Biology subjects

Fan, W.

Publications and source records attributed to Fan, W..

At least 19 recordsLinked to original sources

bioRxiv2026

Imaging biological tissue at extended depth using swept-source visible-light OCT

We present a swept-source visible-light optical coherence tomography (SS-vis-OCT) system with twice the imaging depth of prior SS-vis-OCT and improved sensitivity for imaging biological samples, achieving shot-noise-limited operation. Because second-harmonic generation is limited by the booster optical amplifier's output power, the visible-light SS power is capped at 450 W. Increasing it further would require a more powerful, but costlier, amplifier. Instead, we reduce the receiver noise floor by selecting a balanced detector with NEP approaching the thermal (Johnson-Nyquist) limit. Real-time numerical k-linearization increases the effective number of linear-in-wavenumber samples per sweep, further improving SNR and extending the imaging range. Together, these improvements yield a sensitivity of 89 dB and an imaging depth of 9 mm in air or 6.5 mm in tissue, enabling full anterior-segment imaging of ex vivo porcine eyes.

bioengineering↗

bioRxiv2026

Molecular anatomy of the glomerular filtration barrier reveals topology-encoded albumin sieving

The kidney filters plasma rapidly while retaining albumin, yet where and how this selectivity is encoded within the glomerular filtration barrier remain unresolved. Here we combine cryo-electron tomography (cryo-ET) of vitrified mouse glomeruli with structure-resolved transport modelling to predict albumin passage from the native three-dimensional architecture of the barrier. Among the three barrier layers, endothelial fenestrae and the flexible Nephrin-Neph1 slit-diaphragm lattice are substantially permeable to albumin. The glomerular basement membrane (GBM) instead provides the dominant restriction through steric exclusion governed by void-network topology. In local GBM reconstructions, water traverses broadly connected void space, whereas narrow throats exclude albumin, leaving few accessible paths. To scale this mechanism to the tissue level, we combine structural statistics from local cryo-ET volumes with mesoscale measurements of GBM heterogeneity to generate representative ensembles. Integrating these ensembles with other layers predicts whole-barrier albumin sieving in close agreement with an independent measurement. The topology-driven mechanism also explains early filtration failure in Alport syndrome mice, in which collagen-IV disruption remodels the GBM network and opens albumin-accessible paths while cellular interfaces remain preserved. These findings identify the structural origin of glomerular albumin selectivity and establish a quantitative route from locally resolved architecture to tissue-scale physiology.

physiology↗

bioRxiv2026

Lateral hypothalamic GABAergic projections to the dorsal pons and lateral preoptic area in feeding, predation, and reinforcement

Lateral hypothalamic GABAergic (LHAGABA) neurons regulate arousal, feeding, and reward-related behaviors, but how their downstream projections coordinate motivated behaviors across domains remains incompletely defined. Our histological analyses revealed that LHAGABA fibers were distributed across the dorsal pons (DP) subregions, including the peri-locus coeruleus, laterodorsal tegmentum, and Barringtons nucleus, and extend throughout the lateral preoptic area (LPO), thereby refining existing anatomical descriptions. We then used optogenetics to systematically compare the effects of activating LHAGABA somata and their projections to the DP and LPO across assays of feeding, non-food-directed gnawing, predatory behavior, real-time place preference, and operant self-stimulation. In sated mice, optogenetic activation of LHAGABA somata or their terminals in the DP or LPO increased caloric food intake, whereas non-caloric cellulose intake was minimally affected during terminal stimulation. Across conditions, activation increased gnawing and shredding of non-food objects while reducing inactivity. In cricket hunting, stimulation increased cricket killing and consumption relative to controls. Similarly, all stimulation conditions supported positive-valence and reinforcement-related responding, as indicated by real-time place preference and operant self-stimulation. Together, these results provide new functional evidence that activation of LHAGABA somata and projections to both the DP and LPO recruit largely overlapping behavioral responses across feeding, non-food behavior, predatory hunting, and reinforcement-related assays. These findings support a distributed hypothalamic output architecture in which major ascending and descending LHAGABA pathways contribute to a shared motivational repertoire rather than wholly discrete behavioral functions.

neuroscience↗

bioRxiv2026

Single shot low-dose radiation durably and focally increases cortical excitability: a potential therapy for neuronal circuit disorders?

