Biology subjects

Jones, N.

Publications and source records attributed to Jones, N..

At least 19 recordsLinked to original sources

bioRxiv2026

Aberrant CD4+ T cell refeeding response impairs neuro-immune crosstalk in Parkinson's disease

T cells modulate disease associated neuroinflammation in Parkinsons disease (PD). We report that circulating CD4+ T cells from people with PD have a dysregulated transcriptional and cytokine response to fasting and refeeding and an altered metabolic profile. The CD4+ T cell secretome mediates a metabolic program in neurons that is impaired in PD, revealing dysfunctional neuro-immune signalling that may contribute to disease pathology.

neuroscience↗

bioRxiv2026

Ubiquitinome dynamics and regulation by DUB2 during Leishmania differentiation

Leishmaniasis is caused by Leishmania parasites, which undergo cellular adaptation when transitioning from the insect stage (promastigote) to the mammalian stage (amastigote). While the ubiquitin-proteasome system (UPS) is vital for life cycle progression, global ubiquitination dynamics have remained unmapped. We established a quantitative ubiquitinomics workflow for Leishmania mexicana, identifying over 9,100 ubiquitination sites across 38% of the proteome, revealing thousands of stage-specific regulatory events. Promastigote-enriched sites associate with cell motility, while amastigote-enriched sites link to metabolism and glycosome organization. We identified extensive ubiquitination on UPS components, including the essential virulence factor deubiquitinase 2 (DUB2). Using inducible gene deletion and XL-BioID proximitomics, we identified 111 potential DUB2 substrates. High-confidence substrates include the E2 conjugating enzyme UBC2, which is required for differentiation, and SUMO, a critical regulator of ubiquitin crosstalk. The discovery of UBC2 as a substrate of DUB2 directly links ubiquitination with promastigote to amastigote differentiation. Our findings provide a comprehensive map of the Leishmania ubiquitinome and demonstrate that DUB2 acts as a pleiotropic regulator controlling post-translational modifications of essential proteins involved in life cycle progression.

microbiology↗

bioRxiv2026

Refined USP25/28 inhibitors with improved selectivity towards c-Myc driven squamous lung cancer cells

The ubiquitin specific protease 28 (USP28) is implicated in tumorigenesis by controlling the turnover of substrates including the oncogene c-MYC and the ubiquitin ligase FBW7. Here, we describe small molecule inhibitors of USP25 and USP28, leading to cancer cell cycle arrest and death. However, genetic deletion of USP25/28 does not replicate this effect. An integrated -omics approach revealed off-target effects for thienopyridine and thienopyrazine carboxamide compounds in protein translation. Chemoproteomics and biochemical analyses suggested binding of such compounds to a region near the ribosome complex polypeptide exit tunnel. Structural analysis of a USP28-inhibitor complex enabled the design of modified USP25/28 inhibitor molecules which minimized translation-related off-target effects. In distinction to earlier compounds, the optimized inhibitors were non-toxic to breast cancer cells yet retained potent anti-proliferative activity in squamous lung carcinoma cells, where USP28 is associated with disease progression. Together, our results demonstrate that refined USP25/28 inhibitors can selectively suppress tumor growth by targeting c-MYC driven pathways, offering a more precise therapeutic strategy for treating squamous lung cancers whilst minimizing undesired cytotoxicity.

cancer biology↗

bioRxiv2026

Drosophila melanogaster Nepl15 regulates lifespan, motor function, aging, heart rate, and cellular health in a sex-specific manner

