Biology subjects

Chen, D.

Publications and source records attributed to Chen, D..

At least 55 records · Page 3Linked to original sources

bioRxiv2026

A phage-encoded small RNA that mimics chimeric guide to inhibit CRISPR-Cas9

CRISPR-Cas9 relies on a dual crRNA-tracrRNA guide, yet whether RNA-based anti-CRISPRs exist for this system has remained unknown. Here we identify a phage-encoded small non-coding RNA, rAcrIIA1, that adopts an unexpected chimeric crRNA-tracrRNA architecture, faithfully recapitulating the entire single-guide RNA (sgRNA) of Cas9. Cryo-EM structures of the Cas9-rAcrIIA1 binary complex and the Cas9-rAcrIIA1-DNA ternary complex reveal that rAcrIIA1 engages Cas9 nearly identically to the native sgRNA, competitively blocking crRNA and tracrRNA loading and thereby abolishing DNA interference. Strikingly, beyond its natural inhibitory function, rAcrIIA1 is fully reprogrammable: with variable guide sequences, it directs Cas9 for sequence-specific DNA cleavage with efficiency comparable to the canonical sgRNA, and it activates trans-cleavage more potently. Thus, rAcrIIA1 provides the first experimentally validated, mechanistically resolved RNA-based inhibitor of CRISPR-Cas9, reveals a distinct anti-CRISPR mechanism through complete sgRNA mimicry, and serves as a versatile bifunctional scaffold for genome editing and diagnostics.

biochemistry↗

bioRxiv2026

Closed-loop auditory stimulation during sleep shapes cortical responses and memory consolidation depending on spindle timing

Sleep spindles contribute to memory consolidation, and acoustic stimulation during sleep can modulate spindle activity. However, it remains unclear whether these effects depend on the timing of stimulation relative to the spindle cycle. Using closed-loop spindle detection, we delivered four variants of pink noise either during ongoing spindles or shortly after spindle offset. In Experiment 1, stimulation delivered during a spindle prolonged its duration, whereas stimulation applied shortly after spindle offset, i.e., within the refractory period, delayed the onset of the subsequent spindle. This pattern was consistent across all sound variants, indicating that the stimulation timing, rather than acoustic properties, drove the observed effects. Experiment 2 examined whether post-spindle stimulation influences memory consolidation. Relative to a no-stimulation nap, post-spindle stimulation reduced post-nap deterioration in motor sequence accuracy but did not significantly affect word-pair recall. EEG analyses revealed that stimulation elicited widespread slow oscillation activity without triggering new spindles, demonstrating that cortical processing of external input persists even during the refractory period. Notably, the motor benefit was greatest in participants with lower spindle density during the baseline adaptation nap. Together, these findings challenge the notion that the post-spindle refractory period is a functionally silent interval. Instead, this period remains receptive to external input, capable of eliciting cortical activity and supporting motor memory consolidation even in the absence of new spindle generation.

neuroscience↗

bioRxiv2026

FLASH reduces radiation-induced oral mucositis in a mouse model of Fanconi anemia