Herein, we assess the potential of low-dose stereotactic radiosurgery (SRS) to modulate neuronal network states without apparent damage to cellular integrity. Using a small animal radiation research platform (SARRP), a 1 mm3 focal target in the mouse visual cortex was irradiated with doses of 5, 20, and 40 Gy. One-month later a significant dose-dependent increase in excitatory synapse numbers was observed, notably limited to the treated visual cortex and not the adjacent somatosensory cortex. Six months post-irradiation, cortical neuronal microcircuit activity was monitored in awake mice using high sensitivity two-photon calcium imaging. A single 5 Gy dose resulted in a significant microcircuit-wide increase of spontaneous neuronal activity, consistent with a lasting shift in the functional architecture of the irradiated nodal network. At higher SRS doses (40 Gy) this neuromodulatory window appears to close. In aggregate, these data suggest that low-dose radiation could, in some circumstances, be exploited by selected high precision SRS technologies to durably modulate neuronal circuit disorders. Some, or even all the clinical benefits reported in the companion article by Zhao et al. are likely attributable to the biological properties we sought to characterize in our research.

neuroscience↗

bioRxiv2026

Performance-impacting brain state maladaptation driving disease progression in early mouse and human neuroinflammation

The neuronal mechanisms driving progression in neuroinflammatory disorders from early relapse-remitting phases to later neurodegenerative phases remain largely elusive. Functional brain state shifts towards hyperactivity, persisting beyond relapses, represent an early maladaptive response. Here, in remission stage of an experimental autoimmune encephalitis (EAE) mouse model of RRMS, we identified a reduced excitability upon optogenetic stimulation in the brain stem, the area of active disease, while in the cortex a persistent cortical neuronal hyperactivity and synaptic remodeling emerged, accompanied with an increase of markers of early apoptosis. In contrast, hippocampal circuits, which undergo a functional state shift without hyperactivity, do not show increased apoptosis. Visual cortical networks showed a deterioration of the accuracy of encoding visual information and a decrease in the behavioural visual discrimination ability in mice. In RRMS patients in remission, we identified a reduced visual colour discrimination, indicating both the presence and the clinical relevance of early brain state maladaptation that may contribute to progression independent from relapse activity (PIRA). SummaryIn a RRMS model and in patients, impaired visual processing was reported, indicating brain state maladaptations, associated with persistent cortical hyperactivity, brain stem hypoactivity, synaptic remodeling, and apoptosis. These maladaptations might contribute to relapse-independent disease progression through sustained network dysfunction.

neuroscience↗

bioRxiv2026

Transient suppression of the ECM1 gatekeeper is essential for HGF/c-MET-driven liver regeneration

Hepatocyte growth factor (HGF) is a multifunctional cytokine stored in the extracellular matrix as an inactive precursor and is essential for tissue repair. How HGF activity is dynamically regulated during regeneration remains unclear. Here, we identify extracellular matrix protein 1 (ECM1) as a physiological inhibitor of active HGF during liver regeneration. Following 70% partial hepatectomy, active HGF rapidly increases in parallel with a sharp decline in ECM1, and preventing this downregulation delays liver mass recovery. Mechanistically, ECM1 directly binds the active HGF -subunit through a mechanism dependent on residue R392, thereby suppressing c-MET-ERK-MYC signaling and hepatocyte proliferation. Loss of ECM1 permits activation of this pathway, whereas MYC overexpression rescues ECM1-mediated growth inhibition. In patients, proliferative hepatocytes localize to ECM1-negative regions. Supported by transcriptomic analyses and computational modeling, these findings identify ECM1 as an extracellular gatekeeper whose transient downregulation enables HGF-driven tissue repair. HighlightsO_LIECM1 is temporally downregulated during liver regeneration, while forced ECM1 expression delays liver mass recovery after 70% PHx by suppressing hepatocyte proliferation. C_LIO_LIRapid and transient ECM1 downregulation permits HGF-c-Met-ERK-MYC signaling to drive hepatocyte cell-cycle entry and expansion. C_LIO_LIECM1 directly binds the active HGF -subunit with residue R392 playing a critical role, revealing a novel extracellular mechanism for growth factor inhibition. C_LIO_LILoss of ECM1 marks proliferative hepatocytes in human liver repair, identifying ECM1 as a tunable regulator of regenerative capacity. C_LI

