Biology subjects

Miozzo, F.

Publications and source records attributed to Miozzo, F..

8 recordsLinked to original sources

bioRxiv2026

KAT3 Shuttling Between Neuronal Identity and Activity-Dependent Plasticity Programs Drives Large-Scale Chromatin Remodeling

Activity-dependent transcription is a central feature of neuronal plasticity. Here, we show that neuronal activation triggers genome-wide redistribution of CBP and p300 in hippocampal neurons. Upon stimulation, KAT3 cofactors relocate from super-enhancers supporting neuronal identity to enhancers associated with activity-regulated genes, accompanied by transient changes in H3K27ac, chromatin accessibility, and three-dimensional genome architecture. Mechanistically, distinct TF families control KAT3 shuttling: proneural bHLH factors such as NeuroD2 maintain cofactor occupancy at identity-associated regulatory elements, whereas AP-1 binds de novo at plasticity-associated loci. This dynamic redistribution reshapes enhancer landscapes and chromatin interactions, enabling robust activation of plasticity genes while transiently attenuating neuronal identity programs. Remarkably, FOS overexpression is sufficient to reproduce the repression of neuronal identity genes observed during stimulation. Together, our findings reveal a reversible competition between transcriptional networks governing neuronal identity and plasticity and identify KAT3 redistribution as a key mechanism coupling neuronal activity to large-scale chromatin remodeling.

neuroscience↗

bioRxiv2026

Systematic review and transcriptomic meta-analysis of environmental enrichment reveal core molecular programs of brain plasticity

RATIONALEEnvironmental enrichment (EE) paradigms in rodents have long demonstrated that enhanced sensory, cognitive, social, and motor stimulation positively impacts brain function, improving learning, memory, and neuroplasticity. These effects have significant implications for understanding cognitive development and mitigating cognitive decline and brain aging. While numerous transcriptomic studies have explored EE-induced molecular changes, a unified view of the genes and pathways consistently modulated remains lacking. METHODSTo address this gap, we performed a systematic review and meta-analysis. We conducted a comprehensive PubMed search for all studies published up to February 2025 that matched all the following inclusion criteria: (1) employed EE paradigms; (2) were conducted on rodents; (3) utilized genome-wide transcriptomic methods; (4) examined brain regions or neuronal populations. The 323 retrieved articles were manually screened for relevance to the study aims and data availability. Datasets from 20 eligible RNA-seq reports were reprocessed using a unified analysis pipeline and subjected to a meta-analysis with three complementary statistical methods. RESULTSDespite considerable heterogeneity across studies, our integrative analysis identified consistent gene expression signatures linked to synaptic function, plasticity and their transcriptional regulation. These molecular insights advance our understanding of how EE impacts on neuronal and behavioural outcomes, and may inform therapeutic strategies aimed at replicating or enhancing EE benefits. To promote open science and foster further research, we developed an accessible web application, mEEtaBrain, that enables the neuroscience community to navigate and interrogate our meta-analysis results.

neuroscience↗

bioRxiv2025

Aging alters the distribution, stability, and transcriptional signature of engram cells

While aging impairs memory precision, its effects on engram dynamics and gene expression remain poorly understood. To address this, we used TRAP2 activity-reporter mice, nuclear tagging, and FOS-based activity mapping to track neurons activated during contextual fear memory encoding and reactivated during recall in young and aged mice. Across 378 brain regions, we quantified engram size, spatial distribution, and reactivation stability. We further applied fluorescence-activated nuclear sorting (FANS) combined with single-nucleus RNA sequencing (snRNA-seq) to characterize gene expression changes associated with memory encoding and recall across diverse cell types. In addition, we compared the transcriptional profiles of first-time versus second-time neuronal responder cells in the dentate gyrus. Aged brains exhibited altered engram allocation, reduced reactivation stability, and distinct gene expression patterns during memory retrieval. These findings reveal age-related changes in the organization and molecular identity of memory traces, providing mechanistic insight into cognitive decline and highlighting potential targets for intervention.

neuroscience↗

bioRxiv2025

Rearing conditions bidirectionally modulate cognitive abilities and AP-1 signaling in hippocampal neurons in a cell type-specific manner.

Environmental conditions profoundly influence cognitive development, particularly during early life. Transcriptional and epigenetic mechanisms may serve as molecular substrates for the lasting effects of environmental enrichment (EE) and impoverishment (IE) on cognitive abilities and hippocampal function. However, the specific gene programs driving these changes remain largely unknown. In this study, EE and IE modulated the cognitive abilities of mice in opposing directions. By combining hippocampal microdissection and genetic tagging of neuronal nuclei with genome-wide analyses of gene expression, chromatin accessibility, histone acetylation, and DNA methylation, we uncovered profound differences in the transcriptional and epigenetic profiles of CA1 pyramidal neurons and dentate gyrus (DG) granule neurons. These analyses revealed cell type-specific genomic changes induced by EE and IE, highlighting distinct patterns of neuroadaptation within each population. This multiomic screen pinpointed the activity-regulated transcription factor AP-1 as a crucial mediator of neuroadaptation to conditions during early life in both cell types, albeit through distinct downstream mechanisms. Conditional deletion of Fos, a core AP-1 subunit, in excitatory neurons hampered EE-induced cognitive enhancement, further underscoring the pivotal role of this transcription factor in neuroadaptation.

