Biology subjects

Lee, J.

Publications and source records attributed to Lee, J..

At least 91 records · Page 5Linked to original sources

bioRxiv2026

Metabolically engineered oilcane reshapes rhizosphere microbial guilds while preserving broad functional capacity

Metabolic engineering of crops can redirect host carbon flux, but its consequences for microbiomes remain unclear. Here, we show that engineering oilcane for triacylglycerol (TAG) accumulation reshapes rhizosphere microbial guilds across greenhouse and field environments while preserving functional capacity. Using 36 rhizosphere metagenomes from wild-type sugarcane and engineered oilcane accessions, we reconstructed metagenome-assembled genomes and linked community turnover with shifts in functional potential. Oilcane rhizospheres exhibited taxonomic restructuring relative to wild-type plants, driven primarily by turnover rather than nestedness and marked by genotype-dependent replacement of microbial guilds. These patterns were strongest in accession 1566 and amplified under field conditions. Despite these compositional shifts, broad patterns of functional potential remained similarly distributed, whereas pathway-level differences were evident in energy production and conversion, lipid transport and metabolism, secondary metabolite biosynthesis, transport and catabolism, and signal transduction. These findings extend evaluation of engineered crops beyond host traits alone to include microbiome-scale responses.

microbiology↗

bioRxiv2026

Mechanical contributions of the Myp2 tail revealed by coiled-coil force sensors

Cytokinesis is driven by the constriction of an actomyosin contractile ring, yet how forces generated by individual myosin molecules are transmitted within the ring remains poorly understood. In fission yeast Schizosaccharomyces pombe, the type II myosin Myp2 plays a key role in ring constriction and stability, particularly under stress conditions. Unlike typical type-II myosins, Myp2s tail contains two coiled coils. Although numerous studies have revealed the structure and molecular function of Myp2, the mechanical contribution of its unique tail region has remained unclear. Here, we directly measured forces acting on Myp2 in living cells using genetically encoded coiled-coil force sensors. Insertion of force sensors into the neck region revealed that Myp2 experiences forces of approximately 6.6 pN within the contractile ring. To dissect the contribution of the tail region, we systematically analyzed tail-deletion mutants. Deletion of the proximal tail had little effect on force levels, whereas deletion of the distal C-terminal tail significantly reduced the forces experienced by Myp2. Quantitative analysis of force distributions further showed that truncation of the C-terminal tail reduces the characteristic force by approximately half, demonstrating a major mechanical contribution of the distal tail to the forces experienced by Myp2 at the molecular scale. Deletion of the C-terminal tail slowed the growth rate, consistent with previous macroscopic observations that this region is required for robust ring constriction under stress conditions. We further found that the C-terminal tail forms clusters, which require full-length Myp2 for proper localization to the ring. These findings, together with molecular force measurements and quantitative analysis, demonstrate that the Myp2 tail is not merely a structural or regulatory domain but functions as a load-bearing component in vivo, with its C-terminal region playing a central role in force transmission across scales.

Cell Biology↗

bioRxiv2026

miR-425-5p Regulates Cellular Senescence Through Modulation of Retinoblastoma Protein Phosphorylation

MicroRNAs (miRNAs) are small non-coding RNAs that play critical roles in regulating cellular senescence and aging. Our recent studies identified a conserved C. elegans miRNA cluster (miR-229/64/65/66) that is required for normal adult lifespan, with overexpression significantly extending longevity. Notably, cel-miR-229 is evolutionarily conserved in humans, with hsa-miR-425 sharing an identical seed sequence. Here, we investigated the role of miR-425 in mammalian cellular senescence. We found that miR-425 expression is markedly reduced in pharmacologically induced senescence in human lung cancer cells. Restoration of miR-425 expression attenuates senescence and suppresses the expression of senescence-associated secretory phenotype (SASP) cytokines following senescence induction. We further observed that miR-425 levels decline during replicative senescence, whereas stable overexpression in WI-38 fibroblasts delays senescence accumulation and preserves proliferative capacity. Mechanistically, miR-425 suppresses TGF-{beta} signaling, leading to reduced expression of the cyclin-dependent kinase inhibitor p21/CDKN1A and increased phosphorylation of the retinoblastoma (RB) protein, thereby promoting cell-cycle progression. We further identify PPP2CB, the catalytic subunit of protein phosphatase 2A (PP2A), as a direct target of miR-425. PPP2CB expression is downregulated in miR-425-5p overexpressing cells, even under senescence induction. Knockdown of PPP2CB using siRNA phenocopies the effects of miR-425 overexpression, reducing senescence, enhancing proliferative potential, and increasing RB phosphorylation. Collectively, our findings identify miR-425 as a conserved regulator of cellular senescence that acts through upregulation of RB phosphorylation. These results establish a novel miR-425-PPP2CB-RB regulatory axis controlling proliferation and senescence and suggest miR-425 as a potential therapeutic target for mitigating senescence to promote extended health span.

