Systems Biology

Light Quantity Impacts Early Response to Cold and Cold Acclimation in Young Leaves of Arabidopsis

Fri, 2025-03-28 06:00

Plant Cell Environ. 2025 Mar 27. doi: 10.1111/pce.15481. Online ahead of print.

ABSTRACT

Plant reactions to stress vary with development stage and fitness. This study assessed the relationship between light and chilling stress in Arabidopsis acclimation. By analysing the transcriptome and proteome responses of expanding leaves subjected to varying light intensity and cold, 2251 and 2064 early response genes and proteins were identified, respectively. Many of these represent as a yet unknown part of the early response to cold, illustrating a development-dependent response to stress and duality in plant adaptations. While standard light promoted photosynthetic upregulation, plastid maintenance, and increased resilience, low light triggered a unique metabolic shift, prioritizing ribosome biogenesis and lipid metabolism and attenuating the expression of genes associated with plant immunity. The comparison of early response in young leaves with that in expanded ones showed striking differences, suggesting a sacrifice of expanded leaves to support young ones. Validations of selected DEGs in mutant background confirmed a role of HSP90-1, transcription factor FLZ13, and Phospholipase A1 (PLIP) in response to cold, and the PLIP family emerged as crucial in promoting acclimation and freezing stress tolerance. The findings highlight the dynamic mechanisms that enable plants to adapt to challenging environments and pave the way for the development of genetically modified crops with enhanced freezing tolerance.

PMID:40148745 | DOI:10.1111/pce.15481

Categories: Literature Watch

The genesis of paleogenetics

Fri, 2025-03-28 06:00

Nat Rev Genet. 2025 Mar 27. doi: 10.1038/s41576-025-00835-0. Online ahead of print.

NO ABSTRACT

PMID:40148574 | DOI:10.1038/s41576-025-00835-0

Categories: Literature Watch

Processing-bias correction with DEBIAS-M improves cross-study generalization of microbiome-based prediction models

Fri, 2025-03-28 06:00

Nat Microbiol. 2025 Mar 27. doi: 10.1038/s41564-025-01954-4. Online ahead of print.

ABSTRACT

Every step in common microbiome profiling protocols has variable efficiency for each microbe, for example, different DNA extraction efficiency for Gram-positive bacteria. These processing biases impede the identification of signals that are biologically interpretable and generalizable across studies. 'Batch-correction' methods have been used to address these issues computationally with some success, but they are largely non-interpretable and often require the use of an outcome variable in a manner that risks overfitting. We present DEBIAS-M (domain adaptation with phenotype estimation and batch integration across studies of the microbiome), an interpretable framework for inference and correction of processing bias, which facilitates domain adaptation in microbiome studies. DEBIAS-M learns bias-correction factors for each microbe in each batch that simultaneously minimize batch effects and maximize cross-study associations with phenotypes. Using diverse benchmarks including 16S rRNA and metagenomic sequencing, classification and regression, and a variety of clinical and molecular targets, we demonstrate that using DEBIAS-M improves cross-study prediction accuracy compared with commonly used batch-correction methods. Notably, we show that the inferred bias-correction factors are stable, interpretable and strongly associated with specific experimental protocols. Overall, we show that DEBIAS-M facilitates improved modelling of microbiome data and identification of interpretable signals that generalize across studies.

PMID:40148567 | DOI:10.1038/s41564-025-01954-4

Categories: Literature Watch

DYRK1A inhibition results in MYC and ERK activation rendering KMT2A-R acute lymphoblastic leukemia cells sensitive to BCL2 inhibition

Fri, 2025-03-28 06:00

Leukemia. 2025 Mar 27. doi: 10.1038/s41375-025-02575-w. Online ahead of print.

