Results 51-75 of about 1,000
  1. Extracellular vesicles (EVs) are crucial mediators of intercellular communication that originate through one of two pathways: outward budding of the plasma membrane (PM) or fusion of mature (late) endosomes with the PM. How cells balance these EV biogenesis routes remains unclear. To address this, we performed a genome-wide CRISPR activation screen for genes that increase cell surface levels of the tetraspanin CD63—an EV marker that shuttles between late endosomes and the PM. This unbiased approach identified a membrane adaptor protein, MARCKSL1, commonly upregulated in diverse tumor types. Follow-up studies, integrating genomic activation/ablation with microscopic and proteomic approaches, revealed that MARCKSL1 potentiates EV secretion from the PM, (in part) at the expense of late endosome—PM fusion. Probing the molecular context of MARCKSL1 function, we implicate PM-bridging cytoskeletal components (e.g., Radixin) and SNARE-associated proteins (e.g., STXBP3) as collaborators of MARCKSL1. Collectively, our findings reveal new mechanistic underpinnings of PM remodeling and position MARCKSL1 as a gauge between different platforms of EV biogenesis.
    Date: 2025-07-25
    Authors: Zhong Y, George AE, Liv N, de Heus C, Tjokrodirijo RT, Messchendorp M, Akkermans JJ, Cabukusta B, Janssen GM, van Veelen PA, Wijdeven RH, Neefjes J, Verweij F, Berlin I.
    Ref: bioRxiv
  2. Summary Multipolar migration is a conserved neuronal migration mode in the developing brain, enabling emerging neurons to navigate crowded environments and reach precise laminar positions. Yet how these cells interpret external cues to guide their migration remains unclear. We investigate this question in the developing vertebrate retina using horizontal cells as a model. Combining transcriptomics, targeted CRISPR screening, and live imaging, we reveal the spatiotemporal guidance system underlying horizontal cell lamination: repulsive Slit1b/2–Robo2 signaling in the amacrine cell layer is essential to initiate apical horizontal cell migration, while attractive Neurturin–Gfrα1 signaling from photoreceptors fine-tunes final positioning beneath the photoreceptor layer. Disruption of these pathways causes basal retention of horizontal cells, highlighting the importance of spatially coordinated signaling for proper lamination and functional retinal circuitry. Our results uncover how positional signals and tissue architecture cooperate to achieve neuronal precision, an organizing principle likely relevant across the developing central nervous system.
    Date: 2025-07-24
    Authors: Lehtimäki JI, Lilue J, Del Rosario M, Nerli E, Henriques R, Norden C.
    Ref: bioRxiv
  3. ABSTRACT Disease-associated variants can lead to variable phenotypic outcomes, but the biological mechanisms underlying this variability remain poorly understood. We developed a framework to investigate this phenomenon using the 16p12.1 deletion as a paradigm of variable expressivity. Using induced pluripotent stem cell models from affected families and CRISPR-edited lines with the 16p12.1 deletion, we found that the deletion and secondary variants in the genetic background jointly influenced chromatin accessibility and expression of neurodevelopmental genes. Cellular analyses identified family-specific phenotypes, including altered inhibitory neuron production and neural progenitor cell proliferation, which correlated with head-size variation. CRISPR activation of individual 16p12.1 genes variably rescued these defects by modulating key signaling pathways such as TGF-β and PI3K-AKT. Integrative analyses further identified regulatory hubs, including transcription factors FOXG1 and JUN, as mediators of these effects. Our study provides a functional framework for investigating how individual genetic architectures contribute to phenotypic variability in genetic disorders.
    Date: 2025-07-23
    Authors: Sun J, Noss S, Banerjee D, Bhavana VH, Smolen C, Das M, Giardine B, Prabhu A, Amor DJ, Pope K, Lockhart PJ, Girirajan S.
    Ref: medRxiv
  4. Symbiotic nitrogen fixation (SNF) is a key trait in legume productivity, yet the genetic and regulatory basis underlying its natural variation remains poorly understood. Here, we integrated genome, transcriptome, and chromatin accessibility data from a soybean diversity panel comprising 380 accessions, including 108 wild and 272 cultivated lines. Genome-wide association studies (GWAS) detected multiple loci for SNF traits but with limited resolution due to polygenic architecture and environmental influences. Independent component analysis (ICA) identified 136 co-expression modules; ten ICs were strongly correlated with SNF phenotypes and enriched in circadian clock components (e.g., GmLHY1a/b), lipid metabolism, or defense signaling pathways. Transcriptome-wide association studies (TWAS) linked 1,453, 806, and 178 genes to NFP, NW, and NFE traits, respectively. Among TWAS hits, 185 transcription factors were identified, with 39.0% overlapping selective sweeps, suggesting regulatory evolution under domestication. To further dissect expression regulation, we performed eQTL mapping and detected 4,654 significant eQTLs, including 1,241 local (cis), 2,505 distal (trans), and 908 mixed. By integrating ATAC-seq data from sorted nodule nuclei, we found that eQTLs, particularly local eQTLs, are significantly enriched within open chromatin regions, indicating their regulatory potential. Notably, we validated the circadian clock gene GmLHY1b as a negative regulator of nodulation using CRISPR mutagenesis and CUT&Tag. Our integrative study provides comprehensive genomic and transcriptomic resources from a diverse soybean population, offering novel insights into SNF regulatory networks and a valuable foundation for future SNF research and soybean improvement.
