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Hu, L.

Publications and source records attributed to Hu, L..

At least 37 records · Page 2Linked to original sources

Ripk1 Deficiency or K376R Mutation in Dendritic Cells Promotes Potent Antitumor Immunity

Dendritic cells (DCs) are critical for initiating adaptive immunity through antigen presentation and T cell priming. While immunogenic cell death (ICD) enhances anti-tumor immunity, how programmed cell death in DCs shapes tumor immune responses remains unclear. Receptor-interacting protein kinase 1 (RIPK1) regulates apoptosis, necroptosis, and inflammation. Here, we show that mice with disrupted RIPK1 ubiquitination on K376 (Ripk1fl/K376R Cd11c-Cre, Ripk1DC-KO/K376R) develop inflammation and autoimmunity, phenocopying DC-specific RIPK1-deficient(Ripk1fl/fl Cd11c-Cre, Ripk1DC-KO) mice. These phenotypes were rescued by the genetic ablation of Ripk3 or Mlkl, establishing that RIPK1 ubiquitination is essential for suppressing DC necroptosis to maintain immune homeostasis. Remarkably, both Ripk1DC-KO and Ripk1DC-KO/K376R mice exhibit robust resistance to tumor growth, characterized by significantly enhanced T cell infiltration and activation. Mechanistically, we show that Ripk1 deficiency or the loss of its K376 ubiquitination augments antigen-presenting capacity of DCs through both necroptosis-dependent and -independent pathways. Furthermore, adoptive transfer of T cells from Ripk1DC-KO mice further amplifies anti-tumor immunity in recipient hosts. These results identify RIPK1 as a critical immunological checkpoint in DCs that constrains their immunogenic potential. Targeting this pathway represents a promising therapeutic strategy to potentiate T cell-mediated cancer immunotherapy.

immunology↗

ProMeta: A meta-learning framework for robust disease diagnosis and prediction from plasma proteomics

The plasma proteome offers a dynamic window of human health, capturing the real-time intersections between genetics and physiology. However, the application of deep learning to proteomics is currently hindered by a reliance on large-scale labeled datasets, rendering standard models ineffective for rare or novel diseases where patient samples are inherently scarce. Here, we present ProMeta, a meta-learning framework designed to enable robust disease modeling under extreme data restrictions. By integrating knowledge-guided pathway encoding with bi-level meta-optimization, ProMeta projects unstructured proteomic profiles into biologically interpretable functional tokens. This architecture allows the model to learn a global initialization containing transferable biological priors from biobank-scale data, facilitating rapid adaptation to novel tasks. Through comprehensive benchmark experiments, ProMeta consistently outperformed transfer learning and traditional machine learning baselines in both disease diagnosis and prediction tasks. In the most challenging 4-shot scenarios (utilizing only 2 cases and 2 controls), the model achieved robust generalization with an average AUROC of [~] 0.69, representing a 24.6% relative improvement over the best-performing baseline methods. Mechanistic investigation revealed that ProMeta disentangles cases from controls in the latent space prior to task-specific adaptation, confirming the acquisition of universal biological rules rather than rote memorization. Furthermore, gradient-based interpretation identified disease-specific protein biomarkers and functional pathways consistent with known pathophysiology. Collectively, ProMeta overcomes the data-scarcity bottleneck in precision medicine, providing a scalable, interpretable framework for characterizing the full spectrum of human diseases, particularly for rare conditions lacking extensive clinical cohorts.

bioinformatics↗

Inhalable Polymeric Nanoparticle Vaccine for Lysosome-targeting Co-delivery of Antigen and Adjuvant with Enhanced Immunoprotection

