Biology subjects

Zhang, L.

Publications and source records attributed to Zhang, L..

At least 19 recordsLinked to original sources

bioRxiv2026

Label-free volumetric dynamic atlas of fresh mouse organs using dynamic full-field optical coherence tomography

Dynamic full-field optical coherence tomography (D-FFOCT) enables label-free visualization of tissue microarchitecture and endogenous intracellular dynamics. Here, we establish a volumetric atlas of ten fresh mouse organs using a mobile D-FFOCT imaging platform. The system enables large-area imaging of approximately 1 cm2 within 15 min with 1,024 frames per field of view, achieving 0.75-{micro}m lateral resolution and imaging depths of up to 200 {micro}m. Large-area mosaics, three-dimensional reconstructions, and comparisons with conventional histology reveal diverse organ-specific tissue architectures. Beyond morphological characterization, quantitative analysis of dynamic intensity and mean fluctuation frequency across nine organs reveals distinct dynamic signatures and tissue heterogeneity. Longitudinal imaging of brain, liver, and intestinal tissues further demonstrates organ-dependent temporal changes in endogenous dynamics following excision. Finally, we publicly release raw D-FFOCT imaging datasets from all ten organs, providing an open resource for quantitative tissue characterization, algorithm development, and reproducible research. Together, this study provides a comprehensive, openly accessible optical atlas of fresh mouse organs, establishing a foundation for systematic tissue characterization and advancing the broader application of D-FFOCT in biomedical research.

biophysics↗

bioRxiv2026

Illuminating phage dark matter beyond the reach of structural alignments with PhageFlare

Many phage proteins remain functionally uncharacterized despite advances in structural-similarity-based annotation. We introduce PhageFlare, a deep learning framework for predicting phage protein functions lacking significant structural matches to annotated references. Across three structure-disjoint benchmarks, where no significant Foldseek match was detected between training and test proteins (E-value thresholds of 10-3, 10-4, and 10-2), PhageFlare achieved macro-averaged F1 scores of 0.871, 0.889, and 0.738 outperforming the strongest baseline (0.789, 0.814, and 0.732). Systematic evaluations demonstrated that protein language model selection critically influences performance, with ESM-C achieving stronger overall performance than ESM-2 and ProtBert. Embedding-guided case studies revealed local structural correspondences among proteins with limited global similarity. Applied to the efam and Metagenomic Gut Virus datasets, PhageFlare annotated 38.0% and 51.8% of proteins unresolved by Foldseek, respectively. Furthermore, PhageFlare identified lysogenic potential in 1,866 prophage-designated genomes misclassified as lytic by BACPHLIP. These results show that PhageFlare complements structural-similarity-based annotation and expands functional discovery across viral dark matter.

microbiology↗

bioRxiv2026

Multi-resolution humanness scoring of antibodies via a region-isolated language model

Antibodies recognized as foreign can elicit anti-drug antibodies that compromise efficacy and safety, making humanness scoring, estimating how human-like a sequence appears, an early, repeated step in antibody development. Widely used scores reduce a variable domain to a single framework-dominated number, leaving the complementarity-determining regions (CDRs) grafted during humanization, diversified by generative models weakly supervised and rarely audited. Here we introduce IgScope, a 23-million-parameter antibody language model trained from scratch that scores humanness at chain, IMGT-region, and residue resolution; a region-isolated attention module confines attention to within-region pairs, and chimeric-sequence training supplies region-level supervision. On 2.38 million held-out chains, masking all framework tokens leaves CDR accuracy unchanged, and back-mutated murine residues in human frameworks are detected at 93.4% accuracy. At chain level, IgScope matches the strongest published correlation with clinical anti-drug-antibody incidence (r = 0.567, n = 217) and outperforms a same-protocol recomputation. Region-level scoring exposes what chain-level scoring conceals: antibodies designed de novo by four generative models pass whole-chain humanness (0.966-0.988), while their CDRs score far below natural (P < 1e-30) in every chain class. Quality control turns the same resolution to the mirror-image question: in humanized-mouse platforms, whose domains are human by design, IgScope scores the domain as human and, in HUGO-Nano chimeric VHHs, isolates only the FR2 signal of four camelid hallmark residues deliberately retained to stabilize the VHH. IgScope gives antibody humanization a verified foundation and generative design an audit.

bioinformatics↗

bioRxiv2026

CAR-macrophage immunotherapy targeting fibroblast-like synoviocytes ameliorates inflammatory and degenerative arthritis