    Date: 2025-07-23
    Authors: Li Y, Feng W, Feng X, Liu X, Hao S, Lian L, Gao L, Shao Y, Chen H, Chen Z, Yuan J, Qin L, Li X, Li X, Wang X.
    Ref: bioRxiv
  5. Abstract Lignocellulosic biorefining has traditionally focused on either converting biomass into sugars for fuels or isolating solid cellulose for bioproducts. However, cost-effective strategies to maximize sugar yields while preserving crystalline cellulose remain underexplored. This study addresses that gap by optimizing cellulase enzymes to the co-production of fermentable sugars and crystalline cellulose. Laboratory-scale results also informed a techno-economic analysis (TEA) to evaluate the feasibility of industrial-scale implementation. To this end, we developed a selective hydrolysis process that targets hemicelluloses and amorphous cellulose, while retaining crystalline regions, using an optimized enzyme cocktail tested on three feedstocks: unbleached hardwood pulp, wild-type poplar, and clustered regularly interspaced short palindromic repeats (CRISPR)-edited poplar. Optimization across varying pH and temperature conditions enabled effective selective hydrolysis. Low-lignin unbleached pulp and CRISPR-edited poplar exhibited improved enzymatic accessibility and required less pretreatment, resulting in higher sugar yields and more efficient downstream processing. An engineered yeast strain co-fermented C5 and C6 sugars into ethanol, leaving behind high-crystallinity cellulose. CRISPR-edited poplar outperformed wild type, with 18% more sugar and 25% more ethanol yield, while enhancing cellulose crystallinity. TEA estimated crystalline cellulose production costs at $4,438 per metric tonne from unbleached pulp and $1,474 from CRISPR-edited biomass, highlighting the economic advantage of engineered feedstocks. This work presents a novel lignocellulosic biorefining approach that, for the first time, prioritizes the co-production of fermentable sugars and crystalline cellulose from low-lignin biomass.
    Date: 2025-07-23
    Authors: Cunniffe J, Lavoine N, Wang J, Berrio VR, Sagues WJ.
    Ref: Research Square
  6. Abstract Background Adoptive cell therapy (ACT) with genetically engineered T cells expressing chimeric antigen receptors (CARs) has emerged as a promising treatment option for patients with refractory leukaemia or lymphoma. Despite its success in type B malignancies, CAR-T cell therapy still faces some challenges such as toxicity, functional suppression by the tumour microenvironment (TME), and poor persistence in treated patients. Methods This study employed a second-generation CD19-targeting CAR construct to generate engineered CAR-T cells with enhanced functionality through precise genome editing. Using CRISPR/Cas9 technology, the PDCD1 gene was to mitigate T cell exhaustion, and in a parallel knock-in strategy, an IL-15 transgene was inserted at the PDCD1 locus. Gene editing was performed via electroporation of RNP complexes, with AAV6 vectors used for homology-directed IL-15 integration. Editing efficiency and off-target activity were assessed by flow cytometry, Sanger sequencing, ICE, and CAST-Seq. Functional characterization included bulk RNA sequencing, metabolic profiling using Seahorse technology, and cytotoxicity assays against CD19 + target cells. Results We initially demonstrated that αCD19 CAR-T cells lacking PD-1 expression (PD-1 KO) exhibited reduced expansion capacity and overall fitness compared to control CAR-T cells but showed a superior cytotoxicity against PDL1 + target cells. To address the impaired fitness of PD-1 KO CAR-T cells, we generated PD-1KIL-15 CAR-T cells, which combine PD-1 KO with the expression of IL-15 under the control of the PD-1 endogenous promoter. Compared to CAR T PD-1 KO cells, PD-1KIL-15 CAR-T cells displayed improved phenotype, viability, and metabolism. More importantly, they also demonstrated enhanced cytolytic capacity of PDL1 + CD19 + target cells, which correlated with increased resistance to apoptosis and improved cell fitness. Conclusions In summary, we present a next 4th generation CAR-T cells platform (TRUCKs) that integrates PD-1 deletion with the inducible expression of IL-15 upon T cell activation and/or exhaustion. This strategy addresses the limitations associated with knocking-out PD-1 and those associated with sustained IL-15 cytokine expression. The same platform can be used to generate PD-1 KO TRUCKs targeting different antigens and expressing different cytokines under the control of the PD-1 locus.
    Date: 2025-07-23
    Authors: Cortijo-Gutiérrez¹ M, Maldonado-Pérez N, Tristán-Manzano¹ M, Pavlovic¹ K, Justicia-Lirio⁵ P, Fuster-García⁶ C, Cathomen⁶ T, Bak⁷ RO, Jurado-Bascón¹ PP, Carmona-Sáez¹ P, Herrera⁹ IC, Luo⁷ Y, Martín F, Benabdellah K.