cell biology↗

bioRxiv2026

Locus coeruleus activation transforms cortical taste representations

Norepinephrine neurons in the locus coeruleus (LC) shape sensory responses across the brain, yet how LC activity reorganizes population representations of behaviorally relevant sensory attributes remains unclear. We addressed this question in the primary gustatory cortex (GC), a system largely unexplored in neuromodulation research and well-suited for linking sensory coding to affective value. Using miniscope calcium imaging in awake mice combined with optogenetic LC activation, we tested how phasic and tonic LC activity modulate GC encoding of three taste attributes: palatability, mixture ratio, and intensity. Phasic LC activation enhanced correlations between neuronal responses and tastant palatability and expanded the dynamic range of taste representations along a palatability-relevant axis. This expansion was driven primarily by an aversive shift in the representation of all tastants except sucrose, the most palatable stimulus. For mixture ratio and concentration, LC activation induced both stretching and rotation of attribute axes, potentially reflecting dependencies between these attributes and palatability. Analysis of LC-induced changes in neuronal tuning revealed that these population-level transformations likely arise from a combination of multiplicative gain modulation and flexible, tastant-specific changes in tuning. In contrast, tonic LC activation engaged fewer GC neurons and did not produce stretching along any attribute axis, demonstrating that LC effects on population coding depend on activation pattern. Together, these findings provide causal evidence that phasic LC activation reshapes GC population geometry to preferentially enhance palatability encoding, establishing a framework for understanding how neuromodulation may bias taste representations relevant to feeding behavior.

neuroscience↗

bioRxiv2026

Dual-Stream Compression of High Bit-Depth Medical Images with Application to DNA Storage

High bit-depth medical images preserve subtle intensity variations that are important for quantitative analysis and clinical interpretation, but their large dynamic range poses challenges for efficient compression. We propose a bit-plane-aware dual-stream compression framework for 16-bit medical images by separately modeling the most significant bit (MSB) and least significant bit (LSB) components. The MSB structural stream is encoded using JPEG coding with a Duplicate Segment Skipping (DSS) strategy to exploit spatial and segment-level redundancy, while the LSB detail stream is compressed using learned image compression to represent residual variations and fine-grained details. Experiments on four MRI and CT datasets show that the proposed method consistently outperforms representative traditional and learning-based codecs, achieving the lowest bit rate across all datasets. Meanwhile, it preserves high reconstruction fidelity. As a downstream application, we further demonstrate that the compressed bitstreams can be effectively integrated with DNA encoding and converted into sequences with favorable biochemical properties.

bioinformatics↗

bioRxiv2026

HDAC Inhibition Sensitizes Pancreatic Tumors to DNA Damage by Global Redistribution of the Transcriptional Machinery

The DNA damage response (DDR) is critical for pancreatic ductal adenocarcinoma (PDAC) development and therapeutic responses, including to genotoxic agents. While epigenetic modulators have been shown to contribute to the DDR, how chromatin regulation dictates responses to DNA damage in PDAC remains incompletely understood. Here, we identify Class I histone deacetylases (HDACs) as critical regulators of the DDR. HDAC1/2 directs the genomic distribution of H3K27ac, ensuring sufficient BRD4 and RNA polymerase II (Pol II) occupancy at DDR gene promoters. HDAC inhibition by entinostat shifts the balance of H3K27 acetylation preferentially towards intergenic regions, diverting BRD4 and Pol II from promoters, thereby suppressing DDR gene expression. In line with this, HDAC inhibition heightens DNA damage and sensitizes PDAC to diverse DNA-damaging and DDR-targeting agents. Since the clinical development of HDAC inhibitors has been limited by systemic toxicity, we developed bottlebrush prodrug (BPD) nanoparticles for tumor-selective entinostat delivery. Entinostat-BPD achieved tumor-specific HDAC inhibition while displaying potent efficacy and reduced systemic toxicity. These findings reveal an HDAC-dependent DDR vulnerability and offer combinational and precision targeting strategies to facilitate clinical translation and improve PDAC patient outcomes. SIGNIFICANCE STATEMENTThe ability of tumor cells to tolerate DNA damage limits the efficacy of many anticancer therapies. Our study reveals that pancreatic cancer cells enforce this resistance by sustaining expression of DNA damage response (DDR) genes through Class I histone deacetylases (HDACs). HDACs maintain genome-wide acetylation patterns required for efficient recruitment of the transcriptional machinery to DDR genes. Pharmacological HDAC inhibition disrupts this process and sensitizes pancreatic cancer cells to diverse DNA-damaging agents. To overcome systemic toxicity that limits translational potential, we further establish a bottlebrush prodrug nanoparticle platform that enables tumor-selective HDAC inhibition. Given the central role of the DDR in cancer, targeting HDAC-mediated DDR regulation through drug combinations and precision delivery may have broad therapeutic relevance across cancer types.

