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Wilson, T.

Publications and source records attributed to Wilson, T..

At least 19 recordsLinked to original sources

Spinal microglia are dispensable for the development of opioid-induced hyperalgesia

Adverse side effects of chronic opioid use, including analgesic tolerance, opioid-induced hyperalgesia, and addiction, are serious clinical challenges for pain management and opioid deprescribing. Microglia have been implicated in the development of these adverse effects, but the extent to which opioids alter microglia and the mechanisms behind opioid effects on microglia are poorly understood. We performed morphological and single-cell transcriptomic analysis on spinal microglia from opioid-withdrawn and saline-treated mice, and found that while morphological changes recapitulated prior reports, transcriptomic changes in these cells were modest. Furthermore, peripherally, but not centrally, restricted opioid administration was sufficient to induce both hyperalgesia and microglial morphological changes in mice. Finally, complete loss of microglia in Csf1r{Delta}{Delta}FIRE mice did not prevent the development of opioid-induced hyperalgesia, analgesic tolerance, and somatic withdrawal symptoms. These data argue against any microglial involvement in the development of these phenomena.

neuroscience↗

Gut Microbiome Composition in Older Adults with PTSD Symptoms and Trauma-Exposed Controls: Findings from the GUMP Study

Background: Emerging evidence suggests that alterations in the gut microbiome may contribute to mental health outcomes through the gut-brain axis. However, older adults with post-traumatic stress disorder (PTSD) remain underrepresented in microbiome research. This pilot study investigated associations between PTSD symptoms, dietary fibre intake, cognitive function, and gut microbiome functional capacity in adults aged 50 years and older. Methods: Participants with PTSD symptoms and trauma-exposed controls (TEC) completed validated assessments of mental health, trauma exposure, and dietary fibre intake. A subset of participants provided stool samples for microbiome analysis and undertook cognitive function assessment. Quantitative PCR was used to assess phylum-level taxonomy and butyrate-producing bacterial pathways (terminal butyrate generating enzyme), with abundances normalised to the 16S rRNA gene. Results: Participants with PTSD demonstrated significantly greater mental health symptom burden and poorer performance on cognitive tasks related to executive function, working memory, and learning. Dietary fibre intake did not differ significantly between PTSD and TEC groups and no significant differences in overall microbial composition were identified at the phylum level. In contrast, differences were more apparent when assessing functional microbiome pathways, with butyrate kinase abundance significantly lower in PTSD participants than TEC participants. When stratified by fibre intake, a greater butyrogenic capacity was observed in the High fibre TEC participants compared to the Low fibre TEC participants, while little difference was observed in the PTSD fibre-stratified groups. Substantial inter-individual variation was also evident across both taxonomic and functional measures. Conclusions: These findings suggest that functional characteristics of the gut microbiome may provide greater insight into PTSD-related biological processes than broad taxonomic measures alone. Dietary fibre intake may be associated with greater butyrate-producing capacity in trauma-exposed older adults without PTSD symptoms, although this relationship appeared less evident among older adults living with PTSD symptoms. These findings support further investigation of microbiome function, diet, and cognition within the gut-brain axis. Larger studies incorporating metagenomic and metabolomic approaches are warranted.

microbiology↗

Engineered Amphiregulin Promotes Tissue Healing via Dual Regenerative and Immunomodulatory Functions in Tissue-Resident Non-Immune Cells

Amphiregulin (AREG), a growth factor prominently expressed by immune cells, has emerged as an important mediator of tissue healing. However, its therapeutic potential and immunomodulatory effects remain elusive. Here, we engineered an optimized AREG (eAREG) with enhanced signaling and show that it promotes robust skin repair and muscle regeneration in murine models. Beyond its growth factor function, eAREG acts on tissue-resident non-immune cells to suppress inflammation-induced chemokine programs, thereby limiting the recruitment of pro-inflammatory immune cells. We further demonstrate that eAREG constrains chromatin accessibility at regulatory regions of key chemokine genes, revealing an epigenetic mechanism of immune regulation operating within non-immune tissue compartments. Importantly, the regenerative and immunomodulatory effects of eAREG are preserved in diabetic mice with elevated inflammation and impaired healing. Together, these findings identify eAREG as a dual-function regenerative biologic and establish a design principle for regenerative therapies that integrate morphogenic signaling with immunomodulation mediated by tissue-resident cells.

