bioRxiv Science⌕ Search

Biology subjects

Wang, S.

Publications and source records attributed to Wang, S..

At least 145 records · Page 8Linked to original sources

Singlet-states-mediated highly efficient two-photon fluorescence in organic dyes

This study reports a brand-new continuous-wave-excited (CW-excited) two-photon fluorescence emission mechanism in indocyanine green (ICG), an organic fluorescent dye widely used in clinical practice. This mechanism is based on the excited state absorption (ESA) process of the first singlet excited state. Intramolecular electrons sequentially absorb two photons to reach a high-energy singlet excited state, followed by direct radiative transition to the ground state to generate fluorescence. The entire process is exclusively mediated by singlet states. We further summarize the essential requirements for organic dyes to realize this luminescence mechanism. First, the dye must possess at least two well-separated singlet excited states with distinct energies, corresponding to two absorption peaks at different wavelengths in the absorption spectrum. The wavelength of the high-energy singlet excited state is about half that of the first singlet excited state. Second, the peak in the absorption spectrum corresponding to the transition from the ground state to the first singlet excited state has a sufficiently large molar extinction coefficient. Third, the first singlet excited state exhibits the capability of ESA. Fourth, electrons at the high-energy singlet excited state can directly transit to the ground state and emit fluorescence. We validated this mechanism in a variety of organic dyes satisfying the above conditions, confirming its universality. Using CW laser as the excitation source, we achieved two-photon fluorescence imaging of mouse cerebral blood vessels at a depth of 400 m, which clearly resolves three-dimensional vascular networks with high resolution. We also performed two-photon fluorescence imaging on human gastric cancer tissue samples at a depth of around 150 m, which provides a low-cost strategy for clinicians to rapidly acquire high-contrast tumor tissue images.

bioengineering↗

A multi-agent system for spine MRI report generation from multi-sequence imaging

Spinal pathology is a leading cause of pain and disability worldwide. Spine magnetic resonance imaging (MRI) is central to clinical evaluation, yet its interpretation remains complex and time-consuming, requiring integration of information across multiple imaging sequences and anatomical regions. Despite recent advances in automated MRI analysis, effectively combining multi-sequence data while preserving sequence-specific diagnostic information remains an open challenge. Here we present SpineAgent, a multi-agent framework for spine MRI report generation built upon a multi-sequence foundation model trained on routine clinical data from 32,047 patients and 453,683 MRI series, comprising a total of 13,441,191 MRI slices. To accommodate diverse modalities of sequences, we first pre-train two DINOv3-based encoders separately on T1- and T2-weighted sequences. We then introduce a continual training strategy that learns a synthesizer to embed images of other sequences using the T1 and T2 encoders, producing patient-level embedding that integrates various signals across MRI sequences. Using these embeddings, SpineAgent achieves state-of-the-art performance, with mean 10.8% AUROC improvement across 17 spinal condition-prediction tasks compared to the best competing method, and demonstrates strong generalizability under cross-manufacturer and cross-cohort evaluation. Beyond classification, SpineAgent enables pathology localization by identifying findings-relevant slices and segmenting pathological regions. It also supports multimodal image-report retrieval, providing a solid foundation for scalable and explainable MRI report generation. We further integrate these validated capabilities of SpineAgent into 37 specialized agents for condition diagnosis, pathological-region localization, and clinically-similar-cases retrieval. Finally, we incorporate their outputs as structured tokens within a Medical Report Agent trained end-to-end for report generation. Through both automated metrics and expert evaluation by five radiologists, SpineAgent achieves leading performance in spine MRI report generation. Together, SpineAgent introduces a continual training approach for multi-sequence spine MRI understanding. By decomposing report generation into clinically grounded subtasks addressed by specialized agents, the SpineAgent framework enables accurate, interpretable and generalizable spine MRI reporting across diverse imaging sequences and anatomical regions.

bioinformatics↗

DyMoTree decodes early cell state transitions and drivers from single-cell transcriptomes using a tree-structured neural network

