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Chen, W.

Publications and source records attributed to Chen, W..

At least 145 records · Page 8Linked to original sources

Genetically encoded assembly recorder temporally resolves cellular histories in cellulo and in vivo

Mapping cellular activity with high spatiotemporal precision in complex tissues is essential for understanding organ physiology, pathology, and regenerative processes. Here, we introduce Granularly Expanding Memory for Intracellular Narrative Integration (GEMINI), an in cellulo recording platform that leverages a computationally designed protein assembly as an intracellular memory device to record individual cells activity histories. GEMINI grows predictably within live cells with minimal interference to cellular functions, capturing cellular activities as tree-ring-like fluorescent patterns in the expanding scaffolds for imaging-based retrospective readout. Absolute chronological information of activity histories was attainable with hour-level accuracy through the integration of fiducial timestamps. GEMINI effectively resolved differential NF{kappa}B-mediated transcriptional changes, distinguishing fast dynamics of 15 minutes, and providing quantifiable signal amplitudes. In a xenograft model, GEMINI recorded inflammation-induced signaling dynamics across tissue with cellular resolution, revealing spatial heterogeneity linked to vascular density. When expressed in the mouse brain, GEMINI exhibited negligible impact on neuronal survival, with animals maintaining normal motor and cognitive behaviors. In physiological contexts, GEMINI successfully resolved both transcriptional changes and activity patterns of neurons in the brain. Together, GEMINI provides a robust and generalizable means for spatiotemporal mapping of cell dynamics underlying physiological and pathological processes in both culture and intact tissues.

bioengineering↗

Establishment and comparison of three kinds of chronic bacterial cystitis models in mice

Cystitis is a common urinary system disease in women. However, there are currently no effective treatment options except antibiotics. Therefore, establishing an effective and stable animal model is helpful for further study of cystitis. In this study, we established three chronic cystitis models from C57BL/6 female mice inoculated with urinary tract pathogenic Escherichia UTI89 through urethral perfusion: CPP co-infection group, seven days interval repeated infection group, and two consecutive days repeated infection group. The three models were successfully constructed, and the survival rates of the three models were 66%, 75%, 100%, respectively. The bladder infection rates of the surviving mice were 100%, 100%, 50%, respectively. H&E staining showed that the inflammation and damage were the most severe in seven days interval repeated infection group. Sirius red staining showed that the degree of fibrosis was the highest in CPP co-infection group. Immunofluorescence staining of bladder inflammatory cells showed that inflammatory cells and macrophages in the CPP co-infection group and the seven days interval repeated infection group expressed more. Basal layer epithelial cell staining showed that the epithelial cells of the three infection models had different degrees of proliferation. The three strategies can all prepare mouse chronic cystitis models with their own characteristics, and these models can be used for experimental studies related to different levels of bladder infection and fibrosis, laying a foundation for further research on the mechanism of chronic cystitis.

microbiology↗

Multi-omic mapping of Drosophila protein secretomes reveals tissue-specific origins and inter-organ trafficking

Secreted proteins regulate many aspects of animal biology and are attractive targets for biomarkers and therapeutics. However, comprehensively identifying the "secretome", along with their tissues of origin, remains extremely challenging. To address this, we employed multiple omics methods to define a tissue-secretome map of 535 blood plasma proteins derived from specific cell-types and organs in Drosophila melanogaster. This map was enabled by methodological improvements including a collection of transgenic flies to label endogenous secreted proteins in 10 major tissue types, large-scale blood isolation, whole animal snRNA-seq, and a collection of 40 knock-in strains. Using this map, we discover surprising findings about circulating proteins: most originate from specific tissues including unusual sources (e.g. glia), many are uncharacterized, and some are shed ectodomains of transmembrane proteins. In addition, in vivo experiments revealed circulating proteins with remarkably tissue-specific expression, as well as proteins that are deposited in a different tissue from where they are synthesized, suggesting potential inter-organ functions. Our secretome map will serve as a resource to investigate blood protein function, discover novel tissue-tissue communication signals, and mine for homologues of human biomarkers.

