Biology subjects

Li, Y.

Publications and source records attributed to Li, Y..

At least 55 records · Page 3Linked to original sources

bioRxiv2026

A 21-Color Spectral Flow Cytometry Panel for Comprehensive Immunophenotyping of Rat Tissues and a Companion 9-Color T-Cell Functional Assay

Although rats are crucial translational research models due to their immunological homology and surgical feasibility, the scarcity of conjugated antibodies has hampered high-dimensional immune profiling. To bridge this gap, we created a synergistic two-panel method that uses full-spectral flow cytometry: a 21-color comprehensive immunophenotyping panel and a 9-color intracellular cytokine staining (ICS) panel. The 21-color panel navigates the limited fluorophore pool and maps innate and adaptive lineages at high resolution. While it can be used to profile neutrophils and monocytes in peripheral blood it reaches its full potential in lymphoid organs, allowing for the simultaneous evaluation of tissue-resident macrophages, dendritic cells, T cell differentiation (including Tregs), and APC function. Based on this phenotypic paradigm, the 9-color ICS panel dissects effector T cell activation and Th1/Th2/Th17 cytokine production. Furthermore, we reserved the PE color during panel creation, allowing for the use of antibodies and probes with PE or comparable fluorophores in conjunction with this panel, hence increasing overall flexibility. This combination technique, designed for rat peripheral blood, spleen, and lymph nodes, combines panoramic phenotyping with functional analysis, offering an adaptable foundation for complicated tissue microenvironments in tumor immunology, rheumatology, and autoimmunity research.

immunology↗

bioRxiv2026

Nicotinic modulation of frontal circuits breaks the cycle of attentional performance failure

The ability to recover from consecutive failures is critical for adaptive behavior, yet the underlying neural mechanisms remain unclear. In vivo screening of neuromodulatory inputs onto frontal-sensory cognitive control circuit identified a frontal cholinergic mechanism that counteracts lapses in attentional engagement following repeated errors. Cholinergic input from the basal forebrain to the frontal cortex was necessary and sufficient to restore performance after errors, specifically after repeated-but not after a single-failure. This effect was mediated by 7-nicotinic acetylcholine receptors in frontal-sensory cortical neurons, which sustained cortical circuit activity and frontal-sensory cortical oscillations during attentional engagement. Targeted optogenetic activation of these frontal-sensory neurons disrupted cycles of attentional performance failure and reinstated behavioral performance in a mouse model of neuropsychiatric syndrome. These findings reveal a circuit-level mechanism of cholinergic control that confers cognitive resilience under conditions of persistent failure.

neuroscience↗

bioRxiv2026

Matrix-Mechanical Genetic Susceptibility and Reduced Inflammatory and Immediate-Early Programs in Keratoconus

Purpose. To determine which proposed keratoconus (KC) mechanisms carry its genetic susceptibility and how it relates to corneal structure, and which describe its corneal tissue. Methods. Six mechanism modules and two attribution sets (transforming growth factor-{beta} [TGF-{beta}] and canonical type-2 atopy) were tested for enrichment in three independent European KC genome-wide association studies (GWAS) and in GWAS of central corneal thickness (CCT) and corneal resistance factor (CRF), with colocalization at matrix loci. Tissue expression was pooled across nine arms from eight studies with control-source meta-regression; activator protein-1 (AP-1)/immediate-early regulatory activity was scored in 107 donors, spatial expression in 21, and serum responses in human and rabbit stromal cells. Results. Extracellular matrix (ECM) was the only module enriched in all three KC sources (P [≤] 5.46 x 10-) and for CCT, CRF, and thickness-independent CRF (P [≤] 2.07 x 10-). COL5A1 shared causal variants with CCT in all three sources (posterior probability 0.985-0.991), and FNDC3B and COL1A1 with CRF or its thickness-independent component (0.961-0.986). Pooled, KC corneas had lower general and corneal-local inflammatory and stress/immediate-early expression (log2 fold-change -0.97, -0.98, -0.82; P [≤] 0.049). In whole-cornea and stromal tissue, ECM expression reversed between postmortem-donor and pathological controls (log2 fold-change +0.36, -2.34), whereas inflammatory and TGF-{beta} programs were lower against both. AP-1/immediate-early regulatory activity was lower in four donor cohorts (Hedges' g -1.50) and stress/immediate-early expression in two spatial cohorts; serum raised immediate-early readouts in human and rabbit cells. Conclusions. KC combines matrix-mechanical genetic susceptibility with a low-inflammatory, low-immediate-early corneal state whose matrix expression direction depends on the control source. Because this susceptibility is genetically shared with corneal thickness and resistance, interventions on the inherited disease are judged by corneal structure and mechanics.