Cell Biology↗

bioRxiv2026

Mitochondrial one-carbon enzyme MTHFD1L sustains stemness and metastatic progression in breast cancer

One-carbon (1C) metabolism is frequently upregulated in cancer to support anabolic growth and nucleotide biosynthesis. However, the contribution of mitochondrial 1C metabolism to cancer stemness and metastatic progression remains incompletely understood. Here, we identify methylenetetrahydrofolate dehydrogenase 1-like (MTHFD1L), a mitochondrial 1C metabolic enzyme, as a critical regulator of breast cancer stemness, tumor initiation, and lung metastasis. Genetic depletion of MTHFD1L in triple-negative breast cancer (TNBC) cell lines and patient-derived breast cancer models markedly impaired proliferation, sphere formation, tumorigenicity, and lung colonization. Metabolomic profiling revealed extensive metabolic rewiring following MTHFD1L loss, characterized by accumulation of the purine biosynthetic intermediates SAICAR and AICAR together with perturbations in glycolytic and pentose phosphate pathways. Importantly, suppression of lung metastasis was accompanied by reduced expression of the stemness-associated transcription factor SOX2 and decreased proliferative activity in metastatic lesions. Collectively, our findings establish MTHFD1L as a key metabolic dependency linking mitochondrial 1C metabolism to stem-like properties and metastatic progression in breast cancer, and highlight MTHFD1L as a promising therapeutic target in metastatic TNBC.

Cancer Biology↗

bioRxiv2026

Adaptive Charge Modulation Enables Focal, Selective Spinal Cord Stimulation

Clinical neuromodulation primarily employs near-field low frequency electrical stimulation to activate neurons in the immediate vicinity of the electrode. We introduce Adaptive Charge Modulation (ACM), a spatiotemporal, charge-balanced stimulation strategy that focuses activation at deep tissue sites distant from the stimulating contacts. We apply ACM to stimulate deep regions of the spinal cord, distant from dorsal root entry zones which are preferentially activated during low frequency stimulation (LFS). ACM applies multipolar, biphasic rectangular pulses to exceed activation thresholds in deeper neuronal populations, with reduced surface activation, potentially due to high-frequency suppression of neural activity. In epidural spinal cord stimulation in rats, ACM achieved single-muscle selectivity among fourteen monitored muscles with minimal co-activation of other muscles. Using simultaneous, high spatiotemporal resolution, 2,112-channel brain-spine recordings, we characterized the response latencies and pathways consistent with focal recruitment at depth. We observed chronic stability of the electrode and ACM in freely behaving animals over 68 days post-implantation. By enabling focal activation with epidural surface electrodes, ACM may expand the reach and precision of neuromodulation and neural interfaces.

bioengineering↗

bioRxiv2026

Detection of Melanoma Using Deep Serum Proteome Profiling and Machine Learning

Early detection determines melanoma outcomes, yet current screening relies on visual inspection that misses molecular changes preceding clinical diagnosis. To identify serum protein signatures of melanoma development, we leveraged the Department of Defense Serum Repository, analyzing 390 longitudinal serum samples from 73 melanoma cases and matched controls across four timepoints (4 and 2 years prior, diagnosis, and 2 years post-diagnosis) using data-independent acquisition mass spectrometry with Seer Proteograph nanoparticle enrichment. We quantified 3,364 proteins and applied machine-learning strategies combining cross-sectional case-control comparisons with longitudinal tracking of within-individual changes. Cross-sectional analysis at diagnosis achieved AUC 0.823 (95% CI: 0.723-0.923), identifying eight consensus features selected in >50% of cross-validation folds: PRSS1, GSK3B, FAM20C, CES1, CCL14, EPHA10, LMAN2, and ITIH1. These signatures, spanning proteases, immune activation, and extracellular matrix remodeling, demonstrate proof-of-concept for serum-based melanoma detection and provide candidate biomarkers for validation.

