Biology subjects

Zhang, N.

Publications and source records attributed to Zhang, N..

At least 73 records · Page 4Linked to original sources

bioRxiv2025

The interaction of the Arabidopsis Xyloglucan Xylosyltransferases XXTs with the COPII member SAR1 via their di-Arginine motifs is critical for delivery to the Golgi.

Golgi-localized Xyloglucan Xylosyltransferases (XXT2 and XXT5) participate in xyloglucan biosynthesis, and to do this, they require the proper localization. The COPII complex is responsible for delivering cargo proteins from the ER to the Golgi, which is facilitated by the complexs member proteins Sec24 and Sar1. Additionally, the N-termini of glycosyltransferases (GTs) play a crucial role in their transportation and localization. In this study, we demonstrated for the first time that XXTs interact with Sar1 protein in the COPII complex but not with Sec24, which was previously reported to be the main recruiter of cargo proteins into COPII-coated vesicles. The mutation of the arginine to glutamine residues of di-arginine motifs in the N-termini of XXT2 and XXT5 caused protein mislocalization and significantly reduced the strength of the interaction with Sar1. These mutations caused 90% of XXTs to either remain in the ER or localize to non-Golgi small compartments. In turn, such mislocalization significantly suppressed the recovery of xyloglucan biosynthesis in Arabidopsis thaliana (Arabidopsis) mutant plants (xxt1xxt2 and xxt3xxt4xxt5), failing to restore their root phenotypes to normal. Our results demonstrate the interaction between cargo proteins and Sar1 proteins, highlighting the critical role of di-arginine motifs in this interaction. These results provide new insights into the mechanism of ER-to-Golgi delivery of plant GTs, which significantly advances our understanding of polysaccharide biosynthesis in the Golgi and the enzymes responsible for it. Significance statementThis study demonstrates that plant glycosyltransferases directly interact with the SAR1 protein of the COPII complex. The di-arginine motifs present in the N-termini of glycosyltransferases play a critical role in cargo selection and transport from the ER to the Golgi apparatus via COPII-coated vesicles, while interacting with SAR1.

plant biology↗

bioRxiv2025

Ferritin Nanoparticle-Based Indirect ELISA for Immunodominant Region Screening and B-cell Epitope Validation of African Swine Fever Virus

African swine fever virus (ASFV) poses a severe threat to the global pig industry, creating an urgent need for effective vaccines and reliable diagnostic tools. While numerous ASFV B-cell epitopes have been reported based on murine-derived monoclonal antibodies (mAbs), such epitopes may not fully represent the antibody targets recognized in naturally infected pigs. Therefore, we need an approach to screen immunodominant regions by evaluating the reactivity of pre-defined epitopes with ASFV-infected pigs sera. In this study, we developed an indirect enzyme-linked immunosorbent assay (iELISA) based on recombinant epitope-ferritin nanoparticles (EFNs), as a platform for immunodominant region screening and epitope validation. This assay, hereafter referred to as EFNs-iELISA, shows an approximately twofold improvement in sensitivity compared with synthetic peptide-based ELISA for linear B-cell epitopes, and improved discrimination over GST-His-peptide and BSA-conjugated peptide formats. Using EFNs-iELISA, we evaluated 22 known murine-derived B-cell epitopes and 17 predicted epitopes from ASFV proteins CD2v, P30, P54, and P72 with ASFV-positive and negative porcine sera. According to the calculated cut-off threshold, tested epitopes were classified into different groups with positive or negative reactivity. Our analysis confirmed that among 22 known murine-derived ASFV B-cell epitopes, 16 (72%) also showed positive reactions with porcine-derived sera. Whats more, we also screened 7 new porcine-specific immunoreactive regions on these proteins. The EFNs-iELISA method provides a practical tool for screening immunodominant regions of ASFV, with potential applications in vaccine and diagnostic research.