genomics↗

A complex of MAST1 and 14-3-3 regulates Tau phosphorylation in the developing cortex

The MAST family of serine/threonine kinases has been implicated in a spectrum of human neurodevelopmental disorders. However, little is known about their biological function or regulation. Seeking to fill these gaps in our knowledge, we have identified upstream and downstream partners of MAST1. 14-3-3, a neuronal 14-3-3 paralog, specifically interacts with MAST1 at two regulatory serines, S90 and S161. PAK, a neuronal regulator of the actin cytoskeleton, phosphorylates MAST1 to regulate its interaction with 14-3-3. Exploiting mouse models of human Mega Corpus Callosum Syndrome (MCC) and whole brain phosphoproteomics, we identify the microtubule-associated protein Tau as a substrate of MAST1. We show that pathogenic MAST1 mutations perturb protein function either through misfolding or attenuation of kinase activity. Our data is consistent with a model in which the MAST kinases couple PAK, a neuronal regulator of the actin cytoskeleton, to microtubule remodeling during the differentiation and specification of cortical neurons.

molecular biology↗

Resorbable Poly-(D,L)-Lactide Anchorage of Nanoparticulate Mineralized Collagen Materials Maximizes In Vivo Skull Regeneration

BackgroundA clinical demand exists for bone biomaterials that mirror tissue-specific extracellular matrix (ECM) properties and regulate progenitor cell fate. Nanoparticulate mineralized collagen glycosaminoglycan (MC-GAG) scaffolds have demonstrated to promote skull regeneration in vivo without addition of growth factors or exogenous progenitor cells, offering a materials-only solution for cranial defect reconstructions. Further enhancement of the safety and regenerative potential of MC-GAG is however necessary for clinical translation. Here, we investigated the regenerative effect of MC-GAG scaffold fixation with a resorbable poly(D,L-lactide) (PDLLA) implant for cerebral protection. MethodsFourteen-millimeter cranial defects were created in New Zealand white rabbits, divided into four groups: 1) defect only, 2) defect with PDLLA, 3) MC-GAG, and 4) MC-GAG with PDLLA. Initial bone healing assessment was conducted at 3 and 9 months using microcomputed tomography (microCT), histology, reference point indentation, and scanning electron microscopy. Long-term effects were evaluated through in vivo microCT imaging at 3, 6, and 9 months, with biomechanical testing of explanted skulls at 9 months. ResultsAt 3 months, MC-GAG significantly enhanced mineralization compared to empty and PDLLA-treated defects, with even greater mineralization observed for MC-GAG-PDLLA. Histologically, MC-GAG demonstrated trabecular mineralization, while MC-GAG-PDLLA had a structural organization resembling native bone. Biomechanical assessment showed enhanced toughness and stiffness for both MC-GAG and MC-GAG-PDLLA. At 6 months, MC-GAG-PDLLA displayed the highest bone mass, and at 9 months, both MC-GAG-containing scaffolds demonstrated superior bone regeneration compared to controls. By 9 months, PDLLA implants were completely resorbed and MC-GAG-PDLLA exhibited mechanical properties surpassing those of all other groups. ConclusionsFixation of MC-GAG scaffolds with PDLLA implants improved mineralization and bone regeneration compared to either material alone for cranial defect reconstruction. Clinical Relevance StatementCranioplasties are essential for cerebral protection and neurological restoration, but current materials have limitations, necessitating alternative bone biomaterials for improved outcomes.

bioengineering↗

Cholinergic Signaling Modulates Intestinal Pathophysiology in a Drosophila Model of Cystic Fibrosis