immunology↗

A Newly Identified Role of the Tectorial Membrane in Aminoglycoside Ototoxicity

Aminoglycoside (AG) antibiotic safety is limited by ototoxicity, the mitigation of which is vital considering bacterial resistance mediated erosion of our antibiotic arsenal. Previously, we observed tectorial membrane (TM) sequestration of Ca2+. We hypothesized that the TM sequesters other cations, including the AG gentamicin. We proposed to test the effect of TM genetic ablation on ototoxicity and TM-AG sequestration. After intraperitoneal AG-furosemide, TM-lacking Tecta{Delta}ENT/{Delta}ENT mice showed limited outer hair cell loss, unlike wildtype littermates. Spectroscopy measurements of gentamicin-Texas red (GTTR) were made in isolated wildtype and TectaY1870C TMs and guinea pig cochleae following direct or intraperitoneal GTTR administration. TM-GTTR sequestration was observed in all cases, while negatively correlated with TectaY1870C zygosity. In summary, we discovered a novel TM component in the AG ototoxicity pathway. Intact TM structure is necessary for sequestration, and the TM modulates AG ototoxicity. TM-GTTR sequestration following systemic injection indicates that this phenomenon occurs during AG therapy. Single sentence summaryOtotoxic aminoglycosides collect inside the acellular tectorial membrane of the inner ear, likely due to electrostatic interactions, and the structural status of that membrane modulates the toxic effect of those aminoglycosides on sensory hair cells.

physiology↗

Zone Equalisation Normalisation For Improved Alignment of Epigenetic Signal

High-throughput genomic technologies have transformed our understanding of biological systems, but analysing these complex datasets remains challenging. Existing normalisation methods often struggle to accurately correct for technical variations across different experimental conditions, potentially leading to misleading biological interpretations. We introduce Zone Equalisation Normalisation (ZEN), a novel approach designed to improve signal normalisation across genomic datasets. By developing a flexible method that reduces technical noise whilst preserving biological signals, ZEN addresses critical limitations in current normalisation techniques. By applying ZEN to diverse genomic techniques, we reveal its robust performance in managing technical variations across different experimental platforms. ZEN provides researchers with a robust tool for more accurate and reliable genomic data analysis, potentially revealing biological insights that were previously obscured by technical variations.

bioinformatics↗

Dynamic Inter-Modality Source Coupling Reveals Sex Differences in Children based on Brain Structural-Functional Network Connectivity: A Multimodal MRI Study of the ABCD Dataset

BackgroundSex differences in brain development are well-documented, yet the dynamic coupling between structure and function remains underexplored. We introduce dynamic inter-modality source coupling (dIMSC), extending our previous work to link structural MRI source-based morphometry (SBM) with dynamic functional network connectivity (dFNC). MethodsWe used data from the Adolescent Brain Cognitive Development (ABCD) study (ages 9-11) and combined SBM-derived gray matter sources with sliding-window dFNC. dIMSC was computed as the time-resolved cross-correlation between these modalities to quantify structure-function coupling strength. We evaluated sex differences in these profiles and their interaction with cognitive performance. ResultsSignificant sex-specific patterns emerged: males exhibited stronger positive coupling in sensorimotor regions (postcentral gyrus), while females showed stronger coupling in higher-order associative regions (inferior parietal lobule). These configurations were functionally distinct: higher positive coupling occupancy predicted better crystallized cognition (vocabulary) in females, whereas it predicted better fluid cognition (working memory) in males. ConclusionTogether, these findings suggest that males and females utilize distinct structural-functional configurations to support cognitive processing, males relying on a sensorimotor-anchored organization and females on an associative-anchored one. The dIMSC method advances our earlier work by enabling time-resolved analysis of brain coupling, providing a powerful framework for investigating sex-specific neurodevelopmental mechanisms.

neuroscience↗

The ultrafine-bridge-associated endonuclease ANKLE1 is stimulated by tension in DNA to process branch-points

Covalent linkages between chromosomes are naturally formed as a result of recombination or DNA replication. These can persist until late mitosis, resulting in interchromosomal ultrafine bridges, preventing cell division and causing genome instability. The endonuclease ANKLE1, localised at the cell midbody during cytokinesis and selective for DNA branchpoints, is ideally poised to act as an enzyme of last resort to process interchromosomal bridges, enabling cell division to proceed. However, how ANKLE1 cleaves DNA under the tension existing in interchromosomal bridges during mitosis remains unexplored. Using optical tweezers, we show that ANKLE1 is a tension-stimulated endonuclease. High tension in DNA increases the ANKLE1 junction cleavage rate, with a twenty-fold increase at 60 pN. This indicates that ANKLE1 has evolved to respond to tension-induced DNA structural changes, thereby facilitating nucleolytic activity. This novel mechano-enzymological response of ANKLE1 reveals how it is well-suited to process ultrafine-bridges during late mitosis.