Rheumatoid arthritis (RA) is an inflammatory arthritis, whereas osteoarthritis (OA) is a degenerative joint disease. Despite their distinct etiologies, both are characterized by the pathogenic activation of fibroblast-like synoviocytes (FLS), which contribute to synovial hyperplasia, persistent inflammation, and cartilage destruction. Accordingly, pathogenic FLS represent an attractive therapeutic target for both RA and OA. Macrophages exhibit remarkable phenotypic plasticity, and interleukin-4 (IL-4) promotes an anti-inflammatory, tissue-reparative M2-like phenotype. Fibroblast activation protein (FAP) and nucleolin (NCL) are highly expressed on the surface of pathological FLS while exhibiting limited accessibility in normal tissues. Here, we developed two IL-4-armored, FLS-targeted chimeric antigen receptor macrophage (CAR-M) platforms directed against FAP or NCL, termed CAR-M2-FAP and CAR-M2-NCL, respectively. In vitro, both platforms enhanced FLS phagocytosis and promoted an M2-like transcriptional profile. Transcriptomic analysis further revealed enrichment of phagocytic, anti-inflammatory, and tissue-reparative programs. In a mouse model of RA, both CAR-M2 platforms attenuated arthritis severity, synovial hyperplasia, cartilage loss, and bone erosion. Similarly, in a mouse model of OA, they reduced synovitis, cartilage degeneration, and osteophyte formation. No overt acute toxicity was observed in either RA or OA mice following treatment with CAR-M2-FAP or CAR-M2-NCL. Collectively, the concordant therapeutic effects of CAR-M2-FAP and CAR-M2-NCL across RA and OA models provide preclinical proof of concept for FLS-targeted CAR-M2 as a potential therapeutic strategy for inflammatory and degenerative arthritis.

bioengineering↗

bioRxiv2026

Chromosome-level Atlantic switchgrass assemblies reveal a supernumerary B-Chromosome with transcriptional and evolutionary impacts

Supernumerary B-Chromosomes are extra genetic elements that frequently deviate from Mendelian inheritance to ensure their own survival. Their evolutionary origins and biological impacts within natural plant populations remain largely unexplored. Switchgrass (Panicum virgatum) is a model for studies of local adaptation, but reliance on a single reference genome has limited the detection of lineage-specific genomic content. We generated chromosome-level genome assemblies from the diverged Atlantic switchgrass subpopulation and discovered a previously undetected genomic element: a ~34 Mb supernumerary B-Chromosome, validated by Hi-C contact mapping and long-read depth, which indicates two to four B copies per nucleus. The B-Chromosome has a bipartite architecture including a gene-rich, single-copy proximal region (~8 Mb) and a repeat-rich, gene-poor distal region (~27 Mb) dominated by LTR/Ty3 (Gypsy) elements and punctuated by Mutator TIR peaks. High-resolution mapping reveals a highly rearranged chimera of fragments from multiple autosomes, biased toward the N-subgenome. Intact LTR retrotransposons on the B-Chromosome are younger than those on the A-Chromosomes, especially in its distal region, consistent with a B-Chromosome that arose and expanded within the Atlantic lineage. Population screening and phylogenetic analysis indicate that the B-Chromosome is largely restricted to the Atlantic subpopulation and likely has a single origin. In a typical family, 70% of open-pollinated progeny of B-positive maternal plants were B-positive, with substantial variation among families. Finally, B-Chromosome presence is associated with expression differences in A-Chromosome genes that differ between genetic backgrounds. Together, our results show how accessory chromosomes contribute to the evolutionary and genomic diversity of natural plant populations.

genomics↗

bioRxiv2026

VenusGenome: Genome-Aware Masked Autoencoding for Microbial Genome Representation Learning

Genomic-context models have shown that contextualizing protein embeddings can improve predictions of microbial function. We observe that a gene's protein embedding is partially predictable from the embeddings of neighboring genes in the genome, motivating high-ratio masking that requires reconstruction from sparser genomic context. Genomic modeling must also distinguish biological relationships from assembly conventions, since the ordering of separate contigs does not imply adjacency and strand labels depend on the reference orientation. We therefore introduce VenusGenome, a gene-resolution masked autoencoder that combines visible-only encoding with genome-aware attention incorporating contig boundaries, relative strand orientations, and gene positions. We pretrain this model on a curated corpus of over 1.7 million microbial genome assemblies from isolate and metagenomic sources, using frozen protein embeddings as gene-level inputs. Across genome-level phenotype prediction and gene-level tasks, the resulting frozen representations achieve the highest mean performance among the evaluated models on nine of eleven primary metrics. An exploratory gene-input perturbation analysis further links representation sensitivity to experimentally measured fitness defects. Ablations support the contribution of genome-aware attention and show the benefits of masked autoencoding over BERT-style masked modeling, with further gains from higher masking ratios.