Cancer Biology↗

bioRxiv2026

FORGE-CRISPR: Reusable Modules for Focused CRISPR Library Construction

Pooled CRISPR screening has become a widely used approach for functional genomics, yet the construction of screening libraries remains tightly coupled to specific vector architectures and experimental formats. Incorporation of barcodes, multiplexed guide configurations, alternative fluorophores, selectable markers, or distinct screening modalities often requires reconstruction of entire libraries, even when the underlying biological content remains unchanged. These limitations are particularly acute in engineered cellular systems that already contain reporters, knock-in alleles, or pre-existing selection markers. Here, we describe FORGE-CRISPR (Functional Oncology Research Genetic Engineering - CRISPR), a CRISPR library-construction system that separates biological guide content from screening-vector context. CRISPR knockout and CRISPR interference guide collections are first converted into reusable guide modules. Barcode modules and second-guide modules are generated separately and combined with guide modules during downstream assembly into screening acceptor vectors. This design allows guide-only, barcoded, and multiplexed libraries to be generated from shared physical components. To support this framework, we developed a manufacturing workflow in which synthetic oligonucleotide pools are converted into reusable FORGE module libraries through PCR amplification, Golden Gate cloning, and background suppression. Using this approach, we constructed nine reusable guide-module libraries ranging from 45 to 4,830 guides (11,303 guides in total), and evaluated library quality through PCR-NGS analysis of guide representation and abundance distributions. As content for these libraries, we defined a modular, non-overlapping set of focused target collections, termed the druggable oncology genome, by partitioning druggable targets according to clinical development status and dependency distribution in DepMap, while drawing guide sequences from established, experimentally validated genome-wide libraries. We report four resources: reusable guide, barcode, and second-guide modules; compatible screening acceptor vectors; a manufacturing and PCR-NGS quality-control workflow demonstrated across nine guide-module libraries; and a versioned set of focused druggable-oncology target collections.

Molecular Biology↗

bioRxiv2026

A biological spike-in enables cost-effective multi-species RNA-seq and reveals global transcriptional collapse under dark stress

RNA sequencing (RNA-seq) is the workhorse of plant functional genomics, but its per-sample cost limits the number of species, conditions and replicates that can be assayed, and its standard normalization assumes that most genes do not change and that total cellular RNA is roughly constant. Both assumptions fail when a treatment globally reprograms transcription. Here we address both problems at once. We pooled carefully weighed frozen tissue from three phylogenetically distant species, Arabidopsis thaliana (A), Brachypodium distachyon (B) and Oldenlandia corymbosa (O), into single RNA-seq libraries, applying a six-day dark stress to A and B while including unstressed O in every pool as an internal biological spike-in. Reads were mapped to a concatenated three-species coding-sequence index. Read assignment was essentially clean: every pure library was [≥]99.8 % correctly assigned and cross-species mis-mapping was [≤]0.2 %, establishing that pooling does not compromise species-level quantification. Because equal mass, not equal RNA, was pooled, the read share captured by the unchanging O reported the global RNA content of the stressed species directly: dark stress reduced total mRNA to [~]50-60 % of control in Arabidopsis and to only [~]25-37 % in Brachypodium, a magnitude difference invisible to conventional analysis. At the gene level, standard per-species analysis returned a balanced set of up- and down-regulated genes, whereas spike-in normalization revealed a response dominated by repression. Conventional pathway enrichment, measured against the bulk transcriptome, likewise failed to register the global shift. Multi-species multiplexing with a biological spike-in is therefore a cheap, quantitatively faithful strategy for stress transcriptomics.