    Ref: Research Square
  7. SUMMARY SnRK1 is an evolutionarily conserved protein kinase belonging to SNF1/AMPK family of protein kinases that is central to adjusting growth in response to the energy status. Numerous studies have shown adaptive and developmental roles of SnRK1, but the understanding of SnRK1 signaling network in monocots is limited. Using CRISPR/Cas9 mutagenesis to target the functional kinase subunits in rice, we carried out a comprehensive phenotypic, transcriptomic, proteomic, and phosphoproteomic analyses of rice snrk1 mutants displaying growth defects under normal and starvation conditions. These analyses revealed the role of SnRK1 signaling in controlling growth and stress-related processes in both energy-sufficient and energy-limited conditions and pointed to sub-functionalization of SnRK1 kinase subunit genes. In addition to the classical protein targets of SnRK1, phosphoproteomics revealed novel targets including the key components of intracellular membrane trafficking, ethylene signaling, and ion transport. The upregulation of stress-related processes and suppression of growth-related processes in snrk1 mutants correlated with their phenotypic defects. Overall, this study highlights the dual role of SnRK1 as promoter of growth under favorable conditions and critical regulator of adaptive response under stress conditions.
    Date: 2025-07-23
    Authors: Faria-Bates MC, Maurya C, Muhammed Jamsheer K, Srivastava V.
    Ref: bioRxiv
  8. Human papillomavirus (HPV) plays a major role in the development of head and neck cancers (HNCs), particularly oropharyngeal squamous cell carcinoma. This review highlights the key molecular mechanisms of HPV-driven carcinogenesis, focusing on the oncogenic E6 and E7 proteins and their disruption of tumor suppressor pathways and epigenetic regulation. We discuss the rising prevalence of HPV-related HNCs, their distinct clinical features, and diagnostic approaches such as p16 immunohisto-chemistry and HPV DNA/RNA detection. HPV-positive tumors show better prognosis and response to treatment, prompting interest in therapy de-escalation. Emerging strategies including immune checkpoint inhibitors, therapeutic vaccines, CRISPR-based gene editing, and ctDNA monitoring are advancing precision oncology in this field. We also examine the preventive potential of HPV vaccination and ongoing research into its role across various HNC subtypes. A deeper understanding of HPV’s molecular impact may guide more effective, targeted, and less toxic interventions.
    Date: 2025-07-22
    Authors: Ozdogan M, Tutkun G, Cakir MO, Ashrafi GH.
    Ref: Preprints.org
  9. Genetic studies of human embryonic morphogenesis are constrained by ethical and practical challenges, restricting insights into developmental mechanisms and disorders. Human pluripotent stem cell (hPSC)–derived organoids provide a powerful alternative for the study of embryonic morphogenesis. However, screening for genetic drivers of morphogenesis in vitro has been infeasible due to organoid variability and the high costs of performing scaled tissue-wide single-gene perturbations. By overcoming both these limitations, we developed a platform that integrates reproducible organoid morphogenesis with uniform single-gene perturbations, enabling high-throughput arrayed CRISPR interference (CRISPRi) screening in hPSC-derived organoids. To demonstrate the power of this platform, we screened 77 transcription factors in an organoid model of anterior neurulation to identify ZIC2 , SOX11 , and ZNF521 as essential regulators of neural tube closure. We discovered that ZIC2 and SOX11 are required for closure, while ZNF521 prevents ectopic closure points. Single-cell transcriptomic analysis of perturbed organoids revealed co-regulated gene targets of ZIC2 and SOX11 and an opposing role for ZNF521 , suggesting that these transcription factors jointly govern a gene regulatory program driving neural tube closure in the anterior forebrain region. Our single-gene perturbation platform enables high-throughput genetic screening of in vitro models of human embryonic morphogenesis.
    Date: 2025-07-22
    Authors: Huang RE, Anand GM, Megale HC, Chen J, Abraham-Igwe C, Ramanathan S.
    Ref: bioRxiv
  10. Background Idiopathic pulmonary fibrosis is a fatal lung disease of progressive lung parenchymal scarring caused by the aberrant response of an alveolar epithelium repeatedly exposed to injury. Understanding epithelial dysfunction has been hampered by the lack of physiological alveolar type 2 (AT2) cell models and defined disease triggers. Monogenic forms of familial pulmonary fibrosis (FPF) caused by toxic gain-of-function variants provide an opportunity to investigate early pathogenic events. One such variant, surfactant protein C (SFTPC)-I73T, abnormally localises within AT2 cells and causes their dysfunction. Methods We used base editing of fetal lung-derived AT2 (fdAT2) organoids to create a heterozygous disease model of endogenous SFTPC-I73T expression. We also created an inducible overexpression system to interrogate temporal changes associated with SFTPC-I73T expression. We cultured fdAT2 both in 3D culture and at air-liquid interface to understand the importance of polarity cues and air exposure on disease phenotypes. Results In our heterozygous endogenous expression system, we found that fdAT2 expressing SFTPC-I73T grew without a lumen and were unable to correctly polarise. SFTPC-I73T accumulated with time and caused gross enlargement of early endosomes, preventing correct apico-basal trafficking of multiple endosomally trafficked cargoes including polarity markers and cell adhesion proteins. This phenotype was exacerbated by air exposure and led to loss of epithelial monolayer integrity and abnormal wound healing after injury. Conclusion Using endogenous gene editing for the first time in differentiated alveolar organoids, we have demonstrated that the pathogenic effects of SFTPC-I73T are mediated through endosomal dysfunction and abnormal epithelial organisation. This has important implications for AT2 function in vivo .