bioinformatics↗

bioRxiv2026

Stabilizing the CHI3L1-Gal3BP complex remodels the glioblastoma immune microenvironment and synergizes with PD-1 blockade

CHI3L1 (YKL-40) is associated with mesenchymal, treatment-resistant glioblastoma (GBM) and shapes macrophage programs through interactions with galectin-3 or galectin-3-binding protein (Gal3BP). However, the CHI3L1-Gal3BP interaction has not been previously targeted. A surface plasmon resonance screen identified LZ6. Ternary complex formation was assessed by fluorescence-based, biophysical, and mass spectrometry methods. Activity was evaluated in five patient-derived GBM lines, myeloid cultures from eight donors, CRISPR interference with guide-resistant rescue, and a four-arm factorial study of orthotopic GL261 tumors. LZ6 increased Gal3BP engagement 3.4-fold while reducing galectin-3 in vitro. In GBM-conditioned cultures, LZ6 raised phagocytosis 22% to 44% and MHC class II 24% to 39% and lowered CD206 45% to 31% and IL-10 105 to 67 pg/mL, with concordant transcripts. Gal3BP knockdown reduced the response 41%; guide-resistant rescue restored it. Oral LZ6 raised the intratumoral Gal3BP:galectin-3 ratio from 1.02 to 1.56 at unchanged CHI3L1. In tumor tissue LZ6 shifted 20 of 24 immune endpoints, lowering CD206 and IL-10 and raising MHC class II and CD8 effector function. Median survival with LZ6 was 52.4 versus 26.3 days (P = 0.0012), and in combination with anti-PD-1 most animals survived to the end of follow-up (median not reached), with a significant factorial interaction (hazard ratio 0.24, 95% CI 0.10-0.57, P = 0.0014). LZ6 is a molecular glue of the CHI3L1-Gal3BP complex that engages its target in brain tumor after oral dosing and extends survival alone and synergistically with PD-1 blockade.

pharmacology and toxicology↗

bioRxiv2026

Prediction transfer does not imply reliability transfer in single-cell foundation models

Single-cell foundation models are increasingly transferred across tissues, diseases, perturbation screens, and experimental platforms. Although substantial effort has focused on prediction transfer, it remains unclear whether a model's assessment of its own reliability transfers similarly across biological contexts. Here we define reliability transfer as the ability to transfer an accurate assessment of when model predictions are likely to be correct or incorrect and investigate its behavior across ten perturbation-prediction systems spanning multiple datasets, models, and evaluation settings. We find that reliability transfer varies substantially across source-target pairs and cannot be inferred from predictive performance alone, indicating that prediction transfer and reliability transfer constitute distinct forms of generalization. Analyses of biological annotations, network connectivity, target exposure, and contextual factors reveal that prediction reliability is associated with both shared and context-dependent signals, with their relative importance differing across systems. To characterize this variability, we introduce reliability-attribution fingerprints, context-level signatures derived from strictly cross-fitted SHAP explanations that summarize how reliability estimators combine biological and contextual information when assigning confidence. Across systems, contexts with similar attribution-magnitude fingerprints tended to transfer reliability more successfully, and fingerprint similarity identified transfer sources achieving higher reliability-transfer performance within the observed candidate set. However, these relationships weakened under stricter cross-family transfer settings, indicating that transferable reliability structure remains partly dependent on shared contextual information. Finally, transferred reliability estimators produced different perturbation rankings despite identical perturbation predictions, illustrating a practical consequence of reliability transfer for downstream prioritization. Together, these results establish reliability transfer as a distinct aspect of foundation-model generalization and introduce reliability-attribution fingerprints as a framework for characterizing transferable reliability structure across biological contexts.

bioinformatics↗

bioRxiv2026

Resistance-Mutant Rescue Establishes On-Target CHI3L1 Inhibition by CHI-DEL, a Brain-Penetrant Small Molecule with In Vivo Efficacy in Glioblastoma