Patients with Fanconi anemia (FA) are particularly susceptible to developing squamous cell carcinoma of the head and neck due to impaired DNA repair pathways. However, their hypersensitivity to DNA damaging agents can limit effective treatment with standard radiotherapy due to severe side effects and complications. In pre-clinical models, ultra-rapid FLASH radiotherapy (FLASH) reduces radiation-induced toxicity in normal tissues while maintaining similar tumor control compared to conventional dose rate radiotherapy (CONV). Here, we investigated the safety of FLASH for treatment of the head and neck in a mouse model of FA. 129/Sv wild-type (WT) and Fanca-deficient (Fanca-/-) mice received single-dose oral cavity irradiation with electron beam FLASH or CONV to evaluate radiation-induced toxicity in non-tumor-bearing mice. Fanca WT and Fanca-/- mice were irradiated with 25 and 18 Gy, respectively, of FLASH (190 Gy/sec) or CONV (0.2 Gy/sec), with tongues harvested at 12 hours (hpi) and 10 days (dpi) post-irradiation. At 10 dpi, FLASH-irradiated tongues in both genetic backgrounds demonstrated reduced ulceration at the dorsal tongue surface compared to CONV-irradiated counterparts. Histopathological analysis of the tongue revealed lower mucositis severity scores with decreased epithelial thinning and ulceration in FLASH-irradiated tongues compared to CONV-irradiated ones. Analysis of {gamma}-H2AX foci formation at 12 hpi demonstrated fewer foci in WT mice treated with FLASH compared to CONV, with a similar trend observed in Fanca-/- mice. These findings suggest a potential normal tissue-sparing effect with FLASH and hold important clinical implications for the treatment of patients with Fanconi anemia and head and neck cancers.

cancer biology↗

bioRxiv2026

Glucose selectively drives a rapid oxidative burst and immunometabolic reprogramming in human neutrophils during Mycobacterium tuberculosis infection

Neutrophil functions have been linked to tuberculosis (TB)-associated tissue damage; however, the mechanisms driving immunopathology in the human TB lung remain poorly understood, due partly to the scarcity of human tissue for study. Here, we examine the metabolic and bioenergetic reprogramming of human neutrophils in response to Mycobacterium tuberculosis (Mtb) infection. In human necrotic TB granulomas, levels of NETosis-associated proteins are increased and co-localize with GLUT3, linking nutrient uptake to tissue damage. In vitro, Mtb elicits an immediate, contact-dependent oxidative burst in human neutrophils, and the magnitude of this response is carbon source-dependent. Glucose enables the most robust responses, indicating that glucose metabolism is a key driver of neutrophil-mediated inflammatory damage during TB. Mtb-induced responses are distinct from those induced by PMA, non-tuberculous mycobacteria, or other pathogenic intracellular bacteria, and are mediated through multiple neutrophil surface receptors. Notably, our data show that while the oxidative burst is carbon source-dependent, cytokine production is not. Further, Mtb infection reprograms neutrophil metabolism from glycolysis to the pentose phosphate pathway (PPP), generating NADPH required for the oxidative burst. Inhibiting G6PD, NADPH oxidase, or PAD4 significantly reduces this response, highlighting the PPP as a promising host target for mitigating TB immunopathology.

microbiology↗

bioRxiv2026

The discovery of missing taxane C13α-O-deacetylases re-delineates the biosynthetic pathway of paclitaxel

The prevalence of naturally occurring C13-acetoxy taxanes, together with the presence of a native C13-acetyltransferase in yew trees, suggests that the natural biosynthetic pathway for paclitaxel may involve a cryptic C13-O-deacetylation step. However, whether a putative taxane C13-O-deacetylase (T13dA) acts in the pathway of paclitaxel biosynthesis remains elusive. Herein, we functionally characterized two novel taxane C13-O-deacetylases (T13dA1 and T13dA2) from Taxus x media cell cultures, providing experimental evidence for the molecular and biochemical plausibility of C13-O-deacetylation in paclitaxel biosynthesis in Taxus species. Furthermore, T7dA1, a novel taxane C7{beta}-O-deacetylase with higher activity than the reported T7dA was discovered and characterized here. Notably, we reconstituted a new 19-gene pathway enabled by the integration of a C13-O-acetylation-deacetylation module for the de novo biosynthesis of baccatin III in Nicotiana benthamiana leaves, reaching a yield of 71{square} g{square} g-1 DW, much higher than that obtained from the 17{square} gene pathway lacking this module. These findings not only demonstrate the functional importance of the C13-O-acetylation-deacetylation module as a branch within the paclitaxel biosynthetic network, but also expand the multi-branched taxane metabolic network in Taxus and provide novel enzymatic tools and engineering strategies to facilitate heterologous pathway reconstitution and efficient paclitaxel production.