neuroscience↗

bioRxiv2024

Disruption of autism-associated Pcdh9 gene leads to transcriptional alterations, synapses overgrowth and aberrant excitatory transmission in the CA1

Protocadherins are cell adhesion molecules with crucial role in cell-cell contacts, whose mutations or altered expression have been implicated in multiple brain disorders. In particular, growing evidence links genetic alterations in Protocadherin 9 (PCDH9) gene with Autism Spectrum Disorder (ASD) and Major Depression Disorder (MDD). Furthermore, Pcdh9 deletion induces neuronal defects in the mouse somatosensory cortex, accompanied by sensorimotor and memory impairment. However, the synaptic and molecular mechanisms underlying Pcdh9 physiological function and its involvement in brain pathology remain largely unknown. To this aim, we conducted a comprehensive investigation of PCDH9 role in the mouse hippocampus at the ultrastructural, biochemical, transcriptomic, electrophysiological and network level. We show that PCDH9 mainly localizes at glutamatergic synapses and its expression peaks in the first week after birth, a crucial time window for synaptogenesis. Strikingly, Pcdh9 KO neurons exhibit oversized presynaptic terminal and postsynaptic density (PSD) in the CA1. Synapse overgrowth is sustained by the broad up-regulation of synaptic genes and the dysregulation of key drivers of synapse morphogenesis, as revealed by single-nucleus RNAseq. Synaptic and transcriptional defects are accompanied by increased EPSC frequency and disturbances in the hippocampal network activity of Pcdh9 KO mice. In conclusion, our work indicates that Pcdh9 regulates the morphology and function of excitatory synapses in the CA1, thereby affecting glutamatergic transmission in hippocampal circuitries.

neuroscience↗

bioRxiv2022

The tetraspanin TSPAN5 regulates AMPARs exocytosis by interacting with the AP-4 complex

Intracellular trafficking of AMPA receptors is a tightly regulated process which involves several adaptor proteins, and is crucial for the activity of excitatory synapses in both basal conditions and during synaptic plasticity. We found that, in rat hippocampal neurons, an intracellular pool of the tetraspanin TSPAN5 specifically promotes exocytosis of newly synthesised GluA2-containing AMPA receptors without affecting their internalisation. TSPAN5 mediates this function by interacting with AP-4 and Stargazin and possibly using recycling endosomes as a delivery route. This work highlights TSPAN5 as a new adaptor regulating AMPA receptor trafficking. In addition, it provides a possible mechanism for the intellectual disability symptoms that occur in AP-4 deficiency syndrome.

neuroscience↗

bioRxiv2020

Maintenance of mitochondrial integrity in midbrain dopaminergic neurons governed by a conserved developmental transcription factor

The degeneration of dopaminergic (DA) neurons in the substantia nigra is a hallmark of Parkinsons disease (PD). Dysregulation of developmental transcription factors is implicated in dopaminergic neurodegeneration, but the underlying molecular mechanisms remain largely unknown. Drosophila Fer2 is a prime example of a developmental transcription factor required for the birth and maintenance of midbrain DA neurons. Using an approach combining ChIP-seq, RNA-seq, and genetic epistasis experiments with PD-linked genes, here we demonstrate that Fer2 controls a transcriptional network to maintain mitochondrial structure and function, and thus confers dopaminergic neuroprotection against genetic and oxidative insults. We further show that conditional ablation of Nato3, a mouse homolog of Fer2, in differentiated DA neurons results in locomotor impairments and mitochondrial abnormality in aged mice. Our results reveal the essential and conserved role of Fer2 homologs in the mitochondrial maintenance of midbrain DA neurons, opening new perspectives for modelling and treating PD.

neuroscience↗

bioRxiv2018

CBP/EP300-dependent acetylation and stabilization of HSF2 are compromised in the rare disorder, Rubinstein-Taybi syndrome

Cells respond to protein-damaging insults by activating heat shock factors (HSFs), key transcription factors of proteostasis. Abnormal HSF protein levels occur in cancer and neurodegenerative disorders, highlighting the importance of the tight control of HSF expression. HSF2 is a short-lived protein, but it is abundant in the prenatal brain cortex and required for brain development. Here, we reveal that HSF2 is acetylated and co-localized with the lysine-acetyl transferases CBP and EP300 in human brain organoids. Using unbiased, biochemical, cell-imaging, and in silico approaches, we show that CBP/EP300 acetylates HSF2 at specific lysine residues, which promotes HSF2 stabilization, whereas the lysine deacetylase HDAC1 catalyzes its proteasomal degradation. The CBP KIX domain and KlX-recognizing motifs in HSF2 are critical for its interaction with acetylating enzymes. The functional importance of acetylated HSF2 is evidenced in Rubinstein-Taybi syndrome (RSTS), characterized by mutated CBP or EP300. We show that RSTS patient cells exhibit decreased HSF2 levels and impaired heat shock response. The dysregulated HSF pathway in RSTS opens new avenues for understanding the molecular basis of this multifaceted pathology.

developmental biology↗