CHI3L1 (YKL-40) drives glioblastoma progression and immunosuppressive neuroimmune signaling, but as a non-enzymatic secreted glycoprotein it has lacked a genetic tool to confirm that small molecule effects are truly on-target. From a DNA-encoded small molecule library we identify CHI-DEL, a potent CHI3L1 ligand, and solve a 2.81 [A] co-crystal structure (PDB 10JV) revealing a binding trajectory centered on Trp99. Structure-guided mutagenesis yields W99F, a compound-resistant CHI3L1 allele that retains native secretion, basal signaling, and thermal stability, unlike the destabilizing W99A control, establishing a clean chemical-genetic separation of biology from drug sensitivity. In isogenic knockout/rescue cells, wild-type rescue restores both phenotype and CHI-DEL sensitivity across invasion, proliferation, and a multi-node signaling program (pSTAT3 and NF-{kappa}B), while W99F rescue restores phenotype but confers resistance to CHI-DEL that is complete for some readouts and partial for others. This same epistasis was reproduced in human iPSC-derived microglia, where CHI-DEL reverses a GBM-conditioned-medium-induced phenotype in a CHI3L1- and Trp99-dependent manner. In vivo, CHI-DEL achieves brain and tumor exposure, engages its target and disrupts CHI3L1-CD44 signaling in a dose-dependent manner, remodels the tumor immune microenvironment, and confers a dose-dependent survival benefit that is specific to the active compound. Together, these data extend CHI3L1 small molecule inhibitor development beyond in vitro optimization, providing genetic proof of on-target pharmacology and a brain-penetrant therapeutic strategy for glioblastoma.

neuroscience↗

bioRxiv2026

METTL3-mediated m6A modification alleviates skeletal muscle atrophy in ALS by regulating ACSL1-dependent triglyceride metabolism

Skeletal muscle-intrinsic defects are increasingly recognized as critical contributors to the pathogenesis of amyotrophic lateral sclerosis (ALS), yet the underlying molecular mechanisms remain poorly understood. N6-methyladenosine (m6A) is the most abundant post-transcriptional RNA modification in mammalian mRNAs that plays important regulatory roles in diverse physiological and pathological processes, however its role in ALS-associated skeletal muscle atrophy remains unknown. Here we found that global m6A methylation and the expression of its methyltransferase METTL3 are reduced in the skeletal muscle of hSOD1G93A transgenic ALS mice. Multi-omics analyses reveal that m6A dysregulation is closely associated with impaired triglyceride metabolism. Functionally, METTL3 promotes triglyceride accumulation in ALS skeletal muscle in an m6A-dependent manner; overexpression of METTL3 in ALS myotubes improves energy supply and alleviates muscle atrophy by promoting triglyceride accumulation. In vivo overexpression of Mettl3 in skeletal muscle attenuates muscle atrophy, improves motor performance, and prolongs survival of ALS mice. Mechanistically, we identify the fatty acid activation enzyme ACSL1 as a key downstream effector of METTL3-mediated regulation of triglyceride metabolism. METTL3-mediated m6A modification promotes the expression of Acsl1 by enhancing its mRNA stability. Further investigation revealed that the regulatory effect of m6A on Acsl1 expression depends on the m6A reader protein IGF2BP2. Collectively, our findings establish m6A modification as a critical regulator of skeletal muscle atrophy in ALS by maintaining triglyceride metabolic homeostasis, highlighting a promising therapeutic target for ALS.

neuroscience↗

bioRxiv2026

Decoding Cell-level Circadian Phase and Rhythm-state Remodeling in Single-cell Transcriptomes With scRhythmBayes

Current circadian omics analysis tools have been developed primarily for bulk time-series. However, heterogeneous single-cell datasets require analysis and interpretation of rhythmic programs across different cells, cell types, and biological conditions. In these datasets, cellular circadian phase is usually unobserved, and sample-level zeitgeber time provides temporal information but does not define the exact phase of every cell. Existing methods address only selected aspects of this problem and do not model how cell-level phase evidence informs gene-level rhythmic parameters and rhythm-state remodeling. Here we present scRhythmBayes, a new probabilistic algorithm for phase-resolved circadian analysis in heterogeneous single-cell transcriptomes. scRhythmBayes combines a seed-gene count likelihood with a stratum-aware circular prior to infer cell-level circadian phase, incorporates phase support into gene-level rhythmic modeling, and assigns posterior probabilities to interpretable rhythm-state categories, including rhythm gain, rhythm loss, amplitude remodeling and phase shifts. In heterogeneous simulations, scRhythmBayes achieved higher phase-recovery accuracy than existing phase-inference methods and maintained balanced performance across rhythmic gene detection, parameter recovery, and rhythm-state classification. Stress tests defined practical requirements for seed-gene support, zeitgeber anchoring, temporal sampling density, and cell number. In mouse liver, scRhythmBayes revealed distinct circadian phase occupancy and rhythm-state organization between periportal and pericentral hepatocytes, supporting a temporal dimension of liver zonation. It also identified cell-type-specific rhythmic markers that were largely distinct from conventional static markers, indicating that cellular identity includes temporal programs not captured by average expression. In human heart disease data, phase-coordination and phase-distribution analyses identified cell-type-selective temporal disorganization rather than uniform circadian disruption across the tissue. scRhythmBayes therefore provides a statistically grounded approach for resolving circadian organization across cells, genes, cell types and biological conditions.