biochemistry↗

bioRxiv2026

MatriSpace: Identification and visualization of spatially resolved ECM gene expression patterns in health and disease

The extracellular matrix (ECM) is a highly dynamic network of proteins forming the structural organizer of all tissues. Different cell populations contribute to the assembly of the 150+ proteins of a functional ECM. In addition, different ECM subtypes, supporting distinct cellular functions, are found in every organ. Spatial transcriptomics (ST) provides a unique, yet untapped, opportunity to identify which cell populations contribute to ECM production with spatial context. Applied to healthy and diseased samples, this method can identify ECM changes that could be exploited for therapeutic purposes. Here, we introduce MatriSpace, a computational framework to mine ST datasets with a focus on ECM genes. MatriSpace offers two operating modes: researchers can either upload their own ST datasets or explore a large collection of public datasets. Upon analysis, MatriSpace returns spatially resolved maps of matrisome gene expression in relation to cell populations, at multiple levels: from single-gene analysis to tissue niches and functional ECM units. MatriSpace is available as an R package and an online Shiny App (https://matrinet.shinyapps.io/matrispace), making it accessible to all users regardless of their level of expertise. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=97 SRC="FIGDIR/small/720198v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@3f8e28org.highwire.dtl.DTLVardef@8e20beorg.highwire.dtl.DTLVardef@107be22org.highwire.dtl.DTLVardef@153b911_HPS_FORMAT_FIGEXP M_FIG C_FIG KEY POINTSO_LIMatriSpace is a computational framework to interrogate ECM gene expression in spatial transcriptomic datasets. C_LIO_LIResearchers can upload their own spatial transcriptomic datasets for processing by MatriSpace. C_LIO_LIResearchers can interrogate a vast collection of public datasets of healthy and diseased tissues through MatriSpace. C_LIO_LIMatriSpace can identify, quantify, and interpret spatial expression patterns of matrisome genes, gene sets, and niches. C_LIO_LIMatriSpace can uncover regional coordinations of matrisome components and their relationships with non-matrisome genes, such as matrisome receptors. C_LI

systems biology↗

bioRxiv2026

Proteome-aware organ proxy aging clocks

The development of minimally invasive multi-organ aging clocks, established through the deconvolution of plasma proteomics, has provided a convenient tool to assess the organ heterogeneity of aging. However, prior studies relied on bulk transcriptomic data for organ marker identification, which may lead to the potential misidentification of protein markers, and their research scope was largely confined to a few common diseases. To address these limitations, this study integrated multi-dimensional data to refine organ-enriched marker panels by incorporating organ-specific proteome information, and developed Proteome-Aware Organ Proxy Proteome Aging Clock (PAOPAC). PAOPAC exhibited decelerated biological age corresponding to improved physiological phenotypes across two independent external datasets, demonstrating its generalizability. We then leveraged PAOPAC to generate a comprehensive disease-aging landscape and to investigate the process of chronological and biological aging. Our analyses revealed that the majority of diseases are associated with an accelerated aging phenotype.

systems biology↗

bioRxiv2026

Dysregulated tissue-resident lymphocytes drive age-associated emphysema by impairing alveolar regeneration

Aging is often associated with progressive tissue degeneration and chronic inflammation, yet the role of immune cells in mediating structural and functional decline in organs remains poorly defined. Here, we investigated immune-tissue interactions in the aged lung and identified emphysematous remodeling characterized by alveolar loss. Notably, aged lungs exhibited a marked expansion of tissue-resident lymphocytes (TRLs) with senescent features, accompanied by a significant reduction in alveolar stem/progenitor cell (AT2) abundance. In vivo adoptive T cell transfer and 3D immune-stem cell organoid assays revealed that these expanded TRLs suppressed AT2 growth via secretion of oncostatin M and interferon gamma. In vivo blockade of IL-7 receptor (IL-7R) reduced TRL accumulation in the lungs and ameliorated age-related emphysematous changes, including restoration of alveolar density. Our findings identify TRLs as key drivers of alveolar degeneration in aging and propose IL-7R inhibition as a therapeutic strategy to mitigate pulmonary decline. TeaserBlocking IL-7R clears harmful lymphocytes and helps rebuild the damaged air sacs of the aging lung.

