Biology subjects

Hunter, A.

Publications and source records attributed to Hunter, A..

11 recordsLinked to original sources

bioRxiv2026

Micro-engineered Konjac Glucomannan-Montmorillonite Hybrids as Multifunctional Biomaterials for Addressing Diet-Induced Obesity in Mice

The growing prevalence of obesity necessitates innovative treatments. This study investigates a spray-dried konjac glucomannan-montmorillonite (KGM-MMT) hybrid designed to combine the fermentable, satiety-promoting effects of KGM with the lipid-binding and anti-inflammatory properties of MMT. In HFD-fed mice treated for 42 days with 2% w/w KGM-MMT, body weight gain was reduced by 7.6%, with an AUC of 5094[{+/-}[52.95, compared to 5513[{+/-}[81.35 in HFD controls (p < 0.0001). Serum IL-6 concentrations were reduced by 97% (p = 0.0002), while blood glucose decreased by 46% (p < 0.0001), outperforming reductions seen with MMT (24%, p = 0.0271) and KGM (16%, ns). Gut microbiota profiling demonstrated a significant 6.2-log[ fold increase in Lactobacillaceae (p = 0.023) and a 2.4-log[ fold increase in Enterococcaceae (p = 0.015) with KGM-MMT treatment. Predicted functional shifts revealed a 1.9-fold increase in short-chain fatty acid synthesis pathways and a 5.4-fold increase in bile acid deconjugation. Although the KGM-MMT hybrid did not consistently outperform its individual components in all measurements within the current study, it generally consolidated their metabolic benefits within a single dosage form. These findings support the utility of spray-dried KGM-MMT as a gut-targeted dietary strategy with additive effects on metabolic health. Future studies should explore underlying mechanisms and dosage effects of the hybrid formulation. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=110 SRC="FIGDIR/small/701163v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@738445org.highwire.dtl.DTLVardef@1f0d465org.highwire.dtl.DTLVardef@86e5aorg.highwire.dtl.DTLVardef@184fba8_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LISpray-dried KGM-MMT reduced HFD-induced weight gain by 7.6% in obese mice C_LIO_LISerum IL-6 and glucose levels decreased by 97% and 46%, respectively C_LIO_LI6.2-log[J and 2.4-log[J increases in Lactobacillaceae & Enterococcaceae relative abundance C_LIO_LIBile acid deconjugation and SCFA pathways increased 5.4- and 1.9-fold C_LIO_LIKGM-MMT microparticles offer additive gut-targeted benefits in metabolic disease C_LI

bioengineering↗

bioRxiv2026

Spray Dried Inulin-Montmorillonite Hybrids Alleviate High-Fat Diet-Induced Inflammatory and Metabolic Dysregulation in Rats

