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Zhao, J.

Publications and source records attributed to Zhao, J..

At least 127 records · Page 7Linked to original sources

Convergent and divergent spatial topographies of individualized brain functional networks and their developmental origins

The human brain is intrinsically organized into canonical functional networks with distinct spatial topographies. While precision functional mapping delineates individualized topographies of single networks, the spatial coordination among networks and its developmental origin remains largely unknown. Here, we propose functional topography covariance analysis (FOCA), a novel framework that quantifies convergent and divergent spatial alignments across individualized functional networks and further delineates their internetwork relationships, neurobiological basis, ontogenetic layouts, and cognitive outcomes. Across two well-established task-free functional MRI (fMRI) datasets encompassing both conventional and densely sampled scans, FOCA consistently revealed self-clustered hierarchies in the coordination of functional topographies, closely aligned with existing functional gradients and characterized by convergent couplings within primary systems and divergent couplings in higher-order systems. Such pattern was well predicted by fundamental neurobiological attributes, especially aerobic glycolysis. In a large public neonatal cohort, FOCA matrix exhibited adult-inverted hierarchical couplings and marked changes in auditory and action-mode networks, primarily driven by prominent redistributions of negative couplings. Moreover, neonatal FOCA profiles in the primary visual system significantly predicted neurodevelopmental outcomes at 18 months. Finally, compared with conventional functional connectivity (FC), FOCA proved more robust to global signals and more sensitive to the maturation of negative couplings. These findings highlight the critical role of negative connectivity in brain functional reorganization and advance our understanding of the cooperative and competitive relationships among functional systems and their developmental origins.

neuroscience↗

Immature C. elegans motor neurons control early embryo behavior via both synaptic and non-synaptic GABA release

Pre-natal brain activity has long lasting effects on subsequent neurodevelopment. It is unclear if early brain activity is dominated by cell intrinsic, synaptic, or non-synaptic mechanisms. We address this question by analyzing C. elegans embryo behavior in snf-11 mutants, which lack a plasma membrane GABA re-uptake pump (orthologous to GAT1). At 510-570 minutes post-fertilization, embryo motion was transiently and potently inhibited in snf-11 GAT1 mutants, which precedes formation of most nerve ring synapses. This transient motion inhibition requires GABA synthesis in DD motor neurons and UNC-49 GABAA receptors in body muscles. When motion inhibition occurs, DD neurons have not yet completed neurite outgrowth. Genetic analysis suggests that motion inhibition was mediated by both synaptic and tonic GABA release from DD motor neurons. These results suggest that DD neurons control embryo behavior prior to completing their developmental maturation. Significance StatementLittle is known about how prenatal circuits control embryo behavior. We show that the motion of early C. elegans embryos is transiently inhibited by immature GABAergic motor neurons that have not yet completed neurite outgrowth. GABAs inhibitory effect on early embryo behavior occurs before most synapses have formed in the worms central neuropil. For this early behavior, we find that synaptic GABA release plays a minor role while non-synaptic mechanisms predominate. Our results suggest that non-synaptic forms of GABA transmission play a significant role in prenatal circuits.

neuroscience↗

FERAL: A Video-Understanding System for Direct Video-to-Behavior Mapping

Quantifying animal behavior often requires segmenting continuous actions into discrete, interpretable states, yet most automated pipelines infer actions from keypoint dynamics and are limited by keypoint tracking quality. Here we present FERAL (Feature Extraction for Recognition of Animal Locomotion), a supervised video-understanding toolkit that maps raw video directly to frame-level behavioral labels, bypassing the keypoint-extraction and pose-classification stages of conventional pipelines. Across benchmarks, FERAL matches or exceeds state-of-the-art pose- and video-based baselines. On the CalMS21 mouse social-interaction benchmark, it exceeds Googles VideoPrism using only a quarter of the training data. FERAL generalizes across species (apes, zebras, mice, ants, flies, and nematodes), recording conditions, and levels of organization, from single animals to social interactions and colony-scale collective behavior. Released as a user-friendly, open-source package, it integrates with existing analysis pipelines. By enabling scalable, species-agnostic behavioral quantification directly from raw video, FERAL broadens the experimental paradigms available for studying animal behavior.

animal behavior and cognition↗

YAP1 Depletion Enhances TAZ and its Complexation with TEAD4 and AP-1 Heterodimer C-JUN/FOSB to Promote Gastric Cancer Progression and Metastases