biophysics↗

Multiscale wrinkling dynamics in epithelial shells

Thin shells buckle and wrinkle when compressed. While this behavior is generally detrimental in engineering, it has been widely implicated in epithelial morphogenesis and patterning during development. Yet the rules governing buckling of active viscoelastic shells like epithelia remain unclear. Here we delineate those rules by combining an experimental system that allows us to sculpt epithelial shells and subject them to controlled deflation with a 3D computational model linking cytoskeletal dynamics to tissue mechanics. Experiments and simulations across several orders of magnitude in time and space reveal that buckling emerges for fast deflation relative to the cortexs relaxation time, and is suppressed by high contractility. We show, further, that the tissue develops wrinkle patterns with different degrees of symmetry breaking that depend on its size and viscous confinement. Strikingly, we find that epithelial buckling is a multiscale phenomenon involving long-lived supracellular folds but also short-lived subcellular wrinkles in the actin cortex. Finally, by forming epithelial shells with anisotropic curvature we rationally direct buckling into predictable wrinkle patterns. Our study shows that epithelial tissues can be understood as hierarchical materials with mechanical instabilities that can be harnessed to engineer epithelial morphogenesis.

biophysics↗

REnformer, a single-cell ATAC-seq predicting model to investigate open chromatin sites

Genome regulatory elements are fundamental to cellular identity and cell type specific gene expression. Understanding how the underlying genetic code is differentially utilised by different cell types is central to understanding human health and disease. To better understand how DNA encodes genome regulatory elements such as promoters, enhancers, and boundary elements, we leverage the Enformer gene expression and epigenetic prediction model. We used transfer learning with high quality single cell ATAC datasets to develop REnformer, a model to predict chromatin accessibility. By introducing a bench-mark for comparing performances against Enformer model, REnformer significantly outperformed Enformer in terms of higher prediction outcomes and lower error rates in all extensive analyses shown; introducing these benchmarks allowed us, and possible future works, to fairly compare such models. We further tested REnformer by predicting the effects of a well characterised -thalassemia variant and found that the prediction aligned with the observed change in genome regulatory element, previously validated. We conclude that REnformer is and can be a state-of-the-art tool to predict cell type specific regulatory elements, and interrogate the effect of genome variation in health and disease.

bioinformatics↗

RNAse-free manufacture of Venezuelan Equine Encephalitis Virus (VEEV) plasmid DNA vaccine

The long shelf-life and stability of DNA makes this platform highly attractive for low-cost, rapid delivery of pandemic response vaccines. Protocols utilized for clinical grade plasmid manufacture by contract development and manufacturing organizations are not readily accessible to academic and public research laboratories engaged in early-phase plasmid vaccine development. We present here the framework for DNA manufacturing using 3L-scale fermentation, anion-exchange chromatography and tangential flow filtration (TFF) leading to RNAase-free manufacture of plasmid DNA. The Venezuelan Equine Encephalitis Virus vaccine plasmid pWRG/VEEV, encoding the glycoprotein (E)3, E2, 6K and E1 genes was used as the prototype for this process development. The current effort yielded >95% pure and >80% supercoiled pWRG/VEEV plasmid preparations at 50-g wet cell weight scale. These data showed feasibility of manufacturing, highly pure pWRG/VEEV plasmid DNA using a cGMP compliant manufacturing process. Distribution StatementApproved for public release: distribution is unlimited

biochemistry↗

Mdx mice dosed with antisense to CD49d and dystrophin exon skip morpholino; reduced force loss and affected gene expression pathways support ATL1102 combination therapy in DMD patients