Aging and obesity are characterized by comorbidities like declines in fertility, lifespan, gut barrier integrity, cardiac function, and motor activity, and an increase in oxidative stress due to altered nutrient and energy homeostasis. A study on Drosophila Neprilysin-like 15 (Nepl15) demonstrated that loss of Nepl15 gene significantly reduced glycogen and glycerolipid reserves in adult males and increased glycogen storage in adult females despite similar food consumption as controls. Therefore, we investigated the sex- and age-specific consequences of Nepl15 loss on cellular and physiological parameters associated with aging and obesity. We observed that egg production, rate of pupariation, and rate of adult fly eclosion were slightly better in the mutant flies. Interestingly, mutant females, but not males, exhibited significantly extended lifespan. Both sexes demonstrated improved locomotor performance, exercise endurance, gut barrier integrity, and preserved heart rate during progressive aging. At the cellular level, female mutants displayed reduced oxidative stress, elevated Sod2 expression, and increased ATP levels, all indicative of enhanced cellular health. Mutant males exhibited an increased mitochondrial membrane potential, indicating an enhanced capacity for rapid ATP production in response to enforced activity. Consistently, the energy-sensing kinase AMPK expression was reduced in the mutants. The lifespan extension of mutant females was supported by downregulation of mTOR and upregulation of Sirt6 expression. However, in mutant males, both mTOR and Sirt6 were downregulated, potentially contributing to improved physiological health without changing their lifespan. Collectively, our findings establish Nepl15 knockout mutation promotes anti-aging and anti-obesity health benefits, with stronger effects in female flies.

cell biology↗

bioRxiv2025

Temporal dynamics of noradrenaline release at fine spatial scales during motor learning

Noradrenaline (NA) released from the locus coeruleus (LC) has been known to play pivotal roles in arousal, sensory processing, decision-making, and learning through global release across the entire neocortex. Recent studies have demonstrated heterogeneous and modular NA release in distinct brain regions and highlighted its spatiotemporal dynamics across the neocortex. However, the spatiotemporal specificity of NA release at fine scales within a single brain region remains unclear, and it has not been reported whether the release patterns evolve functionally throughout prolonged learning processes such as motor skill acquisition. Here, by employing in vivo two-photon imaging with various genetically encoded NA sensors, we reveal that behavior-induced NA release in the primary motor cortex (M1) is spatially heterogeneous at the scale of local microcircuitry. Over the course of learning, the release pattern is locally refined, achieving consistent spatial precision within M1. Intriguingly, pharmacological manipulations that disrupt the spatial specificity also alter local neurons activity and representations. Furthermore, LC-NA axonal calcium imaging uncovered two distinct temporal activity patterns, in which non-behavior-related rapid axonal activity (sub-second duration events) profoundly affect the temporally precise behavior-induced persistent axonal activity (seconds duration events). Closed-loop optogenetic manipulations that bi-directionally modulate non-behavior-related rapid events directly impacted the learning process. Together, our results provide novel insights into the temporal dynamics of NA release at fine spatial scales within one brain region and underscore the critical role of local NA specificity in regulating circuit plasticity during motor skill acquisition.

neuroscience↗

bioRxiv2025

Uncovering a new player in ischemic stroke: a study of intra-arterial interferon-gamma-producing monocytes in hyperacute stroke

Stroke triggers a rapid and complex immune response that is not yet fully understood, especially within hours after an ischemic infarct. Our previous study in stroke patients revealed a significant increase in interferon- gamma (IFN-{gamma}) immediately (hyperacute) and downstream of the ischemic ictus, within the arterial compartment. The present study investigated the source, inciting factors, and role of IFN-{gamma} in a preclinical murine model. Stroke was produced using transient middle cerebral artery occlusion, and immune cells within the arterial vasculature distal to the occlusion (pre- and post-occlusion) were characterized using flow cytometry. Compared with the control samples, the post-occlusion samples presented an increase in IFN-{gamma}+ and CD69+ cells, whereas no significant increase was detected in IL17+, IL4+, and CD25+ cells. Further analysis of the IFN-{gamma}+ population revealed two novel attributes. First, interrogation of the identity of these IFN-{gamma}+ cells revealed that the increase in IFN-{gamma} production was largely driven by CD14+ cells in the post- occlusion sample, with negligible contributions from other canonical IFN-{gamma}-producing cells (CD4, CD8). Second, the IFN-{gamma}+ cells exhibited two distinct clusters, an IFN-{gamma}low and an IFN-{gamma}hi population. Further analysis revealed that the IFN-{gamma} low population was largely composed of CD14+ cells, whereas the IFN-{gamma}hi population was dominated by CD4+ T-cells. To explore the conditions driving IFN-{gamma} production, an in vitro ischemia model involving oxygen-glucose deprivation (OGD) was employed. Co-culturing of naive splenocytes with OGD-treated CNS cells and OGD-derived supernatant resulted in a significant increase in IFN-{gamma}+CD14+ cells, as compared to normoxic controls, an effect that coincided with marked loss of DAPI+ and NeuN+DAPI+ cells in mixed cortical (neuronal and glial) cultures. In summary, this study identified intra-arterial CD14+ monocytes as novel early sources of IFN-{gamma} in the hyperacute phase of stroke, a role traditionally attributed to adaptive immune cells. Using in vivo and in vitro ischemia models, the findings reveal that injury-associated signals from CNS cells are sufficient to directly induce IFN-{gamma} production in CD14+ cells, redefining early stroke immunopathology and uncovering a potential target for timely immunomodulation.