cancer biology↗

bioRxiv2026

The epidermal stem cell-supporting matricellular protein fibulin 7 modulates skin inflammatory response in a psoriasis model

ECM composition and organization are greatly altered during inflammation but it is still elusive if ECM dynamics may protect tissue stem cells against aberrant inflammation. Fibulin 7 (encoded by Fbln7) is part of the basement membrane ECM where epidermal stem cells (EpSCs) reside. It supports the long-term potential of fast-cycling EpSCs and moderates aging-related inflammatory markers in keratinocytes. Here, we assessed fibulin 7s role during imiquimod (IMQ)-induced inflammation in 1-year-old mouse dorsal skin. We found that loss of Fbln7 aggravates epidermal inflammation, marked by increased epidermal thickness, proliferation, and phosphorylation of JNK (c-Jun N-terminal kinase). Fast-cycling EpSCs labeled with Slc1a3-creER-TdTomato demonstrated that IMQ-induced proliferation in Fbln7 KO mice is contributed by cell divisions in the suprabasal layers, a hallmark of inflammatory epidermal responses. EpSC transcriptomes further reveal IMQ-modulated genes that are more substantially affected in Fbln7 KO mice, including IL-17 pathway-related genes known in psoriasis pathogenesis. Mechanistically, fibulin 7 directly binds to IL-17A and decreases IL-17A-mediated p38 MAPK activation. In public human psoriasis datasets, FBLN7 is reduced in lesional skin compared with non-lesional or normal skin, and it is significantly correlated with common psoriasis-associated genes. Altogether, fibulin 7 is potentially beneficial to protect against skin inflammation.

cell biology↗

bioRxiv2026

Accurate detection of mosaic mutations at short tandem repeats from bulk sequencing data

Short tandem repeats (STRs) are among the most mutable regions of the human genome, yet their somatic mosaicism remains poorly characterized due to the technical challenges of distinguishing genuine mutations from high intrinsic polymorphism and sequencing noise. Here, we introduce BulkMonSTR, a computational framework that combines STR-specific error modelling with machine-learning classification to enable accurate detection of mosaic STR mutations from bulk next-generation sequencing data. BulkMonSTR identifies nucleotide-resolution mutations--including insertions, deletions, and single-nucleotide variants (SNVs)--and supports both control-independent and case-control study designs. Leveraging a comprehensive training dataset derived from pedigree-based validation and in silico spike-in simulations, our random forest classifier effectively discriminates true mosaic events from germline variants and technical artifacts. Benchmarking on simulated and real datasets demonstrates that BulkMonSTR achieves substantially improved precision and F1 scores across diverse coverages and variant allele frequencies. In normal samples, cancer samples and controlled in silico mixing experiments, BulkMonSTR consistently outperforms existing methods, capturing a broader spectrum of STR mutations--including those arising on non-reference alleles--while achieving high validation rates. By enabling systematic, genome-wide interrogation of STR mosaicism, BulkMonSTR provides a scalable foundation for investigating the contributions of somatic STR mutations to aging and disease.

bioinformatics↗

bioRxiv2026

Nuclear speckle protein SON safeguards efficient splicing of GC-rich genes

Gene architecture in higher eukaryotes exhibits substantial heterogeneity. While most genes follow a canonical pattern of GC-rich exons and AT-rich introns, a subset displays GC-leveled architecture, characterized by uniformly high GC content across both exons and introns. These genes are often associated with nuclear speckles, membraneless compartments enriched in RNA-processing factors, yet the mechanistic basis of this spatial and functional relationship remains unclear. Here, we identify the nuclear speckle protein SON as a critical factor that safeguards the splicing of GC-rich genes. Acute depletion of SON in mouse embryonic stem cells selectively impairs the splicing of short, GC-rich introns. These SON-dependent introns are enriched in highly expressed and functionally essential genes, whose GC-rich architecture contributes to efficient RNA processing and expression. Mechanistically, these introns harbor atypical C-rich, U-poor polypyrimidine tracts at their 3 splice sites, which exhibit reduced affinity for core splicing factors. SON is recruited to these sites via U2 snRNP and further interacts with SR proteins to stabilize the association of U2 snRNP and U2AFs at these C-rich weak splice sites. Notably, the evolutionary expansion of SONs intrinsically disordered region is required to promote efficient splicing of GC-rich genes that emerged during evolution. Together, our study suggests that the evolutionary transition toward GC-rich gene architecture enhances gene expression efficiency, with SON acting to safeguard the splicing of this gene class.