Inferring early cell fate from single-cell RNA-sequencing data is essential for identifying cellular origins and fate plasticity in development and disease. However, existing methods often fail to exploit tree-structured lineage trajectories, limiting the accuracy and interpretability of fate mapping. Here we present DyMoTree, a computational framework that models cell fate decisions as nonlinear mappings between progenitor and terminal cell states under explicit lineage constraints. By integrating lineage graphs with a tree-structured neural architecture, DyMoTree learns lineage-resolved cell-state transition maps from single-cell transcriptomes, enabling robust inference of early fate bias and identification of fate-specific progenitor substates and driver genes. Across simulations, lineage-tracing experiments, and in vivo systems, DyMoTree outperformed existing methods in resolving early fate biases. Applications to mouse embryogenesis, lung adenocarcinoma progression, and CAR-T immunotherapy revealed regulatory programs underlying developmental and disease-associated transitions. DyMoTree provides a general framework for modeling lineage-resolved cell-state dynamics underlying development and disease progression. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=156 SRC="FIGDIR/small/731114v2_ufig1.gif" ALT="Figure 1"> View larger version (49K): org.highwire.dtl.DTLVardef@11e715dorg.highwire.dtl.DTLVardef@1a4c695org.highwire.dtl.DTLVardef@e98805org.highwire.dtl.DTLVardef@1e14054_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioinformatics↗

Structural basis for loop-dependent inhibition by AcrIIC1 anti-CRISPR proteins

Most known anti-CRISPR proteins exert inhibition via solitary functional pathways, and few natural Acr homologs have been reported to possess coupled inhibitory mechanisms. Here, we demonstrate that AcrIIC1Boe represses Nme1Cas9 activity through loop-coupled inhibitory effects. Beyond canonical occlusion of the HNH catalytic site, the unique extended loop of AcrIIC1Boe further perturbs sgRNA binding and restricts R-loop maturation to reinforce inhibition. Strikingly, loop deletion completely abrogated this layered inhibitory capacity, confirming that the loop is indispensable for full anti-CRISPR function. Consistently, transplantation of this functional loop into the weakly active AcrIIC1Nme1 markedly upgraded its inhibitory performance. Our findings reveal an unprecedented loop-governed coupled inhibition mode, clarify the structural basis for functional divergence within the AcrIIC1 family, and provide a modular engineering strategy for the rational design and optimization of high-potency anti-CRISPR proteins.

Molecular Biology↗

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↗

Hearing Lips and Seeing Voices After Fifty Years: A Large-Scale McGurk Illusion Dataset for Audiovisual Speech Research

Efficient face-to-face communication relies on the integration of auditory speech and visual articulatory signals. Over the past five decades, the McGurk illusion has been widely used as an index of audiovisual speech integration. However, substantial variabilities in susceptibility to the illusion across participants and speakers limit its reliability as a stable measure of audiovisual integration ability. Here, we introduce the McGurk illusion dataset (MID), which, to our knowledge, is the largest publicly available McGurk stimulus dataset to date. The MID comprises auditory (N = 400), visual (N = 400), and audiovisual (N = 640) speech stimuli generated from 80 Mandarin speakers and validated through behavioral judgments across 360,900 trials. Using this dataset, we characterized the acoustic and facial articulatory properties of McGurk stimuli, replicated substantial inter-participant and inter-speaker variabilities in illusion susceptibility, and revealed the associations between variations in McGurk illusion rate and the variations in unisensory perception, audiovisual correspondences, and speakers characteristics. Furthermore, the stimulus set enabled systematic comparisons of the reliability of different McGurk illusion-based indices of audiovisual speech integration. Overall, the MID not only provides a standardized resource for investigating audiovisual speech integration and its alterations across populations, but also supports research on speaker normalization, lip-reading, and speech perception.