BackgroundDysregulation of the Hippo signaling pathway, characterized by aberrant activation of the transcriptional coactivators YAP1 and TAZ, drives tumour progression, immunosuppression and metastasis. Hippo pathway components are emerging therapeutic targets in several solid tumours, however, the expression profiles of Hippo coactivators YAP1, TAZ and their transcriptional factors TEAD1-4 in gastric cancer peritoneal metastases (GCPMs) and their therapeutic value are unknown. ObjectiveTo determine expression status of YAP1, TAZ and TEAD1-4 in GCPMs; and to evaluate whether dual targeting of YAP1 and TAZ provides superior antitumour activity compared with inhibition of either coactivator alone. DesignExpression of YAP1, TAZ and TEAD1-4 was examined in GCPMs by single-cell RNA sequencing and co-immunofluorescent staining. Functional studies using genetic knockout and antisense oligonucleotide (ASO) inhibition of YAP1 or TAZ were performed to assess antineoplastic effects in vitro and in vivo. Co-immunoprecipitation and luciferase reporter assays were used to characterize YAP1/TAZ interactions with TEADs and AP-1 components (JUN and FOSB) and to quantify transcriptional activity. Antitumour efficacy was validated in patient-derived xenograft (PDX) and KP-Luc2 syngeneic models. ResultsYAP1, TAZ, and TEADs1- 4 were highly coexpressed in GCPMs and correlated with poor survival. YAP1 inhibition alone elicited compensatory upregulation of TAZ, while combined inhibition of both coactivators maximally repressed cell proliferation and invasion in vitro, and tumor growth in vivo. Increased TAZ complexation with TEAD4 and AP-1 (c-JUN and FOSB) heterodimer was observed following YAP1 knockdown or pharmacological ASO inhibition. Dual inhibition of YAP1 and TAZ was required to maximally suppress YAP1/TAZ expression and reduce their nuclear accumulation, transactivation of TEAD, and activation of downstream genes. ConclusionsThese findings show that combined YAP1 and TAZ inhibition holds promise for the treatment of GCPMs, a highly lethal disease with an urgent need for novel treatment options. WHAT IS ALREADY KNOWN ON THIS TOPICO_LIGastric cancer with peritoneal metastasis (GCPM), occurring in > 45% of gastric cancer (GC) patients, is a highly lethal malignancy with limited therapeutic options. C_LIO_LIThe Hippo pathway mediator Yes-associated protein 1 (YAP1) is intimately involved in chemoresistance, cancer stemness properties, and the epithelial-to-mesenchymal transition in gastric and other cancers. C_LIO_LIWhile YAP1 represents a promising therapeutic target, clinical trial of YAP1 antisense oligonucleotides has been disappointing. C_LI WHAT THIS STUDY ADDSO_LIHippo coactivators YAP1, TAZ and their main transcription factors TEAD1-4 are markedly upregulated in GCPMs and associated with poor prognosis. C_LIO_LIAntisense targeting of YAP1 results in compensatory upregulation of its paralog TAZ. C_LIO_LIUpon YAP1 depletion, TAZ forms transcriptional complexes with TEAD4 and the AP-1 heterodimer (JUN and FOSB). C_LIO_LIDual targeting of YAP1 and TAZ, by oligonucleotides, achieves maximal suppression of tumour growth in vitro and in vivo. C_LI HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICYO_LIThese findings provide a strong mechanistic rationale for co-targeting YAP1 and TAZ as a therapeutic approach in metastatic gastric cancer. C_LIO_LIDual Hippo coactivator inhibition could inform the design of future clinical trials aimed at improving outcomes for patients with GCPMs. C_LI

cancer biology↗

Integrated Bioinformatics analysis and Metabolomic Responses in finding novel therapeutic approach to treat viral myocarditis