ABSTRACT

Unbiased kinome-wide CRISPR screening identified DYRK1A as a potential therapeutic target in KMT2A-rearranged (KMT2A-R) B-acute lymphoblastic leukemia (ALL). Mechanistically, we demonstrate that DYRK1A is regulated by the KMT2A fusion protein and affects cell proliferation by regulating MYC expression and ERK phosphorylation. We further observed that pharmacologic DYRK1A inhibition markedly reduced human KMT2A-R ALL cell proliferation in vitro and potently decreased leukemia proliferation in vivo in drug-treated patient-derived xenograft mouse models. DYRK1A inhibition induced expression of the proapoptotic factor BIM and reduced the expression of BCL-XL, consequently sensitizing KMT2A-R ALL cells to BCL2 inhibition. Dual inhibition of DYRK1A and BCL2 synergistically decreased KMT2A-R ALL cell survival in vitro and reduced leukemic burden in mice. Taken together, our data establishes DYRK1A as a novel therapeutic target in KMT2A-R ALL and credential dual inhibition of DYRK1A and BCL2 as an effective translational therapeutic strategy for this high-risk ALL subtype.

PMID:40148558 | DOI:10.1038/s41375-025-02575-w

Categories: Literature Watch

Imaging and spatially resolved mass spectrometry applications in nephrology

Fri, 2025-03-28 06:00

Nat Rev Nephrol. 2025 Mar 27. doi: 10.1038/s41581-025-00946-1. Online ahead of print.

ABSTRACT

The application of spatially resolved mass spectrometry (MS) and MS imaging approaches for studying biomolecular processes in the kidney is rapidly growing. These powerful methods, which enable label-free and multiplexed detection of many molecular classes across omics domains (including metabolites, drugs, proteins and protein post-translational modifications), are beginning to reveal new molecular insights related to kidney health and disease. The complexity of the kidney often necessitates multiple scales of analysis for interrogating biofluids, whole organs, functional tissue units, single cells and subcellular compartments. Various MS methods can generate omics data across these spatial domains and facilitate both basic science and pathological assessment of the kidney. Optimal processes related to sample preparation and handling for different MS applications are rapidly evolving. Emerging technology and methods, improvement of spatial resolution, broader molecular characterization, multimodal and multiomics approaches and the use of machine learning and artificial intelligence approaches promise to make these applications even more valuable in the field of nephology. Overall, spatially resolved MS and MS imaging methods have the potential to fill much of the omics gap in systems biology analysis of the kidney and provide functional outputs that cannot be obtained using genomics and transcriptomic methods.

PMID:40148534 | DOI:10.1038/s41581-025-00946-1

Categories: Literature Watch

Potential upscaling protocol establishment and wound healing bioactivity screening of exosomes isolated from canine adipose-derived mesenchymal stem cells

Fri, 2025-03-28 06:00

Sci Rep. 2025 Mar 27;15(1):10617. doi: 10.1038/s41598-025-93219-7.

ABSTRACT

Mesenchymal stem cell-derived exosomes exhibit promising potential in tissue regeneration. Recent studies highlight its significant therapeutic potential in various stages of wound healing. However, the clinical translation of exosome-based therapy was hindered due to issues regarding low productivity and the lack of efficient production protocol to obtain a clinically relevant exosome quantity. Therefore, this study established a potential upscaling protocol to produce exosomes derived from canine adipose-derived mesenchymal stem cells (cAD-MSCs) and explored its potential for wound treatment. The potential upscaling protocol, termed VSCBIC-3-3D, was carried out using VSCBIC-3 in-house serum-free exosome-collecting solution in a three-dimensional (3D) culture system followed by the tangential flow filtration (TFF) isolation. Our findings suggest that culturing cAD-MSCs with VSCBIC-3 maintained cell morphology and viability. Compared to conventional two-dimensional (2D) protocols, The potential upscaling protocol increased exosome yield and concentration in conditioned medium by 2.4-fold and 3.2-fold, respectively. The quality assessment revealed enhanced purity and bioactivity of exosomes produced using the VSCBIC-3-3D protocol. In addition, the cAD-MSCs-derived exosomes were shown to significantly improve fibroblast migration, proliferation, and wound healing-related gene expression in vitro. This study collectively demonstrates that potential upscaling protocol establishment allowed robust production of exosomes from cAD-MSCs, which exhibit therapeutic potential for wound healing in vitro.