Conventional subunit vaccines suffer from premature clearance and poor synchronization of antigen and adjuvant, limiting coordinated immune activation. Here, we develop an amphipathic polymer (YAXA) with acid-labile imine bonds for acid-sensitive degradation and terminal NHS-activated esters for antigen conjugation. YAXA is co-assembled with hydrophobic TLR7 agonist 3M-052 and conjugated to protein antigen, forming nanoparticle vaccine YM3.7. Following aerosolized intratracheal inoculation into the lung, YM3.7 is efficiently internalized by antigen-presenting cell and trafficked into lysosome, where acidic conditions trigger its dissociation and co-release of antigen and adjuvant. This spatiotemporally synchronized delivery promotes robust immune activation, including cell maturation, germinal center formation, systemic and lung-resident B/T cell response, and IgG/sIgA production. In lethal pneumonia models induced by either Pseudomonas aeruginosa or Staphylococcus aureus, YM3.7 markedly improves survival over conventional antigen and adjuvant mixture. This study presents an inhalable nanoparticle platform that coordinately activates innate, humoral, mucosal, and cellular immunity for enhanced protection.

immunology↗

BiOmics: A Foundational Agent for Grounded and Autonomous Multi-omics Interpretation

While AI has automated bioinformatic workflows, biological interpretation remains fragmented and often disconnected from mechanistic insights. Existing AI is bifurcated between statistical "black-box" models that lack logical grounding and simple agents restricted to shallow knowledge retrieval. To bridge this divide, we introduce BiOmics, a foundational agent that synthesizes multi-omics data with adaptive knowledge for biological interpretation. BiOmics introduces a novel dual-track architecture comprising a harmonized explicit reasoning space for grounded logic and a unified latent embedding space for high-dimensional association mapping. This architecture enables a transformative "Retrieving-Reasoning-Predicting" paradigm for purposeful, cross-scale inference traversing the biological hierarchy, from molecular variants to disease phenotypes. Empirical evaluations demonstrate that BiOmics surpasses state-of-the-art AI agents and specialized algorithms, markedly augmenting the granularity and depth of biological insights. Specifically, BiOmics exhibits unique superiority in uncovering indirect pathogenic variants, achieving reference-free cell annotation, and prioritizing drug repurposing candidates tailored to specific datasets. BiOmics further enriches the interpretive landscape of biological entities, leveraging its reasoning-grounded knowledge graph to uncover deep functional contexts. Ultimately, BiOmics provides a versatile engineering foundation to transition AI for Science from descriptive "data fitting" to autonomous, knowledge-driven interpretation.

bioinformatics↗

System-wide extraction of cis-regulatory rules from sequence-to-function models in human neural development

The genomic cis-regulatory code (CRC) underlies spatiotemporal specificity of gene expression. While sequence-to-function (S2F) models can accurately encode the CRC of transcriptional enhancers, decoding these models into human-interpretable rules remains a major challenge. Here we tackle this challenge in human neural development, for which we generate two new single-cell multiome atlases, one from a human embryo and one from neural tube organoids. We use this comparative framework to robustly extract combinations of transcription factor (TF) binding sites that are necessary and sufficient to design enhancers. As such we extract cis-regulatory rules for dorsal-ventral progenitors, neural crest, mesenchyme and neurons. To enable this, we develop a new strategy and computational package, called TF-MINDI, to embed, cluster, and annotate candidate TF binding sites, and to extract combinatorial rules for each cell type. We evaluate rule-based models in conjunction with blackbox S2F models through simulations, evolutionary comparisons with zebrafish, topic modeling, and enhancer reporter-assays. Our findings show robust and interpretable rule extraction and constitute a step forward in deciphering, explaining, and formalizing the CRC. TF-MINDI is available at: https://github.com/aertslab/TF-MINDI.

bioinformatics↗

OpenStride: an inexpensive, open-source force plate actometry system for quantification of rodent motor activity and behaviour