genomics↗

bioRxiv2026

Compressive stress couples calcium signalling to translational control and proteostasis

Compressive stress is a pervasive feature of solid tumour growth, and mechanical loading is known to activate calcium signalling through the mechanosensitive channel Piezo1. How this signal is converted into changes in cellular biosynthetic capacity, however, remains unclear. Here we show that compressive stress engages a Piezo1-dependent calcium checkpoint that reduces translational output with increasing mechanical load, independently of mTORC1 and the integrated stress response. Compression triggers Piezo1-dependent release of endoplasmic reticulum Ca2, activating eEF2 kinase to slow translational elongation. This same Ca2 signal drives mitochondrial remodelling and reactive oxygen species production, which reinforce translational repression through redox-dependent oxidation of the translation initiation factor eIF2{beta}. In parallel, Ca2-dependent AMPK activation triggers autophagic ribosome degradation, alleviating compression-induced macromolecular crowding and restoring cytoplasmic rheology despite sustained mechanical load. These mechanisms act at distinct levels of translational control: initiation, elongation and ribosome abundance; yet converge to limit biosynthetic output under compression. Consistent with a role for this pathway in tumour adaptation to mechanical constraint, eEF2K expression correlates with poor overall survival in a public PDAC patient dataset. Together, these findings define a mechano-metabolic checkpoint through which cells actively tune biosynthetic capacity to their physical environment.

cell biology↗

bioRxiv2026

CryoFAST: A Fab-Aided Cryo-EM Workflow for High-Resolution Structure Determination of Sub-50-kDa Protein Targets

Single-particle cryo-electron microscopy (cryo-EM) plays an increasingly important role in structure-based drug discovery (SBDD) by revealing target protein-ligand interactions at the molecular level, but its application has largely focused on large- and medium-sized protein complexes. Many therapeutically important targets are smaller than 50 kDa and remain highly challenging for cryo-EM analysis because of low signal-to-noise ratios and difficulties in particle alignment. Here, we describe cryoFAST, an integrated workflow that couples ligand-compatible Fab discovery and structure-guided computational maturation with biochemical triage, fiducial-complex assembly, and single-particle cryo-EM. Through phage-display screening and/or AI-guided design, we developed high-affinity Fab binders of approximately 50 kDa that stabilize the target without disrupting ligand-target interactions and then assembled Fab-target complexes for cryo-EM analysis. Using the therapeutically relevant extracellular domain (~20 kDa) of interleukin-4 receptor (IL-4R) as a proof of concept, we determined its cryo-EM structure at 2.74 Angstrom resolution and established a framework for elucidating ligand-binding modes. This workflow provides a practical, efficient, and potentially broadly applicable route to the structural characterization of small protein targets that are otherwise challenging to study. By extending the applicability of cryo-EM to high-value but technically challenging small targets, cryoFAST may open new opportunities for structure-based drug discovery.

biophysics↗

bioRxiv2026

De novo protein design in an expanded chemical space

Generative protein design has made sequence and structure programmable, yet its chemical alphabet remains largely confined to the canonical twenty. Here, we establish CheMoDesign, an experimentally validated generative framework for designing proteins de novo around user-specified chemistry. CheMoDesign weakens pair-representation conditioning in a pretrained all-atom structure-prediction model while preserving chemical anchors, then refines generated backbones through sequence-conditioned denoising. By treating post-translational modifications, synthetic residues, and chemical modifications as user-defined building blocks, the framework generated proteins with chemistry-dependent recognition and reactivity in single-round experimental campaigns. Sulfotyrosine and nitrotyrosine enabled modification-dependent recognition of thrombin and HER2, respectively. Genetically encoded noncanonical residues enabled bioorthogonal affinity switching and light- or proximity-triggered covalent target capture. Post-expression chemical modifications yielded a light-activated covalent PD-L1 binder and an isoform-selective CA IX inhibitor (KD = 45 nM) designed to engage catalytic Zn2+;. CheMoDesign makes chemical mechanism a programmable dimension of de novo protein design.