PMID:40148423 | DOI:10.1038/s41598-025-93219-7

Categories: Literature Watch

Molecular basis for the regulation of human phosphorylase kinase by phosphorylation and Ca<sup>2</sup>

Fri, 2025-03-28 06:00

Nat Commun. 2025 Mar 28;16(1):3020. doi: 10.1038/s41467-025-58363-8.

ABSTRACT

Phosphorylase kinase (PhK) regulates the degradation of glycogen by integrating diverse signals, providing energy to the organism. Dysfunctional mutations may directly lead to Glycogen Storage Disease type IX (GSD IX), whereas the abnormal expression of PhK is also associated with tumors. Here, we use cryo-electron microscopy (cryo-EM) to resolve its near-atomic structures in the inactive and active states. These structures reveal the interactions and relative locations of the four subunits (αβγδ) within the PhK complex. Phosphorylated α and β subunits induce PhK to present a more compact state, while Ca2+ causes sliding of the δ subunit along the helix of the γ subunit. Both actions synergistically activate PhK by enabling the de-inhibition of the γ subunit. We also identified different binding modes between PhK and its substrate, glycogen phosphorylase (GP), in two distinct states, using cross-linking mass spectrometry (XL-MS). This study provides valuable insights into the regulatory mechanisms of PhK, thereby enhancing our understanding of GSD IX and its implications in tumorigenesis.

PMID:40148320 | DOI:10.1038/s41467-025-58363-8

Categories: Literature Watch

Metabolomic approaches suggest two mechanisms of drought response post-anthesis in Mediterranean oat (Avena sativa L.) cultivars

Thu, 2025-03-27 06:00

Physiol Plant. 2025 Mar-Apr;177(2):e70181. doi: 10.1111/ppl.70181.

ABSTRACT

Oats (Avena sativa L) is a temperate cereal and an important healthy cereal cultivated for food and feed. Therefore, understanding drought responses in oats could significantly impact oat production under harsh climatic conditions. In particular, drought during anthesis (flowering) affects grain filling, quality and yield. Here, we characterised metabolite responses of two Mediterranean oat (Avena sativa L.) cultivars, Flega and Patones, during drought stress at anthesis. In the more drought-tolerant Patones, the developing grains from the top (older) and bottom (younger) spikelets of primary panicle were found to be larger in size in response to drought, suggesting accelerated grain development. Flega showed a more rapid transition to flowering and grain development under drought. The metabolomes of source (sheath, flag leaf, rachis) and sink (developing grains) tissues from Patones showed differential accumulation in fatty acids levels, including α-linolenic acid, sugars and amino acids with drought. Flega showed enhanced energy metabolism in both source and sink tissues. Lower levels of glutathione in source tissues and the accumulation of ophthalmic acid in the grains of Flega were indicators of oxidative stress. Our study revealed two distinct metabolite regulatory patterns in these cultivars during drought at anthesis. In Patones, α-linolenic acid-associated processes may accelerate grain-filling, while in Flega oxidative stress appears to influence traits such as flowering time. Overall, this work provides a first insight into the metabolite regulation in oat's source and sink tissues during anthesis under drought stress.

PMID:40148256 | DOI:10.1111/ppl.70181

Categories: Literature Watch

Sex differences in durability: A field-based study in professional cyclists

Thu, 2025-03-27 06:00

J Sci Med Sport. 2025 Mar 5:S1440-2440(25)00062-3. doi: 10.1016/j.jsams.2025.02.009. Online ahead of print.

ABSTRACT

OBJECTIVES: Durability is emerging as a key performance determinant in cycling, but scarce evidence exists on the durability of female cyclists, and particularly on whether there are sex differences. We therefore aimed to determine potential sex differences in durability.

DESIGN: Observational field-based study.