immunology↗

bioRxiv2025

Neocortical temporal patterning by a two-layered regulatory network

In the developing neocortex, a diverse array of neurons with defined types and abundances are systematically generated by a limited population of radial glial progenitors (RGPs) as they undergo successive fate changes. The molecular regulation behind this intricate temporal patterning remains elusive. We undertook in-depth single-cell multi-omics analyses, discovering a two-layered regulatory framework at the core of this process. Central to this are global temporal regulators positioned above a temporal network, consisting of series of transcriptional factor (TF) hub groups under sequential state transitions. This temporal network operates not by restricting TF expressions to discrete temporal windows, but through coordinated transcriptional and chromatin-accessibility dynamics that modulate transient TF regulatory activity. Moreover, global temporal regulators specify the duration of each cascading stage and, consequently, the number of progenies generated at each stage. Loss of global temporal regulators protracts RGP lineage progression, whereas their increased activity accelerates it. These findings suggest a two-layer temporal regulatory system controlling RGP lineage progression and neural progeny output duality in mammalian neocortical development.

neuroscience↗

bioRxiv2025

Integrating physiology and transcriptomics reveals the mechanisms underlying the differences in cotton (Gossypium hirsutum L.) growth and development under different photoperiods

Photoperiod is a crucial environmental factor that regulates plant growth and flowering. While the photoperiodic flowering pathway has been extensively studied, the mechanisms underlying photoperiodic regulation of cotton (Gossypium hirsutum L.) growth and development remain unclear. In this study, we selected different genotypes of cotton varieties, XJ12 and XJ21-11, to investigate the effects of long-day (LD) and short-day (SD) conditions on cotton photosynthesis, dry matter accumulation, flowering time, and related gene expression, utilizing physiological index measurements, transcriptomics, and WGCNA analysis. The results indicated that LD treatment significantly enhanced photosynthetic parameters and dry matter weight in both cotton varieties, with the net photosynthetic rate (Pn) being 154.79% and 111.86% higher under LD compared to SD treatment. Additionally, the flowering time of the two varieties was advanced by 12 and 13 days, respectively, under LD treatment relative to SD treatment. LD conditions promoted gene expression in sucrose and starch metabolism, facilitating cotton growth. Furthermore, LD inhibited the expression of genes associated with flavonoid biosynthesis, thereby altering the secondary metabolism of cotton, and activated transcription factors through signaling pathways (including phytohormone signaling and MAPK signaling pathways) and biological clock rhythms, which induced earlier flowering in cotton. This study provides new insights into the molecular mechanism of the effect of photoperiod on cotton growth and development.

physiology↗

bioRxiv2025

Effects of a novel proteasome inhibitor, UR238 on the tumor immune microenvironment and growth in epithelial ovarian cancer

High-grade serous ovarian cancer (HGSOC) is a deadly gynecologic malignancy, often diagnosed at an advanced stage and most patients will experience recurrence and resistance to platinum-based chemotherapy. While there are few targeted therapies available for HGSOC, there are no effective immunotherapies available to treat this disease. The ubiquitin-proteasome system (UPS) maintains cellular protein homeostasis by degrading misfolded or damaged proteins. In epithelial ovarian cancer (EOC) elevated expression of proteasome subunit PSMB4 correlates with epithelial ovarian cancer growth and poor prognosis. A proteasome inhibitor has yet to be approved for EOC treatment despite evidence of activity in phase-1/2 clinical trials. Limitations of past generation proteosome inhibitors include sub-optimal solid tumor/tissue penetration due to boronic acid functionality, and poor solubility. Here, we show that a novel proteasome inhibitor, UR238, suppresses viability of several EOC cell lines and reduces tumor burden in both murine xenograft and rat syngeneic models. In a rat EOC model, UR238 treatment reduced tumor burden, shifted the predominantly suppressive immune microenvironment to an inflammatory phenotype with reduced suppressive macrophages, and decreased PD-L1 expression on myeloid cells. Additionally, in a mouse model, UR238 also induced robust immune changes in HGSOC bearing mice without a corresponding reduction in tumor burden. Our data highlights the promise of UR238 for the treatment of ovarian cancers as a single-agent or in combination with immunotherapies, where modulating the immune composition of these tumors will be important in improving outcomes for ovarian cancer patients.

immunology↗

bioRxiv2025

Cardiac Hemorrhage Precedes Hypertension-induced Fibrosis inPlasminogen Activator Inhibitor-1 Deficient Mice