Cystic fibrosis (CF) is a monogenic genetic disease caused by mutations in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) chloride/bicarbonate channel, which is expressed in certain epithelial cells. Current therapies focus on restoring CFTR function, but many gut-related pathologies persist, highlighting the need for complementary treatments to improve the quality of life of people with CF. In this study, we use Drosophila melanogaster as a model to investigate the gut-specific effects of Cftr loss. We demonstrate that enterocyte specific knockdown of Cftr in flies recapitulates several CF pathologies, including reduced intestinal motility, nutrient malabsorption, and decreased energy stores. Using single-nuclei RNA sequencing (snRNA-seq), we identify significant transcriptional changes in the CF model gut, including the upregulation of acetylcholine esterase (Ace, human AChE), which leads to reduced cholinergic signaling. Cholinergic signaling has been shown to affect CFTR function but this is the first time CFTR loss of function has been shown to alter cholinergic signaling. Functional assays confirm that cholinergic sensitivity is diminished in CF guts. Furthermore, restoring cholinergic signaling via Ace knockdown rescues multiple CF-associated phenotypes. Additionally, we identify the transcription factor Fork head (Fkh), the Drosophila homolog of human FOXA1/FOXA2, which is known to be a positive regulator of Cftr transcription in the intestine, as a positive regulator of Ace expression in CF guts. This study establishes the Drosophila gut as a powerful model to investigate CF pathogenesis, genetic modifiers, and identifies Ace and fkh as genetic modifiers. This work also suggests that enhancing cholinergic signaling may represent a viable therapeutic strategy for gastrointestinal manifestations of CF. Author SummaryCystic fibrosis (CF) is a genetic disease that causes complications in multiple organ systems, including the lungs and gastrointestinal tract. While recent therapies have greatly improved life span and respiratory outcomes in people with CF (pwCF), they continue to report significant gastrointestinal symptoms that impact their quality of life. Therefore, there is a need to better understand the progression of CF in the gut and identify gut specific therapeutic targets to improve patient quality of life. In this study we use Drosophila to model gut specific complications of CF. We show our model recapitulates many CF clinical presentations in the gut demonstrating our model may be clinically relevant. Furthermore, we identify acetylcholine esterase (Ace) as a gene that is increased in our CF model guts that is important for the development of CF pathologies. We additionally, perform a screen to identify a transcriptional regulator of Ace, whose genetic manipulation also regulates CF phenotypes. Our findings not only identify a potential target to alleviate GI symptoms in patients with CF, but also validate the Drosophila gut as a robust model for studying CF pathogenesis, genetic modifiers, and screening therapeutics.

genetics↗

Cell Type-Specific Changes in Dendritic Spines Across Adolescence Within Mouse Medial Prefrontal Cortex

Across species, cognitive capacities that rely on the frontal cortex do not fully mature until adulthood. Adolescent circuit refinement, including structural remodeling of dendritic spines, is believed to underlie this protracted maturation. Understanding cell type-dependent patterns of structural maturation would provide important insight into frontal cortex development. Here, we leveraged retrograde adeno-associated viruses to quantify dendritic spines on pyramidal tract (PT) vs. intratelencephalic (IT) neuronal populations in parallel within the mouse medial prefrontal cortex (mPFC) across adolescence. IT-type neurons showed opposing changes in mushroom and thin spines that were: 1) consistent with increasing synaptic maturity and 2) largely absent in PT-type neurons. We next probed the function of brain-resident immune cells, microglia, by transiently ablating them within the mPFC at mid-adolescence. This led to cell type-dependent changes in dendritic spines in late adolescence, with thin spine proportion increasing on both cell types but total spine density increasing on IT-type neurons only. Meanwhile, there was no effect on performance in an mPFC-dependent task of cognitive flexibility at either late adolescent or adult time points following microglia ablation. These findings provide evidence that mPFC IT-type neurons undergo greater spine remodeling during adolescence compared to PT-type neurons and implicate microglia as potential mediators.

neuroscience↗

The Drosophila proventriculus lacks stem cells but compensates for age-related cell loss via endoreplication-mediated cell growth