BackgroundMyocarditis is one of the most common health problems in young people. Despite imaging techniques and endomyocardial biopsies advancing, there is still inadequate for myocarditis characterization. Some studies have shown that myocarditis is closely associated with mitochondrial dysfunction. Therefore, this study was aimed to identify mitochondrial-related biomarkers and gene regulatory networks in myocarditis and potential therapeutic targets. MethodsWe downloaded GSE95368 dataset from GEO to get myocarditis gene expression profiles, then used EdgeR and AI algorithm for bioinformatics analysis of DEGs functions. Established CVB3-induced mouse myocarditis model via intraperitoneal injection, and assessed energy metabolism differences using targeted metabolomics. CVB3 stimulus induced myocarditis in H9C2 cells. We assessed mitochondrial dysfunction (ATP, MMP) with commercial kits, MAPK8 release via ELISA, and MAPK8, p-PI3K, p-AKT levels by western blot. Furthermore, a total of 8 patients primarily diagnosed with myocarditis were enrolled, and levels of MAPK8 and CK in serum were detected. SP600125, an inhibitor of MAPK8, was administrated to CVB3-infected mice to study its potential protective effect in viral myocarditis. ResultsWe obtained 77 DEGs enriched in myocarditis. Analysis yielded 11 modules, MEpurple module genes linked to myocarditis progression were identified via WGCNA. MAPK8, NAMPT and ALB are associated with mitochondrial function. CVB3-infected mice showed cardiac inflammation and high MAPK8 expression in serum or heart tissues.The target metabolism results indicated altered central carbon metabolism distinguished CVB3 group from control, with higher D-Glucose-1-phosphate and D-Glucose-6-phosphate and lower L-Cystine, dCMP, IMP and Xylulose-5-phosphate levels. CVB3 treatment caused mitochondrial dysfunction in H9C2 cells (decreased ATP, MMP), and increased MAPK expression. Western blot showed MAPK8 consolidated the levels of p-PI3K and p-AKT. CK activity was notably higher in myocarditis patients than healthy individuals. MAPK8 levels in myocarditis patients serum also exceeded those in healthy individuals. Pearson analysis indicated that MAPK8 and CK may contribute to myocarditis progression via distinct mechanisms. In CVB3-infected mouse model with SP600125 treatment, cardiac inflammation and MAPK8, p-PI3k, p-AKT expression were reduced, confirming MAPK8s crucial role in viral myocarditis. ConclusionOur study identified MAPK8 as a key biomarker of myocarditis, and it may be a potential therapeutic target for myocarditis.

pathology↗

Morphological Identification of Ticks in district Swabi, Mardan, and Charsadda

Ticks are ectoparasitic arthropods that play a significant role in transmitting pathogens to humans and animals. This study aimed to address the research gap in understanding the morphological diversity and distribution of tick species in Swabi, Mardan, and Charsadda districts of Pakistan, where tick-borne diseases are prevalent but poorly documented. The primary objectives were to identify tick species, document their morphological characteristics, and map their distribution patterns across different habitats. Field surveys were conducted over nine months, collecting tick specimens from forests, grasslands, and residential areas. Specimens were preserved and analyzed using stereo-zoom microscopy and taxonomic keys for accurate classification. Key findings revealed a diverse tick fauna, including hard ticks (Ixodidae), with variations in body size, colour patterns, capitulum shape, and scutum features. Some species were widely distributed across all three districts, while others exhibited localized patterns. The study provides the first comprehensive morphological identification of tick species in these regions, highlighting their potential role in disease transmission. The implications of this research are significant for public health and disease control. The data can inform targeted interventions, enhance disease surveillance programs, and support the development of preventive measures to mitigate tick-borne diseases. By contributing to tick taxonomy and epidemiology, this study lays the groundwork for protecting public health in the study regions and beyond. This study addresses the lack of data on tick diversity in high-prevalence regions of Pakistan, providing critical insights for disease control and public health strategies. Limited information exists on the morphological diversity and distribution of tick species in Swabi, Mardan, and Charsadda districts. To identify tick species, document morphological characteristics, and map their distribution patterns in the study areas. Field surveys, specimen collection, stereo-zoom microscopy, and taxonomic classification were employed over nine months. Diverse tick fauna was identified, including hard ticks, with variations in morphology and distribution. Some species were widespread, while others were localized, highlighting potential disease transmission risks. The findings support targeted interventions, disease surveillance, and preventive measures, contributing to public health protection and tick-borne disease control in the region.