AimsPlasminogen activator inhibitor-1 (PAI-1) regulates plasmin-mediated proteolysis, thereby influencing vascular stability and tissue remodeling. Angiotensin II (AngII) induces an increase in PAI-1 during the development of ascending thoracic aortic aneurysm (ATAA). The initial purpose of this study was to determine whether deletion of PAI-1 influenced development of ATAA. Subsequently, this study aimed to define the early pathological events preceding cardiac fibrosis in PAI-1 deficiency and the structural domain responsible for its protective effect. Methods and resultsAngII was infused for 4 weeks in whole-body PAI-1 deficient (PAI-1-/-) mice and their wild-type littermates (PAI-1+/+) to examine the role of PAI-1 in ATAA. PAI-1 deficiency did not alter AngII-induced aortopathy but revealed a striking cardiac phenotype characterized by replacement fibrosis predominantly within the epicardium and posterior septum. Ferric iron, indicative of prior hemorrhage, was coincident with fibrosis. Similar phenotypes were observed in PAI-1-/- mice infused with norepinephrine for 4 weeks. To define the pathological events preceding cardiac fibrosis, either AngII or norepinephrine was infused for 1 week in PAI-1+/+ or -/- mice. Both infusions induced extensive epicardial hemorrhage and posterior septal fibrosis in PAI-1-/- mice. To explore the initiation of cardiac pathology, AngII was infused for approximately 1 day. PAI-1-/- mice developed diffuse hemorrhage and cardiomyocyte injury localized to the posterior septum, pathologic changes that preceded overt fibrosis. Finally, to determine the protective domain of PAI-1, saline or AngII was administered to mice harboring loss-of-function point mutations in the protease inhibitory (PAI-1Ala/Ala) or somatomedin B-binding domains (PAI-1AK/AK). Compared to saline infusion, 1 week of AngII induced hemorrhage and heterogeneous fibrosis in PAI-1Ala/Ala, but not PAI-1AK/AK mice. ConclusionsThese findings support that, under hemodynamic stress, PAI-1 deficiency promotes early cardiac hemorrhage and cardiomyocyte injury that lead to fibrosis. Mutational studies implicate dysregulated plasmin generation as an initiator of cardiac injury and fibrosis. TRANSLATIONAL PERSPECTIVECardiac fibrosis has been reported in a human population with PAI-1 deficiency and currently lacks targeted therapy. Our findings demonstrate that in animal models, PAI-1 deficiency confers susceptibility to cardiac injury in response to hemodynamic stress, which may accelerate fibrotic remodeling. Mutational disruption of the protease-inhibitory domain of PAI-1 induced similar pathology, supporting a protective role for this function. These observations suggest that interventions aimed at controlling hypertension, promoting endothelial integrity, or regulating plasmin activation could reduce fibrotic remodeling in this population.

pathology↗

bioRxiv2025

Enabling regiospecific di-halogenation in one-pot reactions using an engineered single-component flavin-dependent tryptophan halogenase

Installation of halogen atoms to organic compounds through flavin-dependent halogenases (FDHs) catalyzed reactions has emerged as an attractive strategy in organic biochemistry and synthetic biology. A cyanobacterial FDH termed AetF that contains FDH and flavin reductase in the same polypeptide chain could become a useful tool enzyme as the need of including a reductase is omitted. Notably, AetF exploits a unique substrate-interaction network to consecutively brominate tryptophan (Trp) on C5 and then C7 to generate di-brominated Trp. In this study, structure-based engineering is used to eliminate the C7 halogenation capacity of AetF. The resulting variant AetF-AIF that contains three residue substitutions mainly catalyzes bromination or iodination on C5 of Trp. We also show that combining AetF-AIF in tandem with the wild type AetF enables the generation of heterogeneously halogenated Trp in a one-pot reaction. The final products, 5-Br-7-I-Trp or 5-I-7-Br-Trp depending on the addition order of halides, account for a high ratio in the reaction mixture without additional purification step. These results display the potentials of single-component Trp-FDHs in a wide application of the halogenation reactions. Table of Content Graphic O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=105 SRC="FIGDIR/small/687318v1_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@101bd34org.highwire.dtl.DTLVardef@12ca797org.highwire.dtl.DTLVardef@aee280org.highwire.dtl.DTLVardef@1984907_HPS_FORMAT_FIGEXP M_FIG A single-component flavin-dependent halogenase that catalyzes di-bromination of tryptophan was engineered as a mono-halogenase and coupled in a one-pot reaction for the synthesis of heterogeneously halogenated tryptophan. C_FIG

