Biology subjects

Xiao, H.

Publications and source records attributed to Xiao, H..

At least 19 recordsLinked to original sources

bioRxiv2026

Redox activation of ATG5 licenses autophagy upon nutrient restriction

Dietary restriction (DR) protects against metabolic disease, extends lifespan, and is associated with remodeling of tissue reactive oxygen species (ROS). ROS control biological adaptation through reversible oxidation of protein cysteines, yet the targets of DR-initiated redox signaling are unknown. Here we generate OxiDR, a tissue-resolved atlas of the cysteine redox proteome that quantifies oxidation state under DR. Rather than oxidizing the proteome broadly, DR selectively targets a high-amplitude set of cysteines in a tissue-specific manner, allowing systematic classification of biological processes subject to DR-mediated redox regulation. Among the cysteines most highly oxidized upon DR is Cys19 of the core autophagy protein ATG5. We show oxidation of Cys19 is required for ATG5-mediated autophagosome formation and for autophagy triggered by nutrient restriction in human cells and mice. Reversible oxidation of this cysteine promotes ATG5 binding to ATG10, thus forming the ATG5-ATG12 conjugate that lipidates LC3B/ATG8 and matures the autophagosome. In mice, loss of this redox switch prevents effective initiation of autophagy upon nutrient restriction, resulting in gross tissue pathology and rapid onset of mortality. The autophagic response to nutrient restriction is thus gated by oxidation of a single cysteine.

cell biology↗

bioRxiv2026

ResLit: A Large-Scale Automated Literature Mining Database for Antimicrobial Resistance

Antimicrobial resistance generates a vast, rapidly growing literature, yet no resource offers a comprehensive, evidence-linked repository of AMR findings at scale. We present ResLit, an automated pipeline and public database that mines the AMR literature for resistance genes, mutations, organisms, and mechanisms. From 2 million candidate PubMed records, BioMistral-7B screened abstracts to 356,000 relevant papers; multi-tier retrieval yielded 117,000 full texts, from which Qwen3-30B performed two-step extraction. ResLit contains 3,120 genes and 13,593 mutations, cross-linked to CARD, ResFinder, and NCBI Reference Gene Catalog across four evidence tiers. It further supports community-driven curation of automated outputs and reference databases. Freely available at www.reslit.info.

microbiology↗

bioRxiv2026

Ultrasound-reconfigurable scaffolds enable dynamic control of biochemical and biophysical cues for vascular network formation

Vascularization, which is critical for most engineered tissue constructs, is dependent on interactions between endothelial cells and spatiotemporally presented biochemical and biophysical cues. Yet, most hydrogels define these cues at the time of fabrication, thus precluding adjustments to actively drive vascular formation. We developed acoustically responsive scaffolds (ARSs) that use focused ultrasound to trigger growth factor release and localized matrix remodeling within fibrin hydrogels. ARSs were formed by incorporating phase-shift emulsions containing basic fibroblast growth factor (bFGF) along with perfluorohexane (C6) or perfluorooctane (C8). Upon ultrasound exposure, stable bubbles were generated in C6-ARSs that locally compacted the matrix and increased macroscale stiffness. Comparatively, in C8-ARSs, ultrasound generated macropores without impacting viscoelastic properties. Ultrasound increased bFGF release from both ARS types, which enhanced in vitro and in vivo vasculogenic assembly in ARSs with co-encapsulated endothelial cells and fibroblasts. Our data also show that ultrasound-driven matrix remodeling without bFGF release increased endothelial sprouting. In C6-ARSs, elevated levels of F-actin were observed in both cell types adjacent to bubbles as well as increased YAP intensity and nuclear asymmetry. Together, these results establish ARSs as reconfigurable hydrogels that couple on-demand release of biochemical cues with programmable matrix restructuring to direct three-dimensional microvascular assembly.

bioengineering↗

bioRxiv2026

The evolutionarily conserved APP-Spastin cooperation regulates endolysosomal homeostasis and apoptotic cell degradation