Obesity-related metabolic disorders are linked to excessive dietary lipid absorption and gut microbiota imbalances, particularly under high-fat diet (HFD) conditions. This study evaluates a spray-dried hybrid of inulin and montmorillonite (INU-MMT) designed to concurrently restrict intestinal lipid digestion and modulate the gut microbiota. Using an in vitro simulated intestinal lipolysis model, INU-MMT significantly reduced free fatty acid (FFA) release from medium-chain triglycerides by 4.0-fold compared to HFD conditions, outperforming INU and MMT individually. This superior inhibition is attributed to INUs ability to prevent MMT aggregation, resulting in smaller, more dispersed particles with enhanced lipid-binding capacity. In a 21-day in vivo study in HFD-fed rats, INU-MMT (1g/kg bodyweight/d) supplementation significantly attenuated cumulative weight gain by 4.7% compared to the HFD control, exceeding the effects of INU (2.0%) and MMT (1.5%) alone. 16S rRNA gene sequencing of fecal samples revealed improved gut microbial diversity (Simpsons index, p = 0.0161) and enrichment of health-associated taxa including Peptostreptococcaceae (8-fold), Ruminococcaceae (3.5-fold), Akkermansiaceae (2.5-fold), and Eggerthellaceae (7.7-fold). Beta diversity analysis highlighted that INU-MMT induced a distinct microbial composition from HFD and INU groups (PERMANOVA, adjusted p < 0.05), driven largely by MMT. Predictive metagenomic analysis using the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States 2 (PICRUSt2) software demonstrated a 98% reduction in microbial triacylglycerol lipase abundance, aligning with the observed in vitro lipolysis suppression results. These findings highlight the dual-mechanistic potential of INU-MMT in managing diet-induced obesity by targeting lipid digestion and imbalances within the gut microbiota. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/701174v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@1d2c787org.highwire.dtl.DTLVardef@1298bacorg.highwire.dtl.DTLVardef@90da36org.highwire.dtl.DTLVardef@1e6271c_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LISpray-dried INU-MMT restricts FFA release 4-fold in intestinal conditions C_LIO_LIHybrid outperforms INU and MMT in reducing HFD-induced weight gain in rats C_LIO_LIPromotes beneficial microbiota shifts and key SCFA-producing taxa C_LIO_LISuppressed predicted microbial lipase levels by 98% with INU-MMT treatment C_LIO_LIINU-MMT offers a multi-mechanistic strategy for future metabolic disease therapies. C_LI

bioengineering↗

bioRxiv2024

The atypical antipsychotic lurasidone positively modulates the gut microbiota in rats: A comparative study to olanzapine

Background and PurposeAntipsychotics like olanzapine are associated with significant metabolic dysfunction, attributable to gut microbiota dysbiosis. A recent notion that most psychotropics are detrimental to the gut microbiota has arisen from consistent findings of metabolic adverse effects. However, unlike olanzapine, the metabolic effects of lurasidone are conflicting, with most reports observing weight loss rather than gain. Thus, this study investigates the contrasting effects of olanzapine and lurasidone on the gut microbiota to explore the hypothesis of "gut neutrality" for lurasidone exposure. Experimental ApproachUsing a Sprague-Dawley rat model, the impact of olanzapine and lurasidone administration on the gut microbiota was explored. Faecal and blood samples were collected weekly over a 21-day period to analyse changes to the gut microbiota and related metabolic markers. Key ResultsLurasidone triggered no significant weight gain or metabolic alterations, instead positively modulating gut microbiota through increases in mean OTUs (+50 OTUs) and alpha diversity (+0.5 increase in Shannons index). This novel finding suggests an underlying mechanism for lurasidones metabolic inertia. In contrast, olanzapine triggered a statistically significant decrease in mean OTUs (-75 OTUs) and substantial compositional variation, suggesting a decrease in microbial richness. Microbiota alterations correlated with metabolic dysfunction, evidenced through a statistically significant 30% increase in weight gain, increase in pro-inflammatory cytokine expression, and increase in blood triglycerides and glycaemic levels. Conclusion and ImplicationsThe study challenges the notion that all antipsychotics disrupt the gut microbiota similarly and highlights the potential benefits of gut positive or neutral antipsychotics like lurasidone in managing metabolic side effects. Further research is warranted to validate these findings in humans to guide personalised pharmacological treatment regimens for schizophrenia. Bullet point summary- What is already known: O_LIOlanzapine induces weight gain by disrupting the gut microbiome. C_LIO_LIThe impact of lurasidone on the gut microbiome is unknown and weight gaining propensities unclear. C_LI - What this study adds: O_LILurasidone positively modulates gut microbiota through enhancement of microbial diversity and richness. C_LIO_LIPotential mechanisms underlying lurasidones weight and metabolic neutrality are elucidated. C_LI - Clinical significance: O_LIGut neutral antipsychotics like lurasidone could be favourable alternatives for patients unable to tolerate olanzapine. C_LIO_LIPersonalised treatment for schizophrenia considering individual sensitivities to metabolic effects is emphasised. C_LI

pharmacology and toxicology↗

bioRxiv2023

Development of a robotic cluster for automated and scalable cell therapy manufacturing

