Biology subjects

Li, H.

Publications and source records attributed to Li, H..

At least 55 records · Page 3Linked to original sources

bioRxiv2026

An accumbal cholinergic ISR-HCN2 axis sustains maladaptive cue motivation

Environmental cues associated with rewarding outcomes can exert persistent control over behavior long after the reward is absent, yet the cellular adaptations that stabilize such maladaptive motivation remain unclear. Here we identify nucleus accumbens cholinergic interneurons (CINs) as causal regulators of persistent cue-driven seeking. Self-administration of addictive drugs or high-fat reward, but not sucrose, selectively increased CIN pacemaker firing. Cocaine-paired cues evoked rapid acetylcholine release in the nucleus accumbens core, and bidirectional manipulation of CINs suppressed or enhanced cue-induced cocaine seeking. Mechanistically, cocaine experience engaged the integrated stress response (ISR) in CINs, increased HCN2 expression and Ih, and stabilized a hyperexcitable state. CIN-specific ISR suppression or HCN2 knockdown reduced cocaine seeking, whereas HCN2 overexpression enhanced it. Local HCN blockade and systemic treatment with the clinically approved HCN blocker ivabradine reduced cue-driven seeking across addictive-drug and high-fat-reward paradigms while sparing sucrose seeking. These findings identify an ISR-HCN2-dependent cholinergic mechanism that stabilizes maladaptive cue-driven motivation and nominate HCN-dependent excitability as a tractable target for therapeutic intervention.

neuroscience↗

bioRxiv2026

The OxyR-Responsive TacAT Module Promotes Oxidative Stress Adaptation and In Vivo Fitness in K. pneumoniae

During infection, Klebsiella pneumoniae must withstand host-derived oxidative stress not only by detoxifying reactive oxygen species (ROS) but also by repairing oxidative damage to cellular physiology. How these detoxification and stress-adaptive responses are coordinated remains unclear. Here, we identify a plasmid-encoded tacAT locus as an OxyR-responsive regulatory module that supports peroxide tolerance and in vivo fitness in K. pneumoniae. Guided by the conservation of the OxyR DNA-binding domain and its consensus binding motif, we surveyed promoter-proximal regions of the K. pneumoniae CRK3022 chromosome and plasmids for candidate OxyR-responsive loci. This analysis identified tacAT, a putative type II toxin-antitoxin (TA) module, as the only plasmid-associated candidate. OxyR directly bound the tacAT promoter and contributed to tacAT induction during hydrogen peroxide (H?O?) stress. The TacAT complex exhibited DNA-binding and transcriptional regulatory activity, promoting the expression of genes linked to protein quality control and membrane/envelope homeostasis, including clpB, htpG, cadC, bhsA, and marA. Deletion of tacAT compromised survival under lethal peroxide challenge and attenuated bacterial dissemination, tissue pathology, and inflammatory responses in a murine bacteremia model. These findings define an OxyR-TacAT regulatory branch that connects peroxide sensing with stress-adaptive gene expression, revealing how a TA-associated module can be integrated into stress-adaptive programs during host-associated oxidative stress.

microbiology↗

bioRxiv2026

Spatiotemporal atlas resolves the mesenchymal-epithelial stem cell axis governing human hair follicle aging and pathology

How adult stem cell populations coordinate tissue regeneration across physiological and pathological states remains unclear. Hair follicles contain epithelial and mesenchymal stem cells that codetermine hair regeneration. Here, we integrate a multimodal spatiotemporal atlas with functional validation to define the mesenchymal-epithelial stem cell dynamics governing human hair follicle homeostasis, aging, and androgenetic alopecia. Aging is characterized by passive depletion of hDSC-derived regenerative cues, whereas AGA involves a shift of hDSC toward an inhibitory signaling hub that promotes HFSC dysfunction. We further pinpoint hDSC-secreted PTN as a key regenerative factor that promotes hair growth and counteracts androgen-induced growth suppression. This study provides a holistic framework of adult stem cell crosstalk across physiological and pathological states, offering a mechanistic roadmap to reinstate tissue regeneration.

