Biology subjects

Wang, L.

Publications and source records attributed to Wang, L..

At least 109 records · Page 6Linked to original sources

bioRxiv2026

Concurrent Stereotactic Body Radiation Therapy and KRAS Inhibition Synergistically Improve Pre-clinical Pancreatic Cancer Treatment

Pancreatic ductal adenocarcinoma (PDAC) is one of the most challenging cancers to treat due to the dismal survival rate, poor post-treatment outcome and profound resistance to a wide range of therapies. With mutant KRAS being a key driver, small molecule inhibitors targeting KRAS or pan-RAS (KRASi) have demonstrated exciting preclinical and early clinical anti-tumor efficacy, and the pan-RAS(ON) inhibitor daraxonrasib (RMC-6236) recently achieved Phase 3 clinically meaningful improvements in patient survival compared to chemotherapy. But resistance to RAS/KRAS inhibitor inevitably develops, which limits and compromises the treatment outcome. In this study, we investigated the combination of stereotactic body radiation therapy (SBRT) and KRAS inhibition (MRTX1133 and daraxonrasib) in the treatment of preclinical PDAC models. We found that this combination strategy synergistically suppresses PDAC cell growth in vitro and enhances tumor control while minimizing local recurrence in orthotopically implanted KPC (LSL-KrasG12D/+;Trp53R172H/+;Pdx1-Cre) murine PDAC tumors in vivo. As radiation therapy (RT) induces ferroptosis in multiple cancer types and mutant KRAS promotes various anti-ferroptotic mechanisms, we tested the role of ferroptosis in promoting tumor-control efficacy. Intriguingly, the addition of a ferroptosis inhibitor, liproxstatin-1, to the combination therapy significantly abrogated the in vivo synergism between SBRT and KRAS inhibition, suggesting that treatment-induced ferroptosis at least partially drives the synergistic efficacy of this combination strategy. Our study indicates that this SBRT-KRASi combination has the potential to overcome treatment resistance and improve outcomes in PDAC patients. These data directly support the design of a planned multi-center Phase 2 clinical trial with this combination strategy in locally advanced PDAC.

cancer biology↗

bioRxiv2026

Higher-order assembly of a type IX retron enables exploitation for designer antimicrobials

Bacterial defense systems provide a rich reservoir for biotechnological innovation. Retrons are tripartite abortive infection systems that detect phage invasion using reverse-transcribed DNA (msDNA), but how they structurally couple threat detection to effector activation remains poorly understood. Here, we determine the cryo-EM structure and activation mechanism of retron-Kva2, a type IX retron from the human pathogen Klebsiella variicola. We reveal that retron-Kva2 assembles into an asymmetric, higher-order ribonucleoprotein complex that sequesters a toxic dimeric HEPN RNase at its core. We identify a natural phage trigger as the phage T5 protein D5, which activates the retron through structural mimicry. Mirroring the retron-Kva2 winged-helix protein, the helix-turn-helix fold of D5 binds the msDNA sensor, driving conformational remodeling that unleashes HEPN-mediated tRNA cleavage and growth arrest. Because retron-Kva2 surveils a structural fold via msDNA binding, rather than a primary sequence, this recognition mechanism provides a broadly exploitable pathway for programmable activation. Harnessing this structure-based logic, we computationally designed de novo synthetic triggers that activate retron-Kva2-mediated bacterial growth arrest in vivo. Our findings reveal the architectural basis of type IX retron immunity and establish a structure-guided paradigm for repurposing bacterial defense systems into precision-honed antimicrobial therapeutics.

microbiology↗

bioRxiv2026

Joint analysis of multiply perturbed cells improves statistical power and cost efficiency in Perturb-seq

Perturb-seq measures transcriptomic responses to genetic perturbations at scale, but conventional designs that enrich for one guide RNA per cell remain resource-intensive. Standard analyses discard cells carrying multiple guides, further limiting the usable yield from each experiment. Here, we characterize how incorporating these guide multiplets affects signal recovery, information loss, and cost reduction. At the highest guide burden, cells showed increased stress and suppressed cell-cycle progression. We develop PerturbMatch, a scalable statistical framework to analyze guide multiplets. Among different classes of guide multiplets, doublets and triplets recovered perturbation responses more accurately than higher-order multiplets. Across three 5000-gene Perturb-seq screens with increasing guide loading, per-cell costs decreased by up to 81% while information loss remained within 1.5-fold of the loss observed between technical replicates. In existing genome-wide Perturb-seq data, incorporating previously discarded guide multiplets increased usable cell numbers and improved statistical power. Compared with a singlet holdout set, adding guide multiplets moved signal recovery closer to the theoretical expected reproducibility. Overall, we recommend a design that intentionally includes single-guide cells, guide doublets, and guide triplets to improve cost efficiency while preserving signal recovery.