immunology↗

bioRxiv2025

Machine Learning Guided Structure Activity Discovery of Polymer Configurations in Lipid Nanoparticles for Kiss-and-Run Endosomal Escape

Endosomal escape remains a major barrier to effective nucleic acid delivery via lipid nanoparticles (LNPs). Here, we address this challenge by incorporating a pH-sensitive polymer, polyhistidine, into LNPs (pLNPs) to facilitate endosomal escape, with a focus on optimizing the polymers molecular weight (MW) and configuration--parameters that remain largely unexplored. Through systematic engineering, we designed linear and branched polyhistidine architectures with varied MWs and configurations. In vivo screening identified an optimized pLNP formulation incorporating a symmetrical bis-lysine histidine dendron with a MW of [~]1800 g/mol, which achieved a 266-fold increase in liver bioluminescence following intravenous delivery of luciferase mRNA compared to standard LNPs at an equivalent RNA dose. Mechanistic studies revealed that polymer configuration within pLNPs is critical for eliciting the proton sponge effect, leading to osmotic swelling and endosomal rupture. This configuration also promoted rapid endosomal membrane destabilization via a kiss-and-run mechanism, enabling efficient cytosolic release. When delivering base editor mRNA and single-guide RNA, the optimized pLNPs achieved 8% gene editing efficiency in the mouse liver at a low dose of 0.1 mg/kg, compared to 1% with standard LNPs. To accelerate discovery and address macromolecular design challenges, we developed a machine learning (ML) framework based on amino acid-level graph neural networks (GNNs). This approach identified branched, dendritic configurations with densely arranged histidine residues on a multivalent core as key determinants of delivery performance. The top ML-predicted candidate, NS535, achieved a 705-fold increase in liver bioluminescence over standard LNPs, validating our data-driven design strategy. Together, these findings establish a closed-loop platform integrating rational design, mechanistic validation, and ML-guided optimization to advance RNA delivery. By elucidating structure-activity relationships for polyhistidine carriers and demonstrating efficient, low-dose genome editing, this work provides a blueprint for next-generation nucleic acid therapeutics.