neuroscience↗

Methylmalonic acid: a new target for Hadamard-edited MRS

BackgroundMethylmalonic acidemia (MMAemia) is a genetic metabolic disorder characterized by an accumulation of methylmalonic acid (MMA) and impaired energy metabolism leading to increased lactate (Lac). The signals of MMA (1.23 ppm) and Lac (1.33 ppm) overlap, making their separation using conventional MRS challenging. An MRS method to differentiate the two metabolites could enhance pathophysiological understanding and improve treatment monitoring - Hadamard-edited MRS has the potential to achieve this. PurposeTo develop a Hadamard-encoded J-difference editing approach for independent detection of MMA and Lac at 3T. MethodsA novel Hadamard-encoded editing scheme was implemented and evaluated with density-matrix simulations, phantom and in vivo experiments. The new four-step scheme uses frequency-selective editing pulses, applied at 3.2 ppm and 4.1 ppm to modulate the J-coupled methyl resonances of MMA and Lac, respectively. Hadamard combinations of the four sub-experiments yield the separate difference-edited spectra for each target metabolite. ResultsSimulations and phantom experiments clearly illustrate the separated signals of MMA and Lac. In vivo validation experiments show a Lac signal (but no MMA) in a healthy infant, and both Lac and MMA (separated into their respective Hadamard-combination spectra) in a patient with MMAemia. ConclusionHadamard-encoded editing at 3T can separate MMA and Lac signals and shows promise for studying altered metabolism in patients with MMAemia.

biochemistry↗

X-Gutor: a high-fidelity in vitro platform for long-term gut microbiome recovery

In vitro gut microbiome-culturing models are essential for studying host-microbe interactions, yet achieving high microbial recovery and long-term stability remains a long-standing challenge. Here we devise X-Gutor, an ecologically designed in vitro platform that recapitulates the monogastric digestive system with precise control of pH, redox potential, and a mucin-based biofilm matrix. Using an integrated assessment framework, microbial source tracking, a curated gut metabolism database (GutDB), and short-chain fatty acid profiling, we benchmarked gut community recovery. Building on this platform, HanGutor and PigGutor were developed to recover 96.27{+/-}4.92% and 90.48{+/-}5.95% of human and swine gut microbiota, respectively. Ecological fine-tuning revealed that redox potential drives the Prevotella-Bacteroides trade-off and that spatial biofilm structure suppresses cheater (Succinivibrio) growth. The X-Gutor provides a scalable, modular platform for gut microbiome engineering, dietary intervention, and microbiota-targeted therapy development.

microbiology↗

Light-dependent and predator inducible aldehyde synthesis in Prochlorococcus for specific defense against Uronema

Cyanobacteria as a primary producer provide energy and carbon sources for the marine food web, of which predation-interactions play central roles in regulating global element cycles and marine ecosystem stability. Here, we report the anti-predation activity of a typical marine cyanobacterium Prochlorococcus MED4 to defend the predation by Uronema marinum. MED4 synthesize formaldehyde as the anti-predation chemical, of which the synthesis was light-dependent and predator-inducible. Compared to other protists, both the higher concentration of accumulated formaldehyde in U. marinum and the lower formaldehyde tolerance of U. marinum resulted in the specific anti-predation of MED4 against U. marinum. This specific anti-predation could regulate the cyanobacterial growth and the U. marinum infection of marine fishes. Metadata analyses showed the mutually exclusion of Prochlorococcus and Uronema in global marine environments. These findings significantly advance our understanding of the marine food web and biogeochemical cycles. Significance StatementPredation-driven interactions in the ocean are critical regulators of global biogeochemical cycles, yet active defense mechanisms in marine picophytoplankton remain largely unknown. This study reveals that Prochlorococcus MED4 as the most abundant primary producer in the ocean synthesize light-driven and predator-inducible aldehydes to actively and specifically defend predation against the ciliate Uronema marinum. The anti-predation of Prochlorococcus against Uronema could have broad implications in biocontrol of Uronema infection in marine fishes and regulation of the marine food web.