molecular biology↗

bioRxiv2025

Adipocytes are dispensable in shaping the ovarian cancer tumor microenvironment in the omentum

The omentum, a specialized adipose tissue within the peritoneum, is a primary niche for ovarian cancer (OC) dissemination during peritoneal carcinomatosis. Traditionally, omental adipocytes are thought to promote OC growth by supplying lipids, supported by evidence that global FABP4 deficiency reduces tumor progression. Here, we generated mice lacking mature adipocytes in the peritoneum, including the omentum. ID8p53-/-Brca2-/-, BPPNM, and KPCA OC cells retained a propensity to seed regions typically associated with adipocytes, even without mature adipocytes. However, the lack of mature adipocytes did not suppress peritoneal OC expansion, whereas removing the adipocyte-free omentum did. Murine and human single-cell RNA sequencing revealed that endothelial FABP4 was high in the omentum. Indeed, endothelial cell-selective deficiency of FABP4 reduced OC growth in the peritoneum. These findings prompt a reevaluation of adipocyte contributions to OC progression and suggest a key role of the omental vasculature in supporting OC metabolic growth.

cancer biology↗

bioRxiv2025

Structural basis of the π-stacking network governing cofactor-substrate cooperativity of SbSOMT

SAM-dependent methyltransferases are ubiquitous enzyme catalyzing methylation of substrate by consuming S-adenosyl methionine (SAM) cofactor. In this study, we discovered the positive cofactor-substrate cooperativity of SbSOMT and uncovered the underlying mechanism at structural basis. The binding kinetics analyses show that SbSOMT exhibits bilateral positive cooperativity except the unproductive pairing between SAM and product due to the steric hindrance of an additional methyl group. Unprecedentedly, two cofactor-analogous inhibitors, S-adenosyl homocysteine (SAH) and sinefungin demonstrated opposite effects on substrate binding kinetics while attaining positive cooperativity. SAM-resembling sinefungin demonstrated higher foldchange in the acceleration of substrate association rate constant than deceleration of dissociation rate constant. Integrating SbSOMT structural insights at multiple states, we identified the dynamical W279-driven {pi}-stacking network governs the cofactor-substrate cooperativity. SbSOMT exhibits closed conformation at first-ligand bound states, where the C-terminal W279 serves as the central plane for {pi}-{pi} interaction between N-terminal H196, catalytic H282, and/or substrate. We propose that the binding of first ligand overcome the energy barrier represented by W279 {pi}-stacking network, leading to the conformational landscapes in favor to second binding event. Our study highlights the intrinsic design of SbSOMT in pertaining enzyme competency and serves as a foundation to expand the knowledge and applications of cofactor-substrate cooperativity of the structurally diverse methyltransferases.

biophysics↗

bioRxiv2025

Robust footprinting with sample-specific Tn5 bias correction for bulk and single cell ATAC-seq

Footprint analysis of assay for transposase-accessible chromatin via sequencing (ATAC-seq) enables base-resolution mapping of regulatory elements but is often underpowered and prone to false positives due to data sparsity and Tn5 transposase cleavage bias. We uncover substantial sample-to-sample variability in Tn5 transposase cleavage bias across samples, revealing a previously underappreciated source of batch effects and highlight the motivations for sample-specific Tn5 bias modeling. We present TraceBIND, a computational framework that corrects sample-specific Tn5 bias and use it to identify TF and nucleosome footprints through a dynamic flanking window statistical scan. Compared to existing approaches, TraceBIND substantially reduces false discoveries, controlling type 1 error while maintaining high sensitivity. Even though TraceBIND is completely unsupervised and does not require training on ChIP-seq data, we used multiple validation analyses to demonstrate that TraceBIND matches the power of supervised methods for detection of known TF binding sites. In scATAC-seq data from aging rat kidney, TraceBIND discovers age-associated dynamic regulatory changes, linking footprint activity to age-associated epigenetic drift. This demonstrates that footprint-informed scATAC-seq analysis reveals rich regulatory signals missed by conventional peak-based approaches.