Plant Biology↗

bioRxiv2026

Perturbation of genes linked to common schizophrenia risk variants identifies cilia programs

Schizophrenia (SCZ) is a common psychiatric disorder characterized by psychosis, emotional withdrawal, and cognitive deficits. Most SCZ risk variants reside in non-coding regions of the genome and are thought to influence disease risk by modulating gene regulation. However, the target genes, biological pathways, and cell types through which these variants exert their effects remain poorly understood. To address this gap, we employed in vivo CRISPR droplet sequencing (CROP-seq) in the postnatal mouse neocortex. We perturbed 12 SCZ risk genes previously linked to functionally validated risk variants, followed by single-cell RNA sequencing. We identified 3,031 differentially expressed genes (DEGs) that recapitulate transcriptional alterations observed in postmortem SCZ brains. Integrative analysis using DEG clustering, factor analysis, and gene regulatory network inference uncovered convergent gene programs with distinct biological functions and cell type specificity. Notably, ciliary transcriptional programs consistently emerged across analytical frameworks. The primary cilium is a neurocircuit modulating signaling organelle in neurons and glia that remains understudied in SCZ. Perturbation of key contributors to the ciliary transcriptional programs led to significant alterations in ciliary structure, suggesting that SCZ genetic risk factors may influence how brain cells sense and transduce extracellular signals through synapse-independent mechanisms. Together, this study provides the first in vivo characterization of the functional consequence of common variant architecture in SCZ and implicates ciliary dysfunction as a convergent downstream mechanism.

neuroscience↗

bioRxiv2026

Structural Basis for Inhibition of the HKU5-CoV Main Protease by Clinical SARS-CoV-2 Protease Inhibitors

The identification of Pipistrellus bat coronavirus HKU5 lineage 2 (HKU5-CoV-2) as a human ACE2-adapted virus highlights the need for antiviral strategies to control emerging HKU5-related merbecoviruses. However, despite the importance of the main protease (Mpro) as a key antiviral target, structural and biochemical characterization of HKU5-CoV Mpro in the context of clinical inhibitors has remained limited. Here, we obtained high-resolution crystal structures of HKU5-CoV-1 Mpro in its apo state (1.75 [A]) and in complex with the approved covalent inhibitor nirmatrelvir (1.91 [A]) and the non-covalent inhibitor ensitrelvir (1.55 [A]). These structures reveal an induced-fit mechanism, in which the S2 loop containing Met49 adopts an open conformation in the apo state and undergoes inhibitor-specific conformational changes upon nirmatrelvir and ensitrelvir binding. These structures served as a foundation for the characterization of HKU5-CoV-2 Mpro via modeling and molecular dynamics simulations. Biochemical assays revealed that HKU5-CoV-1 and HKU5-CoV-2 Mpro exhibited nearly identical kinetic profiles, with turnover rates approximately two-fold higher than SARS-CoV-2 Mpro. Structural analysis revealed a highly conserved S1 subsite but distinct local environments in the S1', S2, and S4 substrate-binding sites relevant to inhibitor recognition. Despite these variations, nirmatrelvir and ensitrelvir showed potent inhibitory activity, with comparable double-digit nanomolar IC50 values across all three Mpro proteins. Computational analyses indicated that HKU5-CoV-2 Mpro engages nirmatrelvir and ensitrelvir in binding modes comparable to those observed for HKU5-CoV-1, supporting a conserved mechanism of inhibitor recognition and providing a structural basis for developing pan-coronavirus antivirals targeting emerging merbecoviruses.

biochemistry↗

bioRxiv2026

Colchicine Directly Targets Aldehyde Dehydrogenase 2 (ALDH2) to Suppress Radiation-Induced Senescence and Atherosclerosis

