Biology subjects

Schofield, Z.

Publications and source records attributed to Schofield, Z..

6 recordsLinked to original sources

bioRxiv2024

Maternal gut Bifidobacterium breve modifies fetal brain metabolism in mice

In recent years, our understanding of the gut microbiomes impact on host physiology and metabolism has grown exponentially. Yet, the specific role of certain microorganisms in regulating gestational health and fetal development remains largely unexplored. During pregnancy, Bifidobacterium represents a key beneficial microbiota genus that provides multiple benefits, including changes in placental development and fetal glycaemia. In this study, using germ-free mice colonized with or without Bifidobacterium breve UCC2003 during pregnancy, we demonstrated that this bacterium is important for controlling fetal brain metabolism. In particular, presence of maternal Bifidobacterium led to reduced levels of ten metabolites (including citrate, 3-hydroxyisobutyrate, and carnitine) in the fetal brain, with concurrent elevated abundance of transporters involved in glucose and branched-chain amino acid uptake. B. breve supplementation was also associated with increased expression of critical metabolic and cellular pathways, including the PI3K-AKT, AMPK, STAT5 and Wnt-{beta}-catenin (including its receptor Frizzled-7) in the fetal brain. Furthermore, maternal-associated Bifidobacterium resulted in HIF-2 protein stabilization and altered a number of https://pubmed.ncbi.nlm.nih.gov/38269505/ genes and proteins involved in cellular growth, axogenesis, and mitochondrial function. These findings highlight that Bifidobacterium breve colonisation of the maternal gut is important for the metabolism and growth of the fetal brain.

developmental biology↗

bioRxiv2023

Emergence of synchronised growth oscillations in filamentous fungi

Soil fungi are important decomposers of organic matter and play crucial roles in the biogeochemical cycles in the soil. Many species of fungi grow in the form of branched networks. While there have been investigations on the growth and architecture of the fungal networks, their growth dynamics in space and time is still not fully understood. In this study, we monitor the growth dynamics of the plant-promoting filamentous fungus Serendipita indica for several days in a controlled environment within a microfluidic channel. We find that this species displays synchronized growth oscillations with the onset of sporulation and at a period of 3 hours. Quantifying this experimental synchronisation of oscillatory dynamics, we show that the synchronisation can be captured by the nearest neighbour Kuramoto model. Our analysis suggested the existence of millimetre-scale cell-cell communication across the fungi network. The microfluidic setup presented in this work may aid the future characterization of the molecular mechanisms of the cell-cell communication, which could in turn be exploited in order to control fungi growth and reproductive sporulation in soil and plant health management.

biophysics↗

bioRxiv2021

Thioflavin T indicates membrane potential in mammalian cells and can affect it in a blue light dependent manner.

The fluorescent benzothiazole Thioflavin T (ThT) has a high binding affinity to protein aggregates and is used as a marker for the study of this process, most commonly in the context of neurodegenerative disease research and diagnosis. Recently, this same dye was shown to indicate membrane potential in bacteria due to its cationic nature. This finding prompted a question whether ThT fluorescence is linked to the membrane potential in mammalian cells, which would be important for appropriate utilisation of ThT in research and diagnosis. Here, we show that ThT localises into the mitochondria of HeLa cells in a membrane-potential dependent manner. Specifically, ThT colocalised in cells with a well-established mitochondrial membrane-potential indicator Tetramethylrhodamine methyl ester (TMRM) and gave similar temporal responses as TMRM to treatment with a protonophore, carbonyl cyanide-4-(trifluoromethoxy) phenylhydrazone (FCCP). Additionally, we found that presence of ThT together with exposure to blue light ({lambda}=405 nm) exposure, but neither factor alone, caused depolarisation of mitochondrial membrane potential. This depolarisation effect was recapitulated by a mathematical model implementing the potential-dependent distribution of ThT and its light-dependent binding in mitochondria. These results show that ThT can act as a membrane potential dye in mammalian cells, when used at low concentrations and with low blue-light exposure, while it causes dissipation of the mitochondrial membrane potential at higher concentrations and in the presence of blue light excitation. This conclusion motivates a re-evaluation of ThTs use at micromolar range in live-cell analyses, while indicating that this dye can enable future studies on the potential connections between membrane potential dynamics and protein aggregation.

cell biology↗

bioRxiv2021

Dissemination and pathogenesis of toxigenic Clostridium perfringens strains linked to neonatal intensive care units and Necrotising Enterocolitis