Efferocytosis, the recognition, engulfment, and degradation of apoptotic cells by phagocytes, is essential for tissue homeostasis and development, and its failure contributes to chronic inflammation and neurodegeneration. The amyloid precursor protein (APP), a central pathogenic factor in Alzheimers disease, retains physiological functions independent of amyloid production that remain poorly understood. Here, we identify a conserved, non-amyloidogenic role for APP in regulating apoptotic cell degradation via the endolysosomal pathway. Using Drosophila APPL as a model, structure-function analysis demonstrated that the intracellular internalization domain of APPL, but not its secreted ectodomain, is required for efficient apoptotic cell degradation. Immunoprecipitation coupled with mass spectrometry revealed a physical interaction between APPL and the microtubule severing ATPase Spastin, mediated by the microtubule-interacting and trafficking domain of Spastin. APPL interacts with Spastin on endosomal microtubules and modulates the dynamics of the Spastin-ESCRT-III complex, enabling Spastin to sever microtubules and promote endosomal tubule fission. Loss of APPL disrupts this process, causing aberrant endosomal tubulation and impaired lysosome biogenesis. Furthermore, it compromises the function of residual lysosomes, characterized by reduced acidity, diminished proteolytic activity, and increased lysosomal damage, which ultimately impairs the degradation of engulfed apoptotic cells. Critically, this phenotype is evolutionarily conserved in C. elegans and mice. Together, these findings establish a conserved APP-Spastin axis that regulates endolysosomal homeostasis and apoptotic cargo digestion. This reveals a critical non-amyloidogenic function of APP in maintaining tissue homeostasis through efficient efferocytosis, with broad implications for inflammatory and neurodegenerative disorders that warrant further investigation.

cell biology↗

bioRxiv2026

GALILEO: Embodied AI scientist for autonomous therapeutic discovery in dynamic membrane systems

Generalizable Agentic Laboratory Intelligence for Learning, Experimentation, and Optimization (GALILEO) closes the prediction-to-intervention gap in therapeutic peptide discovery. Unlike prior AI-scientist systems, GALILEO couples an Observation-Thought-Action-Summary (OTAS) reasoning loop with robotic peptide synthesis and multimodal phenotyping. Candidate peptides are retrieved from a clinically informed peptide prior (CPP) and locally edited through auditable operations. GALILEO autonomously prioritized LRRC8C and SLC25A1 branches and used wet-lab feedback to update target beliefs, sequence policies, assay choices, and mechanism hypotheses. Peptides generated under this framework blocked LRRC8C currents, perturbed osmolyte/redox homeostasis, and promoted tumor-dependent T-cell activation, while SLC25A1 peptides disrupted citrate-export metabolism, reduced extracellular acidosis, and enhanced CD8+ T-cell function. These results establish retrieval-and-editing-based physical learning as a route for auditable, experimentally grounded interventions and transferable membrane-blocker rules.

Molecular Biology↗

bioRxiv2026

The engulfment receptor CED-1/MEGF10 activates the GPCR LAT-1/ADGRL3 for apoptotic cell degradation

Efferocytosis, the clearance of apoptotic cells, is crucial for tissue homeostasis, inflammation suppression, and repair. While several G protein-coupled receptors (GPCRs) are involved, the broader role of GPCRs in efferocytosis remains unexplored. Through a genome-wide RNAi screen in Caenorhabditis elegans, we identified the adhesion GPCR LAT-1 as a key regulator of apoptotic cell degradation through the promotion of phagosome maturation. Our secondary RNAi scrween for transcriptional regulators revealed that the transcription factor AST-1 acts downstream of LAT-1 to mediate apoptotic cell degradation. We show that the engulfment receptor CED-1 functions as a ligand for LAT-1, activating a Gs protein/adenylyl cyclase/PKA/AST-1 signaling cascade and inducing the transcription of vps-34 and piki-1, which encode phosphatidylinositol 3-kinases essential for PtdIns3P generation on phagosomes. This pathway maintains appropriate VPS-34 and PIKI-1 levels for efficient efferocytosis. Notably, LAT-1 is evolutionarily conserved, with homologs in Drosophila (CIRL) and mammals (ADGRL3) performing similar functions. These findings reveal a conserved CED-1/MEGF10-LAT-1/ADGRL3 axis that orchestrates apoptotic cell clearance via a novel transcriptional regulatory pathway, providing new insight into the molecular mechanisms underlying tissue homeostasis and diseases associated with defective efferocytosis, including autoimmunity and neurodegeneration.