The Drosophila proventriculus is a bulb-shaped structure at the juncture of the foregut and the midgut, which plays important roles in ingestion, peritrophic membrane synthesis, and the immune response to oral pathogens. A previous study identified a population of cells in the proventriculus which incorporate bromodeoxyuridine (BrdU), a marker of DNA synthesis, and proposed that these cycling cells are multipotent stem cells that replace dying cells elsewhere in the tissue. Here, we re-investigate these cycling cells and find that they do not undergo mitosis, do not generate clonal lineages, and do not proliferate in response to tissue damage, and are therefore not stem cells. Instead, we find that these cells continually endocycle throughout the flys life, increasing their ploidy and size, while at the same time cells in this tissue are lost into the gut lumen as the fly ages. Functionally, these cells play a critical role in the synthesis of peritrophic membrane components, and we show that when endocycling in these cells is experimentally increased or decreased, there is a concomitant change in ploidy, tissue size, and peritrophic membrane synthesis. Further, we show that inhibition of endocycling makes flies more susceptible to orally infectious bacteria. Altogether, we show that continual endocycling of these cells is critical for maintaining tissue size and function in the face of cell loss due to aging or tissue damage.

genetics↗

Strategies to improve the efficiency of homing gene drives with multiplexed gRNAs

CRISPR homing gene drive holds great potential for pest control, but its success is challenged by the generation of resistance alleles. To mitigate the impact of resistance, multiplexed gRNA strategies have been demonstrated. However, unless both outmost sites are cleaved simultaneously, poor homology during DNA repair may compromise efficiency, leading to decline in drive conversion efficiency when the number of gRNAs is higher than two. Here, to better estimate the rate of drive efficiency decline, we designed and assessed the efficiency of single gRNA drives with imperfect homologous arms, refining a detailed gRNA multiplexing model. To mitigate the greater than expected efficiency loss, we further evaluated two new strategies: (1) extended homology arms to span all target sites with mutations in the PAMs and (2) a population-level multiplexing gRNAs system involving two or more drives, each carrying two gRNAs. Specifically, the population-level multiplexing system has four adjacent gRNA target sites, and the drives have small mutations in their homologous arms to prevent cleavage by the other drive. Mutations in both strategies did not impair efficiency, but they were not consistently inherited, and undesired cutting in the homologous arms decreased drive efficiency. We simulated homing suppression drive using a dual 2-gRNA population-level gRNA multiple xing strategy based on our experimental evaluation. Despite being somewhat more vulnerable to functional resistance than a standard 4-gRNA drive, the higher individual drive efficiency of the population-level multiplexing system increased successful population elimination outcomes. Thus, population-level multiplexing can be a useful for improving suppression drive power.

genetics↗

Downregulation of LATS1/2 Drives Endothelial Senescence-Associated Stemness (SAS) and Atherothrombotic Lesion Formation