biochemistry↗

bioRxiv2026

SpiE is a distinct gut microbial 4-cholesten-3-one 5β-reductase that acts with SpiR to convert cholesterol to coprostanol

Gut microbes convert cholesterol into coprostanol, a poorly absorbed sterol that is largely excreted in feces and is linked to lower serum cholesterol levels. However, the enzymes responsible for this process remain poorly characterized. The second step of the pathway, cholestenone reduction into coprostanone, has long been established, yet the enzyme(s) responsible were unknown. Here, we use comparative genomics to identify SpiE, a cholestenone (4-cholesten-3-one) reductase that is part of the steroid processing (spi) pathway with SpiR. We confirm that SpiE binds to and reduces both cholestenone and progesterone into 5{beta}-reduced forms. SpiR and SpiE together convert cholesterol into coprostanol, indicating that both enzymes are sufficient for coprostanol formation. SpiE belongs to the short-chain dehydrogenase (SDR) family and represents an evolutionarily distinct lineage of SDR ene-reductases. Metagenomic analyses reveal that spiE relative abundance is strongly correlated with stool coprostanol (Spearman's {rho}=0.81, p=5.99e-65). In longitudinal patient cohorts, antibiotic treatment coincided with loss of SpiE and coprostanol production. Post antibiotics, the emergence of distinct SpiE-encoding genera rescued coprostanol production in some individuals. Our findings provide the biochemical basis of the cholesterol to coprostanol pathway and lay the groundwork for future studies linking it to host physiology.

microbiology↗

bioRxiv2026

RORγ Inverse Agonism Redirects Tumour-Conditioned Emergency Myelopoiesis and Attenuates Established Tumour Progression

Systemic inflammation is associated with poor outcomes in gastroesophageal adenocarcinoma (GEA), but how it contributes to disease progression remains unclear. We investigated retinoic acid receptor-related orphan receptor gamma (ROR{gamma}) as a regulator of tumour-conditioned myeloid responses. In treatment-naive GEA patients, elevated circulating neutrophil-to-lymphocyte ratio (cNLR) tracked with circulating ROR{gamma} positive neutrophils and tumoural spatial organization of ROR{gamma} positive myeloid cells, rather than neutrophil abundance. In syngeneic tumour models, pharmacologic ROR{gamma} inverse agonism altered marrow progenitor composition before tumour-growth divergence and remodeled myeloid organization across bone marrow, tumour and lung despite no endpoint change in circulating neutrophil proportions, which did not capture the earlier marrow response or subsequent tumour trajectory. ROR{gamma} perturbation enhanced longitudinal tumour control with PD-L1 blockade, whereas effects on metastatic establishment depended on tumour conditioning and treatment timing. These findings identify ROR{gamma} associated myeloid programming as a therapeutically tractable, context-dependent regulator linking systemic inflammation, hematopoiesis, tissue immune organization, and cancer progression.

cancer biology↗

bioRxiv2026

Tractable and Thermodynamically Consistent pKa Prediction via First-Dissociation Aggregation

Ionization governs molecular behavior, yet predicting aqueous pKa accurately and tractably remains a fundamental challenge. Rigorous ensemble methods require enumerating a protonation-state space that grows exponentially with the number of ionizable sites, while fast graph predictors return numbers without thermodynamic consistency. Here we derive an exact thermodynamic identity showing that the macroscopic first-dissociation constant is fully determined by protonated-microstate populations and unique first-deprotonation events, eliminating the deprotonated ensemble algebraically and reducing aggregation to O(n+E) operations. We implement this identity in DTi-pKa, a dual-head graph neural network whose free-energy and dissociation heads are coupled by thermodynamic constraints. On four external benchmarks (355 molecules), DTi-pKa achieves a pooled MAE of 0.5665 pKa units, with 0.6285 on the 169 records lacking training-cache matches, while providing site-resolved micro-pKa values and protonation-state populations. Controlled ablations show that constraint placement at the level of the reported macroscopic equilibrium matters more than microscopic label precision--a design principle transferable to physics-informed machine learning beyond chemistry. Closure diagnostics expose numerical self-consistency as an open frontier, which we report transparently. By replacing an intractable computation with a physical identity, DTi-pKa unifies macroscopic accuracy and microscopic interpretability in a single framework.