IntroductionForce plate actometry (FPA) enables quantitative assessment of rodent motor and behavioural activity. Through tracking centre of mass at high temporal and spatial resolution, FPA can directly quantifying motor performance and various behaviours in the context of operator-independent, naturalistic movement. Previously designed systems have been expensive and non-customisable, and they are no longer commercially available. MethodsWe designed OpenStride, an open-source FPA system consisting of both hardware and software. Our system was designed to be able to be constructed with standard tools worldwide at a cost of [~]$550 USD, with modifiable hardware files, modular software, and support for both Mac and Windows operating systems. Required tools include 3D printing and acrylic laser cutting. ResultsOpenStride reliably tracks position within a 30 x 30 cm2 environment. Based on these positional data, OpenStride currently quantifies tremor, ataxia, distance, velocity, low-mobility bouts, and centre-vs-margin time, with potential to expand to additional analyses. ConclusionsOpenStride is intended to provide a valuable tool for high-throughput, inexpensive study of motor and behavioural function and dysfunction. Software and hardware files will be freely disseminated online via GitHub at the time of final publication to enable others to construct and utilise the OpenStride system.

neuroscience↗

An Fc-silent OspA monoclonal antibody passively protects mice from tick and intradermal Borrelia burgdorferi challenge

The monoclonal antibody, LA-2, has played a pivotal role in the development of Outer surface protein A (OspA)-based vaccines for Lyme disease, a multisystem illness caused by the tick-borne spirochete, Borrelia burgdorferi sensu lato. Of particular significance was the demonstration more than three decades ago that LA-2 equivalent antibody titers, defined by a competitive-inhibition ELISA, serve as a reliable correlate of vaccine-induced protection across different species, including humans. In vitro characterization of LA-2 has identified both complement-dependent and -independent activities, although which of these attributes contribute to protection against B. burgdorferi remains unresolved. To address this issue, we generated and characterized an "Fc-silent" version of LA-2 IgG1 carrying so-called LALAPG substitutions (L234A, L235A, P329G). We demonstrate that LA-2 LALAPG retained OspA binding activity but was severely attenuated in in vitro complement deposition and complement-dependent borreliacidal assays. Nonetheless, LA-2 LALAPG was as effective as LA-2 at passively protecting C3H mice against nymphal tick-mediated B. burgdorferi challenge. LA-2 LALAPG was also equivalent to LA-2 in passively protecting BALB/c mice against intradermal B. burgdorferi challenge. In the intradermal challenge model, viable spirochetes were not recoverable 24 h after injection from skin biopsies of mice treated with LA-2 or LA-2 LALAPG, and an influx of pro-inflammatory cytokines and chemokines to the injection site was abrogated. Collectively, these results suggest that LA-2s primary mode of action involves direct physical interactions with the spirochete rather than complement-dependent killing. Elucidating these mechanisms may have implications for understanding the mechanistic correlates of OspA-based vaccine-induced immunity in humans.

immunology↗

Excitable dynamics of ParA during bacterial cell division

ParABS system is a conserved machinery that drives the partitions of genome and other large intracellular cargos in bacteria. It works as a ParA concentration-based Brownian ratchet, which ensures the partition fidelity by operating at the critical point in its parameter space and localizing the ParA nearby to buffer against the large fluctuations in the ParA intracellular concentration. Despite these progresses, our understanding of the ParABS-driven partition mechanism remains incomplete. It is not understood what causes the large cell-to-cell fluctuation in the ParA intracellular concentration and why the bacterium cannot minimize this noise to better control the partition fidelity. We present experimental evidence with low-copy-number F-plasmids in E. coli that ParA robustly oscillates from pole to pole along the nucleoid length, underlying the observed large fluctuations in ParA intracellular concentration. Our theory-experiment synergy demonstrates that the ParA oscillation hinges on the nucleoid dimension and the ParB-mediated negative feedback with ParA in nucleoid binding. We suggest that the low-copy-number plasmid manages its partition fidelity with "autonomy": The plasmid harnesses the same ParB-mediated negative feedback - that dissociates the ParA from the nucleoid underneath the plasmid - to maintain the nucleoid-bound ParA at a proper level further away. And the ParA oscillation is reminiscent of this underlying feedback mechanism, which adapts the partition fidelity to the nucleoid growth. Our work may provide an overarching framework of intracellular partitioning in bacteria. Significance StatementParABS system is a conserved partition machinery for genome and other large cargos inside bacteria and works as a ParA concentration-based Brownian ratchet. It operates at the critical point in parameter space for sensitive adaptation and localizes the ParA nearby to buffer against the large cell-to-cell ParA concentration variations evidenced in bacteria. Why cannot the bacterium minimize this noise to better control the partition fidelity? Hereby, we showed that the large cell-to-cell ParA concentration variations stem from the ParA pole-to-pole oscillations along the nucleoid length and embodies an automony strategy that the intracellular cargo controls the nucleoid-bound ParA at a proper level to ensures its partition fidelity. Our work may provide an overarching framework of intracellular partitioning in bacteria.