The production of commercial autologous cell therapies such as chimeric antigen receptor T cells requires complex manual manufacturing processes. Skilled labor costs and challenges in manufacturing scale-out have contributed to high prices for these products. Here, we present a robotic system that uses industry-standard cell therapy manufacturing equipment to automate the steps involved in cell therapy manufacturing. The robotic cluster consists of a robotic arm and customized modules, allowing the robot to manipulate a variety of standard cell therapy instruments and materials such as incubators, bioreactors, and reagent bags. This system enables existing manual manufacturing processes to be rapidly adapted to robotic manufacturing, without having to adopt a completely new technology platform. Proof-of-concept for the robotic clusters expansion module was demonstrated by activating and expanding human CD8+ T cells. The robotic cultures showed comparable cell yields, viability, and identity to those manually performed. Such modular robotic solutions may support scale-up and scale-out of cell therapies that are developed using classical manual methods in academic laboratories and biotechnology companies.

bioengineering↗

bioRxiv2023

Targeting ABCB4 using mRNA-LNP for the treatment of rare liver diseases

Mutations in the ABCB4 gene lead to a wide-spectrum of rare liver diseases including progressive familial intrahepatic cholestasis type 3 (PFIC3) and low-phospholipid associated cholelithiasis (LPAC) syndrome. PFIC3 patients develop symptoms during late infancy, including severe itching, jaundice, and failure to thrive. The condition may progress to liver failure during childhood or adulthood. This is a highly unmet medical condition where liver transplantation is the only option to correct this disease. Recently, exciting data suggested that restoration of the ABCB4 function via gene replacement could rescue liver phenotypes associated with ABCB4 dysfunction in a preclinical PFIC3 mouse model. Here, we used mRNA LNP platform to determine expression and durability of ABCB4 in the liver of wildtype mice. In addition, we generated Abcb4-/- mice to study the efficacy of systemic delivery of ABCB4 mRNA LNP. We observed a robust and durable expression of hABCB4 up to 72 hours post systemic dosing in the liver of wild-type mice. Systemic administration of hABCB4 mRNA achieved a remarkable restoration of phosphatidylcholine levels in bile, a significant decrease in liver stiffness as measured by shear wave elastography, and amelioration of liver histopathology including fibrosis and ductular reaction. We conclude that administration of hABCB4 mRNA LNPs was sufficient to ameliorate fibrosis markers in the PFIC3 mouse model. Our data suggests that gene replacement using mRNA LNP modality could provide an excellent opportunity for patients with biliary diseases.

molecular biology↗

bioRxiv2022

Differentiation of human induced pluripotent stem cells into cortical neural stem cells

Efficient and effective methods for converting human induced pluripotent stem cells (iPSC) into differentiated derivatives are critical for performing robust, large-scale studies of development and disease modelling, and for providing a source of cells for regenerative medicine. Here, we describe a 14-day neural differentiation protocol which allows for the scalable, simultaneous differentiation of multiple iPSC lines into cortical neural stem cells (NSCs). We currently employ this protocol to differentiate and compare sets of engineered iPSC lines carrying loss of function alleles in developmental disorder associated genes, alongside isogenic wildtype controls. Using RNA sequencing (RNA-Seq), we can examine the changes in gene expression brought about by each disease gene knockout, to determine its impact on neural development and explore mechanisms of disease. The 10-day Neural Induction period uses the well established dual-SMAD inhibition approach combined with Wnt/{beta}-Catenin inhibition to selectively induce formation of cortical NSCs. This is followed by a 4-day Neural Maintenance period facilitating NSC expansion and rosette formation, and NSC cryopreservation. We also describe methods for thawing and passaging the cryopreserved NSCs, which are useful in confirming their viability for further culture. Routine implementation of ICC Quality Control confirms the presence of PAX6-positive and/or FOXG1-positive NSCs and the absence of OCT4-positive iPSCs after differentiation. RNA-Seq, flow cytometry, immunocytochemistry (ICC) and RT-qPCR provide additional confirmation of robust presence of NSC markers in the differentiated cells. The broader utility and application of our protocol is demonstrated by the successful differentiation of wildtype iPSC lines from five additional independent donors. This paper thereby describes an efficient method for the production of large numbers of high purity cortical NSCs, which are widely applicable for downstream research into developmental mechanisms, further differentiation into postmitotic cortical neurons, or other applications such as large-scale drug screening experiments.