genomics↗

bioRxiv2025

Relationship between SARC-F score and Peripheral Blood Lymphocytes in Juvenile Idiopathic Arthritis: An Observational Pilot Study

BackgroundGiven the relatively high prevalence of sarcopenia and immune profile abnormalities in inflammatory arthritis such as rheumatoid arthritis (RA), we investigated the relationship between exercise habits, SARC-F score and peripheral blood lymphocyte profiles in patients with Juvenile idiopathic arthritis (JIA). MethodsAll participants with JIA completed the SARC-F survey and self-reported exercise habits through online questionnaires. We defined two groups based on SARC-F scores as musculoskeletal function impaired (SARC-Fhi+) and musculoskeletal function not impaired (SARC-Fhi-). We used flow cytometry of peripheral blood mononuclear cells to define immune cell subpopulations. Statistical analyses were performed using GraphPad Prism software version10. ResultsOf the 18 participants with a median age of 24 years - five belonged to the SARC-Fhi+ group and 13 to the SARC-Fhi-group, of whom 80% and 38% were female, respectively. The SARC-Fhi + group had fewer CD45RA+CD27+ naive CD4+ T cells (26.60% vs. 45.30%, p=0.0264) and greater CD45RA-CD27-effector memory CD4+ T cells (11.90% vs. 7.00%, p=0.0350). The SARC-Fhi+ group also had fewer CD56-CD16+ NK cells compared to the SARC-Fhi-group (2.60% v. 4.28%, p = 0.0194). The moderate exercise group (n = 13) had increased numbers of total CD4+ T cells (54.06% vs. 37.30%, p=0.0140) and 3-fold fewer CD45RA+CD27-EMRA CD8+ T cells (3.17% vs. 10.40%, p=0.0350). There were no other significant differences for other immune cells / subpopulations including B cells. ConclusionsOur study findings suggest notable differences in immune profile relative to SARC-F score. Furthermore, the 3-fold lower frequency of CD8+ TEMRA subpopulation of T cells, reflective of immunosenescence, suggest a potential inverse relationship between moderate exercise and peripheral immune cell profile in JIA. Key messagesO_LISARC-F score was used as a clinically relevant tool to identify musculoskeletal function in JIA C_LIO_LISARC-Fhi+ group had fewer naive CD4+ T cells and greater effector memory CD4+ T cells C_LIO_LIModerate exercise group had 3-fold lower frequency of CD8+ TEMRA T cells C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=54 SRC="FIGDIR/small/681879v1_ufig1.gif" ALT="Figure 1"> View larger version (11K): org.highwire.dtl.DTLVardef@1eb9d4org.highwire.dtl.DTLVardef@13a18a4org.highwire.dtl.DTLVardef@127d55corg.highwire.dtl.DTLVardef@28bddf_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2025

De Novo Design of Anti-Aging Peptides

Aging, a universal biological process in complex organisms, is increasingly recognized to be driven by progressive loss of epigenetic information, as proposed in the Information Theory of Aging (ITOA). However, research on anti-aging peptides remains scarce, with most existing efforts confined to derivatives of natural proteins, while systematic design attempts are virtually absent. This limitation not only restricts discovery within the evolutionary sequence space but also hampers the identification of candidates with novel mechanisms and improved efficacy. Here, we present ElixirSeeker2, the first computational framework for de novo design of anti-aging peptides. By integrating modeling of known anti-aging peptides, activity scoring from the IC50 database, and penalty constraints from toxic peptides, ElixirSeeker2 enables large-scale virtual screening and identification of novel peptide candidates. Several lead peptides demonstrated significant effects in delaying cellular senescence, restoring cellular functions in vitro and in enhancing locomotor activity of aged Caenorhabditis elegans. This study not only validates the feasibility of de novo design in anti-aging interventions but also establishes a strategy for the development of next-generation biologics.

