Biology subjects

Kumar, P.

Publications and source records attributed to Kumar, P..

At least 37 records · Page 2Linked to original sources

bioRxiv2026

Computational drug repurposing identified Artemisinin and Mebendazole as potential inhibitors of virulence-associated proteins SKSR and essential kinases CpCDPK1 of Cryptosporidium parvum

Cryptosporidium parvum is a protozoan parasite responsible for cryptosporidiosis, significantly threatening immunocompromised individuals, particularly HIV/AIDS patients, by causing severe diarrhea and potential mortality. Current treatments are largely ineffective, prompting investigations into new therapeutic options. This study evaluated two antiparasitic drugs: Mebendazole, used for helminth infections, and Artemisinin, used for malaria. The SKSR gene family encodes virulence factors in C. parvum, and Calcium-dependent protein kinase1 (CpCDPK1) regulates the life cycle of C. parvum; targeting these proteins may reduce growth and infection in hosts. In the current study, molecular docking was conducted taking Mebendazole and Artemisinin drugs as ligands, SKSR gene family and CpCDPK1 proteins as drug targets. Results with SKSR showed binding energy of -4.9 kcal/mol, -6.72 kcal/mol for Mebendazole and Artemisinin, respectively. Whereas, with CpCDPK1, the binding energies were -6.44 kcal/mol, -9.18 kcal/mol for Mebendazole and Artemisinin, respectively. Docking of Nitazoxanide (an in-use drug for C. parvum) with SKSR and CpCDPK1 revealed binding energies -4.2 kcal/mol, -4.81 kcal/mol, respectively. The stability of the proteins (targets) upon binding to the ligands was assessed by performing all-atom MD simulations for 100ns using the GROMACS package. No major variations were observed upon binding of Artemisinin and Mebendazole to SKSR and CpCDPK1. The findings of MD simulations imply that both proteins maintain their stability upon binding of Artemisinin and Mebendazole. Molecular Docking and MD simulation studies suggest that Artemisinin and Mebendazole are potential candidates for repurposing in the treatment of C. parvum infections, with recommendations for in vitro studies to validate these findings.

molecular biology↗

bioRxiv2026

Integration of Morphometric and Machine Learning Approaches Strengthens Yield Prediction and Genetic Divergence Assessment in Annona reticulata under Semi-Arid Conditions.

This study integrated morphometric characterization and machine-learning modelling to identify key predictors of yield in Annona reticulata under semi-arid conditions. Thirty-one canopy, fruit, seed, and biochemical traits were evaluated across 62 genotypes, revealing substantial phenotypic diversity, particularly in structural attributes such as tree growth nature and branch angle. Principal Component Analysis and hierarchical clustering differentiated genotypes into three ideotypes representing high-yielding, structurally stable, and quality-oriented groups. Random Forest modelling and SHapley Additive exPlanations (SHAP) interpretation consistently highlighted leaf breadth, leaf length, fruit shape, and pulp-associated traits as dominant yield predictors, underscoring the coordinated influence of source-sink balance. Integration of SHAP importances with trait stability (CV%) further revealed that moderately variable traits provide reliable selection indices. These findings demonstrate that yield performance is governed by multivariate trait networks rather than isolated descriptors. The proposed framework provides a robust basis for precision phenotyping and strategic parent selection to develop high-yielding, nutritionally enriched, and climate-resilient custard apple cultivars.

plant biology↗

bioRxiv2026

SLD5/GINS4 controls dynein-dependent centrosome maturation and exposes a candidate mitotic vulnerability in cancer.