cell biology↗

bioRxiv2026

Symmetric Dimethylarginine Modification Drives Shared and Divergent Antigen Reactivity in Lupus

Systemic lupus erythematosus (SLE) features a broad array of autoantibodies against nuclear components, but the mechanisms driving this diversity are poorly understood. We investigated whether posttranslational arginine methylation creates common neo-epitopes that could unify this response. Using methylome-wide peptide arrays, we identified anti-symmetric dimethylarginine (SDMA) autoantibodies in 30-40% of SLE patients, with individualized reactivity fingerprints. A single anti-SDMA monoclonal antibody from MRL-lpr mice recognized multiple SDMA-modified antigens, and EBNA-1, an Epstein-Barr virus protein, bound SLE plasma in an SDMA-dependent manner, pointing to potential molecular mimicry. In a validation cohort of 201 patients, anti-SDMA titers correlated with SLEDAI-2K scores and inversely with C3/C4; seropositivity was overrepresented in younger patients, those with renal involvement, and anti-Sm-positive individuals. These results establish that anti-SDMA responses are common in SLE, target methylated arginine motifs across self and viral proteins, and serve as markers of active, complement-consuming disease. The patient-specific recognition of SDMA epitopes may underlie the serological heterogeneity that defines SLE.

biochemistry↗

bioRxiv2026

TFE3 fusions drive expression of CD44 and SPP1 in Translocation Renal Cell Carcinoma

Xp11.2 translocation RCC [Xp11.2 tRCC]) is an underdiagnosed and aggressive subtype of RCC with few specific or targeted therapies. The transmembrane glycoprotein CD44 is an emerging target in many advanced malignancies, and with its ligand OPN (SPP1), is a crucial driver of cancer progression, stemness, metastasis, and immune suppression. Here we show that common TFE3-fusions [ including SFPQ-TFE3, PRCC-TFE3, ASPSCR1-TFE3, and NONO-TFE3] are associated with upregulated expression of CD44 and SPP1, as observed in multiple human and murine bulk transcriptomic studies and a murine tRCC snRNA-Seq dataset. CD44 and/or SPP1 protein expression were also upregulated in murine models of transgenic tRCC kidneys and urine specimens, patient-derived cell lines and human tRCC cases, by immunoblotting and/or IHC. Transient deletion of CD44 was associated with profound and specific suppression of tRCC cell line growth, with decreased mTOR signaling. These data suggest that CD44 and/or SPP1 may potentially drive tumorigenesis in tRCC.

cancer biology↗

bioRxiv2026

KMT2E recruitment by H3 serotonylation regulates neurodevelopmental chromatin dynamics

Histone H3 Gln 5 serotonylation (H3Q5ser) is a recently identified epigenetic modification in brain that modulates reader interactions with adjacent H3 Lys 4 trimethylation (H3K4me3) to promote transcriptional permissiveness. However, whether H3K4me3Q5ser and its associated binding proteins regulate neurodevelopmental gene expression programs remains unknown. Here, we identified the catalytically inactive Lysine methyltransferase 2E (KMT2E) as a reader of combinatorial H3K4me3Q5ser. KMT2E preferentially binds H3K4me3Q5ser over H3K4me3 alone, and enriches at broad chromatin domains marking actively transcribed neurodevelopmental loci. Notably, heterozygous variants in KMT2E have been implicated in ODLURO syndrome, a recently characterized neurodevelopmental disorder (NDD). To identify the molecular mechanisms underlying ODLURO syndrome, we generated a Kmt2e transgenic mouse model that reproduces behavioral, physiological, and cellular endophenotypes associated with this and other NDDs. Furthermore, we observed that KMT2E mediates these effects by recruiting the NCoR/HDAC3 repressor complex to H3K4me3Q5ser-marked loci to restrict spreading of co-localized H3 Lys 9 acetylation (H3K9ac). Inhibition of aberrant H3K9ac spreading was sufficient to rescue transcriptional dysregulation in Kmt2e haploinsufficient neurons. These findings thus establish KMT2E as a critical reader of H3 serotonylation during neurodevelopment and provide mechanistic insights into the pathogenesis of ODLURO syndrome.