bioinformatics↗

bioRxiv2025

Nephrobase Cell+: Multimodal Single-Cell Foundation Model for Decoding Kidney Biology

BackgroundLarge foundation models have revolutionized single-cell analysis, yet no kidney-specific model currently exists, and it remains unclear whether organ-focused models can outperform generalized models. The kidneys complex cellular architecture and dynamic microenvironments further complicate integration of large-scale single-cell and spatial omics data, where current frameworks trained on limited datasets struggle to correct batch effects, capture cross-modality variation, and generalize across species. MethodsWe developed Nephrobase Cell+, the first kidney-focused large foundation model, pretrained on ~100 billion tokens from ~39.5 million single-cell and single-nucleus profiles across 4,319 samples, four mammalian species (human, mouse, rat, pig), and multiple assay modalities (scRNA-seq, snRNA-seq, snATAC-seq, spatial transcriptomics). Nephrobase Cell+ uses a transformer-based encoder-decoder architecture with gene-token cross-attention and a mixture-of-experts module for scalable representation learning. ResultsNephrobase Cell+ sets a new benchmark for kidney single-cell analysis. It produces tightly clustered, biologically coherent embeddings in human and mouse kidneys, far surpassing previous foundation models such as Geneformer, scGPT, and UCE, as well as traditional methods such as PCA and autoencoders. It achieves the highest cluster concordance and batch-mixing scores, effectively removing donor/assay batch effects while preserving cell-type structure. Cross-species evaluation shows superior alignment of homologous cell types and >90% zero-shot annotation accuracy for major kidney lineages in both human and mouse. Even its 1B-parameter and 500M variants consistently outperform all existing models. ConclusionsWith organ-scale multimodal pretraining and a specialized transformer architecture, Nephrobase Cell+ delivers a unified, high-fidelity representation of kidney biology that is robust, cross-species transferable, and unmatched by current single-cell foundation models, offering a powerful resource for kidney genomics and disease research.

genetics↗

bioRxiv2025

Dissecting the strain and sex specific connectome signatures of unanesthetized C57BL/6J and DBA/2J mice using magnetic resonance imaging

Mouse models are an essential tool for understanding behavior and disease states in neuroscience research. While genetic and sex-specific effects have been reported in many neurodegenerative and psychiatric illnesses, these factors may also alter baseline neuroanatomical features of mice. This raises the question of whether the observed changes are related to the disease being studied (i.e., pathological differences) or if there are baseline strain or sex differences that may potentially predispose animals to different responses. Over the past decade, tremendous effort has been made in mapping neural architecture at various scales; however, the complex relationships including identifying genetic and sex-specific differences in brain structure and function remain understudied. To bridge this gap, we used C57BL/6J and DBA/2J mice, two of the most widely used inbred mouse strains in neuroscience research, to investigate strain and sex-specific features of the brain connectome in awake animals using magnetic resonance imaging (MRI). By combining resting-state fMRI and diffusion MRI, we found that the motor, sensory, limbic, and salience networks exhibit significant differences in both functional and structural domains between C57BL/6J and DBA/2J mice. Further, functional and structural properties of the brain were significantly correlated in both strains. Our results underscore the importance of considering these baseline differences when interpreting the brain-behavior interactions in mouse models of human disorders.

neuroscience↗

bioRxiv2025

Regulation of Glypican 6-mediated Wnt activation maintains TDP-43 nuclear localization in neurons