Faithful proliferation requires coordinated DNA replication with centrosome maturation and spindle-pole integrity. SLD5, encoded by GINS4, is a core component of the GINS replication complex and is frequently elevated in tumors, but whether it links replication-associated cancer states to centrosome control has remained unclear. Here, we show that GINS4/SLD5 is recurrently upregulated across human cancers at transcript and protein levels and marks tumor programs enriched for DNA replication, chromosome segregation, and mitotic control. In cancer cells, Sld5 depletion dispersed PCM1, AZI1, and CEP290-positive centriolar satellites without eliminating these satellite proteins, reduced dynein heavy chain expression, and destabilized dynein-dynactin localization at spindle poles. Direct depletion of dynein heavy chain, co-depletion analyses, and pharmacological inhibition of dynein motor activity with ciliobrevin D phenocopied Sld5 loss, causing satellite dispersion, defective recruitment of PLK1, Aurora A, CEP192, and CEP215 to centrosomes, and multipolar spindle formation. These defects occurred without detectable DNA damage or checkpoint activation, indicating a non-canonical Sld5 function beyond its role in the replisome. Cancer dependency and kinase network analyses further nominate SLD5-associated mitotic and checkpoint pathways as therapeutic targets. Our findings identify SLD5/GINS4 as a regulator of dynein-dependent centrosome maturation and a candidate vulnerability in replication-driven cancers, with potential value for biomarker-guided therapeutic stratification. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=136 SRC="FIGDIR/small/723511v1_ufig1.gif" ALT="Figure 1"> View larger version (53K): org.highwire.dtl.DTLVardef@525d9org.highwire.dtl.DTLVardef@1f7d7eeorg.highwire.dtl.DTLVardef@815586org.highwire.dtl.DTLVardef@115f286_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2026

Mechanisms of CD4+ T tolerance to a corneal epithelial neoantigen

Tissue-specific peripheral tolerance mechanisms are essential to prevent autoimmunity. The cornea is immune privileged, and anterior chamber-associated immune deviation (ACAID) governs its inner surface. However, the mechanisms that apply to corneal epithelial (outer surface) antigens remain unknown. Using an inducible, cornea-restricted neoantigen mouse model, we found that the cornea relies on inducible regulatory T cells (Tregs) rather than ignorance or ACAID for its epithelial antigens. Although the cornea is both avascular and alymphatic, its epithelial antigens are still efficiently presented by ocular surface-derived antigen-presenting cells to T cells in draining lymph nodes under homeostatic conditions, leading to conventional antigen-specific Treg expansion without ocular pathology. This tolerance was not absolute: systemic immunization redirected antigen-specific responses toward pathogenic effector T cells that disrupted epithelial barrier function. These findings identify Treg induction as a dominant mechanism of corneal epithelial immune homeostasis and demonstrate that inflammatory priming can render a tolerated corneal antigen into an autoimmune target, providing mechanistic insight into dry eye pathogenesis. SummaryThis study shows that immune tolerance to corneal epithelial neoantigens relies not on immune privilege but on peripherally induced regulatory T cells in the draining lymph nodes that can be subverted by innate activation, shedding light on ocular surface disease pathophysiology.

immunology↗

bioRxiv2026

The Common Fund Data Ecosystem (CFDE)

The NIH Common Fund Data Ecosystem (CFDE) integrates data resources from 18 NIH Common Fund programs for discovery and integrative analysis. These programs generate valuable but heterogeneous datasets that can be difficult to discover, access, and reuse. CFDE aims to provide a collaborative, community-built infrastructure that links and enriches Common Fund programs. We describe the evolution, structure, and core technologies of CFDE, including practical approaches that support submission, integration, visualization, and public release of multimodal data. Training programs and workforce initiatives lower barriers to adoption. CFDE has devised solutions to critical issues facing cross-program initiatives, including data scale and heterogeneity, dataset integration, and long-term sustainability. We demonstrate the utility of linking Common Fund resources through integrative tools and cross-dataset queries to yield insights that would otherwise be infeasible. Collectively, CFDE shows that a standards-driven, federated approach enhances and unifies cross-disciplinary resources, fostering collaboration and data-driven discovery.

scientific communication and education↗

bioRxiv2026

Scalable genotyping in fixed transcriptomes resolves clonal heterogeneity via single-cell sequencing

Despite the promise of single-cell transcriptomics for understanding cell states in heterogeneous populations, widely used platforms have limited ability to link transcriptional states to somatic mutations within the same cells. Here, we introduce Genotyping in Fixed Transcriptomes (GIFT) for the simultaneous detection of large numbers of targeted genetic variants with whole transcriptome profiles in single cells. The core innovation of GIFT is a rationally designed gapfilling reaction between adjacent single-stranded DNA (ssDNA) probes that barcodes native transcript sequence to enable highly-specific targeted mutation detection. GIFT achieves greater than 99% genotyping accuracy and flexible capture of hundreds of mutations per cell, including in formalin-fixed, paraffin-embedded (FFPE) tissue, enabling clonal lineage tracing in heterogeneous settings. We demonstrate the unique scalability of GIFT by profiling more than 700,000 cells from 35 donors with myeloproliferative neoplasms (MPN), revealing mutation-dependent hematopoietic responses to systemic inflammation associated with the characteristic JAK2V617 mutation, including an allelic dose gradient of interferon-associated transcriptional programs and priming of hematopoietic stem cells that develop into divergent disease states. The technical advantages of GIFT enable direct resolution of genotype-to-phenotype relationships via clonal tracing with comprehensive cell-state measurements at single-cell resolution.