zoology↗

ProAffinity++

Proteins are essential biological macromolecules that play a crucial role in living organisms. Protein-protein interactions, which govern various biological processes such as signal transduction, cell metabolism, and cell growth, are key aspect of protein function. The strength of these interactions, characterized by protein-protein binding affinity({Delta}G), is a critical thermodynamic property of protein complexes. Accurate prediction of protein-protein binding affinity is meaningful for understanding the mechanisms of biological systems and improving the speed of binding affinity determination. However, current methods are limited in their accuracy and are primarily designed for binary complexes. To address these limitations, we propose ProAffinity++, an end-to-end algorithm that predicts binding affinities using a combined representation of sequence and structure. The core idea of ProAffinity++ is to model the binding regions of protein complexes and utilize graph neural networks to capture the local microenvironment of residues. Our experimental evaluations demonstrate that ProAffinity++ outperforms state-of-the-art methods in predicting protein-protein binding affinities. Moreover, it exhibits remarkable performance in challenging scenarios, such as antigen-antibody interactions and missense mutation problems, where existing methods have limitations.

bioinformatics↗

Inhibition of CGRP receptor ameliorates AD pathology by reprogramming lipid metabolism through HDAC11/LXRβ/ABCA1 signaling

The Calcitonin gene-related peptide (CGRP) receptor has gained attention in Alzheimers Disease (AD) research due to its involvement in regulating neuroinflammation. However, its role and mechanism in AD pathology remain unclear. Here, we demonstrate that CALCRL, a core component of the CGRP receptor, is upregulated in the hippocampus of AD dementia patients and 5xFAD mice. Knockout of the CGRP receptor ligand Calca or pharmacological blockade using Rimegepant (Rim), reduces soluble A{beta}1-42 oligomer-induced neuronal death and glial inflammation. Rim treatment also rescues neurobehavioral impairments, neurodegeneration, and lipid metabolism dysfunction in 5xFAD mice. Mechanistically, these effects are mediated through HDAC11 inhibition, which enhances LXR{beta} acetylation and ABCA1 expression, promoting the reprogramming of neuronal lipid metabolism. Importantly, this CALCRL/HDAC11/LXR{beta}/ABCA1 axis is conserved across both humans and mice. Our findings uncover a novel mechanism underlying AD pathogenesis and highlight the therapeutic potential of targeting CGRP signaling in AD. HIGHLIGHTSInhibition of CGRP receptor ameliorates disease pathology in models of AD HDAC11 mediates CGRP receptor function in AD HDAC11 is a pivotal regulator in lipid metabolism by LXR{beta}/ABCA1 signaling The HDAC11/LXR{beta}/ABCA1 axis is conserved in AD humans and mice

neuroscience↗

Adaptive Multimodal Temporal Transformer for Bio Signal Driven Stroke Rehabilitation Prognosis

Stroke rehabilitation requires continuous, individualized assessment of recovery progress to optimize treatment planning. Existing prognosis models often rely on static, single-timepoint predictions and lack adaptive fusion of multi-modal bio-signals, limiting their clinical interpretability and utility. To address these challenges, we propose AMTT-Net, an adaptive multimodal temporal transformer for dynamic stroke rehabilitation prognosis. AMTT-Net integrates wearable biosensor data, video keypoints, and clinical records through an attention-based Adaptive Fusion Module and Trajectory-Aware Prediction Heads to jointly predict continuous recovery trajectories and responder likelihoods under different rehabilitation modalities. Evaluations on the StrokeBalance-Sim dataset demonstrate that AMTT-Net achieves superior performance in both trajectory regression and responder classification tasks, while providing interpretable, patient-specific insights to support personalized rehabilitation strategies.

bioengineering↗

Targeting the host factor HGS-viral membrane protein interaction in coronavirus infection

While current antivirals primarily target viral proteins, host-directed strategies remain underexplored. Here, we performed a genome-wide CRISPRi screening to identify the host protein, Hepatocyte Growth Factor-Regulated Tyrosine Kinase Substrate (HGS), as essential for the pan-coronaviruses infection both in vitro and in vivo. Mechanistically, HGS directly interacts with the viral membrane (M) protein, facilitating its trafficking to the ER-Golgi intermediate compartment (ERGIC) for virion assembly. Conversely, HGS deficiency caused M retention in the ER, blocking assembly. Leveraging this interaction, we designed M-derived peptides and screened over 5,000 FDA-approved drugs, identifying riboflavin tetrabutyrate (RTB). Both the peptides and RTB bind HGS and disrupt its interaction with the M protein, leading to M retention in the ER and subsequent blockade of virion assembly. These agents demonstrated broad anti-pan-coronavirus activity in vitro and in vivo. Collectively, our findings establish HGS as a druggable host target and identify RTB as a promising broad-spectrum antiviral candidate.