BackgroundAtherothrombosis, the main event leading to acute coronary syndrome (ACS), is strongly linked to disturbed blood flow (d-flow) regions. Although the involvement of the Hippo pathway and its kinases Large Tumor Suppressor Kinase 1and 2 (LATS 1 and 2) in mechanical stress responses is known, the mechanisms by which d-flow simultaneously induces senescence, proliferation, and atherothrombosis remain unclear. MethodsThe role of endothelial cells (EC)-specific LATS1/2 was examined using EC specific knock-out (EKO) mice in a partial left carotid ligation (PLCL) model. Plaque spatial multi-omics analysis was performed by integrating imaging mass cytometry, sequential immunofluorescence (COMET), and spatial metabolomics at the single-cell level in human and mouse atherosclerotic plaques. ResultsIn tamoxifen-inducible Lats1homo(-/-) /Lats2 homo(-/-) EC-specific knockout (EKO) mice, deletion of LATS1/2 induced by tamoxifen led to fatal outcomes, characterized by severe systemic edema and markedly increased vascular permeability. In contrast, Lats1het(+/-)/Lats2 homo(-/-)-EKO mice survived and developed atherothrombotic plaques exhibiting neovascularization even without further additional dietary or genetic intervention. Spatial proteomics analysis revealed that LATS1/2 depletion in ECs triggered a senescence-associated stemness (SAS) phenotype, primarily driven by CD38 upregulation. Complementary spatial metabolomics profiling demonstrated a significant increase in sulfite and taurine within LATS1/2-deficient plaques, indicating lowered sulfite oxidase (SUOX) activity. Mechanistically, CD38 upregulation was found to suppress SUOX expression, induce the reverse mode of mitochondrial complex V, and increase succinate dehydrogenase (SDH) activity along with ATP consumption. Paradoxically, despite ATP depletion, this metabolic disturbance enhanced glutamate metabolism and the tricarboxylic acid (TCA) cycle, sustaining EC proliferation under energetically stressed conditions. The combined effect of LATS1/2 deletion and CD38 activation established a unique EC phenotype defined by increased SAS, leading to proliferation, senescence, and eventual cell death. These pathological processes culminated in the formation of atherothrombotic plaques, which were attenuated by inhibition of CD38. Notably, a similar phenotype--marked by metabolically active ECs--was observed in human atherothrombotic plaques, suggesting translational relevance. ConclusionLoss of LATS1/2 in ECs induces SAS state that promotes excessive EC proliferation, senescent cell accumulation, and the development of structurally fragile, leaky neo vessels--hallmarks of atherothrombotic lesions. CD38-mediated SUOX deficiency further amplifies this pathological process by inducing mitochondrial dysfunction, depleting ATP, and triggering compensatory upregulation of glutamate and TCA cycle metabolism. These findings identify a novel LATS1/2-CD38-SUOX axis in ECs that orchestrates SAS-driven atherothrombosis. Targeting CD38 may represent a promising therapeutic strategy to mitigate vascular dysfunction and plaque instability in high-risk ACS patients. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=191 HEIGHT=200 SRC="FIGDIR/small/660635v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@149d313org.highwire.dtl.DTLVardef@1c0988borg.highwire.dtl.DTLVardef@15efec9org.highwire.dtl.DTLVardef@1a96e03_HPS_FORMAT_FIGEXP M_FIG C_FIG Under normal physiological conditions, LATS1/2 and Lamin A work together to suppress CD38 expression. Lamin A binds directly to the CD38 promoter to repress transcription, and LATS1/2 interact with Lamin A to reinforce this suppression. This collaboration helps maintain low CD38 activity and preserves cellular NAD levels. However, under disturbed flow (d-flow), both LATS1/2 and Lamin A are downregulated. The loss of this dual repression leads to increased CD38 NADase expression. Elevated CD38 accelerates NAD consumption, causing NAD depletion--a hallmark of cellular senescence. Reduced NAD disrupts key metabolic and stress-response pathways, contributing to the onset of the senescent state. At the same time, CD38 suppresses sulfite oxidase (SUOX), leading to sulfite accumulation and mitochondrial redox imbalance. This shift activates the reverse mode of mitochondrial Complex V, which decreases ATP production and increases mitochondrial ROS, intensifying metabolic and oxidative stress in endothelial cells (ECs). In response, ECs compensate by upregulating succinate dehydrogenase (SDH), enhancing TCA cycle activity and glutamate metabolism. This metabolic adaptation provides the biosynthetic building blocks needed for cell growth and proliferation. As a result, ECs adopt a paradoxical phenotype: they show classical features of stress-induced senescence (such as NAD depletion, oxidative stress, and cell cycle arrest signals), while simultaneously undergoing metabolic activation and proliferation, also mediated by YAP. This defines a non-canonical endothelial program known as senescence-associated stemness (SAS), characterized by the formation of abnormal, proliferative, yet fragile neovessels. These dysfunctional vessels contribute to atherothrombosis, setting this process apart from the more stable lesions typical of conventional atherosclerosis.

molecular biology↗

Spleen-derived Small Extracellular Vesicles Protect against Myocardial Infarction via Mediating Spleen-heart Crosstalk