cell biology↗

bioRxiv2026

XIST Is a Key Modulator Associated with the Adhesome Network

A long non-coding RNA (lncRNA) known as the X-inactivation specific transcript (XIST) plays a central role in X chromosome inactivation - a transcriptional process that silences one of the two X chromosomes in females to ensure dosage compensation between males and females. Much research has been conducted on how XIST regulates X chromosome transcription critical to embryonic development, but recent studies suggest a non-canonical role for XIST in regulating cancer stem cells and cellular plasticity. As cell adhesion and adhesome genes are integral to the regulation of cancer stemness, we explored the previously unrecognized link between XIST and the adhesome network. By performing gene expression and gene ontology analysis on XIST-knockdown ovarian cancer cells, our study showed that XIST loss altered adhesome gene expression and downstream adhesion pathways. Using Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) datasets, we identified distinct correlations between XIST lncRNA and adhesome genes across normal and cancer tissue samples, which are associated with cell stemness. Furthermore, network analysis suggests that XIST may interact with specific adhesome genes within the cell nucleus. This interaction may have significant functional implications, as demonstrated by the hazard ratio analysis of XIST and adhesome gene expression in relation to clinical outcomes. Overall, our results show that among well-annotated functional lncRNAs, XIST appears to be a modulator strongly associated with the adhesome network and cell stemness. Our findings thus support a novel link between lncRNA-mediated epigenetic regulation of cell adhesion genes, highlighting XIST as a key regulator contributing to the adhesome network. Significance StatementThis study identified that XIST, a long non-coding RNA essential for X-chromosome dosage compensation and embryonic development, plays a significant role in modulating the adhesome network. We found that XIST knockdown affected adhesion pathways in ovarian cancer cells, whereas XIST expression is strongly correlated with adhesome gene expression across all tissues. We observed that the interaction between XIST and adhesome genes changes significantly between tumors and normal tissues, and this altered interaction is associated with certain cancer outcomes. These findings reveal a possible link between lncRNA-mediated regulation and adhesome control that is associated with cell stemness signatures and the emergence of cancerous tissues.

cell biology↗

bioRxiv2026

GenNA: Conditional generation of nucleotide sequences guided by natural-language annotations

Deciphering the mapping between linear biomolecular sequences and complex biological functions remains a central challenge in genomics. Although existing generative nucleotide language models have made substantial progress in modeling sequence distributions, they generally lack explicit access to high-level biological semantics, limiting their ability to support semantics-guided conditional generation. To address this limitation, we present GenNA, a generative nucleotide foundation model guided by natural-language annotations. GenNA is pretrained on a multimodal nucleotide-text corpus spanning 2,221 eukaryotic species and comprising approximately 416 billion characters, and learns the relationships between sequence patterns and functional annotations within a unified autoregressive framework. Systematic evaluations show that, even without explicit supervision from biological rules, GenNA yields distinguishable perplexity scores in response to semantic mismatches between sequences and functional annotations, to different mutation types, and to perturbations of species labels. Moreover, across a range of natural-language-guided nucleotide generation tasks, the model produces sequences consistent with both target semantics and species context. Overall, GenNA provides a unified framework for natural-language-guided nucleotide modeling and conditional generation, and offers a feasible route toward integrating high-level functional descriptions with low-level sequence design.