    Date: 2025-07-22
    Authors: Rutherford EN, Sun D, Lim K, Edgar JR, Matesic LE, Marciniak SJ, Rawlins EL, Dickens JA.
    Ref: bioRxiv
  11. The establishment of the body plan during gastrulation represents a hallmark of animal life. It emerges from the interplay of gene-regulatory programs and positional cues, yet how these signals are integrated post-transcriptionally remains largely unexplored. Here, we combine the scalability of mouse gastruloids with a single-cell CRISPR screening platform to functionally dissect germ layer specification at single-cell transcriptomic resolution. Focusing on post-transcriptional regulation, we systematically map drivers of mesodermal and endodermal fate and identify the deadenylase Cnot8 . Loss of Cnot8 leads to widespread poly(A) tail elongation and transcript stabilization, shifting mesoderm differentiation toward ectopic notochord fate, thereby profoundly impacting axial patterning. Collectively, our findings identify mRNA deadenylation as a fundamental mechanism linking cellular identity with morphogenetic signaling during mammalian body plan formation.
    Date: 2025-07-22
    Authors: Taborsky D, Valdivia-Francia F, Ranjbar N, Llop-Grau L, Duré C, Ghoshdastider U, Renz PF, Weber R, Yigit M, Mironov A, Hyams K, Vianello S, Zavolan M, Lutolf MP, Sendoel A.
    Ref: bioRxiv
  12. Streptococcus mutans is recognized as the primary etiological agent of dental caries, one of the most prevalent infectious diseases globally. Its remarkable acid tolerance enables survival and proliferation in the low-pH biofilm microenvironment, establishing S. mutans as the dominant species in dental plaque and a key contributor to cariogenesis. Although numerous studies have identified genes linked to acid tolerance mechanisms, the full set of essential acid tolerance genes within its genome remains incompletely characterized, largely due to the lack of systematic, genome-scale investigations. To address this knowledge gap, we constructed a genome-wide pooled CRISPR interference (CRISPRi) library targeting 95% of the predicted S. mutans genes and employed next-generation sequencing to identify acid tolerance determinants systematically. Our screen revealed 95 acid tolerance-associated genes, a subset of which were functionally validated through gene knockout studies. Functional enrichment analysis demonstrated significant associations with metabolic pathways (including cofactor biosynthesis and amino/nucleotide sugar metabolism), tRNA modification, and transcriptional regulation. Protein-protein interaction (PPI) network analysis identified critical interactors (ComYC, SMU_1979c, DeoC, AcpP, NadD, and SMU_1988c) and two functionally cohesive modules. These findings provide novel mechanistic insights into the acid adaptation strategies of S. mutans and highlight potential therapeutic targets for caries prevention.
    Date: 2025-07-22
    Authors: Chi Y, Chen Y, Yuan C, Yang L, Zhang M, Chen X, Zhao Y, Li M, Wang X, Li Y.
    Ref: bioRxiv
  13. CRISPR activation (CRISPRa) enables precise, locus-specific upregulation of gene expression, offering potential for both ex vivo and in vivo applications. However, the lack of scalable, high-coverage tools has limited its use in comprehensive genetic screens, particularly in murine models. Here, we introduce Partita, a next-generation, whole-genome CRISPRa sgRNA platform designed for unparalleled efficiency and depth in gene activation studies. Partita employs a high-density targeting strategy, deploying 10 sgRNAs per transcription start site, structured into five gene family-specific sub-libraries to maximize transcriptional induction. To demonstrate its capabilities, we performed a series of large-scale screens: an in vitro enrichment/depletion screen in iBMDMs, whole-genome CRISPRa screens in a double-hit lymphoma model to uncover genes driving resistance to pro-apoptotic drugs (venetoclax, nutlin-3a, etoposide), and an in vivo whole-genome screen identifying accelerators of Myc-driven lymphomagenesis. Each experiment revealed both expected and novel regulators of cellular phenotypes, with a high validation rate in secondary assays. By enabling robust, high-throughput gain-of-function screening, Partita unlocks new avenues for functional genomics and expands the toolkit for discovering key drivers of biological processes across diverse research fields.
    Date: 2025-07-22
    Authors: Diepstraten ST, Deng Y, Potts MA, Heidersbach A, König C, Dorighi KM, Tai L, Kueh AJ, Whelan L, Chang C, Brown F, Kelly GL, Fortin J, Haley B, La Marca JE, Herold MJ.