Abnormalities in TDP-43 (Transactive response DNA-binding protein 43kDa) localization and function span multiple neurodegenerative diseases and are implicated in driving neuronal degeneration and loss. Nuclear pore complex (NPC) abnormalities and disrupted nucleocytoplasmic trafficking (NCT) contribute to TDP-43 mislocalization, but how these cellular changes are initiated in disease is unclear. Glycerophosphodiester phosphodiesterase 2 (GDE2) is a surface glycosylphosphatidylinositol (GPI)-anchor cleaving enzyme that encodes a physiological pathway that ensures NPC integrity, appropriate NCT, and nuclear TDP-43 expression and function in adult neurons by negatively regulating canonical Wnt signaling. Notably, studies of human postmortem tissue and patient-derived neuronal models suggest that the failure of GDE2-dependent regulation of Wnt contributes to TDP-43 abnormalities in disease. Here we show that GDE2 inhibits persistent neuronal Wnt activation by regulating the surface expression of the GPI-anchored protein, Glypican-(GPC)6. Excessive GPC6 surface expression potentiates neuronal Wnt activation in vivo, resulting in NPC disruption, alterations in Ran-dependent NCT, and TDP-43 mislocalization, while genetic reduction of GPC6 in mice lacking GDE2 rescues these cellular abnormalities. Thus, GDE2, GPC6, and the canonical Wnt pathway form a physiologically important signaling axis important for NPC integrity, appropriate NCT, and TDP-43 nuclear function in neurons that, when disrupted, may underlie associated neuropathologies in disease.

neuroscience↗

bioRxiv2025

Internal mechanosensory feedback modulates central pattern generation to coordinate ovulation in Drosophila

Ovulation is a prerequisite for successful reproduction and requires precise coordination of muscle contractions, especially to propel eggs from the paired lateral oviducts into the common oviduct. Although internal mechanosensation is expected to provide critical feedback for this process, the sensorimotor circuitry and mechanisms by which sensory feedback shapes motoneuron activity and coordinates oviduct contractions are still poorly known. Here, in Drosophila, we identify a novel pair of multidendritic mechanosensory neurons (mdn-LO) in the lateral oviducts that express the mechanosensitive channels TMC (transmembrane channel-like protein), PPK (pickpocket), and Piezo. We show that TMC is essential for coordinated ovulation; tmc mutation or neuron-specific knockdown increases egg-jamming at the junction between the lateral and the common oviduct. In contrast, ppk or Piezo mutants display reduced egg-laying but no jamming. Calcium imaging reveals that the mdn-LO neurons are rhythmically activated by oviduct contractions, and chemogenetic stimulation of these neurons triggers muscle contractions. Genetic manipulations of the mdn-LO neurons disrupt egg passage and induce egg-jamming. The axons of the mdn-LO neurons form functional contacts with female-specific oviduct motoneurons in the abdominal neuromeres that express insulin-like peptide 7 (ILP7) and glutamate. Activation of mdn-LO neurons triggers Ca{superscript 2} activity in ILP7 motoneurons and elicits rhythmic oviduct contractions. Importantly, the ILP7 motoneurons exhibit spontaneous rhythmic Ca{superscript 2} activity that is modulated by oviduct contractions and egg movement. Furthermore, triggering activity in the ILP7 neurons induces egg-jamming. Finally, knockdown of ILP7 peptide affects the rate of ovulation, but plays no role in egg jamming, which instead is likely induced by colocalized glutamate. In summary, our study identifies a novel circuit, including the TMC-expressing mdn-LO neurons and a small set of ILP7 motoneurons, that organizes an innate behavior by coupling strategic sensory information and rhythmical motor output to ensure bilateral coordination of oviduct contractions to prevent egg jamming during oviposition. SignificanceOvulation requires precisely coordinated contractions of the lateral oviducts to propel eggs into the common oviduct without jamming. Yet the sensory cells and mechanotransduction channels that coordinate movement through the paired lateral oviducts remain unclear. Here, we identify a novel pair of lateral-oviduct multidendritic neurons (mdn-LO) that express the conserved mechanosensory channels TMC (transmembrane channel-like protein), PPK (pickpocket), and Piezo, and show that TMC is uniquely required to prevent egg jamming at the junction between the lateral and common oviducts. The mdn-LO neurons are activated by oviduct contractions and relay signals to female-specific glutamatergic motoneurons in the abdominal neuromere. These paired oviduct motoneurons are rhythmically active and regulate contractions of the lateral oviducts. Together, our findings demonstrate that TMC-mediated mechanosensory feedback fine-tunes motor output to ensure coordinated ovulation and successful reproduction.