METHODS: Power output data from training and competitions were registered in female and male professional cyclists (n = 42 each) during 1-5 seasons. Participants' highest power output values achieved for different effort durations (10 s, 1 min, 5 min, and 20 min) (or 'record power profile') were determined under non-fatigued conditions (0 kJ/kg) and after varying levels of accumulated work (10, 20 and 30 kJ/kg).

RESULTS: A significant reduction in the record power profile compared with non-fatigued conditions was observed after > 10 kJ/kg in both female and male cyclists (p < 0.001), with no significant impairment observed below this level of accumulated work (p > 0.05 for all). A similar relative decay (% decline compared with the fresh condition) was observed between sexes for 10-s efforts (p > 0.05). However, a significantly higher relative decay was observed in female cyclists after 20 kJ/kg for 1-min, 5-min, and 20-min efforts (4 %, 4 % and 2 %, respectively; p < 0.05), with these differences enlarging after 30 kJ/kg (8 %, 6 % and 7 %; p < 0.001).

CONCLUSIONS: Professional female cyclists show a greater relative decay in the record power profile after a given accumulated work compared to male cyclists, which might reflect a lower durability.

PMID:40148210 | DOI:10.1016/j.jsams.2025.02.009

Categories: Literature Watch

CyFidb: A Molecular Atlas for Cystic Fibrosis

Thu, 2025-03-27 06:00

J Cyst Fibros. 2025 Mar 26:S1569-1993(25)00079-7. doi: 10.1016/j.jcf.2025.03.011. Online ahead of print.

ABSTRACT

BACKGROUND: Cystic fibrosis (CF) is a disease triggered by more than 2,100 variants in a single gene encoding for the CF Transmembrane Conductance Regulator (CFTR) protein, which is expressed in epithelial cells, where it functions an anion channel. A new era of high-throughput technologies ('omics') enabled the production and exploration of large CF-related datasets with unprecedented detail. However, this knowledge is scattered among different resources thus requiring a significant amount of time and training to collect and exploit. The objective of this work is to build a resource (CyFidb) that concentrates CF-related information in a single repository.

METHODS: This tool results from the intense manual curation of 407 scientific articles, including studies with CFTR variants in distinct conditions, drug treatments and cells/tissues.

RESULTS: CyFidb is divided into three levels of information: protein-protein interactions, gene expression and functional studies, from which it is possible to search and extract information.

CONCLUSIONS: CyFidb is an open-access resource (https://cyfidb.di.fc.ul.pt) designed to provide continuously updated, curated information on CFTR variants and their associated biological data.

PMID:40148144 | DOI:10.1016/j.jcf.2025.03.011

Categories: Literature Watch

Bioinformatics-Guided Identification and Quantification of Biomarkers of Crotalus atrox Envenoming and its Neutralization by Antivenom

Thu, 2025-03-27 06:00

Mol Cell Proteomics. 2025 Mar 25:100956. doi: 10.1016/j.mcpro.2025.100956. Online ahead of print.

ABSTRACT

Quantitative mass spectrometry-based proteomics of extracellular vesicles (EVs) provides systems-level exploration for the analysis of snakebite envenoming (SBE) as the venom progresses, causing injuries such as hemorrhage, trauma, and death. Predicting EV biomarkers has become an essential aspect of this process, offering an avenue to explore the specific pathophysiological changes that occur after envenoming. As new omics approaches emerge to advance our understanding of SBE, further bioinformatics analyses are warranted to incorporate the use of antivenom or other therapeutics to observe their global impact on various biological processes. Herein, we used an in vivo BALB/c mouse model and proteomics approach to analyze the physiological impacts of SBE and antivenom neutralization in intact animals; this was followed by bioinformatics methods to predict potential EV biomarkers. Groups of mice (n=5) were intramuscularly injected with Saline or Crotalus atrox venom. After 30 minutes, the mice received saline or antivenom (ANTIVIPMYN®) by intravenous injection. After 24 hours, blood was collected to extract the plasma to analyze the EV content and determine the exposome of C. atrox venom as well as the neutralizing capabilities of the antivenom. The predicted biomarkers consistently and significantly sensitive to antivenom treatment are Slc25a4, Rps8, Akr1c6, Naa10, Sult1d1, Hadha, Mbl2, Zc3hav, Tgfb1, Prxl2a, Coro1c, Tnni1, Ryr3, C8b, Mycbp, and Cfhr4. These biomarkers pointed towards specific physiological alterations, causing significant metabolic changes in mitochondrial homeostasis, lipid metabolism, immunity, and cytolysis, indicating hallmarks of traumatic injury. Here, we present a more comprehensive view of murine plasma EV proteome and further identify significant changes in abundance for potential biomarkers associated with antivenom treatment. The predicted biomarkers have the potential to enhance current diagnostic tools for snakebite management, thereby contributing significantly to the evolution of treatment strategies in the diagnosis and prognosis of SBE.