    Ref: bioRxiv
  14. Clustered regularly interspaced short palindromic repeat Cas endonuclease (CRISPR-Cas) systems, such as RNA-editing CRISPR-Cas13d, are poised to advance the gene therapy of various diseases. However, their clinical development has been challenged by 1) the limited biostability of linear guide RNAs (lgRNAs) susceptible to degradation, 2) the immunogenicity of prokaryotic microorganism-derived Cas proteins in human that restrains their long-term therapeutic efficacy, and 3) off-targeting gene editing caused by the prolonged Cas expression from DNA vectors. Here, we report the development of highly stable circular gRNAs (cgRNAs) and transiently-expressing Cas13d-encoding mRNA for efficient CRISPR-Cas13d editing of target mRNA. We first optimized cgRNA for CRISPR-Cas13d editing of adenosine deaminase acting on RNA type I ( Adar1 ) transcript for the combination immunotherapy of triple negative breast cancer (TNBC). cgRNAs were synthesized by enzymatic ligation of lgRNA precursors. cgRNAs enhanced biostability with comparable Cas13d-binding affinity relative to lgRNA. Next, using ionizable lipid nanoparticles (LNPs), we co-delivered the resulting Adar1 -targeting cgRNA with an mRNA encoding RfxCas13d (mRNA-RfxCas13d), a widely used Cas13d variant, to TNBC cells. As a result, relative to lgRNA, cgRNA significantly enhanced the efficiency of Adar1 knockdown with minimal collateral activity, which sensitized the cancer cells for cytokine-mediated cell apoptosis. In a 4T1 murine TNBC tumor model in syngeneic mice, Adar1 -targeting cgRNA outperformed lgRNA for tumor immunotherapy in combination with immune checkpoint blockade (ICB). Collectively, these results demonstrate the great potential of cgRNA and mRNA-RfxCas13d for RNA-targeted gene editing.
    Date: 2025-07-22
    Authors: Zhou S, Yang S, Xu J, Zhu G.
    Ref: bioRxiv
  15. Soil salinity varies widely across geographies both due to natural factors and human activities, including agriculture, road salt application, sea level rise, and desertification. Increases in soil salinity may affect organisms widely and particularly impact soil foodwebs. As parasites, entomopathogenic nematodes (EPNs) occupy crucial links in soil foodwebs and are important for agriculture as biological control agents of insect pests. Previous research found that the EPN Steinernema carpocapsae may exhibit higher salt tolerance than several of its congeners. We recently identified that S. carpocapsae uniquely evolved two amino acid substitutions in the first extracellular loop of the sodium pump (Na□/K□-ATPase). Here, we tested if these substitutions explain S. carpocapsae ’s reported lower sensitivity to salt. Our results confirm that S. carpocapsae exhibits higher salt tolerance and show it can more effectively locate and infect insect hosts than its congeners S. feltiae and S. hermaphroditum in highly saline environments. We then retraced the evolution of the two amino acid substitutions in S. carpocapsae by introducing them alone and in combination in Caenorhabditis elegans using CRISPR genome engineering. We found that C. elegans mutants with single substitutions showed improved salt tolerance. However, this improvement disappeared in the double mutant, whose sodium pump mimicked that of S. carpocapsae . This pattern of negative epistasis between the amino acid substitutions suggests they are not responsible for variation in salt tolerance between Steinernema species. Sodium pump evolution in S. carpocapsae might instead be driven by encounters with cardiac glycosides, which are released into soil by several clades of plants including milkweeds, sequestered by some of this EPN’s herbivorous insect hosts, and known to target the first extracellular loop of the sodium pump. Our findings provide valuable insights into EPN adaptation to changes in environmental sodium levels and may have implications for their use in biological control.
    Date: 2025-07-22
    Authors: Achi P, McCarthy C, Bavier L, Pena R, Iglesias V, Christensen P, Aljidui A, Baniya A, Goldy C, Adrianza RC, Reddy S, Groen SC, Dillman AR.
    Ref: bioRxiv
  16. ABSTRACT Bacterial flagella drive motility and chemotaxis while also playing critical roles in host-pathogen interactions, as their oligomeric subunit, flagellin, is specifically recognized by the mammalian immune system and flagellotropic bacteriophages. We recently discovered a family of phage-encoded, RNA-guided transcription factors known as TldR that regulate flagellin expression. However, the biological significance for this regulation, particularly in the context of host fitness, remained unknown. By focusing on a human clinical Enterobacter isolate that encodes a Flagellin Remodeling prophage (FRφ), here we show that FRφ exploits the combined action of TldR and its flagellin isoform to dramatically alter the flagellar composition and phenotypic properties of its host. This transformation has striking biological consequences, enhancing bacterial motility and mammalian immune evasion, and structural studies by cryo-EM of host- and prophage-encoded filaments reveal distinct architectures underlying these physiological changes. Moreover, we find that FRφ improves colonization in the murine gut, illustrating the beneficial effect of prophage-mediated flagellar remodeling in a host-associated environment. Remarkably, flagellin-regulating TldR homologs emerged multiple times independently, further highlighting the strong selective pressures that drove evolution of RNA-guided flagellin control. Collectively, our results reveal how RNA-guided transcription factors emerged in a parallel evolutionary path to CRISPR-Cas and were co-opted by phages to remodel the flagellar apparatus and enhance host fitness.
    Date: 2025-07-22
    Authors: Walker MW, Richard E, Wiegand T, Wang J, Yang Z, Casas-Ciniglio AA, Hoffmann FT, Shahnawaz H, Gaudet RG, Arpaia N, Fernández IS, Sternberg SH.