cell biology↗

bioRxiv2026

Behavioural plasticity in Caenorhabditis elegans navigating dynamic granular environments

The mechanisms that steer behavioural plasticity in complex environments remain poorly understood. Here, we introduce Peb2les, a quasi-two-dimensional granular arena, for the behavioural assessment of Caenorhabditis elegans nematodes, as they interact with deformable, dynamic terrains. Using customized deep-learning-based methods, we track both nematodes and particles to characterize coupled animal-environment dynamics. We find that nematodes locomotor performance depends on particle density and surface properties, and is largely independent of mechanosensation, whereas functional touch sense is required for the initial decision to enter rough-textured arenas. In addition, we identify a previously undescribed touch-seeking behaviour that partially depends on mechanosensation, in which C. elegans actively return to the granular arena after exiting. In parallel, locomoting nematodes rearrange and stack surrounding particles, continuously modifying the granular terrain. Together, these findings establish Peb2les as a versatile platform for probing the mechanism and limits of behavioural plasticity and locomotory adaptability of nematodes in sensory-enriched, soil-like environments, while also providing insight into the potential evolutionary origins of adaptive touch-seeking behaviours in animals.

animal behavior and cognition↗

bioRxiv2026

Reversion mutations define minimal BRCA1/2 requirements for therapy resistance

Although platinum salts or PARP inhibitors are effective in delivering anti-tumor responses in people with BRCA1 or BRCA2 mutated cancers, drug resistance is common and is often caused by secondary BRCA1/2 reversion mutations that restore function. By collating and analyzing 848 BRCA1/2 reversion mutations in 384 cancer patients with drug resistance, we confirm that pathogenic BRCA1/2 mutation type influences the acquisition of reversions, and that large BRCA1/2 deletions are an underappreciated form of reversion. Integrating reversion data with systematic CRISPR-Cas9 screens that delete BRCA1/2 exons, we also show that both proteins contain privileged domains whose structure is essential for drug resistance, including the PALB2 interacting domains of both BRCA1 and BRCA2. Reversions in PALB2 also conserve both BRCA1 and BRCA2 binding domains. Surprisingly, exon 11 of BRCA2, which encodes BRC repeats 1-8, is not essential for resistance. Using this patient and functional information, we estimate the likelihood of pathogenic BRCA2 mutations to revert. We show that risk of reversion correlates with both the presence of clinical reversions and the response to treatment, suggesting that the propensity to revert could be a useful clinical parameter.

cancer biology↗

bioRxiv2026

Localized heme sensing through a ternary molecular glue

Molecular glues are an emerging class of therapeutics that stabilize binary interactions and there-by rewire disease-relevant protein networks. Whether glues can integrate additional information to orchestrate signaling beyond initial complex formation is unknown. Here, we report that cells use an endogenous glue strategy to sense heme, an essential metabolite with deleterious pro-oxidant properties. Distinct from other glues, heme bridges three polypeptides to trigger degradation of the transcriptional repressor BACH1 through cytoplasmic, but not mitochondrial, CUL2FEM1B. This mechanism allows cells to eliminate toxic heme in the cytoplasm by inducing expression of the heme-degrading oxygenase HMOX1, yet ignore mitochondrial heme destined for function in the electron transport chain. While protective in healthy cells, ternary glue signaling creates a therapeutic vulnerability for Acute Myeloid Leukemias dependent on high rates of ETC assembly. Molecular glues can therefore drive assembly of higher-order complexes to establish localized signaling, which offers unexplored opportunities for induced proximity therapeutics.

biochemistry↗

bioRxiv2026

Gymnosperm FLS2 orthologues mediate conserved flg22 perception and divergent responses to flg22 variants