bioengineering↗

bioRxiv2025

Preclinical Study of Cannflavins A and B Action Against Glioblastoma Cells

AO_SCPLOWBSTRACTC_SCPLOWO_ST_ABSBackgroundC_ST_ABSFlavonoids represent a large group of naturally occurring polyphenolic compounds, many of which have been found to produce valuable biological outcomes, including action against cancer cells. Glioblastoma multiforme (GBM) is an aggressive type of brain tumor that is associated with a poor prognosis and has limited treatment options. Previous findings suggest that cannflavins can produce promising effects for pancreatic and bladder cancers, but the efficacy of these phytochemicals in attacking brain tumour cells remains unknown. Our study evaluates the potential of cannflavin A and cannflavin B against GBM cells using a range of in vitro approaches. ResultsWe conducted experiments using A-172 and U-87 GBM lines to assess the impact of cannflavins A and B on cell viability, cycle, migration, and invasion capacity. Our results revealed a consistent dose-dependent decrease in cell viability in both lines after the addition of cannflavin B to the culture media. Interestingly, we found that chrysoeriol (the non-prenylated synthesis precursor of cannflavins in the Cannabis sativa plant) only has a limited adverse effect on survival using the same approach, while techtochrysin (an O-methylated flavone) has none. Using time-lapse live-cell imaging and a scratch assay, we also show that cannflavins can inhibit tumor cell migration at concentrations below those that produce significant cell death. Finally, we found that cannflavin B exhibits anti-migratory and anti-invasive properties in transwell and tumorsphere assays, underscoring its multifaceted therapeutic potential. ConclusionThese findings suggest that cannflavin B holds promise as a therapeutic agent in the treatment of GBM. HO_SCPLOWIGHLIGHTSC_SCPLOWO_LICannflavin B but not cannflavin A limits the viability of A-172 and U-87 GBM cells in a concentration- and time-dependent manner. C_LIO_LIUsing time-lapse live-cell imaging and a scratch assay, we provide evidence that cannflavins A and B can inhibit GBM cell migration at concentrations below those that result in a significant reduction in cell viability. C_LIO_LICannflavin B exhibits robust anti-migratory and anti-invasive properties in transwell and tumorsphere assays, underscoring its multifaceted therapeutic potential. C_LIO_LIAlthough previous work had reported the capacity of cannflavins A and B to interfere with TrkB and downstream the MAPK/AKT signaling pathways in mouse primary neurons, the effect of those molecules is limited in GBMs, suggesting that other targets are engaged to produce the cellular effects. C_LI

pharmacology and toxicology↗

bioRxiv2025

ABHD11 inhibition drives sterol metabolism to modulate T cell effector function and alleviate autoimmunity

Chronic inflammation in autoimmunity is driven by T cell hyperactivation. This unregulated response to self is fuelled by heightened metabolic programmes, which offers a promising new direction to uncover novel treatment strategies. /{beta}-hydrolase domain-containing protein 11 (ABHD11) is a mitochondrial hydrolase that maintains the catalytic function of -ketoglutarate dehydrogenase (-KGDH), and its expression in CD4+ T cells has been linked to remission status in rheumatoid arthritis (RA). However, the importance of ABHD11 in regulating T cell metabolism and function - and thus, the downstream implication for autoimmunity - is yet to be explored. Here, we show that pharmacological inhibition of ABHD11 dampens cytokine production by human and mouse T cells. Mechanistically, the anti-inflammatory effects of ABHD11 inhibition are attributed to increased 24,25-epoxycholesterol (24,25-EC) biosynthesis and subsequent liver X receptor (LXR) activation, which arise from a compromised TCA cycle. The impaired cytokine profile established by ABHD11 inhibition is extended to two patient cohorts of autoimmunity. Importantly, using a murine model of accelerated type 1 diabetes (T1D), we show that targeting ABHD11 suppresses cytokine production in antigen-specific T cells and delays the onset of diabetes in vivo. Collectively, our work provides pre-clinical evidence that ABHD11 is an encouraging drug target in T cell-mediated autoimmunity. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/643996v1_ufig1.gif" ALT="Figure 1"> View larger version (59K): org.highwire.dtl.DTLVardef@bb3fcborg.highwire.dtl.DTLVardef@1594fc8org.highwire.dtl.DTLVardef@84e078org.highwire.dtl.DTLVardef@1ad023e_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2025

ChiraKit, an online tool for the analysis of circular dichroism spectroscopy data

Circular dichroism (CD) spectroscopy is an established biophysical technique to study chiral molecules. CD allows investigating conformational changes under varying experimental conditions and has been used to understand secondary structure, folding and binding of proteins and nucleic acids. Here, we present ChiraKit, a user-friendly, online, open-source tool to process raw CD data and perform advanced analysis. ChiraKit features include the calculation of protein secondary structure with the SELCON3 and SESCA algorithms, estimation of peptide helicity using the helix-ensemble model, the fitting of thermal/chemical unfolding or user-defined models, and the decomposition of spectra through singular value decomposition (SVD) or principal component analysis (PCA). ChiraKit can be accessed at https://spc.embl-hamburg.de/.