    Ref: bioRxiv
  17. Background: The emergence and spread of antimicrobial resistance (AMR) genes in environmental microbiomes pose a critical threat to global health security. Current detection methods are time-consuming and often lack the sensitivity required for early environmental surveillance. Methods We developed a novel CRISPR-Cas13a-based biosensor system coupled with isothermal amplification for rapid, field-deployable detection of clinically relevant AMR genes (blaNDM-1, mcr-1, and vanA) in environmental samples. The system integrates microfluidic sample processing with fluorescent readout and smartphone-based detection. Results Our biosensor demonstrated exceptional sensitivity with detection limits of 10 copies/μL for target AMR genes, achieving 100% specificity against non-target sequences. Field testing across 150 environmental samples from wastewater treatment plants, agricultural runoff, and hospital effluents revealed previously undetected AMR hotspots. The system provided results within 45 minutes compared to 72 hours for conventional PCR-based methods. Longitudinal monitoring revealed seasonal fluctuations in AMR gene prevalence, with peak concentrations coinciding with agricultural antibiotic usage patterns. Conclusions This innovative biosensor platform enables rapid, sensitive detection of AMR genes in environmental settings, providing a powerful tool for real-time surveillance and early warning systems. The technology addresses critical gaps in current AMR monitoring capabilities and offers significant potential for global implementation in resource-limited settings.
    Date: 2025-07-22
    Authors: Zakari DA, Godwin AA, Egbeja IT, Aliyu AA, Momoh TB, Omenesa IM, Maji OO, ALIYU GO.
    Ref: Access Microbiology
  18. Abstract Autosomal dominant tubulointerstitial kidney disease -UMOD (ADTKD-UMOD) is characterized by progressive renal interstitial inflammation and fibrosis. However, its underlying mechanisms remain unclear. Here, we identify a large ADTKD pedigree harboring a novel UMOD p.H36Y mutation. Using CRISPR/Cas9 technology, we generated a UmodH36Y/+ mouse model that recapitulates the key phenotypes observed in affected individuals, including renal dysfunction, cyst formation, interstitial inflammation, and fibrosis. Multi-omics analyses revealed marked macrophage pyroptosis in UmodH36Y/+ kidneys. Treatment with disulfiram (DSF), a pyroptosis inhibitor, significantly alleviated interstitial inflammation and improved renal function. Mechanistically, the Umod p.H36Y variant activated the amyloid precursor protein (App)-Cd74 axis which mediated the crosstalk between renal TECs and macrophages. This axis sustains NF-κB pathway activation in macrophages, initiating pyroptosis and pro-inflammatory cytokine release. Disrupting App-Cd74 signaling effectively suppressed macrophage pyroptosis. Notably, pharmacologic inhibition using ARN2966, a small-molecule App inhibitor, markedly attenuated renal injury in UmodH36Y/+ mice. Collectively, these findings uncover a novel, targetable pathway in ADTKD-UMOD.
    Date: 2025-07-22
    Authors: Wang B, Wu Q, Peng S, Zhang Y, Yang Y, Shi W, Wen X, Liu Z, Zhou X, Zheng M, Hu L, Li X, Cao J, Wang X, Yang J, Wei J, Shen J, Wang X, Liu B, Zhang X.
    Ref: Research Square
  19. GPR132 (G2A), a lipid- and pH-sensing GPCR, has been implicated in both pro- and anti-inflammatory signaling, but its in vivo function in wound repair and infection control remains unknown. Here, we investigated the role of GPR132b, a zebrafish homolog of G2A, in regulating innate immune responses. Using CRISPR-Cas9, we generated gpr132b mutants and found that they exhibit enhanced wound healing following sterile injury but increased susceptibility to Listeria monocytogenes infection, indicating that GPR132b modulates a trade-off between wound repair and antimicrobial defense. The enhanced regrowth phenotype was associated with increased macrophage accumulation at the wound site and reduced basal expression of the pro-inflammatory cytokine tnf-α . Macrophage depletion suppressed the enhanced regrowth phenotype, suggesting a functional role for macrophages in GPR132b-mediated repair. Pharmacological inhibition of cyclooxygenase (COX) and 12-lipoxygenase (12-LOX) pathways mimicked the gpr132b mutant phenotype in wild-type larvae, indicating that GPR132b likely responds to lipid-derived signals. Together, our findings reveal that GPR132b acts as a c ontext-dependent regulator of innate immunity, impairing efficient tissue repair in sterile conditions while supporting pathogen resistance during infection. Our results underscore the importance of GPCR-mediated signaling in orchestrating effective responses to tissue injury and infection.
    Date: 2025-07-22
    Authors: Mercado Soto NM, Schoen TJ, Stuntebeck J, García N, Halley M, Keller NP, Huttenlocher A.
    Ref: bioRxiv
  20. Twenty causative genes have been reported that cause non-syndromic childhood glaucoma associated with anterior segment dysgenesis. FOXC1, PAX6 and PITX2 are the most well-known, but cases linked to SLC4A11, PITX3 and SOX11 have also been reported. As genetic testing becomes increasingly widespread and rates of molecular diagnosis rise, the extent of phenotypic overlap between the different genetic causes of non-syndromic glaucoma associated with anterior segment dysgenesis is becoming more evident. Taking aniridia as an example, whilst PAX6 mutations remain the predominant cause, variants in CYP1B1, FOXC1, PXDN and SOX11 have also been reported in patients with childhood glaucoma and aniridia. Developments in molecular-based therapies for retinal and corneal disease are advancing rapidly, and pre-clinical studies of gene-based treatments for glaucoma and aniridia are showing promising results. Use of adeno-associated viral vectors for gene delivery is most common, with improvements in intraocular pressure and retinal ganglion cell survival in Tg-MYOCY437H mouse models of glaucoma, and successful correction of a germline PAX6G194X nonsense variant in mice using CRISPR/Cas9 gene editing. This review will explore the actions and interactions of the genetic causes of non-syndromic glaucoma associated with anterior segment dysgenesis and discuss current developments in molecular therapies for these patients.