O_LIWhether gymnosperm FLAGELLIN-SENSING 2 (FLS2) orthologues are functional receptors and whether their flg22-recognition spectra have already diversified remain unclear, despite the central role of FLS2 in flagellin perception in angiosperms. C_LIO_LIHere, we identified two gymnosperm FLS2 orthologues, GbFLS2 from Ginkgo biloba and PtFLS2 from Pinus tabuliformis, and analysed their function using transient and stable expression in the Nicotiana benthamiana fls2 mutant, in planta cross-linking assays, AlphaFold3 modelling and structure-guided mutagenesis. C_LIO_LIBoth receptors restored flg22Pst-triggered reactive oxygen species production and MAPK activation, physically associated with flg22Pst, and required conserved residues for flg22Pst recognition. In stable transgenic plants, both receptors mediated flg22Pst-triggered PTI outputs and flg22Pst-induced resistance to Pseudomonas syringae. PtFLS2 additionally mediated responsiveness to flg22Rso and enhanced resistance to Ralstonia solanacearum, whereas GbFLS2 retained a typical flg22Pst-recognition profile. C_LIO_LIThese findings provide direct evidence that gymnosperm FLS2 orthologues can function as bona fide flagellin receptors in a heterologous angiosperm background, and further suggest that diversification in flg22 recognition had already emerged within gymnosperms. C_LI

plant biology↗

bioRxiv2026

A druggable redox switch on SHP1 controls macrophage inflammation

Immunological proteins are major disease targets, yet most remain undrugged. Post-translational redox modification of cysteine residues has emerged as an important mode of immune cell regulation, particularly in macrophage cytokine responses. Here, we develop a strategy for systematic discovery and small-molecule functionalization of redox-regulated cysteines on immunological proteins. Using deep redox proteomics, we annotate 788 in vivo redox-regulated cysteines across diverse immune-relevant protein domains. We demonstrate how these sites enable cysteine-directed pharmacology through discovery of a novel cysteine activation site on the immune regulator SHP1. Targeting Cys102, we develop a highly selective covalent agonist, SCA, which binds the N-SH2 domain to relieve autoinhibition and activate SHP1. In mouse and human macrophages, SCA selectively engages SHP1 Cys102, antagonizing IRAK signaling and LPS-induced pro-inflammatory cytokine production. Together, this work identifies a druggable cysteine redox switch controlling macrophage cytokine responses and provides a compendium of redox-regulated sites for therapeutic development.

biochemistry↗

bioRxiv2026

Inhalable Polymeric Nanoparticle Vaccine for Lysosome-targeting Co-delivery of Antigen and Adjuvant with Enhanced Immunoprotection

Conventional subunit vaccines suffer from premature clearance and poor synchronization of antigen and adjuvant, limiting coordinated immune activation. Here, we develop an amphipathic polymer (YAXA) with acid-labile imine bonds for acid-sensitive degradation and terminal NHS-activated esters for antigen conjugation. YAXA is co-assembled with hydrophobic TLR7 agonist 3M-052 and conjugated to protein antigen, forming nanoparticle vaccine YM3.7. Following aerosolized intratracheal inoculation into the lung, YM3.7 is efficiently internalized by antigen-presenting cell and trafficked into lysosome, where acidic conditions trigger its dissociation and co-release of antigen and adjuvant. This spatiotemporally synchronized delivery promotes robust immune activation, including cell maturation, germinal center formation, systemic and lung-resident B/T cell response, and IgG/sIgA production. In lethal pneumonia models induced by either Pseudomonas aeruginosa or Staphylococcus aureus, YM3.7 markedly improves survival over conventional antigen and adjuvant mixture. This study presents an inhalable nanoparticle platform that coordinately activates innate, humoral, mucosal, and cellular immunity for enhanced protection.

immunology↗

bioRxiv2026

Probing the Glymphatic System Using Optical Imaging and Mathematical Modeling

The glymphatic system is a macroscopic waste clearance pathway in the central nervous system (CNS), crucial to maintaining neural homeostasis through the exchange of cerebrospinal fluid (CSF) and interstitial fluid (ISF). Impairments in this system have been associated with neurodegenerative diseases such as Alzheimers and Parkinsons, emphasizing the need to understand and potentially improve glymphatic clearance. We investigate tracer diffusion and transport in the glymphatic system by combining optical imaging in rats and mathematical modeling using a partial differential equation of advection-diffusion type. The experimental conditions differ in the levels of isoflurane-induced anesthesia (1.5, 2 and 3%) and the molecular weight of the tracer compounds (1 and 160 kDa). The optimal parameters show a close clustering of the diffusion coefficients and a wider spread of the flow velocities of the cerebrospinal fluid. Our work contributes to a better understanding of flow processes in the brain parenchyma during sleep.