bioinformatics↗

bioRxiv2026

OneGenomeRice (OGR): A Genomic Foundation Model for Rice

The transition of genomics to a predictive intelligence discipline is driven by the advent of genomic foundation models. While substantial progress has been observed in all-life and human-centric models, plant species, particularly for the staple crops, remains hindered by a lack of models. Here we introduce OneGenome-Rice (OGR), a rice (Oryza sativa) genomic foundation model pre-trained on a genomic dataset comprising 422 high-quality genomes of cultivated and wild rice. OGR is engineered upon a Mixture of Experts (MoE) transformer architecture with 1.25-billion parameters and supports an ultra-long context window of up to 1 million base (Mb) pairs at single-nucleotide resolution. A comprehensive benchmark demonstrated that OGR significantly outperforms existing state-of-the-art multi-plant or all-life genome models in 11 categories (e.g. motif identification, sweep detection, etc). We further demonstrated the utility of OGR in several downstream applications, such as indica-japonica subspecies introgression analysis, identification of agronomy trait-associated functional loci and prediction of gene expression from DNA sequences. These results establish OGR as a promising foundational computational infrastructure for rice functional genomics and precision breeding. The OGR and its fine-tuned models, including pretrained weights, training code and the rice genomic benchmark suit, have been fully opened.

genomics↗

bioRxiv2026

FXR and BET signaling orchestrate to protect β cells

In both type 1 and type 2 diabetes (T1D and T2D), insulin-producing {beta} cells undergo progressive dysfunction due to inflammation, leading to impaired glucose responsiveness, dedifferentiation, and cell loss. While bile acid (BA) dysregulation under diabetic conditions is known to influence metabolic and inflammatory pathways, its mechanistic role in {beta} cell regulation remains incompletely defined1-3. Here we show that bile acid sensor Farnesoid X receptor (FXR) and Bromodomain and Extra-Terminal motif (BET) signaling cooperatively regulates {beta} cell inflammatory response and {beta} cell identity. We identified the physiological protein-protein interaction between FXR and the bromodomain-containing protein 4 (BRD4) as a regulatory axis that protects against {beta} cell dysfunction. We show that FXR activation by Fexaramine (Fex) together with BRD4 inhibition by JQ1 synergistically suppressed IL-1{beta}-induced inflammation while also improving {beta} cell identity and insulin secretion in both db/db model and high-fat diet (HFD) plus multi low-dose streptozotocin (MLD-STZ) model of diabetes. Importantly, this cooperative effect is abolished in {beta} cell-specific FXR knockout ({beta}FXRKO) mice, establishing that FXR is required for the functional synergy between these pathways in vivo. Mechanistically, structure-guided modeling and mutational analyses identified a direct interaction between FXR and the BD2 domain of BRD4, depending on specific lysine acetylation sites. Additionally, inhibition of the BD2 domain of BET combined with FXR activation markedly improved {beta} cell survival in human T1D and T2D models established from human pluripotent stem cell (hPSC)-derived islet-like organoids (HILOs). Collectively, these findings establish a BA-bromodomain axis as a transcriptional interface linking metabolic signaling and chromatin regulation, and highlight FXR-BET targeting as a promising strategy to counter progressive {beta} cell failure in diabetes.

molecular biology↗

bioRxiv2026

Endocytosis at the mouse blood brain barrier is elevated during sleep

Sleep is thought to be important for the clearance of brain waste, but exactly how it does so is still debated. Here, we demonstrate that endocytosis in brain endothelial cells (BECs) of the blood-brain barrier (BBB) is enhanced during sleep, facilitating the removal of brain-derived waste, including amyloid-{beta}, into the circulation. Using proteomics, in vivo tracer imaging, and endothelial-specific genetic perturbations in mice, we demonstrate that sleep enhances endocytic vesicle formation and cargo transcytosis in brain endothelial cells (BECs). Conversely, blocking endocytosis through endothelial Dnm2 knockout suppresses BEC-mediated transport and elevates sleep need, revealing a causal feedback loop between sleep and vascular endocytosis. These findings identify BBB endocytosis as a key sleep-dependent clearance pathway with implications for neurodegenerative disease.