BackgroundClostridium perfringens is an anaerobic toxin-producing bacterium that has long been associated with intestinal diseases, particularly in neonatal humans and animals. More recently, infant gut microbiome studies have suggested an important link between C. perfringens and the devastating preterm-associated disease Necrotising Enterocolitis (NEC), but in-depth studies on this pathogen (genomics and mechanistic) are lacking. Methods/MaterialsWe isolated and whole-genome sequenced 274 infant-associated C. perfringens isolates from 5 hospitals across the UK between 2011-2016 (including longitudinal samples from 31 individuals). We performed in-depth genomic analyses, phenotypically characterised pathogenic traits of 10 strains (including 4 C. perfringens from NEC patients) and established a novel oral-challenge C57BL/6 mouse infection model for microbe-host studies. ResultsPore-forming toxin encoding genes pfoA and cpb2 were enriched within hypervirulent lineages that exclusively consisted of C. perfringens-associated NEC (CPA-NEC) strains, in addition to overabundance of colonisation factors. Importantly, we identified a circulating C. perfringens variant, eventually linked to a fatal CPA-NEC case. The variant was detected consistently within 6 individuals in two sister hospitals across a 40-day window, demonstrating for the first time the intra- and inter-hospital dissemination of C. perfringens. CPA-NEC isolates were determined phenotypically to be more virulent (linked with overabundance of gene pfoA) than isolates obtained from non-NEC preterm babies. In addition, two pfoA-positive CPA-NEC C. perfringens strains were confirmed to induce clinical inflammatory tissue lesions in vivo. ConclusionsHypervirulent lineages are linked to CPA-NEC, potentially due to the production of pore-forming toxins, coupled with higher metabolic, transmission, and pathogenic capacities. These studies indicate C. perfringens is an important bacterial pathogen in preterm infants and highlights the requirement for further investigation into development of intervention and therapeutic strategies.

microbiology↗

bioRxiv2021

Maternal microbiota Bifidobacterium promotes placental vascularization, nutrient transport and fetal growth in mice

The gut microbiota plays a central role in regulating host metabolism. While substantial progress has been made in discerning how the microbiota influences host functions post birth and beyond, little is known about how key members of the maternal gut microbiota can influence feto-placental growth. Notably, in pregnant women, Bifidobacterium represents a key beneficial microbiota genus, with levels observed to increase across pregnancy. Here, using germ-free and specific-pathogen-free mice, we demonstrate that the bacterium Bifidobacterium breve UCC2003 modulates maternal body adaptations, placental structure and nutrient transporter capacity, with implications for fetal metabolism and growth. Maternal and placental metabolome were affected by maternal gut microbiota (i.e. acetate, formate and carnitine). Histological analysis of the placenta confirmed that Bifidobacterium modifies placental structure via changes in Igf2P0, Dlk1, Mapk1 and Mapk14 expression. Additionally, B. breve UCC2003, acting through Slc2a1 and Fatp1-4 transporters, was shown to restore fetal glycaemia and fetal growth in association with changes in the fetal hepatic transcriptome. Our work emphasizes the importance of the maternal gut microbiota on feto-placental development and sets a foundation for future research towards the use of probiotics during pregnancy.

physiology↗

bioRxiv2019

The early life microbiota protects neonatal mice from pathological small intestinal epithelial cell shedding

The gut microbiota plays a crucial role in regulating and maintaining the epithelial barrier, particularly during early life. Notably, patients with chronic intestinal inflammation have a dysregulated process of renewal and replenishment of the intestinal epithelial cell (IEC) barrier, which is linked to disturbances in the gut microbiota. To date, there are no studies focussed on understanding the impact of inflammatory cell shedding events during the early life developmental window, and which host and microbial factors mediate these responses. Here we sought to determine pathological cell shedding outcomes throughout the postnatal developmental period (day 14, 21, 29 and week 8). Surprisingly neonatal mice (day 14 and 21) were highly refractory to induction of cell shedding after intraperitoneal administration of LPS, with day 29 mice showing strong pathological responses, more similar to those observed in adult mice. These differential responses were not linked to defects in the cellular mechanisms and pathways known to regulate cell shedding responses, although we did observe that neonatal mice had elevated anti-inflammatory (IL-10) responses. Notably, when we profiled microbiota and metabolites from these mice, we observed significant alterations. Neonatal mice had high relative abundances of Streptococcus, Escherichia and Enterococcus and increased primary bile acids. In contrast, older mice were dominated by Candidatus Arthromitus, Alistipes and Lachnoclostridium, and had increased concentrations of SCFAs and methyamines. Faecal microbiota transplant (FMT) and antibiotic studies confirmed the importance of early life gut microbiota in cell shedding responses. In these studies, neonates treated with antibiotics restored LPS-induced small intestinal cell shedding, whereas adult FMT alone had no effect. Our findings further support the importance of the early life window for microbiota-epithelial interactions in the presence of inflammatory stimuli and highlight areas for further investigation to probe underlying mechanisms to drive therapeutic development within the context of chronic inflammatory intestinal diseases.

microbiology↗