Background and AimsAcute myocardial infarction (AMI) triggers systemic responses that influence cardiac injury and repair, but protective mediators within the cardiosplenic axis remain incompletely understood. This study aimed to investigate whether spleen-derived small extracellular vesicles (sEVs) exert cardioprotection after AMI, identify critical cargo, and evaluate their clinical relevance. MethodsThe effects of splenectomy, spleen-derived sEVs and pharmacological inhibition of sEVs biogenesis on cardiac injury were evaluated in mice with AMI. Parabiosis, donor splenectomy, and fluorescent labelling traced the origin and myocardial recruitment of circulating sEVs. 4D-proteomics profiled sEVs cargo with a focus on pyruvate carrier-1 (MPC1). ResultsSplenectomy worsened survival, ventricular function, infarct size, and fibrosis in mice with AMI. AMI upregulated splenic extracellular-vesicle pathways, with sEVs release peaking at day 3 (M3D-sEVs). Labelled splenic sEVs preferentially accumulated in ischemic myocardium, confirmed by parabiosis experiments. M3D-sEVs improved survival and cardiac function and reduced infarct size, fibrosis, apoptosis, inflammation, and hypertrophy. In addition, anti-apoptotic effects were reproduced in vitro. Inhibition of sEVs biogenesis decreased circulating sEVs, aggravated injury, and was rescued by M3D-sEVs. M3D-sEVs were enriched in MPC1, and MPC1 neutralization or pharmacological blockade abrogated sEVs-mediated restoration of respiration, ATP generation, and reduction of reactive oxygen species. Plasma sEVs-associated MPC1 was highest in patients with AMI, intermediate in coronary heart disease, and lowest in controls. ConclusionsThe spleen responds adaptively to AMI by releasing MPC1lenriched sEVs that travel to injured myocardium, preserve mitochondrial energetics, and reduce damage, supporting cargolspecific sEVs augmentation and sEVslMPC1 as a potential therapeutic target and biomarker in ischemic heart disease. Structured graphical abstractAcute myocardial infarction activates a spleen-heart axis in which the spleen releases mitochondrial pyruvate carrier 1 (MPC1) enriched small extracellular vesicles that home to the infarcted myocardium, preserve mitochondrial oxidative phosphorylation, reduce ROS, and limit infarct size, apoptosis, fibrosis, and hypertrophy. Circulating sEVs-associated MPC1 might serve as a potential biomarker for estimating risk of ischemic heart disease. Translational perspectiveO_LIOur findings reveal a novel heart-spleen communication axis mediated by splenic small extracellular vesicles (sEVs) following AMI. These vesicular messengers predominantly deliver mitochondrial pyruvate carrier 1 (MPC1), enhancing cardiac mitochondrial energy metabolism in the injured myocardium, ultimately improving post-AMI functional recovery in experimental models. C_LIO_LIA higher plasma sEVs-associated MPC1 level was observed in AMI patients when compared with non-AMI patients. These findings support the clinical relevance of the spleen-heart axis, introduce sEVs-associated MPC1 as a potential circulating biomarker for early myocardial injury and therapeutic target. C_LI