genomics↗

bioRxiv2026

Localization-dependent activation of the DEAD-box ATPase Vasa by eLOTUS domains

DEAD-box RNA helicases remodel RNA structures in many cellular pathways, yet how their activity is spatially controlled in cells remains poorly understood. The Drosophila germline helicase Vasa functions in ovaries only when localized to cytoplasmic granules, a process mediated by eLOTUS-domain proteins. Here, we define the mechanism by which eLOTUS domains activate Vasa. Biochemical analyses reveal that Vasa alone is largely inactive. eLOTUS domains bind the open conformation of Vasa and promote formation of the closed RNA- and ATP-bound state by accelerating RNA engagement. This stimulation requires a positively charged intrinsically disordered sequence within eLOTUS that increases RNA association. Mutations in this element abolish Vasa stimulation while preserving binding. We demonstrate that Vasa activation is essential in vivo. Together, these findings reveal a localization-dependent mechanism for regulating the DEAD-box helicase Vasa, in which enzymatic activity is gated by a spatially restricted cofactor.

biochemistry↗

bioRxiv2026

Macrophage Migration Inhibitory Factor (MIF)-CD74 Signaling Pathway Mediates Trabecular Meshwork Dysfunction in Glaucoma.

PurposeMacrophage migration inhibitory factor (MIF) is a pleiotropic cytokine implicated in many inflammatory and fibrotic diseases; however, its role in primary open-angle glaucoma (POAG) and trabecular meshwork (TM) dysfunction remains unknown. In this study, we investigated whether MIF-CD74 signaling regulates TM pathobiology through modulation of the transcription factor, Blimp-1, and downstream cytoskeletal reorganization and extracellular matrix (ECM) remodeling. MethodPrimary human TM cells (HTMC) were exposed to glaucomatous stressors, including TGF-{beta}2, rMIF, or a pro-inflammatory milieu. Expression of MIF, its receptor CD74, and Blimp-1 was measured by qPCR and immunoblotting. ECM proteins and phosphorylated myosin-light chain (pMLC) were evaluated by immunofluorescence staining. In vivo, MIF-CD74 and Blimp-1 expression were examined in the TM/anterior segment (AS) tissue of Tg.CreMYOCY437H and lentiviral (LV)-TGF-{beta}2-induced ocular hypertension (OHT) mouse models. Functional involvement of MIF signaling in TM pathobiology was examined using the irreversible MIF inhibitor 4-IPP and the immunomodulatory metabolites agmatine and thiamine. ResultsGlaucomatous stressors significantly upregulated MIF and CD74 expression with concomitant suppression of Blimp-1 in HTMC. Similarly, TM/AS tissue from both OHT models (Tg.CreMYOCY437H and LV-TGF-{beta}2) demonstrated increased MIF-CD74 expression accompanied by reduced Blimp-1 levels. Activation of MIF-CD74 signaling triggered pro-inflammatory and cell death pathways and promoted ECM remodeling, characterized by increased fibrotic protein expression and enhanced RhoA/ROCK-mediated MLC phosphorylation, indicating modulation of TM contractility. Pharmacological inhibition of MIF attenuated inflammatory signaling, reduced ECM deposition and cytoskeletal remodeling, and suppressed RhoA/ROCK/MLC activation, restoring a protective TM phenotype. ConclusionOur findings identify MIF-CD74 signaling as a previously unrecognized regulator of TM dysfunction in POAG. MIF-mediated suppression of Blimp-1 mechanistically links inflammatory signaling to cytoskeletal contractility and fibrotic ECM remodeling, key determinants of aqueous humor outflow resistance. Targeting the MIF-CD74/Blimp-1 axis may represent a novel therapeutic strategy to restore TM homeostasis and reduce intraocular pressure in glaucoma.