bioinformatics↗

bioRxiv2026

A direct RNA sequencing workflow for simultaneous profiling of tRNA abundance and modifications in mouse liver

Transfer RNA (tRNA) is highly modified and difficult to profile using reverse-transcription-based sequencing. Here, we established a direct RNA sequencing (tRNA-DRS) workflow to simultaneously characterize tRNA abundance and modification signals in mouse liver. The workflow included small-RNA enrichment, deacylation, splint-adapter ligation, barcoding, reverse transcription, and nanopore sequencing on PromethION with modification-aware basecalling. From 1,678,666 raw reads, 1,421,279 (84.67%) reads were retained after 20-200 nt length filtering, and 17,094 uniquely mapped reads (MAPQ [≥] 10) were obtained. These reads covered 244 tRNA genes and represented all 23 tRNA isotypes. tRNA abundance was strongly skewed, with Asp, Gly, Ser, and Lys accounting for 56.6% of uniquely mapped reads. Read-body coverage indicated that most uniquely mapped reads spanned substantial portions of tRNA molecules (mean 71.1%, median 75.9%; 83.3% reads covering [≥]50% of the reference). Modification analysis identified 41,013 candidate sites, of which 711 passed stringent filtering (modification fraction [≥]50%, coverage [≥]5), spanning eight modification types and dominated by pseudouridine and m5C. Filtered sites showed position-specific clustering and isotype-dependent patterns. Together, these results support tRNA-DRS as a practical single-assay framework for simultaneous tRNA expression and epitranscriptomic profiling in mammalian tissue.

molecular biology↗

bioRxiv2026

A synthetic PGC1α co-activator reprograms microglial immunometabolism to preserve cone function in retinal degeneration

Retinitis pigmentosa (RP) is genetically heterogeneous, yet initiating mutations converge on primary rod degeneration followed by cone dysfunction and loss. Activated microglia are implicated in this secondary phase, but whether selective immunometabolic reprogramming of microglia preserves retinal function remains unknown. In human iPSC-derived microglia and retinal CD11b cells, PGC1 induction suppressed LPS-driven interferon signaling and cytokine release, yet Seahorse analysis and isotopologue tracing showed that energy metabolism remained altered. We therefore fused PGC1 to a multivalent p65-HSF1 module, yielding ~2.5-fold higher nuclear receptor output than native PGC1 and coordinated engagement of oxidative and anti-inflammatory programs in mouse retinal CD11b cells. Microglia-restricted expression in humanized RHOP347L mice preserved photopic responses through six months, increased retinal thickness and promoted ramified subretinal IBA1 morphology. Microglial immunometabolism thus represents a potentially genotype-independent neuroprotective target in RP, and engineered PGC1 co-activators provide a means to sustain oxidative metabolism under inflammatory pressure.

immunology↗

bioRxiv2026

Simultaneous multi-area recordings in macaque frontoparietal cortex during a manual object-interaction task

Dexterous hand control is essential for daily activities and a top restoration priority for people with tetraplegia, yet neurophysiological datasets suitable for studying and decoding naturalistic hand behavior remain scarce. Most available recordings constrain movements to a small number of degrees of freedom or cover only a single stereotypical grasp-and-hold structure. Moreover, previous brain-computer interface (BCI) studies have largely relied on signals from a single cortical area, even though dexterous hand control is distributed across an interconnected frontoparietal network. To address these limitations, we designed a paradigm that elicits rich hand movements across 40 distinct hand-object interaction conditions. We recorded simultaneous frontoparietal activity with hand kinematics from a rhesus macaque performing them. Neural activity was recorded from the primary motor cortex, anterior intraparietal area, and ventral premotor cortex using microelectrode arrays spanning 1,920 channels, while a multi-camera markerless motion-capture system acquired video from which kinematics were extracted offline. The dataset comprises data from 20 sessions, including processed neural features, synchronized 3D coordinates of hand and elbow keypoints, and trial-level metadata including task conditions and event timing. We further provide technical validation, including a neural decoding benchmark with multiple algorithms for continuous keypoint coordination reconstruction. We found that cross-day and cross-task decoding performance varied among algorithms. Variation in channel availability leads to different performance degradation curves in different algorithms. This task-rich dataset offers a valuable resource for investigating the neural mechanisms of dexterous hand control and for advancing the performance of motor BCIs.