microbiology↗

Gap junctions in the alimentary tract regulate reproductive span in C. elegans

Aging does not occur uniformly throughout an organism but is instead differentially regulated across distinct physiological systems. In particular, reproductive aging is often temporally distinct from somatic aging and exhibits species-specific trajectories, suggesting that different physiological functions may age independently. Here we show that mutation of inx-20, an innexin family gene encoding a gap junction component, markedly extends reproductive span, with only a minor increase in overall lifespan. Furthermore, this extension of reproductive span persists in a feminized genetic background, thereby precluding the possibility that it is driven by altered sperm dynamics. inx-20 is expressed in a specific subset of cells within the alimentary tract, and its expression is selectively repressed in a fraction of these cells during dauer diapause, suggesting a role in nutrient responses. Genetic analyses suggest that inx-20 operates via a distinct mechanism that does not intersect with the TGF-{beta} and IIS-FOXO pathways, which are established regulators of reproductive span. Collectively, our results suggest that gap junctions in the alimentary tract are a selective determinant of reproductive span, capable of extending it substantially without a commensurate effect on lifespan.

genetics↗

STITCH: Spatial Transcriptomics Imputation via Flow Matching with Internal Learning

AO_SCPLOWBSTRACTC_SCPLOWSpatial transcriptomics datasets frequently suffer from spatial gaps and missing regions due to sectioning artifacts, tissue damage, and the high cost of sequencing that limits tissue coverage. We present STITCH, a scalable and robust generative framework for multidimensional virtual spatial transcriptomics reconstruction. STITCH models intrinsic spatial-transcriptomic patterns directly from individual tissue samples, enabling reconstruction without requiring external reference atlases or matched histological image priors. The framework adopts a decoupled architecture that separates spatial morphology restoration from transcriptomic generation. STITCH first compresses high dimensional transcriptomic profiles into a low-dimensional latent representation through a spatial-aware graph autoencoder. For 3D cross-slice gaps, STITCH employs optimal transport-conditioned flow matching for spatial reconstruction, whereas 2D in-slice damage is repaired through an internal learning strategy. To generate the corresponding transcriptomic profiles, STITCH further establishes a point-wise conditional flow matching model in the latent space. This module achieves linear computational complexity, enabling continuous 3D atlas reconstruction of over 11 million cells within 5 hours on a single commodity GPU. Extensive evaluations across diverse spatial transcriptomics platforms, spanning both single-cell and spot-level technologies, demonstrate that STITCH consistently preserves transcriptomic identities, spatial topologies, and anatomical continuity. Overall, STITCH provides a scalable and platform-compatible computational framework for reconstructing high-resolution continuous spatial transcriptomic atlases.

bioinformatics↗

DNA remodeling couples target recognition to directional transposition in a Tn7-like CAST

CRISPR-associated transposons (CASTs) couple target recognition to the insertion of large DNA cargoes, but how distinct targeting pathways are converted into productive and directional integration remains poorly understood1. Here we define the assembly pathway of a type I-B1 CAST from Anabaena variabilis, a system closely related to prototypical Tn7 that retains TnsD-mediated glmS recognition while incorporating CRISPR-based RNA-guided targeting2. Cryo-electron microscopy structures across multiple intermediates define a structural trajectory from two-step TnsD-mediated target recognition and stepwise assembly of the AAA+ ATPase TnsC to recruitment and activation of the split TnsA/TnsB transposase module. This trajectory culminates in an asymmetric strand-transfer complex that provides a structural basis for insertion orientation and supports a role for ATP hydrolysis in productive transpososome assembly. In parallel, RNA-guided targeting structures refine the functional PAM to ATG, define TniQ recruitment by Cascade, and show how CRISPR-based recognition converges on the shared TnsABC machinery. Together, these findings establish DNA remodeling and minor-groove positioning of TnsC as a common structural signal that converts protein- and RNA-guided target recognition into directional DNA insertion.

biochemistry↗

Digital Chromosome Banding Reveals Distinct Spatiotemporal Dynamics and Sexual Dimorphism in Meiotic Silencing