immunology↗

bioRxiv2026

Multi-omics and functional analysis of a bioengineered vascularized pancreatic cancer model reveal an immunosuppressive and therapy-resistant niche

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease characterized by therapy resistance and an immunosuppressive tumor microenvironment. To comprehensively characterize the complex stromal-immune cell interactions that drive PDAC aggressiveness, we applied an integrated multi-modal approach combining single-cell RNA sequencing, spatial transcriptomics, proteomics, immunofluorescence, and microfluidic-based functional assays to bioengineered spheroid models with increasing cellular complexity (up to four cell types) integrating human pancreatic cancer cells, pancreatic stellate cells, endothelial cells, and monocyte-derived macrophages. By incorporating vascularization within the OrganiX microfluidic platform, we enable studies of immune cell trafficking in vascularized tumors. Multi-omics phenotyping revealed coordinated molecular programs in our four-cell organotypic spheroid models, including enhanced hypoxic and glycolytic pathways, NF-{kappa}B activation, and ECM remodeling. Stromal and immune cells acquired tumor-associated phenotypes mirroring patient heterogeneity, including IL-1{beta}+ macrophages, inflammatory cancer-associated fibroblasts (iCAFs), and antigen-presenting CAFs (apCAFs). The four-cell model exhibited superior clinical relevance, with gene expression signatures that correlated more closely with poor-prognosis patient cohorts and cancer hallmarks that were functionally validated through microfluidic-based assays demonstrating enhanced tumor invasion, angiogenesis, and therapeutic resistance. Finally, live imaging combined with transcriptomic readouts captures dynamic interactions between neutrophils and cancer cells in the vascularized microtumor, enabling direct observation of intravascular events relevant to metastatic dissemination. This integrated analysis demonstrated the recreation of a human-relevant aggressive PDAC niche, establishing a framework that bridges in vitro cellular crosstalk studies with patient-relevant therapeutic responses, offering a powerful translational tool for therapy development in PDAC.

cancer biology↗

bioRxiv2026

Allosteric Inhibition of NDM-1 by Thanatin Preserves the Di-Zinc Center While Restricting Dynamics

The New Delhi metallo-{beta}-lactamase 1 (NDM-1) is a major driver of carbapenem resistance in Gram-negative pathogens, yet the molecular basis by which antimicrobial peptides inhibit this enzyme has remained unresolved. Thanatin, a disulfide-stabilized {beta}-hairpin peptide, was previously proposed to inactivate NDM-1 by displacing catalytic Zn{superscript 2} ions, but this model lacked direct structural support. Here, we combine high-resolution NMR spectroscopy, intermolecular NOE mapping, HADDOCK-guided docking, and molecular dynamics simulations to reveal a distinct zinc-retaining dynamic allosteric mechanism. Thanatin binds adjacent to the catalytic groove, preserving the native di-zinc coordination environment while simultaneously rigidifying the L3 catalytic loop, as confirmed by Zn-bound spectral fingerprints and EDTA titration experiments. This conformational restriction explains how the peptide inhibits the enzyme while maintaining a zinc-bound but catalytically compromised state, a finding that contrasts with zinc-displacement hypotheses and reconciles prior biochemical observations with structural data. In bacterial assays, this allosteric inhibition translates to a moderate restoration of carbapenem sensitivity, resulting in a 50% reduction in viable cell output even under high-level enzyme expression. Our findings establish a mechanistic framework for designing next-generation peptide inhibitors that target the dynamic vulnerabilities of metallo-{beta}-lactamases.

biophysics↗

bioRxiv2026

Development of a recombinant adeno-associated virus vector for human T lymphocyte- and natural killer cell-targeted gene therapy

Recombinant adeno-associated virus (rAAV) vectors are widely used for gene delivery but show limited efficiency in immune cells, including T lymphocytes and natural killer (NK) cells. To overcome this barrier, we developed a modular rAAV vector engineering strategy that integrates capsid retargeting with genome optimization. We report a CD7-targeted rAAV vector (CD7-AAV6/9) featuring a nanobody-fused hybrid capsid derived from a rationally selected chimeric combination of AAV6 and AAV9. CD7-AAV6/9 enables efficient and selective transduction of immortalized and primary human T and NK cells in vitro and in vivo in a humanized mouse model, achieves high production titers, and exhibits markedly reduced off-target transduction compared with wild-type serotypes. In parallel, we demonstrate that incorporation of a human gene-derived intron into the vector genome overcomes host-mediated transcriptional repression and enables robust transgene expression in human CD7 T lymphocyte and NK cell populations. To our knowledge, this represents the first application of intron-mediated enhancement in a rAAV vector context. Together, our findings establish an integrated capsid-genome design framework for targeting human T and NK cells, notoriously challenging immune cell populations for gene therapy, and provide a versatile platform readily adaptable to alternative surface markers and therapeutic payloads.