genomics↗

bioRxiv2026

Lab on a Capillary: Instrument-Free Compartmentalization Using Photopatterned Hydrogel Rings Embedded inside a Glass Capillary for Amplified Bioassays

Sensitive and low-cost protein biomarker detection is critical for disease diagnosis. Advanced microfluidic systems can generate miniature reaction compartments for a high-sensitivity assay. However, these platforms often require external instruments, skilled operators, and complex setups. Here, we develop a Lab on a Capillary (LabCap) platform that integrates photopatterned hydrogel rings within a glass capillary using a reconfigurable stop-flow lithography system. During sample loading and unloading steps, nanoliter-scale aqueous droplets (torodrops) are spontaneously formed around the hydrogel rings, creating isolated reaction compartments without the need for external instruments or an immiscible oil phase. The LabCap platform enables quantitative detection of clinically relevant biomarkers, including C-reactive protein (CRP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP). By adjusting the incubation protocol, assay speed and sensitivity can be tuned to meet different analytical requirements. A periodic medium exchange protocol enables biomarker detection at concentrations as low as 1 ng/mL, whereas prolonged static incubation extends detection to 0.1 ng/mL. In addition, LabCap offers practical advantages, including low fabrication cost (<{euro}1 per device), low reagent consumption (<100 L per assay step), and minimal wash-buffer usage (1 mL). These results demonstrate that LabCap is a simple, cost-effective, and versatile platform for biomarker detection.

bioengineering↗

bioRxiv2026

A vascular chip for disease-relevant flow shear stress topology

Vascular chips have advanced endothelial mechanobiology by enabling controlled responses to hemodynamic cues, yet disease-relevant wall shear stress (WSS) modeling remains limited. Simplified one-dimensional flow shear systems, designed mainly for physiological mechanobiology, miss the topological organization of pathological flow, whereas patient-specific vascular models capture complex hemodynamics but sacrifice generality and imaging compatibility. Here we develop a programmable vascular chip that converts disease-associated WSS topology into a physiologically parameterized experimental input. The device reconstructs a representative pathological shear-topology field on endothelial layer, supports stationary and physiologically paced oscillatory flow modes, and integrates matched unidirectional-shear references within the same chip. Using this system, we show that oscillatory WSS topology destabilizes endothelial monolayers, drives asymmetric collective emergent behaviors, impairs actin-nuclear mechanotransduction, accompanied by nuclear softening and enhanced perinuclear nanoparticle uptake. Integrated live-cell imaging, fluorescence analysis, Brillouin microscopy, and transport assays enable multimodal phenotyping across collective, subcellular mechanical and functional scales. By making disease-relevant WSS topology experimentally controllable, this vascular-chip framework bridges computational hemodynamics and experimental mechanomedicine, supporting standardized vascular disease modeling and functional screening.

bioengineering↗

bioRxiv2026

Microfluidic Tissue Array Platform for Personalized Drug Screening Using Tumor Explants or Biopsies

Despite major improvements in molecular characterization of breast cancer, current biomarkers still fall short in accurate treatment prediction. Interrogating tumor tissue ex-vivo in its native conformation is a direct strategy for guiding treatment of individual patients but presents a challenge. In this study, we developed a microfluidic tissue array (FTA) using small biopsy samples (< 1mm3) mimicking physiological flow for consistent exchange of nutrients and waste, retaining the tumor native stroma. Cell/patient-derived breast cancer xenograft tissues were maintained over 2 weeks in the array and their response to therapeutic agents, doxorubicin or neratinib, were interrogated. Drug response in the uFTA showed >2-fold reduction in tumor cell viability which corroborated tumor size shrinkage in mice bearing the same tumor load. EdU/Ki67 assays indicated selective retention of cells with higher proliferative capacity after drug treatment, underscoring in vivo clinical relevance . We have also developed a valved-FTA to increase throughput and variety of treatment conditions on the same chip. Together, this FTA can be staged as a powerful, low-cost benchtop theranostic tool for personalized cancer therapeutics compatible with FDAs New Approach Methods.