neuroscience↗

bioRxiv2026

Diverse bacterial pattern recognition receptors sense the conserved phage proteome

Recognition of foreign molecules inside cells is critical for immunity across all domains of life. Proteins of the STAND NTPase superfamily1,2, including eukaryotic NOD-like receptors (NLRs), play a central role in this process3,4. In bacteria and archaea, although several STAND families sense phage proteins5-9, their functional diversity remains largely unexplored. We conducted a systematic phylogenetic analysis of prokaryotic STAND NTPases and identified at least 90 structurally distinct families associated with antiviral defense. We first show that the uncharacterized Avs7 family recognizes the major capsid protein (MCP) of tailed phages. Three cryo-EM structures of Salmonella enterica Avs7 reveal an asymmetric, butterfly-shaped tetramer that assembles stepwise via large, MCP-induced conformational changes, incorporating bacterial elongation factor Tu (EF-Tu) as a structural component that enhances defense. Using genetic screens with a library of 687 phage genes, we further show that 13 additional STAND families sense 13 conserved phage proteins, encompassing most of the core structural and replicative components of tailed phages. These include two distinct MCP-sensing families--Avs8 (PD-{lambda}-4) and Avs10 (Erebus/Hypnos/bNACHT64)--and 11 others (Avs11-21) recognizing the portal, portal adaptor, tail nozzle, head-tail connector, tail terminator, tail tube protein, tail assembly chaperone, tape measure protein, DNA polymerase, helicase/RecA-type ATPase, and single-stranded DNA annealing protein, respectively. Together, our findings highlight structurebased pattern recognition and host factor repurposing as fundamental strategies of bacterial immunity.

molecular biology↗

bioRxiv2025

Sloppiness and Action Confinement in Cell State Transitions: Are Single Cells Sloppy?

Single-cell dynamics during cell state transitions (CST) are highly constrained, enabling precise control. However, there are challenges in achieving a system-level understanding or extracting general principles for CST dynamics due to the complexity of gene-gene interactions. Here, we introduce a new perspective to deal with these challenges using Fisher information. We found that, during CST, single cells exhibit pronounced sloppiness: cell states are sensitive only to a few "stiff" parameters while remaining robust to changes in numerous "sloppy" parameters. Critical transitions coincided with changes in stiff parameters. Moreover, stiff parameters typically exhibited minimal fluctuations and low velocities, whereas sloppy parameters allowed greater flexibility. Together, these findings can be summarized by stating that transition paths approximately adhere to a principle of least action. By characterizing the low dimensionality and constraints of CST through sloppiness and action, our work thus introduces a new conceptual and computational framework for analyzing single-cell dynamics. TeaserExcept when transitions occur, single-cell dynamics exhibit sloppiness, adhering approximately to a least action principle.

biophysics↗

bioRxiv2025

Scalable production of immune-silent circular RNAs for efficient protein expression

Messenger RNA-based therapeutics enable transient protein expression but are limited by its instability. Circular RNA (circRNA) offers enhanced stability, yet scalable production of high-purity circRNA remains challenging. Here, we report an oligo (dT) matrix-based purification strategy for tunable, scalable circRNA production at room temperature. By adjusting poly (A) length, circRNAs are positioned at the midpoint of the oligo (dT) elution profile, enabling one-step separation from both weakly and strongly bound RNA contaminants. We demonstrate that this approach scales linearly with comparable yields for small- and large-scale purifications. In scale-up experiments, 331 mg of highly pure circRNA was recovered in a single run. Incorporating alkaline phosphatase and RNase R digestion prior to chromatography efficiently removes immunogenic contaminants, yielding circRNAs with undetectable immune activation and robust translation in human cells. This workflow provides a practical platform for scalable production of high-quality circRNAs.

bioengineering↗

bioRxiv2025

Neuroinflammatory Stress Preferentially Impacts Synaptic MAPK Signaling and Mitochondria in Excitatory Neurons