neuroscience↗

bioRxiv2026

Monomeric TDP-43 binds GU-rich RNA via its NTD but only its oligomers block cryptic exon inclusion

TDP-43 aggregation is a pathological feature of several neurodegenerative diseases, resulting in nuclear loss of function and RNA dysregulation, including cryptic exon derepression. TDP-43 comprises two RNA recognition motifs required for canonical RNA binding, a low-complexity domain implicated in phase separation, and an N-terminal domain (NTD) that mediates oligomerization. While NTD-driven oligomerization is critical for TDP-43 splicing function, some studies suggest a direct interaction of NTD with RNA. Here, we investigated RNA binding by the NTD and its functional interplay with oligomerization. We show that the NTD preferentially binds UG-rich RNA via residues located at the oligomerization interface. The NTD engaged RNA only on monomeric TDP-43, as RNA binding and oligomerization compete for the same interface and rely on similar interaction modes. By disentangling these competing activities, we demonstrated that oligomerization, but not NTD-RNA interaction, is essential for TDP-43-dependent alternative splicing and repression of cryptic exons. Our findings uncover a previously unappreciated RNA-binding activity within the TDP-43 NTD that directly competes with oligomerization and establish oligomerization as a key determinant of TDP-43 cryptic exon repression.

molecular biology↗

bioRxiv2026

CHAIR an antigen-resolved antibody-reactome resource for healthy adult immune aging

Antigen-recognition histories accumulate across adult life, but existing human aging resources largely emphasize host-state measurements rather than antigen-resolved humoral memory. We present CHAIR, the Chinese Healthy Aging Immune Resource, which integrates self-antigen, human virome and toxin/virulence-factor PhIP-seq with routine clinical measurements and T/B/NK phenotyping in clinically screened adults aged 20-94 years. The resource framework includes 1,008 unique PhIP-seq samples, 995 clinical records, 977 T/B/NK records and 853 participants with all three layers. Across modeled spaces comprising 23,584 self-antigen targets, 210 virome targets and 1,258 virulence-factor source targets, most measured antibody-reactivity architecture was consistent with broad preservation within domains, whereas age- and sex-associated signals were concentrated in focal targets and modules. Together, CHAIR provides a traceable, antigen-resolved reference framework based on clinically screened adults for investigating focal humoral remodeling across healthy adult aging.

immunology↗

bioRxiv2026

Bayesian inference of global land plant diversification dynamics across the Phanerozoic

Underlying diversification patterns and potential drivers of land plants remain puzzling, particularly at deep-time and global scales. Here, we reconstruct the diversification dynamics of land plants using an updated time-calibrated phylogeny comprising approximately 30,000 extant species, and nearly 40,000 fossil occurrences within the Bayesian birth-death frameworks. Our analyses indicate that angiosperms exhibit the highest diversification rates, whereas ferns underwent a marked diversification increase during the Cretaceous, coincident with the rapid radiation of angiosperms. Among the major Phanerozoic mass extinctions, the Cretaceous-Paleogene event has the most significant impact on land plant diversity, with estimated genus-level losses of 13%, 14%, and 4% in bryophytes, pteridophytes, and gymnosperms. We identify a pattern consistent with competitive displacement scenario, in which pteridophytes origination rates declined as gymnosperm diversity increased, accompanying the transition from pteridophyte- to gymnosperm-dominated floras. We find that plant-insect interactions have originated as early as the emergence of pteridophytes, potentially promoting the diversification of pteridophytes and gymnosperms. During the Cretaceous, these associations shifted toward angiosperms, as indicated by a positive relationship between insect diversity and angiosperm origination rates. Finally, continental fragmentation, fluctuations in aridity, atmospheric carbon and sedimentary dynamics, showed stronger associations with the successive rise and decline of major land plant groups.

evolutionary biology↗

bioRxiv2026

Extracellular cGAMP transmission exacerbates neuroinflammation in aging and multiple sclerosis