cancer biology↗

bioRxiv2026

Peri-Locus Coeruleus Controls Endothelial Cell Heterogeneity in Enriched Environments via Region-Specific Norepinephrine Signaling

The brain acts as a central integrator that enables organisms to interpret environmental stimuli and coordinate adaptive responses across the body. While enriched environments are known to enhance neural plasticity and cognitive function, their impact on peripheral organ systems remains less understood. Here, we show that enriched environmental conditions activate a peri-locus coeruleus (peri-LC) neuronal ensemble that preserves CD31hiEMCNhi type H endothelium, a specialized bone-associated endothelial subtype, against age-associated decline, thereby enhancing femoral bone density. Chemogenetic activation and ablation experiments further revealed that this peri-LC ensemble is functionally distinct from other sympathetic regulatory brain regions in its control of bone endothelial heterogeneity and skeletal mass. Three-dimensional bone clearing and spatial analyses showed that CD31hiEMCNhi endothelium is closely associated with sympathetic nerve terminals. The peri-LC mediates this process through sympathetic signaling and {beta}2-adrenergic receptors on bone vascular endothelial cells. In vivo imaging further demonstrated that norepinephrine release is spatially restricted, with sprouting endothelial cells near the growth plate exhibiting the highest sensitivity. Together, these findings reveal a refined brain-periphery regulatory logic in which distinct sympathetic brain circuits engage spatially restricted norepinephrine signaling to coordinate organ-specific vascular and skeletal adaptations.

neuroscience↗

bioRxiv2026

Targeting Cellular Pseudo-Senescence to Overcome PARP inhibitors Resistance in BRCA1 -Mutated Breast Cancer

Poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi) are a mainstay therapy for homologous recombination (HR)-deficient cancers; however, resistance remains a major clinical challenge. Previously, through a genome wide CRISPR screen, we identified ZNF251 haploinsufficiency as a novel driver of PARPi resistance. In BRCA1-mutant (BRCA1mut) cells, ZNF251 deficiency led to HR hyperactivation, conferring PARPi resistance that could be reversed by RAD51 inhibition. In this study, we further show that ZNF251 deficiency induces replication stress and a pseudo-senescence state, in which cells exhibit molecular and phenotypic markers of senescence while retaining proliferative capacity. Because senomorphic and senolytic therapies can target senescent cells, we tested whether these approaches could overcome PARPi resistance in ZNF251-deficient breast cancer cells. Critically, targeting this senescence-like state with either senomorphic agents, such as cytokine inhibitors, or senolytic agents, such as BCL-2 and BCL-XL inhibitors, overcame PARPi resistance ex vivo and in vivo. Importantly, pseudo-senescence was also observed in other PARPi-resistant contexts driven by HR hyperactivation, including 53BP1- and Shieldin-mutant cells, suggesting that it may represent a broader mechanism underlying PARPi resistance in breast cancer. Furthermore, in two olaparib-resistant, BRCA-mutant triple-negative breast cancer organoid models, treatment with DT2216, a BCL-XL-targeting PROTAC, sensitized both models to olaparib. Together, our work defines a novel pathway linking HR hyperactivation, replication stress, and pseudo-senescence, and positions both senomorphic and senolytic therapies as promising strategies to overcome PARPi resistance in BRCA1mut breast cancer. HighlightsO_LIZNF251 deficiency drives PARP inhibitor resistance through HR hyperactivation, replication stress, and pseudo-senescence in BRCA1-mutant breast cancer. C_LIO_LISenomorphic and senolytic therapies overcome PARP inhibitor resistance in vitro, in vivo, and in patient-derived organoid models. C_LIO_LIPseudo-senescence represents a shared vulnerability of HR-hyperactivated PARPi-resistant cancers and can be therapeutically targeted. C_LI