    Date: 2025-07-21
    Authors: Cronbach N, Méjécase C, Moosajee M.
    Ref: Preprints.org
  21. The nuclear pore complex (NPC) forms a large channel that spans the double lipid bilayer of the nuclear envelope and is the central gateway for macromolecular transport between the nucleus and cytoplasm in eukaryotes. NPC biogenesis requires the coordinated assembly of over 500 proteins culminating in the fusion of the inner and outer nuclear membranes. The molecular mechanism of this membrane fusion step that occurs in all eukaryotes is unknown. Here, we elucidate the mechanism by which two paralogous transmembrane proteins, Brl1 and Brr6, mediate membrane fusion in S. cerevisiae. Both proteins form multimeric, ring-shaped complexes with membrane remodeling activity. Brl1 is enriched at NPC assembly sites via a nuclear export sequence and then interacts with Brr6 across the nuclear envelope lumen through conserved hydrophobic loops. Disrupting this interaction blocks fusion and halts NPC assembly. Molecular dynamics simulations suggest that the Brl1-Brr6 complex drives membrane fusion by forming a channel across bilayers that enables lipid exchange. Phylogenetic analyses reveal that Brl1/Brr6 homologues are broadly distributed across eukaryotes, and functional experiments in human cells and D. melanogaster establish CLCC1 as an NPC fusogen in metazoans. Together, our results uncover a novel, conserved mechanism for membrane fusion in eukaryotes.
    Date: 2025-07-21
    Authors: Fischer JS, Wojtynek M, Kumar A, Baird H, Radilova K, Maslennikova D, Ramachandran K, Becker AN, Agote-Aran A, Loffreda A, Kralt A, Jagannathan M, Dey G, Kutay U, Vanni S, Weis K.
    Ref: bioRxiv
  22. Trypanosoma cruzi , the causative agent of Chagas disease, relies on complex gene regulatory mechanisms to adapt to its diverse host environments. Although this parasite lacks canonical transcriptional control, epigenetic regulation plays a pivotal role in modulating gene expression. Bromodomain-containing factors (BDFs), known for recognizing acetylated lysines on histones, have emerged as key regulators of chromatin structure and gene activity. Among the eight predicted BDFs in T. cruzi, Tc BDF6 is part of a TINTIN-like complex with Tc MRGx and Tc MRGBP, homologous to components of the NuA4/TIP60 chromatin remodeling complex. To investigate the function of Tc BDF6, we generated knockout (KO) parasites using CRISPR/Cas9 gene editing. While BDF6-deficient epimastigotes did not exhibit very significative growth differences, the resulting metacyclic trypomastigotes displayed drastically reduced infectivity. Strikingly, once inside host cells, Tc BDF6 deficient parasites differentiated into amastigotes but failed to replicate. This intracellular arrest was partially reversed by episomal re-expression of Tc BDF6. Consistently, BDF6 KO parasites also exhibited impaired infectivity, a defect that was also rescued in the add-back line. Our findings highlight Tc BDF6 as a critical regulator of intracellular parasite development, operating in stages beyond epimastigotes where epigenetic plasticity is essential for host adaptation. The unique, stage-specific phenotype of BDF6 knockouts underscores its functional importance and suggests that bromodomains may represent novel therapeutic targets against T. cruzi . Author Summary To survive in the dramatically different environments of its life cycle, Trypanosoma cruzi , the parasite that causes Chagas disease, must finely tune its gene expression. Unlike many organisms, T. cruzi lacks classical transcriptional regulation and instead relies on epigenetic mechanisms. Among the proteins involved in this regulation are bromodomain containing factors, which interpret chemical marks on chromatin. In this study, we focused on Tc BDF6, a bromodomain protein thought to be part of a chromatin remodeling complex. Using CRISPR/Cas9, we disrupted the TcBDF6 gene and discovered that, while the mutant parasites could still form infective stages, they failed to replicate inside host cells. Reintroducing TcBDF6 , it was rescued this defect, confirming its critical role in intracellular development. Our findings highlight the importance of epigenetic control in parasite survival and suggest that bromodomain proteins could be valuable targets for future treatments against Chagas disease.
    Date: 2025-07-21
    Authors: Boselli V, Perdomo VG, Pacini F, Cueto JA, Pezza A, Romano PS, Docampo R, Perez AR, Serra EC.