neuroscience↗

bioRxiv2026

A NOD2-Encoded Toggle Switch Resolves the Host-Microbe Battle Over Cyclic AMP Control

Pathogens hijack macrophages by triggering pathological cAMP surges that block phagolysosomal killing--a defect mirrored in phagocytes from refractory colitis. We identify a host-encoded, pathogen-specific surge-protector comprised of a three-protein toggle: The innate sensor NOD2 binds and masks an evolutionarily conserved motif in GIV that activates trimeric-GTPase Gi, enforcing a biphasic surge-to-plunge cAMP-program: early, NOD2*GIV assembly permits a brief, tolerogenic cAMP rise, whereas subsequent GIV*Gi engagement collapses cAMP to drive phagolysosomal fusion and microbial clearance. Structural, biochemical, and ultrastructural analyses reveal how molecular toggling imposes precise spatial and temporal control. Pharmacogenomic perturbations pinpoint cAMP-PKA hyperactivation as the defining lesion in GIV-deficient macrophages. Functional studies in primary macrophages and human gut organoid co-cultures show that toggling the NOD2*GIV*Gi-axis is necessary and sufficient to convert tolerant macrophages into microbicidal machines that preserve mucosal barrier integrity. These findings uncover a druggable cAMP-control pathway with therapeutic promise in colitis. GRAPHIC ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/715116v1_ufig1.gif" ALT="Figure 1"> View larger version (70K): org.highwire.dtl.DTLVardef@53cd40org.highwire.dtl.DTLVardef@1c83c82org.highwire.dtl.DTLVardef@fcbc58org.highwire.dtl.DTLVardef@b14f8e_HPS_FORMAT_FIGEXP M_FIG C_FIG eTOC BlurbPathogens hijack macrophages by inducing cAMP surges that help them evade clearance. Anandachar et al. identify a host "toggle switch" in which NOD2 and G proteins compete for GIV, driving a rapid and robust surge-to-plunge transition in cAMP. This temporal switch limits tolerogenic signaling, restores microbial clearance and barrier integrity, and unveils a targetable host pathway in infection and IBD. HighlightsO_LIPathogens exploit cAMP surges in macrophages to block phagolysosomal killing of microbes C_LIO_LIGIV acts as a molecular "toggle" linking NOD2 sensing to Gi-mediated cAMP control C_LIO_LIStructural and mutagenesis studies reveal mutually exclusive binding of NOD2 and Gi to GIV C_LIO_LIPharmacogenomic perturbations pinpoint PKA, not EPAC, as the critical downstream effector C_LIO_LIOrganoid co-cultures show NOD2-GIV-PKA crosstalk safeguards microbial clearance and gut barrier integrity C_LI

immunology↗

bioRxiv2026

Probiotic Lactiplantibacillus plantarum VB165 improves metabolic disorders in Insulin-Resistant Mice

This study investigated the effects of Lactiplantibacillus plantarum VB165, a probiotic strain with intrinsic -glucosidase inhibitor (AGI) activity, on metabolic disorders in high-fat diet (HFD)-induced insulin-resistant (IR) mice. Male C57BL/6 mice were divided into four groups: normal control diet (NCD), NCD supplemented with VB165, HFD, and HFD supplemented with VB165. After 16 weeks, VB165 supplementation significantly attenuated HFD-induced weight gain and reduced epididymal and inguinal white adipose tissue indices. VB165 also improved glucose intolerance and insulin resistance (IR), as demonstrated by oral glucose tolerance tests (OGTT) and insulin tolerance tests (ITT), and lowered fasting blood glucose, fasting insulin, and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) levels. Additionally, it ameliorated dyslipidemia by reducing serum total cholesterol, triglycerides, and low-density lipoprotein cholesterol (LDL-C), while alleviating hepatic steatosis and adipocyte hypertrophy. Mechanistically, VB165 enhanced intestinal barrier function by upregulating tight junction proteins (ZO-1 and Occludin), reduced systemic inflammation by lowering LPS, IL-6, and IL-1{beta}. Gut microbiota analysis revealed that VB165 modulated community composition, suppressing HFD-enriched genera (e.g., Ileibacterium and Coriobacteriaceae_UCG_002) and promoting beneficial taxa (e.g., Faecalibaculum and Oscillibacter). These findings demonstrate that L. plantarum VB165 improves HFD-induced metabolic disorders via multi-target mechanisms, highlighting its potential as a probiotic intervention for IR and related metabolic diseases.