bioinformatics↗

bioRxiv2026

Discovery of a brain-penetrant CHI3L1 inhibitor as an oral modulator of neuroinflammation in Alzheimers disease

Chitinase-3-like protein 1 (CHI3L1) is elevated in Alzheimers disease (AD), but its role in glial dysfunction and therapeutic tractability remain unclear. Here, screening a 4.2-billion-compound DNA-encoded library identified DELC2, a brain-penetrant CHI3L1 modulator. Biophysical and crystallographic studies showed that DELC2 binds the CHI3L1 glycan-recognition groove within an aromatic-hydrophobic pocket centered on Trp99 and Trp352. DELC2 inhibited CHI3L1-RAGE association, suppressed CHI3L1-induced inflammatory signaling, reduced Gal-3-positive microglia, and restored amyloid-{beta} uptake in glial cultures. In human cerebrospinal fluid, CHI3L1 was elevated in AD and correlated with astrocytic NF-{kappa}B activation. DELC2 phenocopied CHI3L1 immunodepletion, whereas CHI3L1 add-back restored inflammatory and amyloid-{beta}-handling defects. Oral DELC2 achieved sustained unbound brain exposure in 5xFAD mice, improved cognitive performance, reduced multiple amyloid-{beta} species, and attenuated astrocytic and microglial inflammatory programs. These findings establish the CHI3L1 glycan-recognition groove as a druggable regulator of RAGE-associated glial dysfunction and identify DELC2 as a chemical scaffold for CHI3L1-directed therapy in AD.

pharmacology and toxicology↗

bioRxiv2026

Single-nucleus chromatin accessibility time course of excisional wound repair in rat skin

We present a time-series single-nucleus ATAC-seq dataset from full-thickness excisional wounds in Sprague-Dawley rats. Samples were taken from unwounded skin (normal control) and at 1, 2, 5, 10, and 19 days post-wounding, spanning the inflammatory, proliferative, and remodeling phases of skin repair. We extracted nuclei with a two-step tissue dissociation protocol and prepared libraries using the DNBelab C Series Single-Nucleus ATAC Kit, then sequenced on the MGI DNBSEQ-T1 platform. After stringent quality filtering, 37,555 nuclei passed quality control; the resulting chromatin accessibility profiles cover 23 cell types: fibroblast subpopulations, keratinocytes, vascular endothelial cells, immune cells, and skin appendage cell types. This genome-wide chromatin accessibility dataset is a resource for studying regulatory dynamics during excisional wound repair and for comparing results with other wound healing systems.

bioinformatics↗

bioRxiv2026

Urban planning leaves an audible legacy in a megacity's bird soundscape

Cities are planned for people, yet planning also determines where wildlife persists and where residents hear it. How can this acoustic footprint guide planning and monitoring? We combined AI-powered passive acoustic monitoring at 31 stations with detection-corrected models and spatial validation to map Asian Koel activity across Shenzhen. Koel acoustic opportunity declined with tree and built cover and increased with starling and myna opportunity; host information improved prediction at unmonitored sites. Weekly opportunity expanded in spring and varied across the city; sampled-minute exposure concentrated around dawn. Supported predictions intersected planning-sensitive places, while 51.5% of the city grid remained a monitoring gap. We translated these boundaries into monitoring priorities for underrepresented environments and uncertain spring predictions. This reproducible workflow reveals the acoustic imprint of the present-day urban landscape and connects ecological diagnosis, prediction boundaries and adaptive monitoring to inform urban coexistence.

ecology↗

bioRxiv2026

U-Chrom: a unified framework for single-cell and spatial 3D genome data

Single-cell Hi-C, spatial Hi-C and chromatin tracing measure the same genomes in incompatible formats. ChromData, one data model, indexes all three by cell and genomic bin; an open-source toolkit, linked browser and 22-dataset atlas build on it. Applied to ten mouse brain datasets of all three assays, the same calls rank cell types alike by short- over long-range proximity, and contact-based reconstructions largely place cell-type differences where imaging does.