molecular biology↗

bioRxiv2026

The Interaction with Nanotopographical Environment regulates nuclear mechanoresponse in mESCs via Histone Demethylase KDM3A

Cell identity is traditionally viewed as a product of biochemical signalling, yet cells are exposed to defined physical landscapes, whose role in fate control remains unclear. In particular, how pluripotent stem cells integrate nanoscale extracellular cues into gene regulatory programs remains poorly understood. Here, we show that biomimetic substrate nanotopography acts as a potent regulator of naive pluripotency in mouse embryonic stem cells (mESCs). Using supersonic cluster beam deposition, we generate substrates with defined nanotopography that recapitulate native features of extracellular matrix. We demonstrate that nanotopography induces a mechanically relaxed cell state characterised by reduced adhesion, cellular and nuclear softening, and altered nuclear architecture. These mechanical changes are coupled with chromatin remodelling, including reduced H3K27me3 and H3K9me2, redistribution of H3K9me3, and increased H3K4me3. Transcriptomic analyses reveal suppression of adhesion- and cytoskeleton-associated programs together with the activation of a naive pluripotency transcriptional signature, including upregulation of Nanog. Mechanistically, we identify the H3K9 demethylase KDM3A as a mechanosensitive epigenetic regulator required for nanotopography-induced Nanog expression. Together, our findings uncover a novel mechanotransductive pathway directly linking extracellular nanotopography to chromatin state and pluripotency control.

molecular biology↗

bioRxiv2026

tRF-3021a, a tRNA-Ala-TGC derived 3' fragment, promotes glioblastoma cell invasion, suppresses apoptosis, and is required for normal levels of protein synthesis

tRNA-derived fragments (tRFs) are a relatively recently discovered class of small RNAs implicated in gene-regulatory processes in diverse biological contexts but there have been very few reports of a clear phenotypic role of these small RNAs in cancer progression. To select tRFs that should receive priority for mechanistic experiments, we analyzed small RNA-seq data from The Cancer Genome Atlas (TCGA) and found that high expression of three 3' tRFs (tRF-3a), tRF-3009a, tRF-3021a or tRF-3030a, is significantly associated with poor overall survival in low-grade glioma (LGG). In glioblastoma cells, tRF-3009a, tRF-3021a and tRF-3030a enhance cell invasion and migration but tRF-3021a was uniquely required for cell proliferation and suppression of apoptosis. Interestingly, tRF-3021a knockdown decreases global protein synthesis prior to and independent of apoptosis in a number of cancer cell lines, both from and outside the glioblastoma lineage. RNA-seq reveals that the results cannot be explained by microRNA-like functions of tRF-3021a. These data indicate that tRF-3021a supports cancer cell survival and particularly protein synthesis while promoting cellular invasion and migration and suggests that strategies to downregulate this short RNA could be a potential therapeutic approach in cancers. ImplicationtRF-3021a promotes malignant cell phenotypes, sustains global protein synthesis and prevents spontaneous apoptosis, motivating efforts to evaluate it as a biomarker and therapeutic target.

cancer biology↗

bioRxiv2026

BiomarkerKB: FAIR and Integrated Biomarker Knowledge Connecting Biomolecular and Clinical Data Types