neuroscience↗

bioRxiv2026

Vritra: gene-specific reference construction for species-resolved functional profiling of metagenomic and metatranscriptomic data

Species-resolved profiling of microbial functional genes is important for linking microbial community composition to biological function, but existing functional profiling approaches are not designed to systematically define user-specified genes and resolve their contributing species. We developed Vritra (Versatile gene-guided Reads-identification with Impartial Taxonomic Refinement and Assignment), a framework for constructing gene-specific reference databases for metagenomic and metatranscriptomic data. Vritra expands and refines the UniRef-based sequence space for user-specified target genes using sequence-similarity network connectivity and functional annotations, retains related homologs as decoys to reduce assignment ambiguity, and links the resulting sequences to standardized microbial taxonomy. Across genes involved in oxalate, urate, and bile acid metabolism, Vritra recovered >97% of sequences represented by established annotation resources for most evaluated genes while substantially expanding the represented sequence space. In real microbiome datasets, the expanded references increased recovery of target-gene reads by up to threefold for poorly annotated genes while maintaining high sequence identity. Application to population-based and publicly available microbiome datasets enabled species-resolved profiling of functional genes and revealed gene-specific associations with microbial taxa, dietary factors, and disease-related phenotypes. Vritra provides a scalable framework for translating continuously expanding sequence resources into gene-specific, species-resolved references for microbiome studies.

bioinformatics↗

bioRxiv2026

Structural Basis for MCAM Mediated Inhibition of Laminin Dependent Cell Migration

MCAM/CD146 is an immunoglobulin-superfamily receptor expressed on endothelial cells, immune cells and numerous carcinomas. Although MCAM has long been associated with metastatic progression, recent work has revealed context-dependent inhibitory effects on transendothelial migration, leaving unresolved how MCAM engagement of basement membrane laminins alters cell migration. Here, we report multiple cryo-electron microscopy structures of human MCAM bound to laminin. We show MCAM engages laminin on a surface centered on the first two laminin globular domains (LG1-2) and that this epitope directly overlaps with the interface used by integrin. Consistent with structural competition, MCAM occupation of laminin abolishes integrin-dependent cell migration. Structure-guided mutation of the MCAM-laminin interface disrupts laminin binding and eliminates MCAM-mediated inhibition. These findings establish that MCAM and integrin compete for a shared interface on laminin and define a structural mechanism by which MCAM occupancy can suppress laminin-dependent migration. The structure resolves a central ambiguity in MCAM biology and provides a framework for developing biologics that selectively modulate pathological cell migration.

biophysics↗

bioRxiv2026

Genetic regulation of circulating metabolome in cattle

The circulating metabolome is a vital intermediate layer linking genetics to complex phenotypes, yet existing genome-wide studies-even in humans-rarely capture dynamic physiological contexts or cellular regulatory mechanisms. Here, we present the Cattle Metabolome Atlas (https://cattlema.farmgtex.org/), a comprehensive resource of 3,436 plasma metabolites and 4,851 serum metabolites from 4,651 animals with matched sequence-level genotypes across highly dynamic parity and lactation stages. We mapped 728 plasma and 622 serum metabolite quantitative trait loci (mQTL), revealing widespread context-dependent regulatory architectures. Integrating these mQTL with the multi-tissue expression quantitative trait loci (eQTL) and single-cell atlas of 59 tissues demonstrates that 74-79% of mQTL colocalize with eQTL across 29 tissues, prioritizing the liver as the primary systemic hub and resolving metabolic programs at single-cell resolution. Furthermore, we charted 538 causal gene-tissue-metabolite-trait cascades across 11 complex traits in cattle. Finally, cross-species analyses demonstrate partial evolutionary conservation of genetic metabolism between cattle and humans, establishing this atlas as a powerful asset for cattle genetics and genomics, selective breeding, and comparative biology.

genetics↗

bioRxiv2026

Deep Learning-based Modeling Enhances Efficacy of Natural Ligand CAR Binders Targeting CD70