PMID:40147718 | DOI:10.1016/j.mcpro.2025.100956

Categories: Literature Watch

A patient-derived T cell lymphoma biorepository uncovers pathogenetic mechanisms and host-related therapeutic vulnerabilities

Thu, 2025-03-27 06:00

Cell Rep Med. 2025 Mar 24:102029. doi: 10.1016/j.xcrm.2025.102029. Online ahead of print.

ABSTRACT

Peripheral T cell lymphomas (PTCLs) comprise heterogeneous malignancies with limited therapeutic options. To uncover targetable vulnerabilities, we generate a collection of PTCL patient-derived tumor xenografts (PDXs) retaining histomorphology and molecular donor-tumor features over serial xenografting. PDX demonstrates remarkable heterogeneity, complex intratumor architecture, and stepwise trajectories mimicking primary evolutions. Combining functional transcriptional stratification and multiparametric imaging, we identify four distinct PTCL microenvironment subtypes with prognostic value. Mechanistically, we discover a subset of PTCLs expressing Epstein-Barr virus-specific T cell receptors and uncover the capacity of cancer-associated fibroblasts of counteracting treatments. PDXs' pre-clinical testing captures individual vulnerabilities, mirrors donor patients' clinical responses, and defines effective patient-tailored treatments. Ultimately, we assess the efficacy of CD5KO- and CD30- Chimeric Antigen Receptor T Cells (CD5KO-CART and CD30_CART, respectively), demonstrating their therapeutic potential and the synergistic role of immune checkpoint inhibitors for PTCL treatment. This repository represents a resource for discovering and validating intrinsic and extrinsic factors and improving the selection of drugs/combinations and immune-based therapies.

PMID:40147445 | DOI:10.1016/j.xcrm.2025.102029

Categories: Literature Watch

Widespread variation in molecular interactions and regulatory properties among transcription factor isoforms

Thu, 2025-03-27 06:00

Mol Cell. 2025 Mar 20:S1097-2765(25)00197-2. doi: 10.1016/j.molcel.2025.03.004. Online ahead of print.

ABSTRACT

Most human transcription factor (TF) genes encode multiple protein isoforms differing in DNA-binding domains, effector domains, or other protein regions. The global extent to which this results in functional differences between isoforms remains unknown. Here, we systematically compared 693 isoforms of 246 TF genes, assessing DNA binding, protein binding, transcriptional activation, subcellular localization, and condensate formation. Relative to reference isoforms, two-thirds of alternative TF isoforms exhibit differences in one or more molecular activities, which often could not be predicted from sequence. We observed two primary categories of alternative TF isoforms: "rewirers" and "negative regulators," both of which were associated with differentiation and cancer. Our results support a model wherein the relative expression levels of, and interactions involving, TF isoforms add an understudied layer of complexity to gene regulatory networks, demonstrating the importance of isoform-aware characterization of TF functions and providing a rich resource for further studies.

PMID:40147441 | DOI:10.1016/j.molcel.2025.03.004

Categories: Literature Watch

Three-dimensional regulatory hubs support oncogenic programs in glioblastoma

Thu, 2025-03-27 06:00

Mol Cell. 2025 Mar 21:S1097-2765(25)00200-X. doi: 10.1016/j.molcel.2025.03.007. Online ahead of print.