Neuroinflammation drives neurodegeneration and cognitive decline in aging, but the signals that spread this inflammation across the CNS remain unclear. Here, we show in mice that advanced age and experimental autoimmune encephalomyelitis (EAE) both result in elevated cytosolic mtDNA in microglia, which stimulates the production and export of cGAMP from these cells. Meanwhile, ENPP1, the dominant cGAMP hydrolase in the brain and spinal cord, is downregulated in both EAE mice and MS patients, releasing the brake on extracellular cGAMP accumulation. In Enpp1H362A mice, which selectively lack cGAMP hydrolysis activity, unrestrained extracellular cGAMP worsens EAE-associated paralysis and drives premature aging phenotypes including impaired motor coordination (rotarod, pole test) and reduced exploration (open field test) in a manner dependent on STING. Single-cell RNA sequencing pinpoints microglia, astrocytes, and inhibitory neurons as the principal cGAMP responders that activate STING-dependent interferon-stimulated gene induction in response to elevated extracellular cGAMP. Mechanistically, microglia import cGAMP through the LRRC8A:C channel, while astrocytes and neurons import cGAMP via the glutamate antiporter system xc-, reinforced by SLC1A2-mediated glutamate uptake in astrocytes and SLC38A1/2-fueled glutamine-to-glutamate synthesis in neurons. In isolated primary astrocytes and neurons, high intracellular glutamate and system xc--driven redox demands favor cGAMP uptake, raising the possibility that neurotransmitter cycling and redox burden shape cellular vulnerability to cGAMP immunotransmission in vivo. Together, these findings position ENPP1 as a protective brake on neuroinflammation in aging and MS, nominating cGAS inhibition and CNS ENPP1 enhancement as therapeutic strategies.

cell biology↗

bioRxiv2026

Seizures in a Dravet Syndrome mouse model inhibit the locus coeruleus but locally evoke supraphysiologic norepinephrine release

Locus coeruleus (LC) neurons are the primary source of norepinephrine / noradrenaline (NE) released to most brain structures, including seizure-prone neocortical and limbic regions. LC-NE networks regulate numerous physiological processes, including arousal, attention, and memory. Previous evidence suggests that LC-NE neurons may be involved in epilepsy and that their activation may have therapeutic effects on seizures, but the endogenous activity of the LC-NE network during seizures remains largely unclear. We combined electrocorticography recordings and in vivo imaging to measure somatic activity of LC-NE neurons as well as downstream NE release during hyperthermia-induced seizures in a well-characterized pre-clinical model of Dravet Syndrome. We found that population LC-NE somatic activity was inhibited during seizures, whereas downstream NE release was dramatically elevated. To reconcile these discordant findings, we established that activation of downstream regions is capable of locally evoking NE release, in part via activation of glutamate receptors, consistent with the Glutamate Amplifies Noradrenergic Effects (GANE) model. Finally, we confirmed that ictal NE release occurred across additional downstream brain regions, epilepsy models, and seizure induction methods. Thus, disruption of NE signaling is likely a widespread ictal signature, with implications for impaired consciousness during and after seizures.

neuroscience↗

bioRxiv2026

Partial sleep deprivation diminishes and uncouples neuronal activity and energy metabolism in the live mouse hippocampus

Sleep disorders and wakefulness constitute a pronounced and pervasive health risk that contributes to numerous cerebral pathologies such as stroke, depression, and neurodegenerative disorders. The hippocampus (HC) plays vital roles in learning and memory and is especially susceptible to the pathological insults imposed by sleep deprivation (SD). While SD disrupts neuronal network signaling and triggers inflammatory processes, the impact of SD on metabolism within the HC presently remains poorly understood. In this study, we assessed the progressive and cumulative effects of partial SD in the live mouse HC CA1 region using two-photon microscopy. Using a custom-designed implantable cannula enabling direct HC visualization and administration of dyes and pharmacological agents directly to HC tissue, we longitudinally monitored spontaneous neuronal activity and partial pressure of oxygen (pO2) within HC CA1 tissue before and during a 7-day period of partial SD and after a 7- day period of recovery. Our results revealed a progressive decline in spontaneous neural activity, alongside sustained elevation in tissue pO2; during the 7-day partial SD period. Notably, after 7 days of recovery, neuronal activity did not return to baseline, and tissue oxygenation continued to increase. Our findings emphasize chronic SD's cumulative and enduring impairments to neuronal function and metabolism in the HC and reveal uncoupling between metabolic and functional recovery that outlasts the sleep restriction period.

neuroscience↗