BackgroundIonizing radiation (IR) accelerates atherosclerosis through induction of cellular senescence, DNA damage, defective efferocytosis, and dysregulation of clonal hematopoiesis (CH) drivers. Although low-dose colchicine reduces ischemic cardiovascular events in coronary artery disease, the precise molecular mechanisms underlying its vasculoprotective effects remain incompletely defined, and whether it mitigates radiation-associated vascular injury is unknown. MethodsBone marrow-derived macrophages (BMDMs) were pretreated with low-dose colchicine and exposed to 2 Gy IR. Molecular effects were assessed by RNA-seq, immunoblotting, and molecular docking. In vivo effects were tested in a partial carotid ligation (PLCL) model using spatial proteomics. Human monocyte-derived macrophages (HMDMs) from thoracic malignancy patients were analyzed before and after radiation therapy (RT). ResultsLow-dose colchicine suppressed IR-induced macrophage senescence signaling while preserving NRF2 activity. In a cell-free assay, colchicine directly activated aldehyde dehydrogenase 2 (ALDH2) in a dose-dependent manner (EC50 1-5 nM), identifying ALDH2 as a direct molecular target of colchicine. Following irradiation, colchicine restored ALDH2, reduced mitochondrial (mt)ROS-dependent p90 ribosomal S6 kinase (p90RSK) activation and lipid peroxidation, preserved TET2 and DNMT3A expression, and rescued impaired efferocytosis while preventing nicotinamide adenine dinucleotide (NAD) and adenosine triphosphate (ATP) depletion. These protective effects were ALDH2-dependent, as they were lost with ALDH2 inhibition or depletion and were mimicked by pharmacologic ALDH2 activation. In vivo, colchicine attenuated radiation-induced atherosclerosis and macrophage senescence-associated stemness (SAS). Consistently, macrophages from patients after RT showed reduced ALDH2 with increased mtROS, lipid peroxidation, and senescence. ConclusionThese findings identify ALDH2 as a previously unrecognized molecular target of colchicine that links mitochondrial redox control to suppression of radiation-induced macrophage senescence and atherosclerosis and may contribute to the efficacy of low-dose colchicine in cardiovascular disease.

cell biology↗

bioRxiv2026

Comparative connectomics reveals stage-specific gap junction rewiring that reshapes avoidance behavior

Environmental stress can remodel neural circuits, yet how such rewiring generates behavioral adaptation remains poorly understood. The dauer stage of Caenorhabditis elegans provides a unique model to address this question. Here, we investigated how dauer-specific circuit remodeling alters nociceptive behavior. We found that dauers exhibit markedly shorter avoidance durations than adults. Comparative connectomics revealed substantial expansion of gap junctions within the dauer nociceptive circuit. Calcium imaging further showed that dauer neurons exhibit faster and more transient activity dynamics throughout the circuit. Introducing synthetic dauer-specific gap junctions into adults was sufficient to recapitulate dauer-like neuronal activity patterns and significantly shorten avoidance duration. Despite extensive circuit rewiring, however, avoidance initiation remained preserved across developmental stages. Together, our findings demonstrate that the dauer connectome is selectively rewired through gap junction remodeling to tune behavioral persistence while robustly preserving behavioral initiation, revealing how developmental circuit reorganization balances flexibility and stability for survival under stress.

neuroscience↗

bioRxiv2026

Late induction of IgG4 following SARS-CoV-2 mRNA vaccination in pregnant and non-pregnant individuals includes clonotypes raised early in the response

To better understand how pregnancy impacts humoral immunity, we conducted an in-depth longitudinal analysis of the kinetics and characteristics of vaccine responses in a prospective cohort of pregnant and non-pregnant women. Humoral immune responses observed among pregnant participants who received the mRNA-delivered SARS-CoV-2 vaccination, including their effector functions, were in some cases marginally lower than those among non-pregnant controls, while prior infection was associated with some potentiation in humoral responses. Importantly, vaccine-induced antibodies were efficiently transferred across the placenta, providing the fetus with passive immunity and underscoring the dual benefit of maternal vaccination for both mother and neonate against COVID-19. Delayed induction of spike-specific IgG4 following the primary two-dose vaccination series was observed in vaccine recipients, independent of pregnancy status. In a subset (n=6) of pregnant women whose spike-specific serum IgG repertoires were extensively profiled at the clonotypic level over time as part of another study, we proteomically identified secreted IgG clonotypes that had class-switched to IgG4. Matching of these clonotypes detected as IgG4 to those defined as SARS-CoV-2 spike-specific revealed that, while a minority of total clonotypes, they were elicited early in the immunization series and tended to be more highly mutated, more prevalent, and more persistent than clonotypes in the serological repertoire that were not detected as IgG4. Consistent with the increase in secreted vaccine-specific IgG4 over time, but its poorer placental transfer, these clonotypes were detected at greater levels in maternal but not cord blood at the time of delivery as compared to 28 days post the second vaccine dose. These findings indicate some impact in the kinetics, characteristics, and functions of the humoral response that may be associated with pregnancy-related immune modulation. Conservation of the late class-switch recombination to IgG4 that has previously been associated with mRNA-based SARS-CoV-2 vaccines raises questions about how different immunological states and vaccine components influence short- and long-term characteristics of the humoral immune response.