microbiology↗

bioRxiv2026

Metabolic adaptation to maternal hyperglycemia via ACLY-dependent acetyl-CoA production drives epigenetic remodeling and dysregulated placental development

AbstractsGestational diabetes mellitus (GDM) is a common metabolic complication of pregnancy that is paradoxically associated with both fetal overgrowth and fetal growth restriction (FGR). While maternal hyperglycemia is widely presumed to drive macrosomia through excessive nutrient supply, the mechanisms underlying FGR remain poorly understood. Here, using a mouse model that recapitulates the small-for-gestational-age (SGA) phenotype observed in human GDM pregnancies, we identify placental underdevelopment as a principal driver of FGR. Despite systemic nutrient abundance, hyperglycemic placentas exhibit reduced mass and an increased fetal-to-placental weight ratio, indicative of placental insufficiency. Mechanistically, maternal hyperglycemia induces anabolic metabolic rewiring while suppressing oxidative phosphorylation (OXPHOS), accompanied by upregulation and nuclear redistribution of ATP-citrate lyase (ACLY). ACLY converts glucose-derived carbon into acetyl-CoA in the cytosol and nucleus, thereby coupling glycolytic flux to lipid and hexosamine biosynthesis as well as to global histone hyperacetylation. This hyperacetylation-associated epigenetic reprogramming activates metabolic, innate immune, and inflammatory gene programs while repressing pro-proliferative and anti-apoptotic pathways. Consequently, placental growth is compromised despite nutrient excess. Importantly, activation of the ACLY-acetyl-CoA axis and global histone hyperacetylation is consistently observed in human GDM placentas across diverse birth outcomes, suggesting a conserved metabolic-epigenetic adaptation to maternal hyperglycemia. Together, these findings identify ACLY-dependent acetyl-CoA production as a central metabolic node linking maternal hyperglycemia to chromatin remodeling and placental development control, thereby reshaping fetal growth trajectories.

developmental biology↗

bioRxiv2026

Hippocampal Neuroinflammation and Altered Peripheral Neurobiological Protein Profile in Experimental Arthritis and Systemic Juvenile Idiopathic Arthritis