In mammals, meiotic silencing of unsynapsed chromatin (MSUC) is initiated by the DNA damage response (DDR) pathway, as marked by {gamma}H2AX. During normal male meiosis, MSUC is restricted to the unsynapsed sex chromosomes, a process known as meiotic sex chromosome inactivation (MSCI). While the initiation of MSCI has been well studied, its full silencing dynamics and underlying structural mechanisms remain unclear. In contrast to MSCI, broader MSUC can occur on autosomes in response to synapsis failure, but its cell-to-cell variability obscures its quantification. To address these challenges, we introduce "digital-chromosome-banding", a single-cell-based approach that allows quantitative analysis of MSCI and MSUC at chromosomal resolution. Using this approach, we identified two distinct silencing transitions during MSCI, occurring from zygonema to early pachynema and from early to mid-pachynema. The latter step coincides with mature sex body formation and involves a gel-like diffusion barrier to enforce transcriptional repression. Applying this approach to synapsis-defective mouse models (Spo11-/-, Tardbp cKO, and Nelfb cKO), we observed divergent MSUC patterns that correlate with the severity of asynapsis. Comparative analysis between sexes also uncovered notable sexual dimorphisms in meiotic silencing. Together, our data provide a quantitative framework to dissect the spatiotemporal dynamics and sexual differences of meiotic silencing.

cell biology↗

Decoding Hierarchical Cell-Cell Communication in Spatial Multi-Omics with CellSTIC

Cell-cell communication coordinates tissue development, homeostasis, and immunity, yet defining signaling interactions within intact tissues remains challenging. Single-cell transcriptomics enables systematic ligand- receptor inference, but tissue dissociation removes spatial context and obscures local and region-specific signaling. Spatial transcriptomics and spatial multi-omics can recover communication in situ, although existing methods often incompletely integrate heterogeneous data or produce poorly interpretable ligand-receptor lists. Here we present CellSTIC, a framework that resolves cell-cell communication in spatial multi-omics as structured programs grounded in tissue architecture. CellSTIC integrates multimodal evidence from local neighborhoods and organizes interactions into a hierarchical semantic representation that remains traceable to underlying molecules. This enables analysis from individual ligand-receptor pairs to functional modules comparable across tissues, regions, and states. In simulations and diverse tissue datasets, CellSTIC recovered spatially coherent communication structures and domains, revealing immune, brain, developmental, and regenerative programs, and providing a general approach for generating mechanistic hypotheses in situ. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=81 SRC="FIGDIR/small/728114v2_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@a04e82org.highwire.dtl.DTLVardef@826435org.highwire.dtl.DTLVardef@81092dorg.highwire.dtl.DTLVardef@1818e8b_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioinformatics↗

Gut Microbiota Dysbiosis Drives Myocardial Hypertrophy Through GBP2b/GBP1-Mediated Immune Reprogramming and Exosomal Signaling in Chronic Colitis