Biomarkers are essential tools for disease detection, risk assessment, therapeutic monitoring, and precision medicine. However, biomarker data are dispersed across heterogeneous resources, inconsistently reported in the literature, and rarely standardized for computational use. This fragmentation limits reproducibility, cross-study integration, and the discovery of novel biomarker and disease relationships. We developed BiomarkerKB, a knowledgebase designed to harmonize and integrate biomarker information under a standardized data model. The model follows the FDA-NIH BEST biomarker definition and captures both core fields (biomarker entity, disease/condition, exposure agent) and contextual metadata (specimen, biomarker role, evidence, provenance). Biomarker data and related annotations were either curated from publications or collected from public resources (e.g., OpenTargets, GWAS Catalog, ClinVar, CIViC, OncoMX) and were also contributed by the Common Fund Data Coordinating Centers and the Early Detection Research Network (EDRN). Standardization was achieved using ontologies and reference resources such as Disease Ontology, UBERON, UniProtKB, and HUGO Gene Nomenclature Committee (HGNC) gene symbols. BiomarkerKB data were ingested into a Neo4j-based knowledge graph and integrated with the Common Fund Data Ecosystem (CFDE) Knowledge Graph. The initial release of BiomarkerKB contains over 200,000 biomarker-disease associations spanning genes, proteins, metabolites, glycans, and chemical elements. The knowledge graph comprises more than 300,000 nodes and 1.2 million edges, enabling structured exploration of biomarker relationships within CFDE data as demonstrated through the knowledge graph query-based use cases presented in this study. A publicly accessible web portal (https://biomarkerkb.org) provides keyword search, filtering, data downloads, and access to graph visualization to support both researchers and computational analyses. BiomarkerKB addresses a critical gap in biomarker informatics by providing an integrated, FAIR (Findable, Accessible, Interoperable, and Reusable), and unified framework for biomarker knowledge exploration and discovery.

bioinformatics↗

bioRxiv2026

Deeper neuronal and glial proteomic insights using an optimized pipeline for proximity labeling proteomics

Proximity-based proteomics using TurboID has enabled cell-type-specific profiling without the need for cell purification, although major bottlenecks in sample lysis, biotinylated protein enrichment, digestion, and mass spectrometry (MS) parameters have limited depth of proteome coverage. Here, we systematically optimized these variables using TurboID-based labeling of BV2 microglia in vitro and brain astrocytes in vivo to define conditions that maximize proteome coverage. In microglia, the optimized protocol using 8 M urea lysis with on-bead S-Trap digestion and data-independent acquisition MS (DIA-MS) identified 4,016 proteins, double the depth of prior studies, and revealed metabolic, ribosomal, lipid-processing, autophagy, and trafficking signatures. Brain astrocyte proteomes were best recovered using SDS lysis with S-Trap digestion and DIA-MS, yielding a proteome of over 3,600 highly enriched proteins, twice the depth of prior astrocyte-TurboID studies. The expanded astrocyte proteomes captured canonical astrocyte markers as well as membrane-associated, vesicular trafficking, and presynaptic protein signatures, consistent with labeling of astrocyte-neuron interface regions, including proteins involved in receptor signaling, lipid metabolism, and plasticity at tripartite synapses, and several AD risk proteins. The increased peptide recovery following S-Trap digestion allowed the reduction of starting material to 20 {micro}g protein for DIA-MS, and enabled multiplexed tandem mass tag (TMT-MS) proteomics using even smaller samples. When applied to synaptosomes enriched from mouse brains with neuronal TurboID labeling, our pipeline identified a synapse-specific proteome of 2,529 proteins, revealing synaptic, mitochondrial and disease-relevant signatures not detectable in prior studies. By tackling critical bottlenecks from tissue processing to MS, our optimized pipelines enable cell-type and compartment-specific proximity-labeling proteomics to obtain comprehensive biological and disease-relevant insights across various biological fields.

neuroscience↗

bioRxiv2026

HSF1-dependent, long-range directional HSPA1 gene motion to nuclear speckles is coupled to DDX39B condensate dynamics

Approximately 5-10% of the genome, enriched [~]10-fold in the most highly active genes, positions near deterministically within several hundred nm of nuclear speckles (NS). This includes the HSPA1 locus, among the most strongly NS-associated genes. Here we address how HSPA1 endogenous genes and transgenes stably position adjacent to the nuclear speckle periphery, facilitating their gene expression amplification. Live-cell imaging demonstrates a transcription-dependent speckle-anchoring of HSPA1 genes. Removal of this anchoring reveals sustained, long-range, curvilinear oscillations of the HSPA1 genes away from and back to nuclear speckles or between nuclear speckles. Curvilinear transgene movements are dependent on the transcription factor HSF1, largely independent of nuclear actin or cohesin, but unexpectedly spatially and temporally correlated with DDX39B condensate dynamics and dependent on DDX39B protein levels. We propose that stable nuclear speckle association of HSPA1 results from combining metastable speckle anchoring with constitutive, restorative long-range chromosome movements driven by DDX39B condensate dynamics.