CD70 is well-recognized as a promising "pan-cancer: chimeric antigen receptor (CAR) T-cell target. Prior work has shown that a "natural ligand" (NL)-based CAR targeting CD70, employing its physiological interaction partner CD27, may have therapeutic advantages over antibody-based CARs. Yet while antibody-based CARs are routinely optimized by affinity maturation of their scFv, whether the binding sequence of an NL CAR can be engineered to improve its function remains unexplored. Here, we combined deep learning with physics-based modeling to redesign residues at the CD27:CD70 interface, identifying a CD27 variant, "N88A", which enhances the efficacy of CD70-targeting CAR T-cells across models of acute myeloid leukemia, multiple myeloma, and renal cell carcinoma. Biophysical approaches, including molecular dynamics simulations, support a mechanism of increased binder conformational freedom underlying potency enhancement. Our work presents CD27N88A CAR T-cells as a promising new therapeutic option and proposes that computational modeling could be applied to enhance efficacy of other NL-based immunotherapies.

cancer biology↗

bioRxiv2026

Cytosolic MagLOV Magnetofluorescence in Mammalian Cell Lines and Primary Neurons

Magnetic fields can influence the outcome of photochemical reactions through the radical pair mechanism, but whether this sensitivity extends to standard experimental conditions in mammalian cells has remained unclear. Here, we quantify the cytosolic magnetofluorescence of MagLOV, a genetically encoded, flavin-binding fluorescent protein, in mammalian cells, validated against extensive artifact controls. Excitation intensity and magnetic field strength differentially tune response kinetics and amplitude, respectively, with amplitude saturating above approximately 8 mT. Magnetic field-effect amplitude is further modulated by cellular culture state. This response generalizes across HEK293T, HeLa, U2OS, and A549 cells and primary mouse cortical neurons, with plateau amplitudes ranging from 1.4% to 2.7%. Together, these results establish that genetically encoded spin-dependent photochemistry can be quantitatively interrogated under standard mammalian live-cell imaging conditions, and generalizes across mammalian cell types.

biophysics↗

bioRxiv2026

Widespread structural variations at human chromosome ends

The highly repetitive regions of the human genome were long underrepresented from reference assemblies, limiting study of their biological function. Long-read sequencing and improved assembly algorithms have since resolved many of these regions, from centromeres to ribosomal DNA arrays, revealing structural variation increasingly linked to human disease. However, the subtelomeres, the repeat-rich regions adjacent to the telomeres at each chromosome end, have remained poorly characterized. Here we present a collection of complete subtelomeric sequences spanning all non-acrocentric chromosome arms, derived from 860 haploid assemblies across six ancestry groups. We find that while subtelomeres are mosaics of blocks shared between chromosome arms, individual arms diverge extensively, such that most non-acrocentric autosomal arms (54%, 21 of 39) carry multiple haplotypes differing by up to 100-200 kb. These blocks are broadly conserved across the great apes. In humans, their diversity is associated with chromosome arm rather than ancestry, suggesting that cross-arm paralogy block duplications predate human population divergence, although some haplotypes show ancestry-specific enrichment. Remarkably, these divergent haplotypes differ in gene content, driving gene copy-number variation between individuals among olfactory receptors and other genes. This study also revealed rare subtelomeric recombination. We further show that our subtelomere data set enables the accurate measurement of telomere length at individual chromosome ends from long-read data. Together, these assemblies reveal an unappreciated scale of variation at human chromosome ends and provide a resource for studying the roles of this variation in disease, telomere biology and genome evolution across diverse populations.