BackgroundVLA-4 is a disease progression biomarker in patients with Duchenne Muscular Dystrophy (DMD) including those treated with corticosteroids. ATL1102 an antisense oligonucleotide (ASO) inhibitor of human CD49d chain of adhesion molecule VLA-4 shows promising phase-2 results in non-ambulant DMD stabilizing upper limb function (PUL2.0), grip strength, and MRI muscle fat fraction, compared to worsening with corticosteroids. MethodsASO to mouse CD49d (ISIS348574) was used in combination with a known mdx dystrophin morpholino exon-23 skipping restoration drug (PMO), dose-time chosen for low dystrophin restoration. Mdx mice were treated once weekly for 8 weeks with ASO, control mismatch oligonucleotide, saline, or PMO alone for 4 weeks, and PMO in combination with ASO or mismatch. ResultsASO+PMO demonstrated increased specific maximum force and eccentric muscle force retention in the exterior digitorum longus (EDL) muscle after 1-7 muscle eccentric contractions relative to saline. Area-under-curve force remaining after 8-10 contractions was higher for ASO+PMO versus PMO monotherapy and ASO monotherapy, PMO monotherapy versus saline, and the ASO monotherapy versus saline and mismatch. RNA-sequencing of quadriceps muscle evaluated gene expression changes, with false discovery rate (FDR) adjusted p-values up to <0.1. ASO monotherapy at FDR<0.05 showed 2 unique genes, Gm2a in immune neutrophil function and Trdn with Ryr2 muscle calcium channel function, versus mdx saline and none with MM. The lowest FDR PMO gene was another calcium channel Cacna1s, with PMO+MM FDR<0.05. ASO+PMO treatment at FDR<0.05 modulated 55 genes, 53 unique to the combination and 2* also in ASO FDR<0.06. Affected genes were involved in immune response (Btla*, Ppml1, Tnfsm13), lipolysis (Fabp4*, G0s2), fibrosis (Igfbp-7, Calu), muscle cell (Asb15) and muscle stem cell function (Adam10, Mt-Tp, Myom1). ConclusionASO+PMO EDL muscle function protection in mdx mice, and gene expression pathways affected, support the development of ATL1102 in combination therapy with conditionally approved morpholino dystrophin restoration drugs in DMD patients.

molecular biology↗

Generation of humanized mouse models to support therapeutic development for SYNGAP1 and STXBP1 disorders

Heterozygous variants in SYNGAP1 and STXBP1 cause distinct neurodevelopmental disorders due to haploinsufficiency of essential synaptic proteins. As gene targeted approaches to correct these disorders often target non-conserved genomic regions, thus limiting their clinical translation, we generated humanized mouse models wherein the entire Syngap1 or Stxbp1 loci were replaced with their human counterparts. Stxbp1 humanized mice exhibited impaired viability, while Stxbp1 hybrid mice (Stxbp1Hu/+) were viable and suitable for evaluating target engagement of human-specific therapeutics. Syngap1 humanized mice were viable and successfully crossed with Syngap1 heterozygous mice to produce a Syngap1 humanized-haploinsufficient model (Syngap1Hu/-). Syngap1Hu/- mice displayed haploinsufficient levels of human SYNGAP1, disease-relevant behaviors, and EEG abnormalities including epileptiform activity and generalized slowing. Importantly, parallel analysis in a cohort of patients with SYNGAP1-disorder revealed similar electrophysiological signatures. Finally, we showed that human gene-targeted antisense oligonucleotides modulate human SYNGAP1 expression in Syngap1Hu/- neurons. Together, we describe new models to support pre-clinical therapeutic development for SYNGAP1 and STXBP1 disorders and identify translational biomarkers of SYNGAP1-disorder in mice and humans to benchmark therapeutic testing.

neuroscience↗

Ancient biomolecular analysis of 39 mammoth individuals from Kostenki 11-Ia elucidates Upper Palaeolithic human resource use

Circular structures made from woolly mammoth bones are found across Ukraine and west Russia, yet the origin of the bones remains uncertain. We present ten new mammoth radiocarbon dates from the largest circular structure at Kostenki 11-Ia, identifying two mammoth mandibles [~]200-1,200 years older than the other dated materials from the site, suggesting skeletal material from long-dead individuals was scavenged and used in the site construction. Biomolecular sexing of 30 individuals showed a predominance of females, suggesting the Kostenki mammoths are primarily from herds. We identify six mitochondrial lineages across 16 samples, showing they are not all from the same matriline. Integrating biomolecular sexing with stable{delta} 13C and{delta} 15N isotope analysis, we find no isotopically-differentiated resource use by females and males, providing the first analysis of foraging differences between sexes in any Late Pleistocene megafauna. Our study highlights the significance of integrating ancient biomolecular approaches in archaeological inference. TeaserIntegrating 14C dating, ancient DNA, palaeoproteomics, and stable isotopes improves our understanding of Kostenki 11-Ia

evolutionary biology↗

A Demographic-Conditioned Variational Autoencoder for fMRI Distribution Sampling and Removal of Confounds

