Systems Biology
From microbes to microbiomes: Applications for plant health and sustainable agriculture
Phytopathology. 2024 May 22. doi: 10.1094/PHYTO-02-24-0054-KC. Online ahead of print.
ABSTRACT
Plant-microbe interaction research has had a transformative trajectory, from individual microbial isolate studies to comprehensive analyses of plant microbiomes within the broader phytobiome framework. Acknowledging the indispensable role of plant microbiomes in shaping plant health, agriculture, and ecosystem resilience, we underscore the urgent need for sustainable crop production strategies in the face of contemporary challenges. We discuss how the synergies between advancements in 'omics technologies and artificial intelligence can help advance the profound potential of plant microbiomes. Furthermore, we propose a multifaceted approach encompassing translational considerations, transdisciplinary research initiatives, public-private partnerships, regulatory policy development, and pragmatic expectations for the practical application of plant microbiome knowledge across diverse agricultural landscapes. We advocate for strategic collaboration and intentional transdisciplinary efforts to unlock the benefits offered by plant microbiomes and address pressing global issues in food security. By emphasizing a nuanced understanding of plant microbiome complexities and fostering realistic expectations, we encourage the scientific community to navigate the transformative journey from discoveries in the laboratory to field applications. As companies specializing in agricultural microbes and microbiomes undergo shifts, we highlight the necessity of understanding how to approach sustainable agriculture with site-specific management solutions. While cautioning against over-promising, we underscore the excitement of exploring the many impacts of microbiome-plant interactions. We emphasize the importance of collaborative endeavors with societal partners to accelerate our collective capacity to harness the diverse and yet-to-be-discovered beneficial activities of plant microbiomes.
PMID:38776137 | DOI:10.1094/PHYTO-02-24-0054-KC
A Model of Gastric Mucosal pH Regulation: Extending Sensitivity Analysis Using Sobol' Indices to Understand Higher Moments
Bull Math Biol. 2024 May 22;86(7):77. doi: 10.1007/s11538-024-01308-x.
ABSTRACT
Several recent theoretical studies have indicated that a relatively simple secretion control mechanism in the epithelial cells lining the stomach may be responsible for maintaining a neutral (healthy) pH adjacent to the stomach wall, even in the face of enormous electrodiffusive acid transport from the interior of the stomach. Subsequent work used Sobol' Indices (SIs) to quantify the degree to which this secretion mechanism is "self-regulating" i.e. the degree to which the wall pH is held neutral as mathematical parameters vary. However, questions remain regarding the nature of the control that specific parameters exert over the maintenance of a healthy stomach wall pH. Studying the sensitivity of higher moments of the statistical distribution of a model output can provide useful information, for example, how one parameter may skew the distribution towards or away from a physiologically advantageous regime. In this work, we prove a relationship between SIs and the higher moments and show how it can potentially reduce the cost of computing sensitivity of said moments. We define γ -indices to quantify sensitivity of variance, skewness, and kurtosis to the choice of value of a parameter, and we propose an efficient strategy that uses both SIs and γ -indices for a more comprehensive sensitivity analysis. Our analysis uncovers a control parameter which governs the "tightness of control" that the secretion mechanism exerts on wall pH. Finally, we discuss how uncertainty in this parameter can be reduced using expert information about higher moments, and speculate about the physiological advantage conferred by this control mechanism.
PMID:38775877 | DOI:10.1007/s11538-024-01308-x
Growth-induced collective bending and kinetic trapping of cytoskeletal filaments
Cytoskeleton (Hoboken). 2024 May 22. doi: 10.1002/cm.21877. Online ahead of print.
ABSTRACT
Growth and turnover of actin filaments play a crucial role in the construction and maintenance of actin networks within cells. Actin filament growth occurs within limited space and finite subunit resources in the actin cortex. To understand how filament growth shapes the emergent architecture of actin networks, we developed a minimal agent-based model coupling filament mechanics and growth in a limiting subunit pool. We find that rapid filament growth induces kinetic trapping of highly bent actin filaments. Such collective bending patterns are long-lived, organized around nematic defects, and arise from competition between filament polymerization and bending elasticity. The stability of nematic defects and the extent of kinetic trapping are amplified by an increase in the abundance of the actin pool and by crosslinking the network. These findings suggest that kinetic trapping is a robust consequence of growth in crowded environments, providing a route to program shape memory in actin networks.
PMID:38775207 | DOI:10.1002/cm.21877
Confinement induces internal flows in adherent cell aggregates
J R Soc Interface. 2024 May;21(214):20240105. doi: 10.1098/rsif.2024.0105. Epub 2024 May 22.