BackgroundUnderstanding synapse-specific effects of neuroinflammation can provide mechanistic and therapeutically relevant insights across the spectrum of neurological diseases. MethodsWe applied neuron-specific proteomic biotinylation in vivo, differential centrifugation of brain for crude synaptosome enrichment (P2 fraction) and mass spectrometry (MS) analysis of biotinylated proteins to derive native-state proteomes of Camk2a-positive neurons and their corresponding P2 synaptic compartments. Next, in an in vivo model of systemic lipopolysaccharide (LPS) dosing, we examined the effects of neuroinflammation on whole neuron and synaptic compartments using a combination of MS, network analysis, confirmatory biochemical and ultrastructural assays and integrative approaches across our mouse-derived and existing human datasets. ResultsUltrastructural and biochemical analyses of P2 fractions verified enrichment in synaptic elements, including synaptic vesicles and mitochondria. MS of biotinylated proteins from Camk2a-specific bulk brain homogenates (whole neuron) and P2 fractions (synaptosome) showed enrichment of >1000 proteins, consistent with neuron-specific biotinylation, also confirmed by immunofluorescence microscopy. Camk2a-specific synaptic proteome revealed molecular signatures related to mitochondrial function, synaptic transmission, protein translation. LPS-treated mice displayed body weight loss and neuroinflammation, characterized by glial activation, increased pro-inflammatory cytokine levels and upregulated expression of Alzheimers disease (AD)-related microglial genes. LPS-induced neuroinflammation exerted distinct effects on the synaptic proteome, including increased mitochondrial and reduced cytoskeletal-synaptic proteins, while suppressed synaptic MAPK signaling. Importantly, these changes were not observed at the whole neuron level, indicating unique vulnerability of the synapse to neuroinflammation. In line with synapse proteomic and signaling changes, LPS altered the ultrastructure of asymmetric synapses, suggesting dysregulation of excitatory neurotransmission. Co-expression network analysis of Camk2a neuronal proteins further resolved mitochondria- and synapse-specific protein modules, some of which were neuroinflammation-dependent. Neuroinflammation increased levels of a mitochondria-enriched module, and decreased levels of a pre-synaptic vesicle module, without impacting a post-synaptic membrane module. LPS-dependent mitochondrial and LPS-independent post-synaptic modules in mouse neurons mapped to post-mortem human AD brain proteomic modules which were decreased in cases with AD dementia and positively correlated to cognitive function, including pro-resilience markers for AD. ConclusionOur findings using native-state proteomics of Camk2a neurons combined with synaptosome enrichment identify proteome-level mechanisms of early synaptic vulnerability to neuroinflammation relevant to AD.

neuroscience↗

bioRxiv2025

Oncogenic PTPN11/SHP2 drives immune escape in juvenile myelomonocytic leukemia (JMML) through activation of ectonucleotidase/adenosine signaling

Juvenile myelomonocytic leukemia (JMML) is a myelodysplastic/myeloproliferative neoplasm of early childhood driven by RAS pathway mutations. Allogeneic hematopoietic stem cell transplantation (HSCT) is the therapy of choice for most patients. However, relapse rate is high, in patients with adverse features, frequently noted in PTPN11-mutated JMML, or in patients without evidence of graft-versus-host disease (GvHD). Here we set out to understand the mechanisms associated with oncogenic PTPN11 immune escape. Analyzing primary PTPN11-mutated JMML samples and MxCre;Ptpn11D61Y/+ mice, we observed elevated expression of immune checkpoint molecules, including ectonucleotidases CD39 and CD73 - key mediators of the adenosine pathway - on monocytic and granulocytic leukemic cells. Stimulation with GM-CSF, a central mediator of JMML pathogenesis, induced ectonucleotidases expression on granulocytes and monocytes. In contrast, MEK inhibition downstream of Ptpn11D61Y/+ reduced ectonucleotidases expression. Functionally, Ptpn11D61Y/+-mutated myeloid cells suppressed activation and proliferation of wild-type (WT) T lymphocytes, an effect recapitulated by adenosine and reversed by pharmacological CD39 inhibition with POM-1. In vivo, POM-1 treatment of MxCre;Ptpn11D61Y/+mice presenting with myeloproliferation reduced spleen size and partially restored immune responsiveness. Moreover, POM-1 induced apoptosis in murine Ptpn11D61Y/+ myeloid cells, highlighting a dual therapeutic benefit of CD39 inhibition in JMML. Together, these findings suggest that targeting the adenosine pathway may represent an immunomodulatory approach to enhance T cell-mediated control of JMML, particularly in the context of HSCT and relapse prevention.

cancer biology↗