pronucleotide probe to infiltrate cellular AMPylation pathways and report distinct modifications in intact cancer cell lines, human-derived stem cells, neural progenitor cells (NPCs), neurons and cerebral organoids (COs) via LC-MS/MS as well as imaging methods. A total of 162 AMP modified proteins were identified. FICD-dependent AMPylation remodelling accelerates differentiation of neural progenitor cells into mature neurons in COs, demonstrating a so far unknown trigger of human neurogenesis.

biochemistry↗