Cancer Biology↗

bioRxiv2026

A GPX4 phosphorylation switch by FGFR1 guards against ferroptosis

Ferroptosis is driven by lipid peroxidation, yet the mechanisms by which cells rapidly adjust their sensitivity to ferroptosis in response to extracellular cues remain elusive. We identify a direct phosphorylation switch controlling the activity of glutathione peroxidase 4 (GPX4), the core ferroptosis regulator. The receptor tyrosine kinase FGFR1 directly binds and phosphorylates GPX4 at Tyr180/Tyr196 in a kinase-dependent manner, requiring its Tyr730 as a docking site. This phosphorylation enhances GPX4s catalytic activity and suppresses ferroptosis. In cardiac ischemia/reperfusion injury, the FGFR1-GPX4 axis is suppressed, and a selective FGFR1 agonist (FGF-1{Delta}NT) reactivates it to protect against ferroptosis-mediated damage. Critically, a phosphorylation-deficient GPX4 knock-in mouse exhibits hypersensitivity to injury and non-responsive to this agonist, proving that GPX4 phosphorylation is essential. Our findings reveal a rapid mechanism for regulating ferroptosis via GPX4 tyrosine phosphorylation, directly linking receptor tyrosine kinase signaling to ferroptosis, and offering new strategies for treating ischemic-and other ferroptosis-associated diseases.

Cell Biology↗

bioRxiv2026

The structure of a 2-MDa chloroplast RNA polymerase reveals unexpected evolutionary complexity

Transcription in chloroplasts depends on the Plastid-Encoded RNA polymerase (PEP), a bacterial-derived enzyme whose catalytic core remains encoded by the highly reduced genome inherited from the cyanobacterial ancestor. In land plants, PEP has roughly doubled in size, expanding into a [~]1 MDa multisubunit machinery through the acquisition of numerous nuclear-encoded subunits. Based on phylogenetic analyses, this added complexity has been widely attributed to the demands of plant terrestrialization. Contrary to this view, we show that in the unicellular green alga Chlamydomonas reinhardtii, PEP assembles into an even larger [~]2 MDa complex containing twelve previously uncharacterized nuclear-encoded subunits (PEPS1-12), representing an RNA polymerase architecture of unprecedented size. A cryo-EM structure at 2.7 [A] resolution reveals that several of these subunits occupy positions analogous to those in land plant PEP, and that metabolic enzyme folds have been repurposed as structural scaffolds stabilizing the highly expanded plastid-encoded core. Despite this, most of the newly identified PEPS subunits lack detectable sequence or structural similarity to their land plant counterparts. These findings demonstrate that PEP complexity is not a hallmark of land plant evolution and may instead reflect, at least in part, the evolutionary entrenchment of additional subunits around an expanded plastid-encoded core. More broadly, they suggest that essential organellar machines can acquire substantial structural complexity that leaves little trace in sequence-based analyses, a pattern consistent with constructive neutral evolution.

molecular biology↗

bioRxiv2026

nanoASM: Long-Read Allele-Specific DNA Methylation Profiling Enables Functional Annotation of Regulatory Noncoding Variants in Human Prostate Tissues

Long-read nanopore sequencing enables simultaneous detection of germline variation and native DNA base modifications on individual DNA molecules, providing a unique opportunity to investigate allele-specific epigenetic regulation. Here, we performed whole-genome nanopore sequencing on normal and tumor prostate tissues to characterize differential methylation, methylation entropy, and allele-specific methylation (ASM) associated with noncoding genetic variants. Genome-wide analysis identified extensive cancer-associated differentially methylated regions (DMRs), with hypermethylated DMRs significantly enriched near transcription start sites and transcriptional regulatory regions. Integration with transcriptomic datasets revealed strong inverse relationships between promoter methylation and gene expression, while 5-hydroxymethylcytosine (5hmC) levels positively correlated with transcriptional activity across gene bodies. Using fragment-level methylation patterns enabled by long-read sequencing, we further quantified methylation entropy incorporating both 5mCG and 5hmCG states. Cancer-hypermethylated DMRs exhibited markedly reduced entropy, consistent with clonal fixation of methylation states during tumor progression. Entropy profiling across chromatin annotations demonstrated maximal epigenetic heterogeneity at partially modified enhancer-associated regions. To investigate cis-regulatory genetic effects, we developed a simple ASM framework (nanoASM) that can partition sequencing reads by allelic state and identifies allele-specific DMRs directly from long-read data. Compared with conventional population-level mQTL analysis, ASM demonstrated substantially improved statistical efficiency by leveraging within-individual contrasts and reducing sample-level heterogeneity. Although germline single nucleotide polymorphisms (SNPs) were largely shared between normal and tumor tissues, ASM patterns differed substantially, with tumor-associated ASM regions displaying significantly larger genomic span and stronger allelic methylation differences. Comparative analysis with TCGA prostate mQTL and GTEx prostate eQTL datasets demonstrated substantial concordance between ASM directionality and downstream transcriptional effects, particularly for variants located within DMRs and near transcription start sites. At the IRX4 prostate cancer risk locus, ASM identified an androgen-responsive regulatory domain overlapping AR ChIP-seq and H3K27ac peaks, nominating rs6885084 as a candidate functional variant. At the PSCA locus, ASM anchored by rs4736369 was associated with allele-specific methylation, chromatin activation, transcript abundance, and isoform usage. Together, these findings establish nanopore-based ASM analysis as a powerful approach for resolving functional noncoding variants and their regulatory domains they control in prostate cancer.