ABSTRACT

Dysregulation of enhancer-promoter communication in the three-dimensional (3D) nucleus is increasingly recognized as a potential driver of oncogenic programs. Here, we profiled the 3D enhancer-promoter networks of patient-derived glioblastoma stem cells to identify central regulatory nodes. We focused on hyperconnected 3D hubs and demonstrated that hub-interacting genes exhibit high and coordinated expression at the single-cell level and are associated with oncogenic programs that distinguish glioblastoma from low-grade glioma. Epigenetic silencing of a recurrent hub-with an uncharacterized role in glioblastoma-was sufficient to cause downregulation of hub-connected genes, shifts in transcriptional states, and reduced clonogenicity. Integration of datasets across 16 cancers identified "universal" and cancer-type-specific 3D hubs that enrich for oncogenic programs and factors associated with worse prognosis. Genetic alterations could explain only a small fraction of hub hyperconnectivity and increased activity. Overall, our study provides strong support for the potential central role of 3D regulatory hubs in controlling oncogenic programs and properties.

PMID:40147440 | DOI:10.1016/j.molcel.2025.03.007

Categories: Literature Watch

Five-month real-ambient PM<sub>2.5</sub> exposure impairs learning in Brown Norway rats: Insights from multi omics-based analysis

Thu, 2025-03-27 06:00

Ecotoxicol Environ Saf. 2025 Mar 26;294:118065. doi: 10.1016/j.ecoenv.2025.118065. Online ahead of print.

ABSTRACT

PM2.5, recognized as a potential pathogenic factor for nervous system diseases, remains an area with many unknowns, particularly regarding its effects on human health. After five-month real-ambient PM2.5 exposure, we observed no significant pathological damage to the lung, liver, spleen, or kidney tissues. However, PM2.5 exposure led to neuronal degeneration in the hippocampal CA1 region of Brown Norway (BN) rats. The level of IL-6, IL-13, IL-1β, IL-12, IL-4, GRO/KC, MIP-1α, CM-CSF significantly increased in lung lavage fluid (P < 0.05 for all). Notably, we detected a slight impairment in spatial learning ability, as evidenced by the Barnes maze training outcomes. There were no significant changes in the bacterial community in lung lavage fluid (P = 0.621), but the bacterial community in the gut significantly changed (P < 0.001), with more species identified (P < 0.05). The metabolomic analysis revealed 147 and 149 significantly changed metabolites in the pulmonary system and serum, respectively (P < 0.05). PM2.5 exposure caused a decrease in Nervonic acid (NA) in both the lung and serum, which likely contributed to spatial learning impairment (P < 0.01). The correlation between lung metabolites, gut bacterial species, and serum metabolites indicated that PM2.5 exposure likely impaired spatial learning through the lung-gut-brain axis pathway. Lung and serum metabolic disorders and intestinal microbial imbalance occurred in BN rats post-five-month real-ambient PM2.5 exposure. There were two potential ways that PM2.5 exposure caused the decline of spatial learning ability in wild-type BN rats: (1) PM2.5 exposure led to a significant decrease of neuroprotective Nervonic acid in lung and serum metabolites. (2) PM2.5 exposure likely led to reduced spatial learning ability through the lung-gut-brain axis.

PMID:40147172 | DOI:10.1016/j.ecoenv.2025.118065

Categories: Literature Watch

Biases in Race and Ethnicity Introduced by Filtering Electronic Health Records for "Complete Data": Observational Clinical Data Analysis

Thu, 2025-03-27 06:00

JMIR Med Inform. 2025 Mar 27;13:e67591. doi: 10.2196/67591.

ABSTRACT

BACKGROUND: Integrated clinical databases from national biobanks have advanced the capacity for disease research. Data quality and completeness filters are used when building clinical cohorts to address limitations of data missingness. However, these filters may unintentionally introduce systemic biases when they are correlated with race and ethnicity.