microbiology↗

scGPD: single-cell informed gene panel design for targeted spatial transcriptomics

In targeted spatial transcriptomics technologies, a key challenge is to select an informative gene panel that captures the complexity of cellular and spatial heterogeneity within tissues. Many existing methods use prior knowledge or heuristic selection rules, such as selecting highly variable genes, which overlook gene-gene correlations and may consequently result in suboptimal coverage. To address the limitations of the existing methods, we introduce scGPD, a deep learning-based framework for gene panel design that leverages single-cell RNA-seq data to identify compact, nonredundant sets of genes for spatial profiling. scGPD uses a gene-gene correlation-aware gating mechanism to extract informative features from data, encouraging diversity among selected genes and eliminating redundancy. Across diverse single-cell datasets, scGPD outperforms existing gene panel design methods in recovering transcriptome-wide expression using a limited number of genes. When applied to spatial transcriptomics data, it achieves superior cell type classification accuracy, demonstrating strong generalization across modalities. The gene panels selected by scGPD further exhibit well-defined spatial expression patterns, highlighting their robustness and relevance for spatial analysis. The scGPD framework is flexible and can be adapted to multiple use cases, enabling the prioritization of genes relevant to specific diseases or phenotypes. Together, these results demonstrate that scGPD provides a robust and adaptable solution to design efficient gene panels for spatial transcriptomics, with broad applicability to tissue mapping and disease characterization.

bioinformatics↗

Accurate and efficient phylogenetic inference through end-to-end deep learning

Accurate phylogenetic inference is crucial for understanding evolutionary relationships among species. Deep learning technique has been introduced for phylogenetic inference; however, the existing deep learning-based approaches either suffer from limited accuracy as they split inference into several disjoint stages, or exhibit low efficiency and hardly apply to the cases with over 20 species. Here we present an accurate and efficient approach to phylogenetic inference. Our approach, called NeuralNJ, employs an end-to-end framework that directly constructs phylogenetic trees from the input taxa, thus effectively avoiding the inaccuracy incurred by the split inference stages. The key innovation of NeuralNJ lies in its learnable neighbor joining mechanism, which iteratively joins neighbors guided by learned priority scores and thereby achieves accurate tree reconstruction. The inference accuracy is further enhanced through incorporating reinforcement learning-based tree search. Using both simulated and empirical data as representatives, we demonstrate that NeuralNJ can effectively infer phylogenetic tree with improved computational efficiency and reconstruction accuracy. The study paves the way to accurate and efficient phylogenetic inference for hundreds of taxa in complex evolutionary scenarios.

bioinformatics↗

A New Aneurysm Rupture-Prone Marfan Mouse Model with FBN1Q2467X Nonsense Mutation Reveals Adventitial Inflammation

Marfan syndrome (MFS) is a genetic disorder caused by mutations in fibrillin-1(FBN1), which encodes FBN1, a key structural component of the extracellular matrix. Mutations in FBN1 influence the severity of aortic disease and therapeutic responses, with aortic aneurysm being the leading cause of mortality in patients with MFS. To investigate the mechanisms driving aneurysm progression, we generated a mouse model (Fbn1Q2469X/+) carrying the FBN1Q2467X nonsense mutation identified in MFS patients. This mutation results in FBN1 deficiency. Although Fbn1Q2469X/+ mice appear normal, showing only mild, nonprogressive dilation of the aortic root and ascending aorta with minor reductions in blood pressure, homozygous Fbn1Q2469X/Q2469X mice develop spontaneous thoracic aortic aneurysms (TAA) that progress to rupture between 10 and 25 days of age, with 100% penetrance. Histopathology shows progressive vessel wall degeneration characterized by disorganized vascular smooth muscle cells, collagen loss, and elastic fiber fragmentation from early to late stages. RNA-seq analysis identifies inflammation as the dominant process in late-stage aneurysms. Immunofluorescence assay reveals inflammatory cells prominently localized to the adventitia near rupture sites, linking adventitial inflammation to aneurysm progression. This genetically modified Fbn1Q2469X/Q2469X mouse model consistently develops progressive aortic aneurysms and provides a reliable, cost-effective platform to investigate the molecular mechanisms of aneurysm progression and to evaluate therapeutic strategies in aneurysm diseases, including Marfan syndrome and related disorders.