genetics↗

bioRxiv2026

Multivariate Random Forests for Cross-Modal Multi-Omics Integration

Multi-omics studies are widely used across many areas of biomedical research. In many diseases, some signals are shared across data types, while others are strongest in a single omics layer. Current multi-omics clustering methods often either merge all data types into a single representation, which can blur biology that is strong in one layer, or rely on linear structure that may miss more complex relationships across data types. We introduce O_SCPLOWMULTIC_SCPLOWRF, a random-forest-based method that handles complex data types and separates shared and modality-specific structure for multi-omics data. O_SCPLOWMULTIC_SCPLOWRF learns sample similarities across omics layers from multivariate random forests, combines them across data types, and uses the resulting weights to estimate the part of each omics layer that is predictable from the others. The remaining residual is treated as modality-specific signal, allowing shared and modality-specific similarities to be clustered separately. In simulations, O_SCPLOWMULTIC_SCPLOWRF recovered shared clusters as well as or better than established integrative methods while more reliably separating modality-specific signal under nonlinear data structures. In TCGA head and neck squamous cell carcinoma, the shared component aligned with the main subtype structure across established reference classifications, while gene- and miRNA-specific components revealed additional immune and developmental biology. In the ADNI cohort with matched blood DNA methylation and structural MRI, the shared cross-modal aging signal was associated with future conversion to mild cognitive impairment or Alzheimers disease, and a DNAm-specific residual signal showed exploratory additional information. These results show that O_SCPLOWMULTIC_SCPLOWRF can recover a common disease axis while retaining biologically meaningful signals specific to one data type. O_SCPLOWMULTIC_SCPLOWRF is available as an open-source R package at https://github.com/novawz/multiRF.

bioinformatics↗

bioRxiv2026

ROS Impair Mitophagy via PARylation of PINK1

Mitophagy is the process of selective autophagic clearance of damaged mitochondria and is closely implicated in neurodegenerative disease. PTEN-induced kinase 1 (PINK1) and a RBR E3 ubiquitin-protein ligase (Parkin) constitute a positive feedback loop in mitophagy initiation. It is known that reactive oxygen species (ROS) modulate mitophagy, while the exact regulatory mechanism remains largely elusive. Here, we found that exogenously applied ROS effectively block mitophagy induced by acute mitochondrial damage agents, which could be reversed by antioxidants. Mechanistically, ROS activate poly(ADP-ribose) polymerase 1 (PARP1), and suppression of PARP1 eliminates the inhibitory effect of ROS on mitophagy. Notably, PARP1 directly interacts with PINK1 and mediates its PARylation at residue E417, thereby negatively regulating PINK1 function. Collectively, our study identifies PARylation as a new form of post-translational modification of PINK1 and reveals a novel mechanism underlying the regulatory role of ROS in mitophagy by PARP1 activation and PARylation of PINK1. In briefGao et al. demonstrate that exogenous ROS inhibit mitophagy. Mechanistically, ROS activate PARP1, which mediates PARylation of PINK1, a central regulator of mitophagy, leading to its functional impairment. This study reveals a novel regulatory mechanism of ROS on mitophagy through PARP1 activation and identifies PARylation as a novel form of post-translational modification of PINK1. HighlightsO_LIROS block PINK1-Parkin-mediated mitophagy. C_LIO_LIROS activate PARP1. C_LIO_LIPARP1 suppression eliminates the inhibitory effect of ROS on mitophagy. C_LIO_LIPARylation of PINK1 by PARP1 impairs its activity and mitophagy. C_LI

Cell Biology↗

bioRxiv2026

Disrupted Mitochondrial Copper Homeostasis Promotes Ferroptotic Stress, Senescence and MASLD Progression