OBJECTIVE: In this study, we examined the race and ethnicity biases introduced by applying common filters to 4 clinical records databases. Specifically, we evaluated whether these filters introduce biases that disproportionately exclude minoritized groups.

METHODS: We applied 19 commonly used data filters to electronic health record datasets from 4 geographically varied locations comprising close to 12 million patients to understand how using these filters introduces sample bias along racial and ethnic groupings. These filters covered a range of information, including demographics, medication records, visit details, and observation periods. We observed the variation in sample drop-off between self-reported ethnic and racial groups for each site as we applied each filter individually.

RESULTS: Applying the observation period filter substantially reduced data availability across all races and ethnicities in all 4 datasets. However, among those examined, the availability of data in the white group remained consistently higher compared to other racial groups after applying each filter. Conversely, the Black or African American group was the most impacted by each filter on these 3 datasets: Cedars-Sinai dataset, UK Biobank, and Columbia University dataset. Among the 4 distinct datasets, only applying the filters to the All of Us dataset resulted in minimal deviation from the baseline, with most racial and ethnic groups following a similar pattern.

CONCLUSIONS: Our findings underscore the importance of using only necessary filters, as they might disproportionally affect data availability of minoritized racial and ethnic populations. Researchers must consider these unintentional biases when performing data-driven research and explore techniques to minimize the impact of these filters, such as probabilistic methods or adjusted cohort selection methods. Additionally, we recommend disclosing sample sizes for racial and ethnic groups both before and after data filters are applied to aid the reader in understanding the generalizability of the results. Future work should focus on exploring the effects of filters on downstream analyses.

PMID:40146917 | DOI:10.2196/67591

Categories: Literature Watch

Women-driven community education in Nepal

Thu, 2025-03-27 06:00

Science. 2025 Mar 28;387(6741):1362. doi: 10.1126/science.ads8799. Epub 2025 Mar 27.

NO ABSTRACT

PMID:40146823 | DOI:10.1126/science.ads8799

Categories: Literature Watch

Growth-coupled continuous directed evolution by MutaT7 enables efficient and automated enzyme engineering

Thu, 2025-03-27 06:00

Appl Environ Microbiol. 2025 Mar 27:e0249124. doi: 10.1128/aem.02491-24. Online ahead of print.

ABSTRACT

Traditional directed evolution is limited by labor-intensive iterative steps and low-throughput selection and screening. To address these challenges, we developed a growth-coupled continuous directed evolution (GCCDE) approach, enabling automated and efficient enzyme engineering. By linking enzyme activity to bacterial growth and utilizing the MutaT7 system, GCCDE combines in vivo mutagenesis and high-throughput selection of superior enzyme variants in a single process. To validate this approach, we evolved the thermostable enzyme CelB from Pyrococcus furiosus to enhance its β-galactosidase activity at lower temperatures while maintaining thermal stability. CelB activity was coupled to the growth of E. coli, allowing variants with improved activity to utilize lactose more efficiently and promote faster growth in a minimal medium. Using a continuous culture system, we achieved automated high-throughput mutagenesis and simultaneous real-time selection of over 10⁹ variants per culture. Integrating in vitro and in vivo mutagenesis further increased genetic diversity, yielding CelB variants with significantly enhanced low-temperature activity compared to the wild type while preserving thermostability. DNA sequencing identified key mutations likely responsible for improved substrate binding and catalytic turnover. This GCCDE approach is broadly applicable for optimizing diverse enzymes, demonstrating the potential of automated continuous evolution for industrial and research applications.

IMPORTANCE: Enzyme engineering aims to develop enzymes with improved or novel traits, but traditional methods are slow and require repetitive manual steps. This study presents a faster, automated protein engineering approach. We utilized an in vivo mutagenesis technique, MutaT7 tools, to induce mutations in living bacteria and established a direct link between enzyme activity and bacterial growth. A continuous culture setup enables automated mutagenesis and growth-coupled selection of better-performing variants in real time. Bacteria with improved enzymes grew faster, selecting superior variants without manual intervention. Using this method, we engineered CelB with better performance at lower temperatures while maintaining thermal stability. By combining high-throughput mutagenesis and selection in a single process, this system bypasses iterative cycles of error-prone PCR, transformation, and screening. Our approach is adaptable to various enzymes, providing a faster and more efficient solution for enzyme engineering.