developmental biology↗

bioRxiv2022

Mouse and cellular models of KPTN-related disorder implicate mTOR signalling in cognitive and progressive overgrowth phenotypes

KPTN-related disorder (KRD) is an autosomal recessive disorder associated with germline variants in KPTN (kaptin), a component of the mTOR regulatory complex KICSTOR. To gain further insights into the pathogenesis of KRD, we analysed mouse knockout and human stem cell KPTN loss-of-function models. Kptn-/- mice display many of the key KRD phenotypes, including brain overgrowth, behavioural abnormalities, and cognitive deficits. Assessment of affected individuals has identified concordant selectivity of cognitive deficits, postnatal onset of brain overgrowth, and a previously unrecognised KPTN dosage-sensitivity, resulting in increased head circumference in their heterozygous parents. Molecular and structural analysis of Kptn-/- mice revealed pathological changes, including differences in brain size, shape, and cell numbers primarily due to abnormal postnatal brain development. Both the mouse and differentiated iPSC models of the disorder display transcriptional and biochemical evidence for altered mTOR pathway signalling, supporting the role of KPTN in regulating mTORC1. Increased mTOR signalling downstream of KPTN is rapamycin sensitive, highlighting possible therapeutic avenues with currently available mTOR inhibitors. These findings place KRD in the broader group of mTORC1 related disorders affecting brain structure, cognitive function, and network integrity.

genetics↗

bioRxiv2022

Structures of the Type IX Secretion/gliding motility motor from across the phylum Bacteroidetes

Gliding motility using cell surface adhesins and export of proteins by the Type IX Secretion System (T9SS) are two phylum-specific features of the Bacteroidetes. Both of these processes are energized by the GldLM motor complex which transduces the protonmotive force at the inner membrane into mechanical work at the outer membrane. We previously used cryo-electron microscopy to solve the structure of the GldLM motor core from Flavobacterium johnsoniae at 3.9 [A] resolution (Nat Microbiol (2021) 6: 221-233). Here we present structures of homologous complexes from a range of pathogenic and environmental Bacteroidetes species at up to 3.0 [A] resolution. These structures show that the architecture of the GldLM motor core is conserved across the Bacteroidetes phylum although there are species-specific differences at the N-terminus of GldL. The resolution improvements reveal a cage-like structure that ties together the membrane-proximal cytoplasmic region of GldL and influences gliding function. These findings add detail to our structural understanding of bacterial ion-driven motors that drive the T9SS and gliding motility. ImportanceMany bacteria in the Bacteroidetes phylum use the Type IX Secretion System to secrete proteins across their outer membrane. Most of these bacteria can also glide across surfaces using adhesin proteins that are propelled across the cell surface. Both secretion and gliding motility are driven by the GldLM protein complex which forms a nanoscale electrochemical motor. We used cryo-electron microscopy to study the structure of the GldLM protein complex from different species including the human pathogens Porphyromonas gingivalis and Capnocytophaga canimorsus. The organisation of the motor is conserved across species, but we find species-specific structural differences and resolve motor features at higher resolution. This work improves our understanding of the Type IX Secretion System, which is a virulence determinant in human and animal diseases.

biochemistry↗

bioRxiv2021

A spatial multi-omics atlas of the human lung reveals a novel immune cell survival niche