genetics↗

Dual Modes of Gene Regulation by CDK12

The process of transcription is driven forward by the activity of kinases including CDK7, CDK9 and CDK12. Accordingly, acute inhibition of any of these kinases results in profound downregulation of gene expression. Here, we discover that loss or inhibition of CDK12 also significantly upregulates a set of coding and non-coding loci, whose activation could contribute to the anti-proliferative effects of CDK12 inhibitors. Mechanistically, CDK12 inhibition impairs transcription elongation, leading to increased RNA polymerase II termination or arrest in long genes. However, short genes such as MYC and enhancer RNAs are highly transcribed in the absence of CDK12 activity. Indeed, in HER2+ breast cancer, a malignancy where CDK12 is co-amplified with HER2 and its expression correlates with disease status, CDK12 inhibition markedly elevates MYC expression to induce lethality. The dual effects of CDK12 inhibition elucidated herein clarify its role in transcriptional control and have significant translational implications.

cancer biology↗

Loss of the tumor suppressor PTEN activates cell-intrinsic interferon signaling to drive immune resistance

Loss of the tumor suppressor PTEN is strongly associated with a lack of response to immune checkpoint blockade therapies in cancer patients, but the underlying mechanisms are not fully understood. We have developed a transformation model where knocking out PTEN in human mammary epithelial cells drives dependence on the p110{beta} subunit of PI3K and, notably, elicits a robust induction of endogenous retroviral elements (ERVs) and activation of the interferon signaling. This constitutive cell-intrinsic interferon response, hallmarked by hyperactivated STAT1, is also observed in human tumors with a PTEN-low status. We further find that PTEN deficiency renders cancer cells resistant to the cytotoxic effects of immune cells and interferon-{gamma}. Notably, PTEN loss also results in a dependency on an activated DNA damage response pathway, leading to an exquisite vulnerability to CDK12 inhibition. Our study suggests an interferon adaptation model in which tumors driven by PTEN deficiency inherently activate the interferon response, enabling them to adapt to interferon cytotoxicity and gain resistance to immunotherapies.

cancer biology↗

Bioinformatics-based stereochemical elucidation of MM 46115: an unusual antiviral spirotetronate that inhibits clathrin-mediated endocytosis

The influenza virus is a leading cause of respiratory tract infection in humans, with the emergence of antiviral drug resistance posing an ongoing challenge to the treatment of influenza. This underscores the urgent need for effective new antiviral treatments. Spirotetronates are a family of bacterial natural products with a range of potent bioactivities. Some members of this family have antiviral activity. Here, we report the bioinformatics-based stereochemical assignment, antiviral properties, and mechanism of action of the unusual type II spirotetronate MM 46115 (renamed pellemicin). We show that pellemicin is active against both influenza A and B viruses at non-toxic concentrations, and inhibits clathrin-mediated endocytosis, which is required for virus internalisation. Given the need for new treatments for viral infections, the results of our work suggest that pellemicin and related spirotetronates could provide a basis for developing promising alternatives to existing antivirals to combat drug-resistant influenza. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=199 SRC="FIGDIR/small/677008v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@177aacforg.highwire.dtl.DTLVardef@16f0b26org.highwire.dtl.DTLVardef@144f9dcorg.highwire.dtl.DTLVardef@16fe673_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIMM 46115 (here renamed pellemicin) produced by a mycetoma pathogen is a promising antiviral C_LIO_LIThe pellemicin biosynthetic gene cluster was identified in Actinomadura pelletieri DSM 43383 C_LIO_LISequence analysis of biosynthetic enzymes enabled full stereochemical assignment C_LIO_LIPellemicin inhibits clathrin-mediated endocytosis, an early stage of the viral life cycle C_LI SignificanceThe influenza virus is a respiratory pathogen with epidemic and pandemic potential, resulting in tens of thousands of deaths each year and causing significant health, social and economic impact. The rise of resistant influenza strains against existing antiviral drugs creates a pressing need for alternative treatments. Natural products - specialised metabolites of bacteria, fungi, and plants that often have antimicrobial activity - are a promising source of therapeutics to treat human disease. Here, we identify a cryptic polyketide biosynthetic gene cluster in the genome sequence of Actinomadura pelletieri DSM 43383, an Actinomycete that causes mycetoma in humans. This is proposed to direct production of the previously reported spirotetronate MM 46115 (here renamed pellemicin), which has activity against the influenza virus. Sequence analyses of a polyketide synthase and Diels-Alderase involved in pellemicin biosynthesis, combined with comparative analysis of NMR data for other spirotetronates, enabled us to fully resolve longstanding stereochemical ambiguities in the structure of pellemicin. This underscores the emerging power of bioinformatics-based approaches, and their complementarity to traditional spectroscopic methods, for natural product structure elucidation. We also report extensive insights into the antiviral properties and mechanism of pellemicin, demonstrating that it exhibits antiviral activity at non-toxic doses for up to eight hours after administration and inhibits clathrin-mediated endocytosis, a process that many viruses exploit to enter cells. Only one other bacterial natural product, ikarugamycin, is known to inhibit clathrin-mediated endocytosis. Ikarugamycin contains a tetramate group, which bears a close structural relationship to the tetronate moiety of pellemicin, suggesting that inhibition of clathrin-mediated endocytosis may be a general mechanism of action for antiviral spirotetronates. Our findings therefore indicate that pellemicin, and related spirotetronate natural products, could form a basis for development of new drugs to combat antiviral resistance, and serve as useful tools to study the process of endocytosis.