biophysics↗

Targeting the host factor HGS-viral membrane protein interaction in coronavirus infection

While current antivirals primarily target viral proteins, host-directed strategies remain underexplored. Here, we performed a genome-wide CRISPRi screening to identify the host protein, Hepatocyte Growth Factor-Regulated Tyrosine Kinase Substrate (HGS), as essential for the pan-coronaviruses infection both in vitro and in vivo. Mechanistically, HGS directly interacts with the viral membrane (M) protein, facilitating its trafficking to the ER-Golgi intermediate compartment (ERGIC) for virion assembly. Conversely, HGS deficiency caused M retention in the ER, blocking assembly. Leveraging this interaction, we designed M-derived peptides and screened over 5,000 FDA-approved drugs, identifying riboflavin tetrabutyrate (RTB). Both the peptides and RTB bind HGS and disrupt its interaction with the M protein, leading to M retention in the ER and subsequent blockade of virion assembly. These agents demonstrated broad anti-pan-coronavirus activity in vitro and in vivo. Collectively, our findings establish HGS as a druggable host target and identify RTB as a promising broad-spectrum antiviral candidate.

microbiology↗

Programmable Aptamer-Embedded Circular RNAs for Targeted Antigen-Presenting Cells Immunotherapy

The targeted delivery of mRNA to specific cell types in vivo remains a major unmet need in mRNA-based therapeutics. Conventional strategies rely on nanocarriers engineered with various modifications. However, these exogenous materials could cause adverse reactions, and their complex manufacturing processes often hinder clinical application. By leveraging the innate programmability of RNA sequences, we herein report a carrier-free, scalable, and programmable aptamer-embedded circular RNAs (Apt-circRNAs) design that confers targeting capability through the strategic incorporation of different aptamers at varying densities, while retaining circular RNA stability and protein production capability. Experimental results show that antigen-loaded Apt-circRNAs enable targeted delivery to antigen-presenting cells (APCs), drive endogenous antigen expression, activate antigen-specific T cells, and elicit potent immune responses that mediate clearance of both early-and late-stage tumors in mouse models. In humanized models of colorectal cancer, the combination of Apt-circRNA and PD-1 blockade produced synergistic antitumor effects and significantly reshaped the tumor microenvironment. In a first-in-human (FIH) clinical trial, Apt-circRNA vaccine encoding KRAS G12D/G12V neoantigens exhibited a favorable safety profile and induced robust immune activation, T cell mobilization, and neoantigen-specific immune responses. With this study, we have established a new paradigm in carrier-free, APC-targeted RNA vaccine design, offering a safe and effective platform for next-generation cancer immunotherapy.