genomics↗

bioRxiv2026

m1A58 acts as a conformational checkpoint coupling human initiator tRNA maturation to translation initiation

tRNAs are characterized by extensive chemical modifications that influence tRNA fate. N1-methyladenosine at position 58 (m1A58) is a widespread core tRNA modification linked to physiological and pathological processes. However, how m1A58 coordinate tRNA folding and processing to ensure translational efficiency in mammalian cells remains largely unknown. Using acute dTAG-mediated degradation and CRISPR-Cas9 knockout, we identified initiator methionine tRNA (tRNAiMet) as selectively vulnerable to m1A58 loss, lacking the isodecoder buffering observed for most other tRNA isoacceptors. NMR analysis of the tRNAiMet showed that m1A58 stabilizes D/T-loop interactions, consistent with a maturation-competent conformation. In vitro processing assays further demonstrated that m1A58 promotes RNase P-mediated 5'-leader removal and RNase Z-mediated 3'-trailer cleavage, while La/SSB protects accumulated precursors. Disrupting this checkpoint impaired the assembly of the eIF2-containing 43S pre-initiation complex and global protein synthesis, which was substantially rescued by adding m1A58-modified tRNAiMet. Acute TRMT6 degradation elicited temporally coordinated gene-expression responses involving proteostasis, transport and signaling. Together, these findings establish m1A58 as a conformational checkpoint coupling human initiator-tRNA maturation to translation initiation and stress responses.

molecular biology↗

bioRxiv2026

Combining 3D-multispectral and hyperspectral imaging to identify environmental stress treatments imposed during plant growth

Non-invasive, high-throughput phenotyping tools are needed that can identify environmental effects on plant structure and function to diagnose factors responsible for reduced growth in commercial and non-commercial settings. In this study, we explored whether the integration of 3D-multispectral (3D) and 2D-hyperspectral imaging (HSI), aided by machine learning (ML), could be used to identify environmental stress treatments imposed during plant growth. Controlled environment-grown Nicotiana Benthamiana plants were subjected to a range of abiotic treatments - including different growth irradiances, heat treatment and drought stress - with the treatments resulting in differences in shoot height, biomass, leaf area and spectral reflectance. ML models were trained to identify these treatments using morphological and spectral traits measured at 27, 29, 31, and 34 days after sowing (DAS). A 3D-multispectral scanner was used to obtain information on plant height, biomass, and leaf area. A visible and near-infrared (VNIR) HSI camera provided detailed spectral information for deriving spectral indices including the Normalised Difference Vegetation Index (NDVI), Photochemical Reflectance Index (PRI) and Normalized Difference Red Edge (NDRE). Manual measurements provided baseline comparative data. The 3D-multispectral scanner reliably estimated above-ground traits, with high correlations between manual and scanner-derived measurements. The ML models accurately differentiated among environmental stress treatments, with the fused 3D+HSI model achieving the best overall predictive performance across all evaluated metrics compared with models based on either imaging modality alone. Results demonstrated the effectiveness of combining 3D-multispectral and 2D-HSI data with ML analyses for non-destructive, high-throughput phenotyping. The integration of these techniques enabled non-destructive, high-throughput identification of environmental stress treatments imposed during plant growth.

plant biology↗

bioRxiv2026

A multi-tissue epigenomic atlas links the sheep non-coding genome to domestication and complex traits

Non-coding regulatory variation drives complex traits, domestication, and evolutionary adaptation, yet the sheep genome lacks high-resolution functional annotation. Here we present SheepEpimap, a multi-tissue regulatory atlas harmonizing 516 CUT&Tag histone modifications, ATAC-seq, and RNA-seq datasets across 43 adult tissues in sheep. We annotated 2.93 million cis-regulatory elements, yielding 557,441 enhancer-gene pairs and 145,407 variants with allele-specific effects. By training a sequence-to-function deep-learning model, we decoded the base-pair syntax of chromatin accessibility, annotated transcription factor motif instances genome-wide, and constructed 12,210 tissue-specific gene regulatory networks (GRNs). Integrating this resource with multi-tissue expression quantitative trait loci, selection sweeps, and genome-wide association studies prioritized non-coding variants driving domestication and complex traits. Finally, cross-species analysis revealed that sequence-conserved, tissue-matched enhancers were significantly enriched in the heritability of complex traits and diseases in humans. In summary, SheepEpimap (https://genome.ucsc.edu/s/mengzhu/SheepEpimap) provides an open-access foundational ecosystem for sheep functional genomics, precision breeding, and comparative biology.