biophysics↗

bioRxiv2024

Assessing neurocognitive maturation in early adolescence based on baby and adult functional brain landscapes

Adolescence is a period of growth in cognitive performance and functioning. Recently, data-driven measures of brain-age gap, which can index cognitive decline in older populations, have been utilized in adolescent data with mixed findings. Instead of using a data-driven approach, here we assess the maturation status of the brain functional landscape in early adolescence by directly comparing an individuals resting-state functional connectivity (rsFC) to the canonical early-life and adulthood communities. Specifically, we hypothesized that the degree to which a youths connectome is better captured by adult networks compared to infant/toddler networks is predictive of their cognitive development. To test this hypothesis across individuals and longitudinally, we utilized the Adolescent Brain Cognitive Development (ABCD) Study at baseline (9-10 years; n = 6,489) and 2-year-follow-up (Y2: 11-12 years; n = 5,089). Adjusted for demographic factors, our anchored rsFC score (AFC) was associated with better task performance both across and within participants. AFC was related to age and aging across youth, and change in AFC statistically mediated the age-related change in task performance. In conclusion, we showed that a model-fitting-free index of the brain at rest that is anchored to both adult and baby connectivity landscapes predicts cognitive performance and development in youth.

neuroscience↗

bioRxiv2024

Impact of cryopreservation on immune cell metabolism as measured by SCENITH.

The dynamic functioning of immune cells is regulated by cellular metabolic processes, and there is growing interest in the study of immunometabolic correlates of dysfunctional immune responses. SCENITH is a novel flow cytometry-based technique that allows for ex vivo metabolic profiling of immune cells within heterogeneous samples. Cryopreservation of clinical samples is frequently undertaken to facilitate high throughput processing, but is thought to lead to cellular metabolic dysfunction. We aimed to investigate the impact of cryopreservation on immune cell metabolism, harnessing SCENITHs unique ability to describe the divergent bioenergetic characteristics of distinct immune cell subsets. We demonstrate that T cells undergoing activation with a CD3/CD28 stimulus are less readily metabolically reprogrammed following cryopreservation. Additionally, we find that cryopreservation introduces a time-dependent metabolic artefact that favours glycolysis and impairs oxidative phosphorylation, suggesting that cryopreservation results in mitochondrial dysfunction. Despite this artefact, SCENITH was still able to reveal the distinct bioenergetic profiles of contrasting immune cells populations following cryopreservation - for example, non-classical monocytes have a higher mitochondrial dependence than classical monocytes, and T cell CD69 expression is associated with an upregulation of glycolytic capacity. Whilst we believe that SCENITH can provide valuable information about immune cell metabolism even in cryopreserved samples, our findings have important implications for the design of future studies. Investigators should carefully consider how to process and store clinical samples to ensure that cryopreservation does not confound analyses, particularly where longitudinal sampling is required.

immunology↗

bioRxiv2024

PRMT5 inhibition preferentially targets MYCN-amplified neuroblastoma via altered transcriptional and splicing programmes regulating key cancer cell fitness pathways.