BACKGROUNDPatients with inflammatory bowel disease (IBD) are at increased risk of cardiovascular disease, yet the mechanisms linking chronic intestinal inflammation to cardiac dysfunction remain poorly understood. IBD is characterized by profound gut microbiota dysbiosis, which we hypothesize drives systemic immune dysregulation and contributes to cardiac dysfunction. METHODSA chronic colitis mouse model was used to assess gut microbiota dysbiosis, systemic immune cell metabolism, and cardiac remodeling. Cardiac outcomes were evaluated by echocardiography, histology, and molecular analyses. Mechanisms were examined using fecal microbiota transplantation, immune cell depletion, exosome transfer, bone marrow chimeras, RNA-seq, co-immunoprecipitation, confocal microscopy, and siRNA-mediated gene silencing. RESULTSChronic DSS colitis induced cardiac dysfunction, hypertrophy, and fibrosis in mice. These changes were accompanied by sustained gut microbiota dysbiosis, metabolic reprogramming, and mitochondrial dysfunction in circulating immune cells. Fecal microbiota transfer experiments demonstrated that colitis-associated microbiota were sufficient to reprogram systemic immune cells and promote cardiac dysfunction. Immune cell depletion studies identified macrophages as key mediators of colitis-associated cardiac injury. Colitis increased systemic lipopolysaccharide (LPS) translocation, bone marrow chimera experiments demonstrated that hematopoietic TLR4 signaling was required for immune cell metabolic remodeling and cardiac dysfunction during chronic colitis. Transcriptomic analysis identified guanylate-binding protein 2b (GBP2b/GBP1, hereafter referred to as GBP1) as a key downstream effector of LPS-TLR4 signaling. Upon LPS stimulation, GBP1 localized to mitochondria, where it interacted with DRP1 and FIS1 to promote mitochondrial fission, oxidative stress, and enhanced immune cell migration into the heart. In addition, GBP1 was secreted via exosomes, which were taken up by cardiomyocytes and contributed to hypertrophic remodeling, and cardiac dysfunction. CONCLUSIONSThese findings establish the LPS-TLR4-GBP1 axis as a key driver of colitis-associated cardiovascular dysfunction and highlight this pathway as a promising therapeutic target for reducing cardiovascular risk in patients with IBD. Novelty and SignificanceO_ST_ABSWhat Is Known?C_ST_ABSO_LIPatients with inflammatory bowel disease have an increased risk of cardiovascular dysfunction that cannot be fully explained by traditional cardiovascular risk factors. C_LIO_LIGut microbiota dysbiosis and chronic innate immune activation are hallmarks of inflammatory bowel disease, but their direct contribution to cardiac remodeling remains unclear. C_LI What New Information Does This Article Contribute?O_LIChronic colitis-associated gut microbiota dysbiosis induces systemic immune cell metabolic and mitochondrial reprogramming that is sufficient to drive cardiomyocyte hypertrophy and cardiac dysfunction. C_LIO_LIHematopoietic Toll-like receptor 4 signaling links colitis associated gut microbiota to immune metabolic dysfunction and cardiac impairment, establishing a causal gut-immune-heart axis. C_LIO_LIGuanylate-binding protein 2b (GBP2b/GBP1) is identified as a critical downstream effector that promotes mitochondrial fission, oxidative stress, immune cell cardiac infiltration, and exosome-mediated cardiac remodeling. C_LI

pathology↗

A Sandwich-Structured Silk Fibroin Mesh with ROS-Responsive and Immunoregulatory Functions for Pelvic Floor Repair

Current biodegradable meshes for pelvic floor repair are constrained by a limited ability to actively modulate the hostile immune microenvironment following implantation. To address these challenges, we developed a functionalized degradable silk fibroin mesh (SFM) integrated with a reactive oxygen species (ROS)-responsive nanocomposite hydrogel. The resulting composite mesh, SFM@Gel-NP, features a "hydrogel-mesh-hydrogel" sandwich structure, wherein the hydrogel layers are loaded with self-assembled nanoparticles (NP-H-CRFP) for the co-delivery of the STING inhibitor H-151 and the ROS-scavenging agent catechin. This design provides immediate mechanical reinforcement while enabling microenvironment-triggered drug release. In vitro, NP-H-CRFP demonstrated efficient cellular uptake, significant ROS clearance, and effective attenuation of macrophage inflammation and apoptosis. In vivo, SFM@Gel-NP remodeled the local immune milieu by inhibiting the ROS/cGAS-STING/NF-{kappa}B axis, thereby promoting a shift from pro-inflammatory M1 toward pro-regenerative M2 macrophage polarization. This immunomodulatory effect, coupled with enhanced and well-organized collagen deposition--particularly of early type III collagen--resulted in improved tissue integration and repair. This work presents a novel strategy that combines structural reinforcement with active immune regulation, offering a promising next-generation solution for durable and functional pelvic floor reconstruction.