bioengineering↗

Childhood brain tumours instruct cranial haematopoiesis and immunotolerance

Recent research has revealed a remarkable role for immunosurveillance in healthy and diseased brains, dispelling the notion that this organ is a passive immune-privileged site1-3. Better understanding of how this immunosurveillance operates could improve the treatment of neurological diseases. Here, using a novel genetically engineered mouse model of ZFTA-RELA ependymoma4-a childhood brain tumour-we characterised an immune circuit between the tumour and antigen presenting, haematopoietic stem/progenitor cells (HSPCs) in the skull bone marrow. The presentation of antigens in the cerebrospinal fluid (CSF) by HSPCs to CD4+ T cells, biased HSPC lineages toward myelopoiesis and polarised CD4+ T-cells to regulatory T cells (T- regs), culminating in tumour immunotolerance. Remarkably, a single infusion of antibodies directed against cytokines enriched in the CSF of mice bearing ZFTA-RELA ependymomas, choroid plexus carcinomas or Group-3 medulloblastoma-all aggressive childhood brain tumours-disrupted this process and caused profound tumour regression. These data unmask a mechanism by which skull bone marrow-derived HSPCs and CD4+ T cells cooperate to promote the immunotolerance of childhood brain tumours. Antibodies that disrupt this immunosurveillance could prove an effective therapy for these cancers that are less toxic than current treatments.

immunology↗

Dual effects of nicotinamide on aging-related arrhythmia: protective at low dose, proarrhythmic at high doses

BackgroundCardiac arrhythmia and dysfunction progressively increase with age, both of which are closely associated with a decline in NAD+. Supplementation with nicotinamide (NAM), a critical NAD+ precursor, has shown protection in experimental models of aging-related cardiac diseases, including atrial fibrillation (AF) and heart failure, especially heart failure with preserved ejection fraction. With the potential rise of NAM in treatment of various cardiometabolic diseases, its dose-dependent cardiac-specific adverse effects and underlying mechanisms warrant investigation. MethodsThe effects of NAM on aging-related arrhythmia and cardiac dysfunction were assessed using ex vivo Langendorff mouse hearts and adult Drosophila heart preparations. Different doses of NAM (10-100 mM) were tested for their impact on the contractility of HL-1 cardiomyocytes, lifespan and cardiac function of Drosophila, as well as arrhythmia susceptibility of ex vivo mouse hearts. Acetylation of sarcoplasmic/endoplasmic reticulum Ca{superscript 2} ATPase 2a (SERCA2a) was measured by immunoprecipitation followed by Western blotting. ResultsAcute perfusion with 10 mM NAM had limited influence on aging-related AF susceptibility in ex vivo mouse hearts. Short-term dietary intervention with 10 mM NAM in late-life protected against aging-induced cardiac arrhythmia and contractile dysfunction exclusively in male Drosophila. In contrast, life-long exposure or NAM concentrations above 20 mM led to dose-dependent adverse cardiac effects, including impaired contractility in HL-1 cardiomyocyte and shortened lifespan in Drosophila, with increased arrhythmia observed in both models. In ex vivo mouse hearts, 100 mM NAM increased SERCA2a acetylation, suggesting inhibition of sirtuin1 and impaired calcium handling, which likely underlies the observed effects of high-dose NAM on arrhythmia and cardiac dysfunction. ConclusionsNAM exhibits a narrow therapeutic window in aging-related cardiac dysfunction and arrhythmia, with its efficacy highly dependent on dose, duration, and biological context. While a moderate dose in late-life may be protective, chronic or excessive intake of NAM can induce arrythmia and impair cardiac function, likely through disruption of the SERCA2a activity. These findings underscore the importance of cautious and context-specific application of NAM in clinical settings.