Background & AimsSystemic metabolic dysfunction promotes degenerative diseases in many organs, including liver and kidney. The liver is a master regulator of systemic metal ion homeostasis. Hepatic copper deficiency is increasingly observed in metabolic dysfunction associated steatotic liver disease (MASLD) and is associated with greater disease severity and poor outcomes. However, mechanisms linking copper dysregulation to MASLD and its co-morbidities remain poorly defined. We investigated whether impaired mitochondrial copper homeostasis contributes to MASLD-related pathobiology and represents a modifiable therapeutic axis. Methods & ResultsUsing dietary mouse models of MASLD and in vitro systems, we found that dietary copper deficiency induces lipotoxicity and suppresses mitochondrial metabolic programs. MASLD livers exhibited marked depletion of copper, impaired cytochrome c oxidase integrity, and bioenergetic failure. Targeted restoration of mitochondrial copper with the copper ionophore elesclomol normalized copper-handling programs, improved mitochondrial function, and suppressed ferroptotic stress, hepatocyte senescence, and fibroinflammatory remodeling. Mechanistically, reduced expression of the mitochondrial copper transporter SLC25A3 and MT-CO1 disrupted the SLC25A3-SCO1-MT-CO1-CTR1 axis, limited copper uptake and destabilized copper-iron balance, promoting maladaptive cell fate changes. Across multiple human cohorts and mouse models, copper-iron imbalance tracks with MASLD progression, clinical outcomes, and multiple extrahepatic comorbidities; restoring copper homeostasis in mice with MASLD attenuates both liver and kidney inflammation and fibrosis. ConclusionsMitochondrial copper deficiency is a mechanistically actionable driver of MASLD that promotes bioenergetic failure, ferroptosis, senescence and fibroinflammatory damage in the liver and other organs. Targeting copper-centered mitochondrial regulation represents a novel biomarker and therapeutic strategy for MASLD and its systemic complications.

pathology↗

bioRxiv2026

Multimodal Hypersampling of the adult human heart resolves tissue-specific cell states and disease-associated variants

Cardiovascular diseases often arise in anatomically specialised regions of the heart that remain poorly represented in existing single-cell and spatial atlas references. Here we profiled 28 regions of the adult human heart from 36 donors, combining paired single-nucleus RNA and chromatin accessibility assays with spatial transcriptomics. The resulting atlas integrates 1,059,175 expression profiles and 452,614 chromatin accessibility profiles, and defines spatial niches across the heart. In cardiac valves, we identify a valve fibroblast-macrophage niche that is polarised to the non-fibrosa surface and expands with age. Aortic stenosis genetic risk was enriched in inflammatory regulatory programmes of the Valve Fibroblast Immune cell state. In pulmonary veins, we define PITX2+ Myocardial Sleeve Cells, a region-restricted cardiomyocyte population in which a fine-mapped 4q25 atrial fibrillation variant intersects a cell type-specific open chromatin region. In coronary arteries, we resolve a RUNX1-marked synthetic smooth muscle layer in the subintima that provides a molecular identity for diffuse intimal thickening, a constitutive feature of the healthy vessel wall and a substrate for atherosclerosis, and show by perturbation in human smooth muscle cells that RUNX1 promotes cell-cycle entry while restraining inflammatory cytokine gene expression. Finally, allele-specific accessibility together with deep learning models fine-tuned to predict regulatory activity from DNA sequence identify cell type-specific regulatory effects at GWAS loci for atrial fibrillation, coronary artery disease and calcific aortic valve stenosis, including a variant whose Valve Fibroblast-specific effect on the polyamine transporter ATP13A3 is opposite in direction to the effect seen in bulk-tissue eQTL references that lack valve cells. Together with these cardiac sequence models and CardioSleuth, an AI-powered exploration engine for cardiac regulatory effects, this atlas links cardiac anatomy, gene regulation and disease genetics at single-cell resolution. By placing genetic risk in its precise cellular and anatomical context, it provides a foundation for mechanistic disease understanding, cell-state-specific therapeutic target nomination, and improved interpretation of inherited cardiovascular risk to inform future therapy and management.