molecular biology↗

bioRxiv2026

Detection of Somatic Point Mutations Directly from Spatial Transcriptomics Enables in vivo Spatiotemporal Lineage Tracing

Spatial transcriptomics reveals tissue organization but lacks in vivo lineage-tracing methods applicable to humans. We introduce SpaceTracer, a computational framework that accurately detects somatic single-nucleotide variants (SNVs) directly from spatial transcriptomics data. By leveraging naturally occurring somatic SNVs, SpaceTracer reconstructs cellular phylogenies within native tissue architecture, enabling the mapping of lineage spread, migration, lineage-coupled expression changes and lineage-aware local interactions. Applied to human cutaneous squamous cell carcinoma, it traced tumor initiation and progressions, uncovered widespread pre-invasive migration of dedifferentiated epithelial cells and characterized mutant B cells migrating from tertiary lymphoid structures (TLS) into the tumor boundary. The framework also reconstructed developmental lineages across multiple tissues and identified tissue-resident mutant immune cells. SpaceTracer thus provides a perturbation-free platform for high-resolution spatiotemporal lineage tracing, offering a transformative tool for elucidating complex biological systems--especially tumor-immune ecosystems--with direct implications for advancing cancer immunotherapy.

bioinformatics↗

bioRxiv2026

Unravelling genome-wide mosaic microsatellite mutations at single-cell resolution

Short tandem repeats (STRs), or microsatellites, are highly mutable genomic elements that modulate gene regulations and are implicated in a range of human diseases. However, detecting mosaic STR mutations at single-cell resolution remains challenging due to both technical and biological complexities. To address this, we developed BayesMonSTR, a robust algorithm that enables accurate detection of mosaic STR mutations. Using this tool in single-cell analysis of human tissues, we reveal an accumulation of longer mosaic STR insertions and deletions (indels) in aging mitotic and post-mitotic cells. Strikingly, prefrontal cortex (PFC) neurons accumulate a higher burden of STR mutations than B cells or lung epithelium, with aged neurons exhibiting a particularly pronounced increase in longer STR deletions. These mutations are enriched at transcription start sites (TSSs) and active enhancers of highly expressed genes. Our work establishes a foundation for genome-wide, hypothesis-free discovery of disease-associated mosaic STR mutations and reveals a previously unexplored landscape of mosaic STR variation in development and aging.

bioinformatics↗

bioRxiv2026

Macrophage Antigen Presentation Is Unleashed by Pan-RAS Inhibition to Promote Antitumor Immunity

Pan-RAS inhibitors have emerged as potent targeted therapies designed to suppress oncogenic signaling in RAS-mutant tumors. However, whether these inhibitors possess therapeutic utility beyond tumors with intrinsic RAS dependency remains unclear. Here we show that the clinical-stage pan-RAS(ON) inhibitor RMC-6236 (Daraxonrasib) induces robust regression of NRAS-wild-type B16 tumors in immunocompetent mice, a response mediated by a mechanism independent of direct tumor-cell targeting. Instead, RMC-6236 acts by remodeling the tumor microenvironment, specifically enhancing the antigen-presenting capacity of tumor-associated macrophages through upregulated MHC-I expression. This anti-tumor efficacy is abrogated in T cell-deficient hosts, identifying a macrophage-dependent, T cell-mediated mechanism of control. Mechanistically, RMC-6236 does not directly block canonical RAS signaling in macrophages. Rather, it suppresses a Myc-Hdac2 epigenetic program, leading to enhanced histone H4 acetylation at the Nlrc5 locus and subsequent activation of the MHC-I master regulator NLRC5. Together, our findings reveal a macrophage-centered, epigenetically wired immune mechanism for pan-RAS inhibition that broadens the therapeutic scope of targeting the "undruggable" RAS pathway beyond tumor genotype towards systemic immune modulation.

immunology↗

bioRxiv2026

The novel variant IBDV induces inflammatory responses via VP3-mediated pyroptosis by directly targeting Caspase-9