cell biology↗

bioRxiv2025

Gene functions determine stochastic or adaptive futile transcription in cancers through deregulated start site deployments

BackgroundCancers display near-universal hallmarks, including energy addiction, aerobic glycolysis and biosynthesis. In addition to glucose (and glutamine) addiction, cancers also display futile transcription. Discretely measurable futile transcription occurs between transcription start sites (TSSs) and start codons of protein-coding genes. Multiple TSSs for each gene offer various combinations of futile transcription with no effect on the encoded proteins. The relationship between proximal versus distal TSS deployment, futile transcription and energy addiction of cancers remain unclear. MethodsBy analyzing FANTOM CAGE data we show that TSS deployment dysregulation in cancers increases the energy cost coefficients of cancer transcriptomes. We define the bases of the altered energy cost coefficients of cancer transcriptomes by comparing TSS deployment frequencies, associated entropies and futile transcription distances across heterogeneous pools of cancers and non-cancers. ResultsWe show that TSS deployment entropies differ between cancers and non-cancers. It leads to an overall higher distal TSS deployment in cancers but selectively favors an energy- economical proximal TSS deployment for cancer hallmark genes involved in cell proliferation and biosynthesis. We show that the frequency of TSS deployment is linked to the futile transcription distance and gene function differently in cancers and non-cancers. ConclusionsThis work lays out a theoretical framework describing stochasticity of TSS deployment in the context of cancerogenesis and energetics of transcription. It also suggests that the current human TSS landscape has evolved to minimize futile transcription, an outcome favored by stochastic TSS deployment. Under normal conditions of energy metabolism they form a threshold which incipient cancer cells breach. Highlights Stochastic TSS deployment favors transcription from proximal TSSs. Proximal or distal TSS deployment depends on gene function. Cancers generally deploy distal TSSs at a high resource cost. Key cancer hallmark supporting genes shift to proximal TSSs even in cancers.

cancer biology↗

bioRxiv2025

Kv1.3 inhibition alleviates neuropathology via neuroinflammatory and resilience pathways in a mouse model of Aβ pathology

Inhibition of voltage-gated potassium channel Kv1.3 is a therapeutic strategy to curb microglia-mediated neuroinflammation in neurodegeneration, although the cellular and signaling mechanisms of disease-modification by Kv1.3 blockers are unclear. In this study, we delineate protective mechanisms of Kv1.3 blockade in a mouse model of Alzheimers disease (AD) pathology using comprehensive transcriptomics and proteomics profiling of brain, corresponding with neuropathological effects of two translationally relevant Kv1.3 blockers, namely small molecule PAP-1 and peptide ShK-223. Following 3 months of treatment, both molecules reduced Ab plaque burden. Single nuclear RNA seq (snRNA seq) of brain nuclei showed that PAP-1 disproportionately impacted oligodendrocytes and microglia and increased crosstalk between neurons and astrocytes with endothelial cells. In contrast, ShK-223 had pronounced effects on glutamatergic neurons and astrocytes. Both blockers increased expression of myelination genes in oligodendrocytes and synaptic genes in neurons. Neuroprotective effects of PAP-1 were further confirmed by bulk brain transcriptomics and proteomics whereby PAP-1 increased levels of synaptic, cognitive resilience and mitochondrial proteins, while decreasing glial and immune pathways including STAT1/3 phosphorylation. Using proximity labeling and co-immunoprecipitation, we found that Kv1.3 interacts with STAT1/3 in microglia. Using microglial cell lines and primary microglia, we discovered a preferential functional coupling between Kv1.3 and type 2 but not type 1 IFN signaling. Brain-level disease modification by Kv1.3 blockade was reflected in the cerebrospinal fluid (CSF) via reduced levels of neurofilament-light (NEFL) and resilience protein RPH3A, both of which are increased in human AD CSF. Together, this study demonstrates functional links between Kv1.3 channels and type 2 IFN signaling and reveals distinct cellular effects of Kv1.3 blockers in AD pathology that correspond with reduced neuropathology and neuroinflammation, augmentation of resilience and neuro-vascular pathways, along with biomarkers of therapeutic effect.

neuroscience↗