physiology↗

DynPerturb:Dynamic Perturbation Modeling for Spatiotemporal Single-Cell Systems

Perturbation responses in multicellular systems are inherently spatiotemporal, governed by temporal dynamics, perturbation intensity, and tissue context. However, existing approaches rarely capture explicit spatiotemporal perturbation dynamics, limiting the ability to reconstruct how perturbations propagate over time, spread across space, and induce feedback at multiple biological scales. Here we introduce DynPerturb, a dynamic inference framework for single-cell and spatial transcriptomics that systematically models the "when-how strong-where" dimensions of perturbations. DynPerturb incorporates temporal encoding, spatial adjacency, and memory modules to capture nonlinear signal propagation and cross-regional feedback with mechanistic interpretability. Across temporal benchmarking datasets, DynPerturb consistently outperformed existing methods in regulatory link prediction, demonstrated zero-shot generalization to unseen nodes, and preserved accuracy under varying sparsity conditions and temporal resolutions. Applied to representative biological systems, DynPerturb uncovers dynamic regulatory rewiring in kidney disease, highlighting a mid-age sensitivity window and potential reversibility with early intervention; delineated a temporal fate-switching boundary between megakaryocyte-erythroid progenitors (MEPs) and granulocyte-monocyte progenitors (GMPs) during hematopoiesis; and revealed spatiotemporal interchamber signaling in murine heart development, where Igf2 perturbations induced spatial feedback shaping chamber proportioning. Collectively, these results establish DynPerturb as a unified and versatile system for dissecting dynamic perturbation effects and guiding precision intervention strategies in multicellular systems.

bioinformatics↗

Insectivores exhibit superior microbial transmission efficiency and elevated zoonotic risk by 2035 relative to rodents and bats

Wild small mammals represent critical sources of zoonotic infections due to their high diversity, global distribution, and proximity to humans. Nevertheless, significant knowledge gaps persist in characterizing pan-taxonomic microbial richness and sharing dynamics, particularly regarding ecologically critical yet understudied Eulipotyphla (true insectivores). Here we take a macroecological approach to compare how microbial hosting and transmission differ across insectivores, rodents, and bats, and what ecological factors drive such disparities. We find that insectivores host comparable microbial richness to rodents and bats while exhibiting superior intra- and cross-order transmission efficiency. Urban adaptation, geographic range area, and longevity are shared drivers of microbial richness and transmission across these host orders, while greater body mass and shorter gestation time specifically are positive predictors of these outcomes within insectivores. Climate change projections identify insectivores as primary transmission hosts in new high-latitude hotspots by 2035, including parts of the US, Canada, and Russia, posing greater zoonotic threats than rodents or bats. Our findings challenge the prevailing paradigm that prioritizes rodents and bats as special zoonotic reservoirs, establishing insectivores as critical but overlooked players in disease ecology. Collective proactive surveillance of insectivores, rodents, and bats is imperative for forecasting emerging zoonotic threats and informing global risk assessment frameworks.

ecology↗

Tumor nutrient stress gives rise to a drug tolerant cell state in pancreatic cancer

Systemic therapies are the standard of care for most pancreatic ductal adenocarcinoma (PDAC) patients but provide limited benefit due to pervasive resistance. The fibrotic tumor microenvironment (TME) is thought to drive resistance by restricting perfusion and drug delivery. Here, we show that therapeutically relevant drug concentrations are achieved even in poorly perfused, therapy-resistant murine PDAC tumors, indicating that impaired delivery alone does not explain drug resistance. Instead, we find TME exposure imprints a therapy-resistant state upon PDAC cells. These observations raised the question of how the TME imposes this state. Poor perfusion alters nutrient availability in the TME. To model this, we developed Tumor Interstitial Fluid Medium (TIFM), which recapitulates TME nutrient conditions. TIFM cultured PDAC cells acquire a therapy-resistant phenotype that mirrors resistance observed in the TME. In this state, cytotoxic and targeted therapies retain on-target activity but fail to trigger cell death, resulting in therapeutic tolerance. Mechanistically, drug tolerance is driven by suppression of apoptotic priming and can be reversed by inhibition of the anti-apoptotic regulator BCL-XL. These results identify TME-driven reprogramming of cell death as a key mechanism of therapy resistance in PDAC and establish TIFM as a physiologically relevant model for studying microenvironment-induced drug resistance.

cancer biology↗

STARNet enables spatially resolved inference of gene regulatory networks from spatial multi-omics data