The novel variant infectious bursal disease virus (nVarIBDV), which has been widely prevalent since 2017, threatens the poultry industry by inducing severe bursal atrophy and intense inflammatory responses. Understanding the inflammatory mechanism underlying nVarIBDV infection is critical for preventing virus-induced damage. Pyroptosis, an inflammatory type of programmed cell death, may contribute to the inflammation and bursa of Fabricius damage induced by nVarIBDV. Here, we found that the nVarIBDV infection induced severe inflammatory responses both in vivo and in vitro, which were associated with pyroptosis. Further research revealed that the viral protein VP3 drove pyroptosis induced by nVarIBDV infection by indirectly activating the Caspase-3-GSDME pathway, leading to GSDME cleavage. Mechanistically, VP3 directly interacted with and activated Caspase-9, thereby initiating Caspase-9-Caspase-3-GSDME pathway. More importantly, the Serine 33 of VP3 was identified as the key amino acid for interacting with and activating Caspase-9. Mutation of this residue significantly weakened the ability of VP3 to interact with Caspase-9 and activate the Caspase-9-mediated pyroptosis pathway, altered the binding mode of the Caspase-9-VP3 protein complex, and ultimately reduced the ability of VP3 to induce pyroptosis. In conclusion, our results elucidated a novel mechanism by which nVarIBDV infection induced inflammatory responses whereby viral protein VP3 triggered pyroptosis by targeting the Caspase-9-Caspase-3-GSDME pathway. IMPORTANCEnVarIBDV is globally prevalent and poses a significant threat to the poultry industry by causing inflammation and damage to the bursa of Fabricius. This study revealed that nVarIBDV infection induced inflammatory responses and bursa of Fabricius damage, primarily mediated by the viral protein VP3 targeting Caspase-9 to induce pyroptosis. To our knowledge, this is the first report on the interaction between inflammatory responses induced by IBDV infection and pyroptosis. In addition, serine 33 was identified as the critical amino acid required for maintaining the stability of the interaction between VP3 and Caspase-9 and activation of the Caspase-9-Caspase-3-GSDME cascade pyroptosis pathway and further inflammatory responses. Collectively, our findings not only elucidate a novel mechanism by which nVarIBDV induces pyroptosis and further leads to inflammation but also suggest that the identification of this serine site may represent a potential therapeutic target to block nVarIBDV-induced inflammation and bursa of Fabricius damage.

microbiology↗

bioRxiv2025

Vitreous Inflammation as an Early Indicator of Retinal Ganglion Cell Loss Following Acute Optic Nerve Injury in Mice

Retinal ganglion cell (RGC) degeneration in optic neuropathies is often preceded by neuroinflammatory changes, yet the earliest in vivo indicators of this process remain poorly defined. Here, we identified vitreous hyperreflective foci (VHRFs) by visible-light optical coherence tomography (vis-OCT) as an early inflammatory signature of RGC injury. Longitudinal vis-OCT imaging after optic nerve crush (ONC) revealed that VHRFs emerged as early as 6 hours post-injury and peaked before the significant RGC loss. Confocal analysis showed that these VHRFs corresponded to activated amoeboid microglia undergoing vertical migration from the outer to inner retina and horizontal movement toward the optic nerve head area. Similar amoeboid microglia were also observed in the anterior segment, suggesting a global ocular inflammatory response to the ONC injury. RNAscope in situ hybridization further demonstrated elevated IL-1{beta} expression in vitreous amoeboid microglia. Moreover, pharmacological blockade of IL-1 signaling with an IL-1 receptor antagonist significantly reduced VHRFs, suppressed microglial migration, and delayed RGC loss. Taken together, our findings identify VHRFs as a previously unrecognized early danger signal for RGC degeneration and highlight IL-1-mediated inflammation as a tractable early therapeutic target for preventing RGC degeneration and vision loss. Graphical Overview O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=88 SRC="FIGDIR/small/694725v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@1598c4aorg.highwire.dtl.DTLVardef@9637borg.highwire.dtl.DTLVardef@623bf4org.highwire.dtl.DTLVardef@14e21ce_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2025

Alphaviral nonstructural protein-host RBP co-condensation as a mechanism to sustain virus replication

It has long been recognized that the intracellular replication of alphaviruses critically relies on several key host RBPs, including G3BP1/2 and FXR1/FXR2/FMR1, but how these RBPs modulate alphaviral replication and whether it would be possible to target these RBPs for antiviral treatment are less explored. Here, using SFV as a model, we report that SFV nsP3 exploits G3BP for its condensation and transforms antiviral stress granules into proviral nsP3-G3BP co-condensates. The gel-like co-condensates of nsP3 and G3BP enrich and protect viral genomic RNAs from host RNase degradation and serve as viral translational hubs to promote viral replication. The mode of nsP3-RBP co-condensation is prevalent across alphaviruses, and disruption of nsP3 condensates is an efficient antiviral approach. Thus, these findings uncover a general anti-alphavirus strategy based on the conserved reliance of nsP3-RBP co-condensation.

cell biology↗