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Ninerola, S.

Publications and source records attributed to Ninerola, S..

5 recordsLinked to original sources

Dynamic Modulation of Neural Cell Identity Maintenance via Lysine Acetyltransferase Type 3 Protein Targeted Degradation

Cell identity acquisition during central nervous system development leads to the establishment of cell-specific transcriptional programs. Once acquired, this identity must be actively maintained, among other molecular mechanisms, by the acetylation of cell-type-specific regulatory regions carried out by the lysine acetyltransferases type 3 (KAT3) proteins CBP and p300. Here, we characterize the rapid transcriptional and physiological consequences of KAT3 elimination in neuronal and glial lineages by means of a KAT3-specific PROTAC degrader, providing strong evidence for their central role as neural identity wardens. Importantly, the restoration of KAT3 proteins in glial cells after cell identity erasure resulted in the recovery of the original transcriptome and physiological functions, probing the dynamic nature of neural cell identities. These findings expand the role of CBP/p300 as identity wardens and challenge our perception of terminal cellular identities as static irrevocable states, opening new avenues for neural identity manipulation with biomedical purposes.

neuroscience↗

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↗

Inflammation-induced epigenetic memory restores oligodendrocyte progenitor cell regenerative capacity in the aged central nervous system

Although remyelination, a central nervous system (CNS) regenerative process mediated by oligodendrocyte progenitor cells (OPCs), takes place in an inflammatory environment the long-term impact of inflammation on OPC remyelination capacity remains unclear. Here, we studied the short- and long-term impact of systemic inflammation on adult OPCs to assess whether transient inflammation triggers enduring chromatin remodelling indicative of inflammatory memory in OPCs. We observed long-lasting epigenetic modifications in response to both lipopolyssaccharide (LPS) and polyinosinic:polycytidylic acid (Poly(I:C)), but only LPS induced a tolerance-like memory. LPS-mediated tolerance-like memory enhanced OPC differentiation after demyelination in aged mice, reducing axonal damage. Our findings reveal OPC epigenetic memory of inflammation as a mechanism by which adult OPCs adapt to inflammatory challenges, which could be harnessed to reduce neuroinflammation and enhance remyelination efficiency in ageing and neurodegenerative diseases.

neuroscience↗

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↗

Control of protein synthesis and memory by GluN3A-NMDA receptors through inhibition of GIT1/mTORC1 assembly

De novo protein synthesis is required for synapse modifications underlying stable memory encoding. Yet neurons are highly compartmentalized cells and how protein synthesis can be regulated at the synapse level is unknown. Here we characterize neuronal signaling complexes formed by the postsynaptic scaffold GIT1, the mTOR kinase and Raptor that couple synaptic stimuli to mTOR-dependent protein synthesis; and identify NMDA receptors containing GluN3A subunits as key negative regulators of GIT1 binding to mTOR. Disruption of GIT1/mTOR complexes by enhancing GluN3A expression or silencing GIT1 inhibits synaptic mTOR activation and restricts the mTOR-dependent translation of specific activity-regulated mRNAs. Conversely, GluN3A removal enables complex formation, potentiates mTOR-dependent protein synthesis, and facilitates the consolidation of associative and spatial memories in mice. The memory enhancement becomes evident with light or spaced training, can be achieved by selectively deleting GluN3A from excitatory neurons during adulthood, and does not compromise other aspects of cognition such as memory flexibility or extinction. Our findings provide mechanistic insight into synaptic translational control and reveal a potentially selective target for cognitive enhancement.

neuroscience↗