molecular biology↗

Biosynthesis of glycosylated 5-hydroxycytosine in the DNA of diverse viruses

Characterizing viral strategies for circumventing cellular defenses is critical to understanding the biology and therapeutic application of bacteriophages as antimicrobials. Many bacteriophages synthesize complex modifications (i.e., hypermodifications) to the nucleobases of their virion DNA in order to circumvent the endonuclease-based defenses of their hosts. To date, most hypermodified pyrimidines in viruses are synthesized via group transfer to a pre-existing hydroxyl moiety in DNA during the later stages of lytic development leading up to packaging of the viral chromosome into the capsid. Typically, these occur at hydroxymethylcytosine or hydroxymethyluracil. We find mono- and poly-arabinosylated cytidines completely replacing canonical cytidine in the native DNA of the Escherichia phage RB69 and Acinetobacter baumannii phage DLP3. In both cases, an arabinosyl moiety is connected directly to the pyrimidine through an ether linkage with the bridging oxygen originating from 5-hydroxycytosine (5hoC) in DNA. The 5hoC is synthesized as a mononucleotide by a virally encoded thymidylate synthase homolog. We find diverse virally encoded thymidylate synthase homologs, including the Rhizobium phage RL38J1, are capable of producing 5hoC suggesting this base modification is a starting point for glycodiverse cytosine derivatives. Characterizing these cytosine derivatives adds to our understanding of viral anti-defense mechanisms. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=81 SRC="FIGDIR/small/659550v1_ufig1.gif" ALT="Figure 1"> View larger version (19K): org.highwire.dtl.DTLVardef@fcc165org.highwire.dtl.DTLVardef@1fced2aorg.highwire.dtl.DTLVardef@369ceaorg.highwire.dtl.DTLVardef@177df60_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

PB-scope: Contrastive learning of dynamic processing body formation reveals undefined mechanisms of approved compounds

Membraneless organelles (MLOs) formed by liquid-liquid phase separation contribute to intracellular compartmentalization of specific biological functions. The dynamic regulation of MLOs is critical for RNA metabolism, stress response, and signal transduction. While the number and size of MLOs serve as valuable indicators of cellular states, leveraging their spatial distribution and diverse quantitative characteristics to infer cellular conditions has posed significant challenges. Here, we present processing body (PB)-scope: an unsupervised deep learning-based framework designed for imaging-based phenotypic screening of PB, one representative MLO. The model was trained on a substantial dataset comprising over 400,000 single-cell confocal microscopy images from a colon cancer cell line treated with 280 compounds. PB-scope enabled precise drug classification based on their effects on PB characteristics, including number and size. This artificial intelligence framework offers insights previously obscured by the dynamic and subtle nature of PBs. Notably, PB-scope identified drugs with a shared function in the JAK signaling pathway, a previously unrecognized regulator of PB dynamics. PB-scope holds the potential for adapting to the study of other MLOs, offering broad applicability in this emerging field of cell biology.

cell biology↗

Salmonella hijacks a host glucose transporter for intravacuolar proliferation

AbstractsSalmonella is an intracellular pathogen that resides within a vacuole, which protects it from cytosolic host defenses at the expense of limited nutrient access. Glucose serves as a critical carbon source supporting Salmonellas intracellular replication. However, the molecular mechanisms driving glucose enhancement and the pathways by which cytosolic glucose becomes accessible to intravacuolar Salmonella remain poorly understood. Here, we elucidate a sophisticated three-pronged strategy through which Salmonella hijacks GLUT1 to co-opt host glucose metabolism for pathogenic advantage. Firstly, Salmonella infection upregulates the glucose transporter GLUT1 by activating the MAPK signaling cascade, enhancing host glucose uptake, and accelerating glycolytic flux. Secondly, Salmonella redirects GLUT1 to the bacterial vacuolar membrane to establish a glucose-import conduit that facilitates bacterial acquisition of cytosolic glucose. Thirdly, K29-linked ubiquitination modifications on bacterial vacuolar membranes are a previously unrecognized regulatory mechanism that potentiates GLUT1 transporter activity. Inhibition of GLUT1 potentiates Salmonella-triggered innate immune responses and attenuates bacterial virulence in vitro (RAW264.7 macrophages) and in vivo (murine infection model). Collectively, these findings delineate a novel paradigm of metabolic hijacking, wherein Salmonella systematically rewires host glucose metabolic networks to support intracellular proliferation, providing new insights into host-directed antimicrobial interventions.

microbiology↗

Lack of mRNA Methylation in Schwann Cells Results in Demyelination and Regenerative Failure