PMID:40145755 | DOI:10.1128/aem.02491-24

Categories: Literature Watch

Optogenetic control of Nodal signaling patterns

Thu, 2025-03-27 06:00

Development. 2025 Mar 27:dev.204506. doi: 10.1242/dev.204506. Online ahead of print.

ABSTRACT

A crucial step in early embryogenesis is the establishment of spatial patterns of signaling activity. Tools to perturb morphogen signals with high resolution in space and time can help reveal how embryonic cells decode these signals to make appropriate fate decisions. Here, we present new optogenetic reagents and an experimental pipeline for creating designer Nodal signaling patterns in live zebrafish embryos. Nodal receptors were fused to the light-sensitive heterodimerizing pair Cry2/CIB1N, and the Type II receptor was sequestered to the cytosol. The improved optoNodal2 reagents eliminate dark activity and improve response kinetics, without sacrificing dynamic range. We adapted an ultra-widefield microscopy platform for parallel light patterning in up to 36 embryos and demonstrated precise spatial control over Nodal signaling activity and downstream gene expression. Patterned Nodal activation drove precisely controlled internalization of endodermal precursors. Further, we used patterned illumination to generate synthetic signaling patterns in Nodal signaling mutants, rescuing several characteristic developmental defects. This study establishes an experimental toolkit for systematic exploration of Nodal signaling patterns in live embryos.

PMID:40145591 | DOI:10.1242/dev.204506

Categories: Literature Watch

BCG-derived acellular membrane vesicles elicit antimycobacterial immunity and innate immune memory

Thu, 2025-03-27 06:00

Front Immunol. 2025 Mar 12;16:1534615. doi: 10.3389/fimmu.2025.1534615. eCollection 2025.

ABSTRACT

Tuberculosis (TB) is one of the leading causes of death due to infectious disease. The sole established vaccine against TB is the Mycobacterium bovis Bacillus Calmette-Guerin (BCG) vaccine. However, owing to the lack of durable immunity with the BCG vaccine and its risk of infection, safer vaccines that can also be used as boosters are needed. Here, we examined whether membrane vesicles (MVs) from BCG (BCG-MVs) isolated from BCG statically cultured in nutrient-restricted Sauton's medium (s-MVs) and from BCG planktonically cultured in nutrient-rich medium commonly used in the laboratory (p-MVs) could be used as novel TB vaccines. MVs are extracellular vesicles produced by various bacteria, including mycobacteria. Differences in the culture conditions affected the morphology, contents, immunostimulatory activity and immunogenicity of BCG-MVs. s-MVs presented greater immunostimulatory activity than p-MVs via the induction of TLR2 signaling. Mouse immunization experiments revealed that s-MVs, but not p-MVs, induced mycobacterial humoral and mucosal immunity, especially when administered in combination with adjuvants. In a BCG challenge experiment using BCG Tokyo type I carrying pMV361-Km, subcutaneous vaccination with s-MVs reduced the bacterial burden in the mouse lung to a level similar to that after intradermal vaccination with live BCG. Furthermore, the administration of s-MVs induced a significant lipopolysaccharide-induced proinflammatory response in macrophages in vitro. These results indicate that BCG-MVs obtained from static culture in Sauton's medium induce not only humoral immunity against mycobacteria but also trained immunity, which can allow the clearance of infectious agents other than mycobacteria. Together, these findings highlight the immunological properties of BCG-MVs and the availability of acellular TB vaccines that confer broad protection against various infectious diseases.

PMID:40145097 | PMC:PMC11937015 | DOI:10.3389/fimmu.2025.1534615

Categories: Literature Watch

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