bioengineering↗

Circadian misalignment underlies immune escape in breast cancer

Circadian regulation shapes tissue physiology, yet how it organizes cellular and molecular dynamics within the tumor microenvironment (TME) and influences tumor immunity remains unclear. Using temporal single-nucleus multiomic profiling of mouse breast tumors, we uncovered extensive circadian programs that are both cell-type-specific and shared across the TME, governing proliferation and immune responses. Notably, cancer epithelial cells exhibited global acrophase misalignment relative to immune populations. This intercellular desynchrony manifests as temporal decoupling between tumor proliferation and immune activation, discordant antigen presentation and T cell recognition with intrinsic activation-exhaustion overlap in T cells, and asynchronous PD-1/PD-L1 oscillations that sustain checkpoint-mediated suppression. Similar patterns were observed in human triple-negative breast cancer (TNBC). Together, these findings establish intercellular circadian misalignment as a mechanism of tumor immune evasion and position the circadian architecture of the tumor-immune ecosystem as a previously underappreciated determinant of tumor development and therapeutic response. HIGHLIGHTSO_LISingle-cell multiomics maps circadian regulation of tumor-immune programs. C_LIO_LICircadian regulation in cancer epithelial cells is misaligned with immune cell populations. C_LIO_LITumor-immune temporal misalignment undermines antitumor immunity. C_LIO_LICircadian misalignment in human TNBC suggests relevance for immunotherapy timing. C_LI

cancer biology↗

Microinjection-based Single-Cell Toxicological Assessment Reveals How Physiological Levels of PFOS Impair Oocyte Maturation and Developmental Competence

Perfluorooctanesulfonic acid (PFOS) is a persistent environmental contaminant widely detected in human serum and follicular fluid and has been associated with reduced implantation rates and female fertility. However, its direct effects on mammalian oocyte maturation remain poorly understood. Here, we developed a microinjection-based single-oocyte toxicological assay to directly evaluate how physiologically relevant PFOS concentrations affect mouse oocyte maturation and early embryonic development. Microinjection of PFOS at follicular-fluid level (5.6 nM) and occupational exposure level (60 nM) significantly reduced germinal vesicle breakdown (GVBD) and polar body extrusion (PBE) rates compared with water-injected controls. Notably, all tested concentrations (2.4 nM serum level, 5.6 nM, and 60 nM) induced abnormal polar-body formation, disrupted meiotic spindle morphology, and increased the proportion of unhealthy oocytes. PFOS exposure also significantly elevated intracellular reactive oxygen species (ROS) levels and mitochondrial membrane potential at 5.6 nM, indicating oxidative stress and mitochondrial dysfunction. Cytological analyses revealed chromosome misalignment and widened metaphase I plates, suggesting chromosome missegregation and subsequent prometaphase II arrest with defective polar bodies. Single-cell RNA sequencing of PFOS-treated oocytes exhibiting abnormal small polar bodies identified distinct transcriptional signatures, including dysregulation of genes involved in mRNA processing, chromosome segregation, mitochondrial function, and cell division. Functionally, these oocytes failed to progress beyond the 2-cell stage following in vitro fertilization, indicating loss of developmental competence. Collectively, these findings demonstrate that PFOS directly disrupts meiotic progression through spindle defects, oxidative stress, and transcriptional dysregulation, ultimately compromising oocyte quality even at environmentally relevant exposure levels. Environmental ImplicationPFOS is a persistent environmental contaminant widely detected in human serum and follicular fluid. Our findings demonstrate that PFOS at physiologically relevant levels can impair oocyte maturation, disrupt meiotic chromosome segregation, and compromise early embryonic development. By using a single-oocyte toxicological assay, we reveal that even low-dose PFOS exposure can induce oxidative stress and transcriptional dysregulation. These results highlight the potential reproductive risks of chronic PFOS exposure and underscore the importance of stricter environmental monitoring and regulation to protect female reproductive health and fertility. This novel assay also has the potential to redefine safety thresholds for other environmental toxicants.

cell biology↗