Biology subjects

Allcock, N.

Publications and source records attributed to Allcock, N..

3 recordsLinked to original sources

bioRxiv2026

Identification of a miRNA signature for schizophrenia in plasma-derived extracellular vesicles

Background and Hypothesis: Extracellular vesicles (EVs) are phospholipid bilayer vesicles released from cells containing proteins, lipids and nucleic acids derived from the parent cell. Alterations in miRNA expression within blood-derived EVs have been proposed as potential biomarkers of disease. Specifically, identification of differentially expressed miRNAs in patients with schizophrenia (SZ) compared to healthy individuals could be used as a "miRNA signature" to aid in diagnosis and treatment. We therefore aimed to identify differentially expressed miRNAs in plasma-derived EVs between people living with SZ and healthy controls and to correlate miRNA levels with SZ-relevant clinical measures. Study Design: Plasma-derived EVs were isolated from a cohort of 33 individuals with SZ and 34 controls. Expression of 84 miRNAs was examined using a RT-qPCR panel. Study Results: Three miRNAs (hsa-miR-30e-5p, hsa-miR-103a-3p, hsa-miR-200b-3p) were differentially expressed between controls and patients. Gene ontology analysis of putative target genes shared between these miRNAs revealed enrichment of biological process terms related to neurogenesis. Analysis of miRNA expression compared to clinical measures showed that hsa-miR-103a-3p expression was associated with working memory and negatively correlated with white matter integrity in the combined patient-control group. Conclusions: We have identified a miRNA signature for SZ in plasma-derived EVs and shown for the first time that hsa-miR-30e-5p expression is significantly increased in plasma-derived EVs in SZ. The genetic links between differentially expressed miRNAs and neurogenesis, along with the correlations of hsa-miR-103a-3p with working memory and white matter integrity may underlie the functional importance of altered expression of the identified miRNAs in SZ.

genetics↗

bioRxiv2025

Examination of the enrichment of neuronal extracellular vesicles from cell conditioned media and human plasma using an anti-NCAM immunocapture bead approach

BackgroundThe isolation of neuron-derived extracellular vesicles (nEVs) from biofluids offers the potential to discover novel biomarkers to aid in diagnosis and treatment of psychiatric and neurodegenerative diseases. A few studies have used anti-NCAM antibody-bead-based immunocapture to enrich nEVs from plasma, some with little method validation. We therefore examined in detail this method for nEV enrichment. MethodsEVs were isolated from SH-SY5Y cell-conditioned media by precipitation, or from plasma using size exclusion chromatography. EVs were characterised using nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM) and immunoblot analysis. SH-SY5Y-EVs were incubated with anti-NCAM immunocapture beads and examined by flow cytometry, immunoblot analysis and scanning electron microscopy (SEM). Immunocaptured plasma-derived EVs were examined using a sensitive NCAM ELISA, SEM and qPCR for miRNAs. ResultsCharacterisation of SH-SY5Y-derived and plasma-derived EVs revealed the expected size distributions of EVs using NTA, the presence of EV markers using immunoblot analysis, and a cup-shaped morphology using TEM. Anti-NCAM beads, but not anti-L1CAM or IgG beads, captured NCAM-positive SH-SY5Y-EVs as shown by flow cytometry and immunoblot analysis. Both SH-SY5Y and plasma-derived EVs were visualised on the surface of anti-NCAM immunocapture beads using SEM. A sensitive NCAM ELISA detected NCAM antigen in plasma-derived EVs immunocaptured on anti-NCAM beads. qPCR analysis of plasma-derived EVs detected many miRNAs in total plasma-EVs with high expression of hsa-miR-16-5p, hsa-miR-451a and hsa-miR-126-3p. However, only between two and seven miRNAs were detected in EVs captured on anti-NCAM-beads from three blood donors. Finally, tissue distribution analysis of miRNAs from plasma-derived EVs on anti-NCAM beads revealed that these miRNAs are enriched in tissues or organs such as blood vessels, lung, bone, thyroid and heart, but were not enriched for brain-derived miRNAs. Discussion: This study indicates that anti-NCAM beads can efficiently enrich NCAM-positive EVs from cell culture conditioned media. However, nEV levels in small volumes of plasma are possibly too low to enable efficient anti-NCAM immunocapture for subsequent miRNA analysis. Other neuron-specific markers with high expression levels on nEVs are therefore required for processing patient samples where plasma volumes are likely to be low, and to allow efficient isolation of nEVs in clinical studies for subsequent cargo analysis.

cell biology↗

bioRxiv2023

Air pollution modifies key colonization factors of the beneficial bee gut symbiont Snodgrassella alvi and disrupts the bumblebee (Bombus terrestris) gut microbiome.

Air pollution is the worlds largest environmental health risk. Particulate pollutants, a major component of air pollution, are detrimental to human health and a significant risk to wildlife and ecosystems globally. Black carbon, a by-product of fossil fuel and biomass burning, is a key constituent of air pollution with levels continuing to increase worldwide. Here we describe the effects of black carbon on the beneficial gut microbiome of an important global insect pollinator, the buff-tailed bumblebee (Bombus terrestris). Our data shows that exposure to black carbon particulates alters the biofilm structure, gene expression and initial adhesion of beneficial bee gut coloniser, Snodgrassella alvi in vitro. Additionally, our results show that black carbon disrupts adult Bombus terrestris gut microbiome composition, a vital component to bee health. Exposure to black carbon increased bees viable gut bacteria and significantly altered the abundance of beneficial core bacteria Gilliamella and Bombilactobacillus in the microbiome. These findings demonstrate that exposure to black carbon air pollution has direct, measurable effects on bees beneficial gut commensal bacteria and microbiome. Together these data highlight that particulate pollutants are an underexplored risk for the health of insect pollinators.

microbiology↗