Biological tissues are composed of distinct microenvironments that spatially orchestrate gene expression and cell identity. However, the regulatory principles governing domain-specific cellular functions remain poorly understood due to the lack of effective methods for mapping gene regulatory networks (GRNs) in situ. To address this gap, we introduce STARNet, a representation learning approach that leverages heterogeneous hypergraph modeling of spatial transcriptomic and epigenomic data to resolve tissue-domain-specific regulatory interactions. By integrating graph neural networks with contrastive learning in a self-supervised framework, STARNet learns unified embeddings that preserve both multi-modal molecular features and anatomical spatial context, enabling accurate and domain-resolved GRN reconstruction within complex tissues. Benchmarking on both simulated and real datasets demonstrates that STARNet achieves state-of-the-art performance. We further demonstrate its broad applicability across diverse biological contexts, including neural development, genetic disease risk, and drug-induced developmental toxicity. In the mouse brain, it delineates region-specific regulatory networks and reconstructs spatiotemporal programs underlying neural stem cell differentiation. In human genetics, it provides a mechanistic link between genotypes and phenotypes by showing how genome-wide association study (GWAS) variants for complex diseases perturb hippocampus-specific GRNs. In developmental toxicology, STARNet reveals that drug-induced disruptions of GRNs in defined embryonic regions underlie tissue-specific vulnerability. Collectively, STARNet offers a powerful and versatile framework for resolving the spatial regulatory logic of complex tissues, providing multi-angle insights into tissue patterning, development, and disease mechanisms.

bioinformatics↗

Organotypic Timelapse recording with Transcriptomic Readout (OTTR) links cell behaviour to cell identity in human tissues

Linking dynamic cellular behaviour to molecular states in intact human tissue remains challenging because during live imaging only limited molecular information can be captured while high-dimensional molecular measurements are destructive. Here we describe Organotypic Timelapse recording with Transcriptomic Readout (OTTR), which integrates week-long live imaging of sparsely labelled organotypic slice cultures with highly multiplexed in situ spatial transcriptomics. We applied OTTR to primary human glioblastoma and fetal cortical tissues. Using sparse labelling, we tracked the migration, proliferation, and lineage of tens of thousands of individual cells per sample. Following live imaging, precision resectioning and alignment allowed us to perform spatial transcriptomics on the very same tissue, thereby preserving the link between dynamic cell behaviours and transcriptomic states. We used OTTR to quantify cell-type specific migration patterns, lineage trees and the behaviour of cells near vasculature. OTTR provides a powerful, broadly applicable method for investigating the complex interplay between cell behaviour and molecular state in human tissues.

molecular biology↗

MTARC1 Regulates Lipid Droplet Degradation via Phospholipid Remodeling in Metabolic Fatty Liver Disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a spectrum of liver disease, including simple fatty liver, hepatic steatosis, fibrosis, cirrhosis, and hepatocellular carcinoma, with limited treatment options. MTARC1 p.A165T variant is associated with reduced risk of MASLD. We previously showed that this variant promotes MTARC1 protein degradation, suggesting MTARC1 inactivation may represent a potential therapeutic strategy. Here, we report that global or liver specific Mtarc1 knockout markedly suppresses diet-induced hepatic TG accumulation, liver injury, inflammation, and fibrosis in a manner dependently on lipolysis and lipophagy. MTARC1 inactivation post-transcriptionally upregulates PEMT and CEPT1 expression, consequently elevating GPL levels, including PC, PE, and lyso-PE, three major GPLs of hepatic LDs. Furthermore, we observed that MTARC1-deficient hepatocytes exhibited smaller but more numerous LDs compared to controls, under comparable cellular TG levels during lipolysis/lipophagy inhibition. Importantly, inhibition of CEPT1 or PEMT could attenuated the hepatoprotective effect of MTARC1 deficiency. Mechanistically, subcellular GPL remodeling induced by MTARC1 deficiency reduce LD size while increase their surface-to-volume ratio, which in turn promote TG degradation through lipolysis and lipophagy. Collectively, our findings identify MTARC1-GPL biosynthesis-LD degradation axis as a key regulator of fatty liver disease and highlight MTARC1 inhibition as a promising therapeutic strategy for MASLD.

cell biology↗