About 50% of poor prognosis neuroblastoma arises due to MYCN over-expression. We previously demonstrated that MYCN and PRMT5 proteins interact and PRMT5 knockdown led to apoptosis of MYCN amplified (MNA) neuroblastoma. Here we evaluate PRMT5 inhibitors GSK3203591/GSK3326593 as targeted therapeutics for MNA neuroblastoma and show MYCN-dependent growth inhibition and apoptosis. RNAseq revealed dysregulated MYCN transcriptional programmes and altered mRNA splicing, converging on key regulatory pathways such as DNA damage response, epitranscriptomics and cellular metabolism. Metabolic tracing showed glutamine metabolism was impeded following GSK3203591 treatment, which disrupted the MLX/Mondo nutrient sensors via intron retention of MLX mRNA. Glutaminase (GLS) protein was decreased by GSK3203591 despite unchanged transcript levels, suggesting post-transcriptional regulation. We demonstrate the RNA methyltransferase METTL3 and cognate reader YTHDF3 proteins are lowered following splicing alterations; accordingly, we observed hypomethylation of GLS mRNA and decreased GLS following YTHDF3 knockdown. In vivo efficacy of GSK3326593 was confirmed by increased survival of Th-MYCN mice together with splicing events and protein decreases consistent with in vitro data. Our study supports the spliceosome as a key vulnerability of MNA neuroblastoma and rationalises PRMT5 inhibition as a targeted therapy. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=133 SRC="FIGDIR/small/582087v2_ufig1.gif" ALT="Figure 1"> View larger version (54K): org.highwire.dtl.DTLVardef@1ac6b5org.highwire.dtl.DTLVardef@1eb9520org.highwire.dtl.DTLVardef@18b980corg.highwire.dtl.DTLVardef@1ab46e0_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2024

Iron deficiency in people with obesity drives defective natural killer cell mitochondrial fitness and function

Natural killer (NK) cells are a population of innate effector lymphocytes, involved in host-defences against viral infections and cancer. Upon activation, NK cells can produce a milieu of cytotoxic molecules and cytokines, which can directly target infected and transformed cells, but also amplify an immune response. Metabolic rewiring underpins NK cell effector functionality, providing the required signals, energy and biointermediates to support their immune responses. Obesity is associated with significant defects in the functionality of human NK cells, especially in the periphery. Dysregulated cellular metabolism has been demonstrated to be a major mechanistic driver of the reported defects. However, how obesity links to defective NK cell metabolism and functionality remains unclear. Iron deficiency is a common co-morbidity in people living with obesity (PWO). Recent studies have highlighted the importance for iron in host immunity, with murine models of iron deficiency resulting in defective cellular metabolism and function. We hypothesized that obesity-driven iron deficiency might underpin the reported defects in NK cells. Our data demonstrates that in response to cytokine stimulation, healthy human NK cells utilize iron to support their metabolic activity and cytokine responses. In a cohort of PWO, we demonstrate alterations in NK cell metabolism, mitochondrial fitness and cytokine production. Furthermore, upon stratification into PWO with normal iron status versus low iron status, we show the observed obesity-related defects in NK cell metabolism, mitochondrial fitness and cytokine production are concentrated in the PWO with low-iron status. Collectively, our data highlights the importance of iron for human NK cell responses and provides evidence that obesity-driven defects in NK cell metabolism and function are linked in part to altered iron availability.

immunology↗

bioRxiv2024

Meta-metabolome ecology reveals that geochemistry and microbial functional potential are linked to organic matter development across seven rivers

Rivers receive substantial dissolved organic matter (DOM) input from the land and transport it to the ocean. As DOM travels through watersheds, it undergoes biotic and abiotic transformations that impact biogeochemical cycles and any subsequent CO2 release into the atmosphere. While recent research has increased our mechanistic knowledge of DOM composition within watersheds, DOM development across broad spatial distances and within divergent biomes is under investigated. Here, we combined DOM characterization, geochemical analyses, and shotgun metagenomics to analyze samples from seven rivers ranging from the U.S. Pacific Northwest to Berlin, Germany. Initial analyses revealed that many DOM properties were distinguished by river type (e.g., wastewater, headwater) and that geochemistry often explained variation across rivers. At a global scale, analyses rooted in meta-metabolome ecology indicated that DOM was structured overwhelmingly by deterministic selection. When controlling for scale, however, analyses indicated that ecological assembly dynamics were again partially structured by river type. Finally, microbial analyses revealed that many riverine microbes from our systems shared core metabolic functional potential while differing in peripheral capabilities in across the rivers. Further analysis of the carbon degradation potential for recovered metagenomically assembled genomes indicated that the sampled rivers had strong taxonomically conserved niche differentiation and that carbon degradation potential diversity was significantly related to organic matter diversity. Together, these results help us uncover interconnections between the development of DOM, riverine geochemistry, and microbial functional potential.