    Ref: bioRxiv
  23. ABSTRACT The TTC22 gene encodes a protein containing seven tetratricopeptide repeats (TPRs), which mediate protein‒protein interactions as chaperones. We previously reported that the level of TTC22 transcript variant 1 ( TTC22v1 ) was downregulated in human colon adenocarcinoma (COAD) and that TTC22 upregulated m6A-mediated WTAP and SNAI1 expression via the TTC22‒RPL4 interaction and subsequently promoted COAD metastasis. Thus, a commercially available C57BL/6N mouse model in which the Ttc22 exon 2&3 encoding the TPR4 (equal to the human TTC22 TPR3) domain was knocked out via CRISPR-Cas9 was used to evaluate the contribution of Ttc22 to the development of mice and COAD. Unfortunately, the long-term observation results demonstrated that Ttc22 knockout (KO, including Ttc22 -/+ or Ttc22 -/- ) did not affect the body weight, development, fertility, or spontaneous tumor incidence of male or female mice. No differences in the incidence of AOM/DSS-induced COAD were observed between these mouse groups, although Ttc22 exon 2&3 deletion partially resulted in the upregulation of adaptive response genes in the colon mucosa. Further study revealed that TPR4 deletion did not disrupt the effect of TTC22 on WTAP upregulation. Consistently, TPR4 deletion did not affect the abundance of total RNA m6A in the colon tissues of the mice, suggesting that the TPR4-deleted Ttc22 mutant remains functional. In conclusion, the TPR4 domain is not essential for the Ttc22 protein. Loss of Ttc22 TPR4 caused no observable changes in the development of C57BL mice or their susceptibility to treatment with the chemical carcinogen AOM/DSS. Whether an essential sequence for a target gene is knocked out should be carefully evaluated before a gene knockout model is employed in formal experiments. Highlights Knockout of Ttc22 exons 2 and 3 does not affect the development of C57BL mice. Ttc22 knockout does not affect the induction of mouse colon cancer by AOM/DSS. Loss of the Ttc22 exons 2 and 3 cannot disrupt the functions of TTC22.
    Date: 2025-07-21
    Authors: Liu J, Gu L, You A, Yuan H, Zhou J, Tian W, Deng D.
    Ref: bioRxiv
  24. Summary Brown algae represent the third most complex lineage to evolve multicellularity, independently from plants and animals. However, functional studies of their development, evolution, and biology have been constrained by the lack of efficient and scalable genome editing tools. Here, we report a robust, high-efficiency, and transgene-free CRISPR–Cas12-based genome editing method applicable across four ecologically and biotechnologically important brown algal species. Using Ectocarpus as a model, we optimized a PEG-mediated RNP delivery system employing a temperature-tolerant Cas12 variant, achieving reproducible, high-efficiency editing across multiple loci without the need for cloning or specialized equipment. As proof of concept, we precisely recapitulated the hallmark imm mutant phenotype by editing the IMMEDIATE UPRIGHT (IMM) locus, a phenotype previously described only from a rare spontaneous mutation. APT/2-FA-based selection further improved specificity with minimal false positives. The protocol was readily transferrable to other species, including kelps long considered recalcitrant to transformation. This platform now makes functional genomics accessible in brown algae, enabling mechanistic dissection of developmental processes, life cycle transitions, and the independent origins of complex multicellularity. Our work enables the broader adoption of brown algae as experimental models and provides a valuable platform for marine biotechnology and evolutionary research. Motivation Although most of biodiversity on Earth lives in oceans, a significant proportion of its organisms remain largely uncharacterized. Brown algae represent one of such understudied group of marine photosynthetic eukaryotes. Despite their importance as emerging models for developmental evolution and blue biotechnology, functional genomics in brown algae has remained largely inaccessible due to a lack of efficient and scalable genome editing tools. Our aim is to democratize genome editing in brown algae by developing a high-efficiency, transgene-free protocol that works across multiple species, without the need for specialized equipment. This high-efficiency method fully enables the field of functional genomics in an unexplored multicellular lineage. Highlights High-efficiency, low-cost genome editing in brown algae without specialized equipment. ·Applicable to non-model species, including those of economic importance.
    Date: 2025-07-21
    Authors: Martinho C, Hoshino M, Raphalen M, Bukhanets V, Kerur A, Bogaert K, Luthringer R, Coelho S.
    Ref: bioRxiv
  25. Abstract Culex mosquitoes transmit major pathogens including West Nile virus, encephalitis, filariasis, and avian malaria, threatening public health, poultry, and ecosystems. We engineered a CRISPR-based population suppression gene drive targeting a conserved exon of the doublesex ( dsx ) gene. The drive incorporates a recoded dsxM segment to preserve male function while converting genetic females into sterile intersexes, enabling male-biased propagation and removal of fertile females. It achieves super-Mendelian inheritance (~ 71%) and generates partially dominant sterile resistance alleles via end-joining, resulting in intersex phenotypes with reduced fertility and hatchability. Modeling predicts that this RIDD (Release of Insects carrying a Dominant-sterile Drive) system can suppress populations at low intrinsic growth rates and release ratios, outperforming SIT and fs-RIDL strategies in persistence and efficiency, with further gains achievable through improved cleavage rates. This study establishes a self-limiting gene drive framework for Culex suppression, highlightling the potential of targeting conserved sex-determination pathways for sustainable vector control.
    Date: 2025-07-21
    Authors: Liu F, Feng X, Ding J, Liu Y, Amo VLD, Gantz V, Chen X, Champer J.
    Ref: Research Square
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