Cell Biology↗

bioRxiv2026

Parameterization of the PA endonuclease bimetallic center reveals the dynamics of clinically relevant mutations

Influenza A virus continues to impose a major global health and economic burden through seasonal epidemics and occasional pandemics, highlighting the critical need for continued antiviral development. As the latest addition to anti-influenza therapy, baloxavir marboxil (BXM) targets the highly conserved PA N-terminal endonuclease domain (PAN), blocking the cap-snatching process essential for viral transcription initiation. However, the rapid emergence of resistance mutations significantly reduces BXM susceptibility and compromises its clinical efficacy. Understanding the dynamics underlying resistance through computational modeling has been hindered by the complex electronic properties of the bimetallic catalytic center within the PAN active site, posing a challenge for accurate parameterization. Therefore, in this study, we systematically benchmarked metal-parameterization strategies for molecular dynamics (MD) simulations, including non-bonded, bonded, and hybrid models, using wild-type PAN in both apo and drug-bound states. Identification of reliable parameterization schemes enabled MD simulations of five clinically relevant mutants, I38T/F/M, A36V, and E23K, revealing how each reshapes the conformational landscape to modulate drug binding modes. Together, our results provide a path toward modeling complex sites in metalloenzymes and a mechanistic foundation for vulnerabilities in PAN to guide structure-based optimization of next-generation inhibitors. TOC O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=122 SRC="FIGDIR/small/731895v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@1488315org.highwire.dtl.DTLVardef@196057eorg.highwire.dtl.DTLVardef@42a77forg.highwire.dtl.DTLVardef@2b959_HPS_FORMAT_FIGEXP M_FIG C_FIG

biophysics↗

bioRxiv2026

Aberrant neuron-OPC synaptic transmission and deficient myelination define sex bias in major depressive disorder

Sex bias is a notable feature of major depressive disorder (MDD), yet its cellular and molecular origins remain unclear. We integrated computational analyses of human patient data with histological and biochemical validation in animal models to uncover female-specific MDD pathways. We identified female-specific mechanisms involving oligodendroglial lineage cells, especially oligodendrocyte precursor cells (OPCs), as key signal receivers with unidirectional preference in interactome networks. The neurexin (NRXN) pathway emerged as the most perturbed in MDD, with greater disruption in females. Subclustering further identified committed OPCs (cOPCs) as a disease-associated oligodendroglial subpopulation characterized by high expression of synaptic genes; cOPCs were also enriched of MDD-related transcriptional signatures revealed by trajectory analysis. High-dimensional weighted gene co-expression network analysis identified GABRG3 as an MDD-specific hub gene in cOPCs. The GABRG3 was also involved in the NRXN synaptic assembly cascade. Using Gabrg3 conditional knockout mice, we validated findings in patients and demonstrated that conditional deletion of Gabrg3 in cOPCs recapitulates MDD-like phenotypes, highlighting impaired neuron-cOPC synaptic communication, abnormal myelination, and depression-like behaviors. Together, our work defines a sex-specific cellular and molecular pathobiology of MDD, bridges clinical discovery with preclinical context, and provides a translatable framework for precision medicine targeting fundamental sex differences.

neuroscience↗

bioRxiv2026

Long-read genome sequencing reveals complex variability in lentiviral provirus insertions in deeply characterized Clonal CD19 CAR-T vector copy number reference cell lines

Chimeric antigen receptor (CAR)-T cell therapy is an important therapy involving provirus insertions in the genome. Characterizing these insertions is important for understanding the safety and efficacy of cell products, but the sequence of these insertions is not fully characterized. We generate clonal CD19 CAR-T cell lines with one to five copies of the lentiviral provirus insertions. Vector copy number (VCN) was determined by droplet digital PCR (ddPCR), which revealed that most of the elements (LTR, Psi, RRE, CD19, and WPRE) were 1 to 5 or 6 copies per cell. DdPCR data also revealed that there was an additional copy of eGFP gene in VCN4 and VCN5 cell lines. To fully characterize the sequences and locations of these insertions, we use short- and long-read whole genome sequencing as well as digital PCR and flow cytometry. Long-reads enable full resolution of each insertion, and we find that of 10 insertion events, 3 have the expected insertion sequence, 2 differ from the expected only in small variants, 3 have structural abnormalities, and 2 are small partial insertions missed by most other approaches. One particularly important structural abnormality resolved only by long-reads is a 724 bp deletion of the EF1 promoter disrupting expression of the CD19 CAR. Standard short-read and ddPCR approaches miss this deletion due to this commonly used promoter being in the unengineered human genome. These results demonstrated that these cell lines are suitable VCN reference standards for 1 to 5 or 6 copies and highlight the utility of long-read sequencing in characterizing both quantity and quality of insertions in lentiviral-engineered cells.

genomics↗