Schwann cells are essential for peripheral nerve myelination and regeneration. N6-methyladenosine (m6A) RNA methylation, regulated by methyltransferase-like 14 (Mettl14), is a critical post-transcriptional modification, but its role in Schwann cell biology remains unclear. Using a conditional knockout (cKO) mouse model, we investigated the impact of Mettl14-mediated m6A methylation on Schwann cells. Mice born with Schwann cell-specific genetic deletion of Mettl14 developed normally but starting in young adulthood exhibited progressive motor deficits, severe demyelination, and axonal degeneration, confirmed by behavioral assessments and histological analyses. Mettl14-deficient Schwann cells displayed impaired proliferation and mitochondrial dysfunction in vitro. Following sciatic nerve injury, Mettl14 cKO mice showed defective macrophage recruitment, slowed axonal degeneration, and impaired regeneration. These findings suggest that Mettl14-mediated m6A methylation is critical for Schwann cell maintenance but not development. Given that Mettl14 cKO mice developed a demyelinating polyneuropathy, it is possible that manipulation of m6A methylation in Schwann cells is a promising therapeutic strategy targeting peripheral nerve repair and myelination.

neuroscience↗

Towards Unmanned Proteomics Data Generation: A Fully Automated Sample-to-Data System for Proteomic Experiments

The {pi}-HuB project requires proteomic measurements of millions of low-input samples that are challenging with current technology. Here, we introduce a pilot {pi}-HuB data factory that features a fully automated sample-to-data system to enable high-throughput digitization of human samples. Our platform, as a proof-of-concept towards unmanned proteomics, was demonstrated to show longitudinal robustness and applied for spatial proteomics and the profiling of plasma and cell lines, thereby serving as the workhorse to drive {pi}-HuB.

biochemistry↗

Single-cell Characterization of DNA Hydroxymethylation of the Mouse Brain During Aging

DNA methylation dynamics, including 5-hydroxymethylcytosine (5hmC) and 5-methylcytosine (5mC), critically regulate brain function, yet conventional methods cannot distinguish these modifications, obscuring their distinct roles in gene regulation and aging. We present Joint- Cabernet, a bisulfite-free single-cell platform enabling simultaneous profiling of 5hmC, 5mC, and transcriptomes. Applying Joint-Cabernet to 84,071 nuclei from adult and aged mouse brains, we resolved cell-type-specific DNA hydroxymethylation landscapes, revealing elevated 5hmCG and 5hmCH levels in transcriptionally active genes across neuronal subtypes and spatial gradients in cortical layers. During aging, 5hmCG accumulates globally but is selectively enriched at open chromatin loci, aligning with the upregulation of cell-type-specific genes in distinct brain cell types. This single-cell DNA methylation brain cell atlas provides a framework for studying methylation- driven mechanisms in brain aging and neurodegenerative diseases.

genetics↗

A New Class of Precision Therapeutics that Inhibit Prostate Cancer Mediated Bone Destruction

Cancer mediated bone destruction remains a common cause of morbidity and mortality. Here we couple an inhibitor of cell movement to bone trophic bisphosphonates, forming heterobifunctional compounds termed Dual Acting Bone Defender agents (DABDs). DABDs inhibit prostate cancer cell motility and osteoclast mediated bone destruction in vitro. Our lead compound, BTE-EN1, inhibits circulating human prostate cancer cells from forming bone destructive lesions in mice and prolongs life in a dose-dependent fashion. In mice with established metastatic lesions, BTE-EN1 significantly decreases bone destruction by over 60% compared to the control. Mechanistically, BTE-EN1 binds hydroxyapatite, inhibits prenylation of Rap1A, induces apoptosis in osteoclasts, and inhibits Raf1 activation and formation of bone resorptive cavities in osteoclasts, thus retaining the function of its constituent chemicals. BTE-EN1 is not toxic to mice at doses 4,000-fold over those required for efficacy, exhibits anti-cell motility activity across other bone-destructive cancer cell types, and does not interfere with standard-of-care hormone therapy or chemotherapy. BTE-EN1 is a new class of highly active therapeutics that inhibit cancer mediated bone destruction and holds high potential for translation into humans.

cancer biology↗