immunology↗

bioRxiv2026

Title: Zero-shot automated insulin delivery for type 1 diabetes via dynamic physiology-aware reinforcement learning

Insulin therapy in type 1 diabetes requires constant dose adjustment based on blood glucose, meals, physiological states, and physical activity. This demanding self-management imposes a substantial burden and increases dosing-error risk, underscoring the need for automated insulin delivery (AID) systems that reduce user intervention. However, many current systems depend on fixed, individualized parameters and may not fully adapt to rapid or unobserved physiological changes. We developed the Dynamic Physiology-Aware Reinforcement learning Controller (DPARC), a zero-shot insulin optimizer that infers latent physiological dynamics from recent continuous glucose monitoring (CGM) and insulin-delivery history without prior personalization, carbohydrate announcements, or preset subject-specific parameters. DPARC uses a rolling 24-hour CGM and insulin-history window, but closed-loop operation can begin after 1 hour of observed data by initializing unobserved history with neutral normalized padding and progressively replacing it with observations. In silico, a single frozen DPARC policy adapted within 1 hour, improved time in range compared with a total daily insulin-conditioned reinforcement learning baseline, and approached the upper-bound performance of a fully personalized model under stochastic unannounced meals with randomized timing, carbohydrate amounts, absorption variability, and meal skipping. In supervised porcine studies under unannounced meals, DPARC maintained high time in range without manual configuration, supporting large-animal feasibility while prospective human evaluation is needed before clinical efficacy can be established. Learned latent representations correlated with physiological markers including insulin sensitivity and plasma insulin concentration, supporting physiological alignment and explanatory anchors. Collectively, these findings support DPARC as a preclinical proof-of-concept zero-shot AID framework for future supervised human evaluation.

bioengineering↗

bioRxiv2026

Fully Modified SpyCas9 Guide RNAs Enable Robust Genome Editing In Cells and In Vivo

Precision engineering of CRISPR/Cas9 components has advanced genome editing toward therapeutic applications. Completely chemically stabilized guide RNAs (gRNAs) have the potential to improve in vivo editing efficacy while enabling greater flexibility in delivery strategies. However, previous generations of fully modified guides have been associated with reduced Cas9 activity. Here, we employed an iterative, structure-guided optimization strategy to systematically introduce chemical modifications at each position of SpyCas9 gRNAs. Extending beyond commonly used nucleotide modifications, we incorporated 2-amino-RNA, 4-thio-RNA, and extended nucleic acid (exNA) to generate gRNA designs in which 90-100% of the nucleotides are sugar- or backbone-modified. Although certain modification patterns exhibit sequence-dependent variability, we have established a growing repertoire of guides that consistently maintain or enhance editing efficacy when applied both in vitro and in vivo. Collectively, our heavily and fully modified gRNAs hold potential for applications in nuclease editing, base editing, and other genome editing tools. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=132 SRC="FIGDIR/small/725424v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@1118f08org.highwire.dtl.DTLVardef@1c57069org.highwire.dtl.DTLVardef@1572148org.highwire.dtl.DTLVardef@14a111e_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2026

Inducible lipid storage and steatosis in the human choroid plexus associated with age and adiposity

Cells that store lipids for other cells or organs can contain "giant" or large lipid droplets (LLDs) greater than 2 {micro}m in diameter. In this study, human postmortem choroid plexus was evaluated for lipid droplets. Staining with hematoxylin and eosin (H&E), the lipophilic dye Oil red O, and anti-adipophilin antibodies established the presence of LLDs exceeding 10 {micro}m in diameter in choroid plexus epithelial cells (CPECs). Manual annotation of H&E stains from 105 cases revealed a significant association between age and the percentage of CPECs containing LLDs (reaching up to 69%) and involving LLDs in our largest annotated category (>5 {micro}m in diameter). The LLD association with age was replicated and extended to a total of 245 cases using a trained convolutional neural network, which further showed significant associations with body mass index at time of death (increasing with BMI), sex (higher in females >65 years old), and a near-significant association with Alzheimers Disease (lower in AD). Like HepG2 and derived hepatocytes, excess fatty acids in culture media readily induced LLDs and steatosis in human embryonic stem cell-derived CPECs. Akin to hepatocytes for the human body, we propose that CPECs store lipids for the human brain and become steatotic in the setting of excess adiposity.