microbiology↗

A ratio-based framework using Quartet reference materials for integrating long- and short-read RNA-seq

Long-read RNA sequencing (lrRNA-seq) enables full-length transcript profiling but is confounded by technical batch effects that compromise quantification and prevent data integration across platforms, protocols, and laboratories. The lack of a transcriptome-wide biological ground truth has hindered objective benchmarking. To address these dual challenges, we leveraged certified Quartet reference materials to generate one of the largest multi-center lrRNA-seq resources to date: over one billion long reads from 144 libraries across four PacBio and Nanopore protocols in four independent laboratories. We first establish that ratio-based quantification against built-in reference samples effectively removes technical noise, revealing underlying biological signals. We then constructed the first ratio-based reference datasets for full-length transcripts-- comprising 10,218 isoforms and 6,032 alternative splicing (AS) events--and orthogonally validated them with RT-qPCR. Finally, a comprehensive benchmark using these ground truths reveals that a hybrid strategy integrating long- and short-read data (hybrid-seq) achieves the highest quantification accuracy for both isoforms and AS events. Our work provides a foundational framework and resource for evaluating lrRNA-seq technologies and accelerating the standardization of full-length transcriptomics for research and clinical applications.

genomics↗

Molecular mechanisms of altered contraction with the β-myosin R403Q mutation in porcine ventricular muscle and a human stem cell-derived cardiomyocyte model.

I.The R403Q mutation in the sarcomere protein beta-myosin heavy chain ({beta}-MHC) is a known genetic cause of hypertrophic cardiomyopathy (HCM), associated with ventricular hypercontractility, impaired relaxation, and cardiac arrhythmias. Despite extensive research, the mutations impact on myosin contractile properties remains unclear, likely due, at least in part, to discrepancies cross different model systems. In this study, we used a multidisciplinary approach to explore mutational effects using two distinct heterozygous R403Q systems: a Yucatan minipig model and human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). X-ray diffraction of R403Q minipig ventricular muscle demonstrated reduced order of the thick filament, suggesting destabilization of the inhibited OFF (vs. ON) state of myosin in relaxed muscle, which correlated with elevated force at submaximal calcium. Super-resolution, single-molecule fluorescence microscopy indicated elevated ATPase activity in thick filament zones lacking cMyBP-C. Furthermore, R403Q myofibrils exhibited slower activation and relaxation kinetics, with reduced sensitivity to ADP. Molecular dynamics simulations suggested that altered interactions at the actomyosin interface contribute to these effects, rather than changes at the nucleotide binding pocket, typically associated with ADP release. Human engineered heterozygous R403Q hiPSC-CMs exhibited reduced maximal myofibril force, slowed contractile kinetics, and hypercontraction in engineered heart tissue constructs-consistent with HCM phenotypes observed in the heterozygous porcine model. Our results demonstrate that the R403Q mutation induces early and persistent contractile dysfunction, and that hypercontractility and slower contractile kinetics may result from a combination of an increased population of activated (ON) myosin heads and delayed detachment during cross-bridge cycling, respectively.

biophysics↗