ecology↗

bioRxiv2023

mRNA display reveals a class of high-affinity bromodomain-binding motifs that are not found in the human proteome

Bromodomains regulate gene expression by recognizing protein motifs containing acetyllysine. Although originally characterized as histone-binding proteins, it has since become clear that these domains interact with other acetylated proteins, perhaps most prominently transcription factors. The likely transient nature and low stoichiometry of such modifications, however, has made it challenging to fully define the interactome of any given bromodomain. To begin to address this knowledge gap in an unbiased manner, we carried out mRNA display screens against a bromodomain - the N-terminal bromodomain of BRD3 - using peptide libraries that contained either one or two acetyllysine residues. We discovered peptides with very strong consensus sequences and with affinities that are significantly higher than typical bromodomain-peptide interactions. X-ray crystal structures also revealed modes of binding that have not been seen with natural ligands. Intriguingly, however, our selected sequences are not found in the human proteome, perhaps suggesting that strong binders to bromodomains might have been selected against.

biochemistry↗

bioRxiv2023

A single-cell map of antisense oligonucleotide activity in the brain

Antisense oligonucleotides (ASOs) dosed into cerebrospinal fluid (CSF) distribute broadly throughout the brain and hold the promise of treating myriad brain diseases by modulating RNA. CNS tissue is not routinely biopsied in living individuals, leading to reliance on CSF biomarkers to inform on drug target engagement. Animal models can link CSF biomarkers to brain parenchyma, but our understanding of how individual cells contribute to bulk tissue signal is limited. Here we employed single nucleus transcriptomics on tissue from mice treated with RNase H1 ASOs against Prnp and Malat1 and macaques treated with an ASO against PRNP. Activity was observed in every cell type, though sometimes with substantial differences in magnitude. Single cell RNA count distributions implied target suppression in every single sequenced cell, rather than intense knockdown in only some cells. Duration of action up to 12 weeks post-dose differed across cell types, being shorter in microglia than in neurons. Suppression in neurons was generally similar to, or more robust than, the bulk tissue. In macaques, PrP in CSF was lowered 40% in conjunction with PRNP knockdown across all cell types including neurons, arguing that a CSF biomarker readout is likely to reflect disease-relevant cells in a neuronal disorder.

neuroscience↗

bioRxiv2022

Aspirin reprogrammes colorectal cancer cell metabolism and sensitises to glutaminase inhibition

To support proliferation and survival within a challenging microenvironment, cancer cells must reprogramme their metabolism. As such, targeting cancer cell metabolism is a promising therapeutic avenue. However, identifying tractable nodes of metabolic vulnerability in cancer cells is challenging due to their metabolic plasticity. Identification of effective treatment combinations to counter this is an active area of research. Aspirin has a well-established role in cancer prevention, particularly in colorectal cancer (CRC), although the mechanisms are not fully understood. Here, we comprehensively characterise the metabolic impact of long-term aspirin exposure (2-4mM for 52 weeks) on CRC cells. We show that aspirin regulates several enzymes and transporters of central carbon metabolism and results in a reduction in glutaminolysis and a concomitant increase in glucose metabolism, demonstrating reprogramming of nutrient utilisation. We show that aspirin causes likely compensatory changes that renders the cells sensitive to the glutaminase 1 (GLS1) inhibitor - CB-839. Of note given the clinical interest, treatment with CB-839 alone had little effect on CRC cell growth or survival. However, in combination with aspirin, CB-839 inhibited CRC cell proliferation and induced apoptosis in vitro, and importantly, reduced crypt proliferation in Apcfl/fl mice in vivo. Together, these results show that aspirin leads to significant metabolic reprogramming in colorectal cancer cells and raises the possibility that aspirin could significantly increase the efficacy of metabolic cancer therapies in CRC.

cancer biology↗