BackgroundChildren with juvenile idiopathic arthritis (JIA) are reported to exhibit increased rates of symptoms affecting emotional regulation and behavior. However, underlying biological mechanisms remain unclear. Neuroinflammation in the central nervous system (CNS) can be triggered by peripheral immune effects and may contribute to these observations. In this study, we aimed to investigate if neurobiological alterations are present in systemic JIA (sJIA), and if CNS neuroinflammation occurs during arthritis, and to explore the potential mechanisms involved. MethodsPlasma samples from patients with active sJIA (n = 16) and sex- and age-matched healthy controls (HCs, n = 16), together with paired samples from the same sJIA patients during inactive disease (n = 12), were analyzed using Olink proteomics to determine the peripheral neurobiological and inflammation protein profiles. Clinical data was retrieved from the Swedish Pediatric Rheumatology Register and medical charts. CNS Neuroinflammatory responses and underlying mechanisms were further explored through in vivo and in vitro experiments. FindingsActive sJIA patients exhibited altered neurobiological protein profiles compared with HCs. These alterations correlated with higher scores of pain and life impact in patients, suggesting that the altered profiles may reflect neurofunctional changes in the patients. Notably, the neurobiological protein profile remained altered even during the inactive phase of the disease. In chronic arthritic mice, microglial activation and impaired neurogenesis were observed in hippocampus, with no significant cortical changes. RNA-seq analysis implicated mitochondrial dysfunction and oxidative stress in mediating neuroinflammation during chronic arthritis in mice. Heme oxygenase 2 (HMOX2) was identified as a peripheral biomarker indicating hippocampal microglia activation. Combined neurobiological and inflammation profiling in sJIA patients implicated Interleukin-6 (IL-6) and Interleukin-18 (IL-18) as key drivers of hippocampal microglia activation during arthritis. InterpretationChronic arthritis is associated with neuroinflammation and altered neurobiological protein profiles in sJIA. HMOX2 emerges as a promising plasma biomarker of CNS changes. IL-6 and especially IL-18 are indicated as key drivers of neuroinflammatory processes. These findings offer insights for clinical monitoring and targeted therapies. FundingThis study was funded by grants from the Swedish Research Council and The Swedish Rheumatism Association. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSChildren with juvenile idiopathic arthritis (JIA) have increased rates of emotional and behavioral disturbances compared with healthy peers. Systemic inflammation and chronic arthritis are suspected to affect the central nervous system, but biological mechanisms in systemic JIA (sJIA) are poorly understood. Added value of this studyIn this study, we demonstrate patients with sJIA have a distinct plasma neurobiological protein profile compared with healthy controls, which correlate with higher pain and life impact scores. In chronic arthritic mice, hippocampal microglial activation, impaired neurogenesis, and mitochondrial dysfunction with oxidative stress are presented. By combining patient and mouse data, we identify heme oxygenase 2 (HMOX2) as a candidate plasma biomarker of hippocampal neuroinflammation and implicate IL-6, and especially IL-18, as key mediators linking chronic arthritis to neurobiological changes. Implications of all the available evidenceThis study provides molecular evidence that neurobiological alterations in sJIA patients and supports incorporating neurobiological and neuropsychiatric monitoring into the clinical follow-up of children with sJIA. We highlight the mechanistic targets and measurable biomarkers (e.g. HMOX2) for future studies and trials aiming to modulate neuroinflammation in chronic arthritis. This study may inform the development of personalized treatment strategies, including IL-18-directed therapies, for patients at risk of neurological or psychosocial complications.

immunology↗

bioRxiv2026

Spatially Distinct Myosin II Architectures Regulate Protrusion Dynamics and Directional Persistence during Immune Cell Migration

Directional persistence is essential for efficient immune cell migration in tissues, yet how cytoskeletal systems stabilize migration in complex three-dimensional environments remains unclear. Using intravital subcellular microscopy and quantitative analysis of membrane dynamics, we identify two spatially distinct architectures of non-muscle myosin II (NMII) that coordinate protrusion dynamics during neutrophil migration. In vivo and in collagen matrices, NMII assembles at the leading edge into lattice-like structures that are structurally and functionally distinct from rear contractile actomyosin bundles. Protrusion-resolved analyses reveal that directional persistence correlates strongly with protrusion lifetime and sustained NMII engagement, with rear NMII load showing the strongest association with protrusion persistence. Strikingly, directional migration is not determined by the abundance of favorable protrusions but by their temporal organization during migration. Pharmacological perturbations that redistribute NMII activity disrupt this temporal organization and alter migration trajectories. Together, these findings reveal that spatially distinct NMII architectures coordinate protrusion dynamics across time to stabilize directional migration in complex environments. HighlightsO_LIMigrating neutrophils assemble spatially distinct myosin II architectures at the leading edge and rear C_LIO_LIProtrusion dynamics and directional persistence are linked to sustained myosin II engagement C_LIO_LIDirectional migration emerges from the temporal organization of protrusion states rather than their abundance C_LI

cell biology↗