pathology↗

bioRxiv2026

Hepatocyte TEAD1 drives epithelial-stromal remodeling during cholestatic liver injury

Background & AimsPrimary sclerosing cholangitis (PSC) is a progressive cholangiopathy characterized by ductular remodeling, inflammation, and periportal fibrosis, for which effective medical therapies remain limited. The Hippo pathway effector TEAD1 has been implicated in liver regeneration and fibrogenesis; however, its role in cholestatic injury remains poorly defined. We investigated whether hepatocyte TEAD1 regulates injury-associated remodeling in a PSC-mimicking model and whether this mechanism is conserved in human PSC liver. MethodsHepatocyte-specific TEAD1 knockout mice (Alb-TEAD1-/-) and littermate controls were subjected to DDC-induced cholestatic injury. Ductular reaction, fibrosis, inflammation, and bile acid-related gene programs were assessed by histology, immunostaining, and gene expression analyses. Translational relevance was evaluated using bulk and single-cell transcriptomic datasets from human PSC liver. ResultsHepatocyte TEAD1 deletion attenuated DDC-induced fibrosis, ductular expansion, and inflammatory cell accumulation, while preserving hepatocyte proliferative responses. TEAD1-deficient livers exhibited reduced expression of profibrotic mediators, including Spp1, Ctgf, and Cyr61, with decreased extracellular matrix deposition. In contrast, canonical transcriptional adaptations to cholestatic stress, including suppression of bile acid uptake, induction of efflux pathways, and repression of bile acid synthesis genes, were preserved in the absence of TEAD1. Analysis of human PSC datasets demonstrated coordinated upregulation of TEAD1 and TEAD-associated target genes. Single-cell transcriptomic analysis further revealed hepatocyte-enriched TEAD1 expression and activation of a TEAD1 target gene program across all hepatic zones in PSC, with effect sizes exceeding those observed in non-parenchymal populations. TEAD1 activation was accompanied by co-expression of profibrotic mediators and downregulation of hepatocyte differentiation markers, consistent with a maladaptive hepatocyte state. ConclusionsHepatocyte TEAD1 drives ductular, inflammatory, and fibrogenic remodeling during cholestatic injury without disrupting bile acid metabolic adaptation. These findings identify TEAD1 as a hepatocyte-intrinsic regulator of epithelial-stromal crosstalk and establish conserved activation of this pathway in human PSC, supporting TEAD-directed signaling as a therapeutic target.

pathology↗

bioRxiv2026

Decoy diversification underpins the regulation of an NLR-mediated autoimmunity

Appropriate activation of innate immune receptors is vital for the plant immune system. Immune activation must be strong and robust upon invasion by rapidly evolving pathogen species, while staying inactive in the absence of a pathogen to avoid constitutive defense responses that inhibit plant growth. Nucleotide-binding leucine-rich repeat receptors (NLRs) are intracellular proteins that surveil for pathogen invasion, often by direct or indirect perception of pathogen effector proteins. Indirect recognition of pathogen effector proteins, through monitoring the integrity of guardee or decoy proteins, can allow for a single NLR to detect a wide range of pathogen effectors. In this work, we investigated how the Solanaceae NLR NbPtr1 can recognize six different effector proteins from the bacterial pathogens Pseudomonas syringae, Xanthomonas perforans, and Ralstonia pseudosolanacearum. We identified several NOI-domain containing proteins that are guarded by NbPtr1. These NOI proteins share homology with, but are distinct from, RPM1 INTERACTING PROTEIN 4 (RIN4), a well-known guardee in Arabidopsis. Virus-induced gene silencing and CRISPR/Cas9-assisted deletion of NbNOI genes resulted in stunted growth dependent on NbPtr1 activity. Negative regulation of NbPtr1 requires the interaction between NbPtr1 and the suppressor NbNOIs. A conserved threonine residue of the NOI proteins is required for this interaction and fits into a putative binding pocket of NbPtr1 based on protein modeling. This threonine residue is modified by some of the recognized effector proteins. Our study uncovers the regulatory mechanism of an autoactive NLR and highlights the importance of decoy diversification in establishing compatibility with NLRs.

plant biology↗