genetics↗

bioRxiv2026

A Medicinal Chemistry-Centered Evaluation of AlphaFold 3 and Boltz-2 Across Diverse Binding Modalities

AlphaFold 3 (AF3) and Boltz-2 are state-of-the-art AI-based tools for biomolecular structure prediction, but whether their predictions provide useful guidance for lead optimization, SAR interpretation, and virtual screening remains insufficiently characterized. We benchmarked their performance using newly determined soluble epoxide hydrolase co-crystal structures and matched activity data together with a curated post-training-cutoff dataset spanning kinases, allosteric modulators, covalent systems, PROTACs, molecular glues, fragments, membrane proteins, RNA binders, and activity-cliff pairs. Both models recovered canonical orthosteric enzyme and kinase complexes, including key DFG/C conformational states, whereas allosteric, membrane-protein, and induced-proximity complexes remained challenging. Pharmacophore RMSD was often lower than overall ligand RMSD, indicating preservation of key recognition features despite imperfect whole-ligand alignment. AF3 minPAE correlated with pose accuracy, and very low minPAE values (<0.85 A) were strongly enriched for accurate poses. Model confidence scores were not associated with experimental activity, whereas Boltz-2 predicted affinity captured relative activity trends and distinguished the activity-cliff pair, although its performance varied across ligand series.

biochemistry↗

bioRxiv2026

Multidimensional telomere diversity and inheritance at individual and population scales

Variation in telomere length, sequence composition and epigenetic state influences genome stability, aging and disease, yet its high-resolution characterization across species remains challenging. Here we present TeloXplorer, a computational framework for long-read data that jointly profiles telomere length, telomere variant repeats (TVRs) and DNA methylation at chromosome-end and haplotype resolution. Across simulated and empirical datasets from humans, Arabidopsis and yeast, TeloXplorer accurately resolved chromosome-end-specific telomere features and highlighted the importance of sample-matched, haplotype-resolved assemblies. Analysis of two human trios revealed concordant relative telomere-length profiles, predominantly Mendelian transmission of TVR haplotypes and family-conserved methylation patterns. Across 232 individuals from the Human Pangenome Reference Consortium, chromosome-end telomere-length rankings were conserved across five continental and 28 population groups. High-accuracy reads from 73 individuals further revealed elevated TVR haplotype diversity among individuals of African ancestry, together with extensive interchromosomal sharing and duplication of TVR architectures. Subtelomeric TAR1 elements were strongly associated with local DNA methylation and telomere motif diversity. Together, these analyses provide a multidimensional atlas of telomere diversity across species, chromosome ends, haplotypes and populations, revealing how telomere architecture varies and is inherited across biological scales.

genomics↗

bioRxiv2026

Structural-functional calibration corrects single-neuron identity errors in volumetric calcium imaging

Volumetric calcium imaging is increasingly used to capture larger neuronal populations at higher throughput, but high-speed axial sampling can compromise single-neuron identity. Here we identify cross-plane identity duplication as a structured error in volumetric imaging: anisotropic axial blurring and plane-wise functional segmentation can repeatedly detect the same neuron across adjacent planes, creating duplicate functional nodes that inflate neuronal counts and distort network phenotypes. We developed Comprehensive Label-Guided (CLG) volumetric imaging, a structural-functional calibration framework that uses nuclear labels as stable three-dimensional identity anchors for calcium signals. CLG combines nuclear labeling, deep-learning-based 3D segmentation, anatomical registration and identity-guided trace reassignment. In larval zebrafish whole-brain recordings, CLG resolved ~30,000 redundant detections and reduced estimated neuronal counts by 37-46%. In mouse visual cortex, CLG consolidated ~40% of putative duplicates and recovered over 2,000 active neurons missed by calcium-only analysis. Across baseline and perturbed conditions, calibration stabilized graph-derived measurements of hub organization, long-range correlations and network resilience. CLG therefore defines an anatomy-constrained identity-calibration layer for reliable single-neuron-resolved volumetric imaging.

neuroscience↗