Biology subjects

Leoni, M.

Publications and source records attributed to Leoni, M..

3 recordsLinked to original sources

bioRxiv2026

Psychotic-like experiences in children born very preterm: evidence from clinical and population-based cohorts

Background and aimVery preterm birth (VPT; [≤]32 weeks gestation) is associated with an increased risk of later psychiatric disorders, including psychosis. Although psychosis typically emerges in adulthood, subclinical early signs along the psychosis continuum, such as psychotic-like experiences (PLEs), can be observed much earlier. We therefore aimed to study PLEs in childhood in VPT individuals recruited from a clinical cohort compared with full-term (FT) controls. We subsequently investigated whether findings could be replicated in an independent population-based cohort. MethodsPrimary analyses were conducted in the Brain, Immunity and Psychopathology (BIPP) study, including 197 children born VPT recruited through Neonatal Intensive Care Units and 72 FT controls assessed at a mean age of 10.50{+/-}1.77 years. Between-group differences in PLEs were then examined in the Adolescent Brain Cognitive Development (ABCD) study, including 149 children born VPT and 9519 FT controls assessed at a mean age of 9.94 {+/-} 0.63 years. PLEs were assessed using the Prodromal Questionnaire-Brief Child Version (PQ-BC), yielding frequency and distress-related scores for both the total scale and three specific domains (unusual thought content, perceptual abnormalities, disorganised speech). Regression models tested associations between birth status (VPT and control) and PQ-BC scores adjusting for age, sex, and socio-economic status, with secondary models additionally adjusting for cognitive ability and broader psychopathology. Pooled analyses examined cohort effects (BIPP and ABCD) and cohort-by-group status (VPT and control) interactions. ResultsIn BIPP, VPT birth was associated with higher PQ-BC total ({beta}=1.61, p=0.004) and distress scores ({beta}=0.78, p=0.039), with the strongest and most consistent associations observed for perceptual abnormalities across total score (sum of endorsed items), distressing items, and distress severity scores (all p[≤]0.01). These associations were attenuated but largely persisted after adjustment for cognitive ability and broader psychopathology, particularly for perceptual abnormalities. In ABCD, VPT birth was not significantly associated with global or domain-specific PQ-BC outcomes. DiscussionVPT birth is associated with increased vulnerability to PLEs in childhood, particularly in the domain of perceptual abnormalities. The lack of clear replication in the population-based ABCD cohort may reflect differences in the composition of its VPT subgroup, which may not fully represent VPT individuals typically seen in clinical cohorts.

developmental biology↗

bioRxiv2025

Amyloid beta aggregation promoted by iron leads to neuronal loss in an ex vivo model of Alzheimer's disease

Alzheimers disease (AD) is a progressive neurodegenerative disorder characterized by amyloid beta (A{beta}) plaques and neurofibrillary tangles. Despite well-established iron accumulation in the AD brain, its role in exacerbating A{beta} toxicity is often overlooked in therapeutic research. We developed a 3D ex vivo organotypic brain slice cultures (OBSC) with A{beta} monomers and ferric citrate to mimic A{beta} deposits and iron overload to investigate the impact of excess iron on A{beta} toxicity in pig and human brains. Light and electron microscopy, biochemical assays, and multiple regression modeling were employed to assess iron-mediated A{beta} toxicity in neurons and glial cells. We show that OBSC offer a close approximation of in vivo morphological and physiological properties and can retain both neurons and glial cells for extended periods, and respond to experimental manipulations. We show that iron promotes A{beta} fibrillization into long fibrils, with this process further influenced by temperature. A{beta} selectively accumulated in neurons, leading to their death, sparing glial cells. In contrast, Iron, though generally toxic to neurons, exhibited unspecific cytotoxicity. Notably, the combined presence of A{beta} and iron synergistically increased neuronal death while reducing glial cell loss. Correlation analysis revealed that this synergic interaction enhances the toxicity of each other in a mutual fashion - A{beta} directs the neuronal toxicity while iron promotes A{beta} fibrillization, leading to targeted neuronal loss. In conclusion, our findings emphasize the critical role of excess iron and A{beta} in driving neuronal death in AD, underlining the importance of targeting iron accumulation along with A{beta} clearance but also addressing in future AD therapies, while also supporting our OBSC model as a valuable platform for studying the same.

neuroscience↗

bioRxiv2022

Exploring cognitive, behavioural and autism trait network topology in very preterm and term-born children

Compared to full-term (FT) born peers, children who were born very preterm (VPT; <32 weeks gestation) are likely to display more cognitive and behavioural difficulties, including inattention, anxiety and socio-communication problems. In the published literature, such difficulties tend to be studied independently, thus failing to account for how different aspects of child development interact. The current study aimed to investigate childrens cognitive and behavioural outcomes as interconnected, dynamically related facets of development that influence one another. Participants were 93 VPT and 55 FT children (median age 8.79 years). IQ was evaluated with the Wechsler Intelligence Scale for Children - 4th edition (WISC-IV), autism spectrum condition (ASC) traits with the Social Responsiveness Scale - 2nd edition (SRS-2), behavioural and emotional problems with the Strengths and Difficulties Questionnaire (SDQ), temperament with the Temperament in Middle Childhood Questionnaire (TMCQ) and executive function with the Behaviour Rating Inventory of Executive Functioning (BRIEF-2). Outcome measures were studied in VPT and FT children using Network Analysis, a method that graphically represents partial correlations between variables and yields information on each variables propensity to form a bridge between other variables. Results showed that VPT and FT children exhibited marked topological differences. Bridges (i.e., the variables most connected to others) in the VPT group network were: SDQ Conduct Problems scale and BRIEF-2 Organisation of Materials scale. In the FT group network, the most important bridges were: the BRIEF-2 Initiate, SDQ Emotional Problems and SDQ Prosocial Behaviours scales. These findings highlight the importance of targeting different aspects of development to support VPT and FT children in person-based interventions.

developmental biology↗