bioinformatics↗

bioRxiv2026

Sample overlap in genome-wide association meta-analysis: practical comparisons across significance thresholds

Meta-analysis is widely used in genome-wide association studies (GWAS) to combine evidence across studies without requiring individual-level data. However, as both the number of studies included in meta-analyses and their sample sizes continue to grow, the same participant may be included in more than one study. Such sample overlap induces dependence across studies and violates the independence assumptions underlying standard meta-analysis methods. HostSeq is a Canadian initiative in which 15 clinical and epidemiological studies were assembled with DNA samples from approximately 10,000 Canadians infected by the SARS-CoV-2 virus. We observed duplicate samples across different participating studies. This observation raises an important practical question: what is the impact of sample overlap on association results, and when should such overlap be a concern? Motivated by this real problem, we sought to compare five meta-analysis methods and evaluate their performance against a reference mega-analysis in which the true sample overlap is known. We show that when the degree of sample overlap is relatively small, its impact on association results is minimal, even at the genome-wide significance threshold of = 5*10 -8 . We demonstrate these findings through extensive simulation studies and an application to overlapping cohorts within HostSeq.

genetics↗

bioRxiv2026

Dual blockade of IL-18 and IL-4Rα by a bispecific antibody for improved treatment of atopic dermatitis

Background: Atopic dermatitis (AD) is a chronic inflammatory dermatosis primarily driven by type 2 immunity, with additional type 1 and type 3 components that may limit the benifit of ILRalpha blockade alone. Interleukin18 (IL18), an epithelial alarmin genetically associated with AD and correlated with disease severity, has been implicated as an upstream amplifier of this mixed inflammatory response. Objective: To assess whether concurrent IL18 neutralization and IL4Ralpha; blockade with a bispecific antibody provides broader and more balanced suppression of AD relevant type 1, type 2, and type 3 pathways than single target inhibition. Methods: We generated FJ0125, a bispecific antibody comprising human IL18 binding protein fused to a novel humanized anti IL4Ralpha antibody, and characterized its binding, signaling, and functional activity in vitro and in vivo. The activity was evaluated in human group 2 innate lymphoid cell and primed Th2 cell assays, a keratinocyte & dendritic cell & T cell coculture system, and an MC903/Staphylococcus aureus induced dermatitis model in human IL4/IL4Ralpha; knock in mice. Results: FJ0125 bound to IL18 and IL4Ralpha; with high affinity, engaged both targets, inhibited IL4/IL13 signaling with dupilumab comparable potency, and neutralized human and mouse IL18. In vitro, FJ0125 more effectively suppressed IL18 driven lymphocyte activation and type 1, type 2, and type 3 cytokine production than IL18BPFc or IL4Ralpha; monotherapy. In vivo, FJ0125 reduced multitype cytokines, improved dermatitis, lowered serum IgE, and abrogated the paradoxical IL22 increase observed with selective IL4Ralpha; blockade. Conclusion: Dual IL18/IL4Ralpha; blockade with FJ0125 achieves coordinated suppression of multitype inflammation and represents a mechanistically substantiated therapeutic strategy for AD.

immunology↗

bioRxiv2026

Valine Engages a Prefrontal mGluR5 Allosteric Site to Preserve Social Behavior

Branched-chain amino acid metabolism is linked to neurodevelopmental disorders, but whether a defined amino acid directly modulates cortical receptor signaling to control behavior is unknown. Here, we show that valine is uniquely required for sociability through medial prefrontal cortex (mPFC) circuitry. Partial dietary valine restriction, but not comparable leucine or isoleucine restriction, or mPFC-restricted acceleration of BCAA catabolism through Bckdk loss, disrupts social interaction, and local valine supplementation rescues behavior. LiP-SMap, surface plasmon resonance, cryo-EM, and mutagenesis identify metabotropic glutamate receptor 5 (mGluR5) as a direct valine target and reveal a valine-selective allosteric pocket distinct from the glutamate site. Valine is signaling-biased: it drives {beta}-arrestin-linked output yet has little standalone Gq efficacy, instead potentiating glutamate-evoked mGluR5 signaling to recruit endocannabinoid/CB1 feedback, gate inhibitory transmission, and preserve mPFC-dependent social behavior. Together, these findings identify valine as a diet-derived allosteric ligand that links amino acid availability to cortical circuit control of social behavior.

neuroscience↗