Multiple distinct cell types of the human lung and airways have been defined by single cell RNA sequencing (scRNAseq). Here we present a multi-omics spatial lung atlas to define novel cell types which we map back into the macro- and micro-anatomical tissue context to define functional tissue microenvironments. Firstly, we have generated single cell and nuclei RNA sequencing, VDJ-sequencing and Visium Spatial Transcriptomics data sets from 5 different locations of the human lung and airways. Secondly, we define additional cell types/states, as well as spatially map novel and known human airway cell types, such as adult lung chondrocytes, submucosal gland (SMG) duct cells, distinct pericyte and smooth muscle subtypes, immune-recruiting fibroblasts, peribronchial and perichondrial fibroblasts, peripheral nerve associated fibroblasts and Schwann cells. Finally, we define a survival niche for IgA-secreting plasma cells at the SMG, comprising the newly defined epithelial SMG-Duct cells, and B and T lineage immune cells. Using our transcriptomic data for cell-cell interaction analysis, we propose a signalling circuit that establishes and supports this niche. Overall, we provide a transcriptional and spatial lung atlas with multiple novel cell types that allows for the study of specific tissue microenvironments such as the newly defined gland-associated lymphoid niche (GALN).

cell biology↗

bioRxiv2021

A comparison of wild and captive Comal Springs riffle beetle (Heterelmis comalensis) microbiomes

The gut microbiome is affected by host intrinsic factors, diet, environment, and strongly linked to hosts health. Although fluctuations of microbiome composition are normal, some are due to changes in host environmental conditions. When species are moved into captive environments for conservation, education, or rehabilitation, these new conditions can influence a change in gut microbiome composition. Here, we compared the microbiomes of wild and captive Comal Springs riffle beetles (Heterelmis comalensis) by using amplicon sequencing of the 16S rRNA gene. We found that the microbiome of captive beetles was more diverse than wild beetle microbiomes. We identified 24 Amplicon Sequence Variants (ASVs) with relative abundances significantly different between the wild and captive beetles. Many of the ASVs overrepresented in captive beetle microbiomes belong to taxa linked to nitrogen-rich environments. This is one of the first studies comparing the effects of captivity on the microbiome of an endangered insect species. Our findings provide valuable information for future applications in the management of captive populations of H. comalensis.

microbiology↗

bioRxiv2018

The contribution of mitochondrial metagenomics to largescale data mining and phylogenetic analysis of Coleoptera

A phylogenetic tree at the species level is still far off for highly diverse insect orders, including the Coleoptera, but the taxonomic breadth of public sequence databases is growing. In addition, new types of data may contribute to increasing taxon coverage, such as metagenomic shotgun sequencing for assembly of mitogenomes from bulk specimen samples. The current study explores the application of these techniques for large-scale efforts to build the tree of Coleoptera. We used shotgun data from 17 different ecological and taxonomic datasets (5 unpublished) to assemble a total of 1942 mitogenome contigs of >3000 bp. These sequences were combined into a single dataset together with all mitochondrial data available at GenBank, in addition to nuclear markers widely used in molecular phylogenetics. The resulting matrix of nearly 16000 species with two or more loci produced trees (RAxML) showing overall congruence with the Linnaean taxonomy at hierarchical levels from suborders to genera. We tested the role of full-length mitogenomes in stabilizing the tree from GenBank data, as mitogenomes might link terminals with non-overlapping gene representation. However, the mitogenome data were only partly useful in this respect, presumably because of the purely automated approach to assembly and gene delimitation, but improvements in future may be possible by using multiple assemblers and manual curation. In conclusion, the combination of data mining and metagenomic sequencing of bulk samples provided the largest phylogenetic tree of Coleoptera to date, which represents a summary of existing phylogenetic knowledge and a defensible tree of great utility, in particular for studies at the intra-familial level, despite some shortcomings for resolving basal nodes.

evolutionary biology↗