ObjectivefMRI and derived measures such as functional connectivity (FC) have been used to predict brain age, general fluid intelligence, psychiatric disease status, and preclinical neurodegenerative disease. However, it is not always clear that all demographic confounds, such as age, sex, and race, have been removed from fMRI data. Additionally, many fMRI datasets are restricted to authorized researchers, making dissemination of these valuable data sources challenging. MethodsWe create a variational autoencoder (VAE)-based model, DemoVAE, to decorrelate fMRI features from demographics and generate high-quality synthetic fMRI data based on user-supplied demographics. We train and validate our model using two large, widely used datasets, the Philadelphia Neurodevel-opmental Cohort (PNC) and Bipolar and Schizophrenia Network for Intermediate Phenotypes (BSNIP). ResultsWe find that DemoVAE recapitulates group differences in fMRI data while capturing the full breadth of individual variations. Significantly, we also find that most clinical and computerized battery fields that are correlated with fMRI data are not correlated with DemoVAE latents. An exception are several fields related to schizophrenia medication and symptom severity. ConclusionOur model generates fMRI data that captures the full distribution of FC better than traditional VAE or GAN models. We also find that most prediction using fMRI data is dependent on correlation with, and prediction of, demographics. SignificanceOur DemoVAE model allows for generation of high quality synthetic data conditioned on subject demographics as well as the removal of the confounding effects of demographics. We identify that FC-based prediction tasks are highly influenced by demographic confounds.

neuroscience↗

Seq-Scope Protocol: Repurposing Illumina Sequencing Flow Cells for High-Resolution Spatial Transcriptomics

Spatial transcriptomics (ST) technologies represent a significant advance in gene expression studies, aiming to profile the entire transcriptome from a single histological slide. These techniques are designed to overcome the constraints faced by traditional methods such as immunostaining and RNA in situ hybridization, which are capable of analyzing only a few target genes simultaneously. However, the application of ST in histopathological analysis is also limited by several factors, including low resolution, a limited range of genes, scalability issues, high cost, and the need for sophisticated equipment and complex methodologies. Seq-Scope--a recently developed novel technology--repurposes the Illumina sequencing platform for high-resolution, high-content spatial transcriptome analysis, thereby overcoming these limitations. Here we provide a detailed step-by-step protocol to implement Seq-Scope with an Illumina NovaSeq 6000 sequencing flow cell that allows for the profiling of multiple tissue sections in an area of 7 mm x 7 mm or larger. In addition to detailing how to prepare a frozen tissue section for both histological imaging and sequencing library preparation, we provide comprehensive instructions and a streamlined computational pipeline to integrate histological and transcriptomic data for high-resolution spatial analysis. This includes the use of conventional software tools for single cell and spatial analysis, as well as our recently developed segmentation-free method for analyzing spatial data at submicrometer resolution. Given its adaptability across various biological tissues, Seq-Scope establishes itself as an invaluable tool for researchers in molecular biology and histology. KEY POINTSO_LIThe protocol outlines a method for repurposing an Illumina NovaSeq 6000 flow cell as a spatial transcriptomics array, enabling the generation of high-resolution spatial datasets. C_LIO_LIThe protocol introduces a streamlined data analysis pipeline that produces a spatial digital gene expression matrix suitable for various single-cell and spatial transcriptome analysis methods. C_LIO_LIThe protocol allows for the capture of histology images from the same tissue section subjected to spatial transcriptomics analysis and allows users to precisely align the transcriptome dataset with the histological image using fiducial marks engraved on the flow cell surface. C_LIO_LILeveraging commonly available Illumina equipment, the protocol offers researchers ultra-high submicrometer resolution in spatial transcriptomics analysis with a comprehensive pipeline, rapid turnaround, cost efficiency, and versatility. C_LI

genomics↗

Sub-second Dopamine Signals during Risky Decision-Making in Patients with Impulse Control Disorder