neuroscience↗

bioRxiv2025

Chemotherapy Induces an IL1β-dependent Neutrophil Recruitment that Promotes Chemoresistance in Metastatic Ovarian Cancer

High-grade serous carcinoma (HGSC) of the ovary acquires chemoresistance through diverse cancer cell-intrinsic and-extrinsic mechanisms, culminating in treatment-refractory intraperitoneal metastasis. How chemotherapy-induced remodeling of the tumor microenvironment modulates drug sensitivity remains unclear. In this study, we demonstrate that chemotherapy induced IL1{beta}-dependent neutrophil accumulation in tumors, driving chemoresistance in HGSC. Using patient samples, bulk transcriptomic profiling before and after chemotherapy revealed post-treatment upregulation of IL1B, and single-cell RNA sequencing identified myeloid cells as its principal source. In a chemoresistant murine metastatic ovarian cancer model, chemotherapy increased neutrophils and neutrophil extracellular traps (NETs) in omentum tumors; these increases were abrogated in IL1{beta}-deficient mice, with expansion of activated CD8+ T cells and tumor control. Neutrophil depletion in wild-type mice recapitulated the chemosensitive phenotype of IL1{beta}-deficient mice. In vitro, IL1{beta} did not alter cancer cell-intrinsic chemosensitivity, whereas NETs reduced the chemosensitivity of cancer cells. Additionally, the dominant IL1{beta} receptor (IL1R1) was predominantly expressed in tumor-associated fibroblasts in humans and mice. Consistently, IL1R1-deficient mice exhibited chemosensitivity with decreased neutrophil accumulation and increased IFN{gamma}TNFCD8 T cells. We also found that chemotherapy upregulated CXCL2 in patients and that ablating IL1{beta}-IL1R1 axis decreased CXCL2 expression in tumor-associated fibroblasts in mice. Finally, residual human HGSC tumor after chemotherapy showed increased neutrophils and a trend toward more NETs. Collectively, these findings illuminate a paradoxical, cancer cell-extrinsic mechanism in HGSC whereby chemotherapy itself amplifies chemoresistance and suggest that targeting chemotherapy-induced inflammation may help overcome treatment resistance.

immunology↗

bioRxiv2025

Endogenous corazonin signaling modulates the post-mating switch in behavior and physiology in females of the brown planthopper and Drosophila

Mating in insects typically triggers a post-mating response (PMR) in females, characterized by reduced receptivity to re-mating and increased oviposition, which ensures numerous and viable offspring and male paternity. This PMR is induced by male seminal factors, such as sex peptide in Drosophila melanogaster, as well as intrinsic female signaling components. The latter signaling remains poorly understood in most insects, including the devastating rice pest, the brown planthopper (BPH) Nilaparvata lugens. Here, we show that the neuropeptide corazonin (CRZ) and its receptor (CrzR) are critical for the PMR in female BPHs. Peptide injection, RNAi knockdown, and CRISPR/Cas9 mutagenesis confirm that intact CRZ signaling reduces re-mating frequency and increases ovulation in mated BPH females. The CrzR is highly expressed in the female reproductive tract, and CrzR knockdown phenocopies CRZ diminishment. Importantly, female CRZ/CrzR signaling is required for male seminal factors, such as the peptide maccessin, to induce the PMR; with disrupted CrzR signaling, injection of seminal fluid or maccessin fails to reduce female receptivity. Notably, CRZ is not produced in male accessory glands (MAGs) of BPHs and thus not transferred during copulation. We furthermore demonstrate that also in D. melanogaster disrupted CRZ signaling increases female re-mating and reduces oviposition, while CRZ injection suppresses virgin receptivity and increases oviposition. Finally, we detected no CRZ in the MAG of D. melanogaster, supporting its role as an endogenous signal in the female PMR also in this species. In summary, our findings reveal a conserved role of endogenous CRZ signaling in regulating the female PMR and demonstrate that female CRZ signaling and male-derived signals cooperate to induce post-mating transitions in BPHs and D. melanogaster. CRZ is a paralog of the peptide gonadotropin-releasing hormone, known to regulate reproduction in vertebrates, including humans, suggesting evolutionary conservation of an ancient function.

genetics↗