Biology subjects

Chiariotti, L.

Publications and source records attributed to Chiariotti, L..

3 recordsLinked to original sources

bioRxiv2026

Maternal separation remodels Purkinje cell circuits and impairs cerebellar synaptic plasticity

Introduction: Early-life adversity has been associated with cerebellar abnormalities, but the cellular and circuit-level changes involved and their persistence across development remain poorly understood. We examined whether maternal separation (MS) disrupts cerebellar circuit maturation and whether these changes are accompanied by alterations in synaptic function and behavior. Methods: CD1 mice underwent daily maternal separation from postnatal day 2 to 18, whereas control litters remained undisturbed. Cerebellar alterations were assessed using transcriptomic and DNA methylation profiling, RT-qPCR, immunoblotting, Purkinje-cell morphometric analysis, and VGLUT1/VGLUT2 immunofluorescence. Patch-clamp electrophysiology was used to examine synaptic transmission and plasticity. Motor coordination, spontaneous locomotion, social approach, and stress-coping behavior were also evaluated. Results: RNA sequencing of whole cerebellar tissue revealed early transcriptional remodeling, involving synaptic transmission, neuronal architecture, and plasticity-related pathways. Consistent with this profile, we found that MS altered Purkinje cell dendritic arborization and excitatory input remodeling, together with deficits in cerebellar long-term synaptic plasticity and reduced BDNF-related signaling. In parallel, methylation analysis revealed hypermethylation of the glucocorticoid receptor promoter and reduced cerebellar receptor expression, indicating that early-life stress also engages stress-related epigenetic mechanisms in this region. Importantly, these neurobiological changes were associated with motor coordination deficits, altered stress-coping behavior, and impaired social interaction. Discussion: These findings identify the developing cerebellum as a target of early-life adversity and suggest that disrupted cerebellar maturation may contribute to lasting functional consequences. This study extends our understanding of the effects of maternal separation beyond the brain regions traditionally associated with stress responses.

neuroscience↗

bioRxiv2022

MC profiling: a novel approach to analyze DNA methylation heterogeneity in genome-wide bisulfite sequencing data

DNA methylation is an epigenetic mark implicated in crucial biological processes. Most of the knowledge about DNA methylation is based on bulk experiments, in which DNA methylation of genomic regions is reported as average methylation. However, average methylation does not inform on how methylated cytosines are distributed in each single DNA molecule. Here, we propose Methylation Class (MC) profiling as a genome-wide approach to the study of DNA methylation heterogeneity from bulk bisulfite sequencing experiments. The proposed approach is built on the concept of MCs, groups of DNA molecules sharing the same number of methylated cytosines. The relative abundances of MCs from sequencing reads incorporates the information on the average methylation, and directly informs on the methylation level of each molecule. By applying our approach to publicly available bisulfite-sequencing datasets, we individuated cell-to-cell differences as the prevalent contributor to methylation heterogeneity. Moreover, we individuated signatures of loci undergoing imprinting and X-inactivation, and highlighted differences between the two processes. When applying MC profiling to compare different conditions, we identified methylation changes occurring in regions with almost constant average methylation. Altogether, our results indicate that MC profiling can provide useful insights on the epigenetic status and its evolution at multiple genomic regions.

bioinformatics↗

bioRxiv2020

Long-chain polyphosphates impair SARS-CoV-2 infection and replication: a route for therapy in man

Anti-viral activities of long-chain inorganic polyphosphates (PolyPs) against severe acute respiratory syndrome coronavirus (SARS-CoV)-2 infection were investigated. In molecular docking analyses, PolyPs interacted with several conserved angiotensin-converting enzyme (ACE)2 and RNA-dependent RNA polymerase (RdRp) amino acids. We thus tested PolyPs for functional interactions in vitro in SARS-CoV-2-infected Vero E6, Caco2 and human primary nasal epithelial cells. Immunofluorescence, qPCR, direct RNA sequencing, FISH and Immunoblotting were used to determine virus loads and transcription levels of genomic(g)RNAs and sub-genomic(sg)RNAs. We show that PolyP120 binds to ACE2 and enhances its proteasomal degradation. PolyP120 shows steric hindrance of the genomic Sars-CoV-2-RNA/RdRP complex, to impair synthesis of positive-sense gRNAs, viral subgenomic transcripts and structural proteins needed for viral replication. Thus, PolyP120 impairs infection and replication of Korean and European (containing non-synonymous variants) SARS-CoV-2 strains. As PolyPs have no toxic activities, we envision their use as a nebulised formula for oropharyngeal delivery to prevent infections of SARS-CoV-2 and during early phases of antiviral therapy.

genetics↗