BackgroundImpulse Control Disorder (ICD) in Parkinsons disease is a behavioral addiction arising secondary to dopaminergic therapies, most often dopamine receptor agonists. Prior research implicates changes in striatal function and heightened dopaminergic activity in the dorsal striatum of patients with ICD. However, this prior work does not possess the temporal resolution required to investigate dopaminergic signaling during real-time progression through various stages of decision-making involving anticipation and feedback. MethodsWe recorded high-frequency (10Hz) measurements of extracellular dopamine in the striatum of patients with (N=3) and without (N=3) a history of ICD secondary to dopamine receptor agonist therapy for Parkinsons disease symptoms. These measurements were made using carbon fiber microelectrodes during awake DBS neurosurgery and while participants performed a sequential decision-making task involving risky investment decisions and real monetary gains and losses. Per clinical standard-of-care, participants withheld all dopaminergic medications prior to the procedure. ResultsPatients with ICD invested significantly more money than patients without ICD. On each trial, patients with ICD made smaller adjustments to their investment levels compared to patients without ICD. In patients with ICD, dopamine levels rose or fell on sub-second timescales in anticipation of investment outcomes consistent with increased or decreased confidence in a positive outcome, respectively; dopamine levels in patients without ICD were significantly more stable during this phase. After outcome revelation, dopamine levels in patients with ICD rose significantly more than in inpatients without ICD for better-than-expected gains. For worse-than-expected losses, dopamine levels in patients with ICD remained level whereas dopamine levels in patients without ICD fell. ConclusionWe report significantly increased risky behavior and exacerbated phasic dopamine signaling, on sub-second timescales, anticipating and following the revelation of the outcomes of risky decisions in patients with ICD. Notably, these results were obtained when patients who had demonstrated ICD in the past but were, at the time of surgery, in an off-medication state. Thus, it is unclear whether observed signals reflect an inherent predisposition for ICD that was revealed when dopamine receptor agonists were introduced or whether these observations were caused by the introduction of dopamine receptor agonists and the patients having experienced ICD symptoms in the past. Regardless, future work investigating dopamines role in human cognition, behavior, and disease should consider the signals this system generates on sub-second timescales.

neuroscience↗

Social learning of a challenging two-step action sequence fulfils key criteria of cumulative culture in an insect

Culture in non-human animals refers to behaviour that is socially learned and persists within a population over time. Human culture is notable in that it is cumulative: new innovations have built on previous ones over thousands of years. As a result, what is acquired via social learning often goes far beyond the capacity of any individual to independently discover it during their lifetime1-3. To date, no previous study has convincingly demonstrated this phenomenon in a non-human animal. Here, we show that bumblebees can learn from a trained demonstrator to open a novel, 3D-printed two-step puzzle box to obtain food rewards, even though they fail to do so independently. Experimenters were unable to train demonstrators to perform the unrewarded first step of the behaviour without providing a temporary reward linked to this action: the reward then being removed during later stages of training. However, a third of naive observers learned to open the two-step box from these demonstrators, without ever having been rewarded after the first step. This suggested that social learning might permit the acquisition of behaviours too complex to "re-innovate" via individual learning. Furthermore, naive bees failed to open the box despite extended exposure over the course of 12 days. The temporal and spatial distance of the unrewarded first step from the reward appeared to inhibit acquisition of two-step box-opening via individual associative learning, but this limitation was overcome by the presence of a trained conspecific. To our knowledge, these results make bumblebees the first animal to demonstrate the ability to socially learn a behaviour that is beyond their ability to innovate individually. This finding challenges the prevailing opinion of the field, which generally considers cumulative culture, which is built on this capacity, to be unique to humans.

animal behavior and cognition↗

Discovery of 1,3,4-oxadiazoles with slow-action activity against Plasmodium falciparum malaria parasites

To achieve malaria eradication, new preventative agents that act differently to front-line treatment drugs are needed. To identify potential chemoprevention starting points we screened a sub-set of the CSIRO Australia Compound Collection for compounds with slow-action in vitro activity against Plasmodium falciparum. This work identified N,N-dialkyl-5-alkylsulfonyl-1,3,4-oxadiazol-2-amines as a new antiplas-modial chemotype (e.g., 1 96 h IC50 550 nM) with a different action to delayed-death slow-action drugs. Structure activity relationship analysis of analogues identified multiple compounds with potent and selective in vitro activity against drug-sensitive and multi-drug resistant Plasmodium parasites (e.g., 31 and 32 96 h IC50 <40 nM; SI >2,500). However subsequent studies in mice with lead compound 1, which had the best microsomal stability of the compounds assessed, demonstrated rapid clearance (T1/2 <1.6 h) and poor oral in vivo efficacy. This indicates that improvements in the pharmacokinetic profile of N,N-dialkyl-5-alkylsulfonyl-1,3,4-oxadiazol-2-amines would be needed for the development of this chemotype for malaria chemoprophylaxis.

microbiology↗