ABSTRACT
During mesenchymal migration, F-actin protrusion at the leading edge and actomyosin contraction determine the retrograde flow of F-actin within the lamella. The coupling of this flow to integrin-based adhesions determines the force transmitted to the extracellular matrix and the net motion of the cell. In tissues, motion may also arise from convection, driven by gradients in tissue-scale surface tensions and pressures. However, how migration coordinates with convection to determine the net motion of cellular ensembles is unclear. To explore this, we study the spreading of cell aggregates on adhesive micropatterns on compliant substrates. During spreading, a cell monolayer expands from the aggregate towards the adhesive boundary. However, cells are unable to stabilize the protrusion beyond the adhesive boundary, resulting in retraction of the protrusion and detachment of cells from the matrix. Subsequently, the cells move upwards and rearwards, yielding a bulk convective flow towards the centre of the aggregate. The process is cyclic, yielding a steady-state balance between outward (protrusive) migration along the surface, and 'retrograde' (contractile) flows above the surface. Modelling the cell aggregates as confined active droplets, we demonstrate that the interplay between surface tension-driven flows within the aggregate, radially outward monolayer flow and conservation of mass leads to an internal circulation.
PMID:38774959 | DOI:10.1098/rsif.2024.0105
Addressing the Missing Links in Cardiovascular Aging
Clin Interv Aging. 2024 May 17;19:873-882. doi: 10.2147/CIA.S457180. eCollection 2024.
ABSTRACT
The aim of this manuscript is to provide a review of available options to enhance cardiovascular health and prevent cardiovascular disease (CVD) in the aging population using a systems-biology approach. These include the role of the gut microbiome, the early identification and removal of environmental toxins, and finally age related sex hormones and supplement replacement which all influence aging. Implementing such a comprehensive approach has the potential to facilitate earlier risk assessment, disease prevention, and even improve mortality. Further study in these areas will continue to advance our understanding and refine therapeutic interventions for a healthier cardiovascular aging process.
PMID:38774249 | PMC:PMC11107914 | DOI:10.2147/CIA.S457180
Concomitant diverticulosis among patients undergoing liver transplantation. Does it influence the length of hospitalization after the procedure?
Clin Exp Hepatol. 2023 Dec;9(4):344-350. doi: 10.5114/ceh.2023.132255. Epub 2023 Nov 13.
ABSTRACT
AIM OF THE STUDY: We tried to assess the influence of concomitant diverticulosis and other factors, e.g., Child-Pugh (C-P) and MELD scores, viral etiology, and presence of alcoholic disease, on short-term results of liver transplantation (LT) with an emphasis on duration of patient's hospitalization.
MATERIAL AND METHODS: This prospective study was performed on 206 cirrhotic patients who were selected for LT. In order to assess the presence of diverticculosis we performed colonoscopy.
RESULTS: The duration of hospitalization after LT did not differ significantly between patients with and without diverticulosis (27.5 [21.0-33.5] vs. 24.0 [18.0-32.0] days, p = 0.28). Patients with C-P class C were hospitalized longer in comparison to the class B patients. It is reflected in the positive correlation between C-P score and days of hospitalization (r = 0.22, p = 0.002). Patients with diverticulosis were significantly older (59.6 [51.1-63.3] vs. 52.9 [43.8-59.2] years, p = 0.03). Alcoholic liver disease (ALD) was associated with a greater risk of diverticulosis (OR = 3.89, 95% CI [1.13-15.87], p = 0.04).
CONCLUSIONS: Presence of diverticulosis among subjects undergoing LT did not influence the duration of hospitalization after the procedure. Significantly longer hospitalization was observed in patients with the most advanced liver disease according to C-P score. To determine the exact impact of diverticulosis on short-term results of LT additional studies are required.
PMID:38774193 | PMC:PMC11103805 | DOI:10.5114/ceh.2023.132255
<em>Procambarus virginalis</em> Lyko, 2017: A new threat to Iberian inland waters
Ecol Evol. 2024 May 20;14(5):e11362. doi: 10.1002/ece3.11362. eCollection 2024 May.
ABSTRACT
An eco-monitoring programme to assess faunal biodiversity in the main rivers of the northern Iberian Peninsula (Spain) reveals the first occurrence of the marbled crayfish Procambarus virginalis (Decapoda: Cambaridae) in Iberian inland waters. Iberian specimens have been identified by combining morphological and genetic traits. We discuss the most plausible pathways and introduction vectors, its potential invasiveness and subsequent impacts on host localities. Our preliminary results raise concern about the potential threat of P. virginalis to native fauna and ecosystem dynamics, as P. virginalis was found in an area of great cultural and ecological importance with relevant populations of endangered species. Due to the invasive history of the marbled crayfish, eradication of these individuals is urgent. This study confirms the importance of early warning systems for exotic species, keeping the population, forest guards and field technicians informed about potential invasive species to execute a rapid and effective response.
PMID:38774140 | PMC:PMC11106043 | DOI:10.1002/ece3.11362
A non-lipid nucleic acid delivery vector with dendritic cell tropism and stimulation
Theranostics. 2024 May 5;14(7):2934-2945. doi: 10.7150/thno.95267. eCollection 2024.
ABSTRACT
Rationale: Nucleic acid constructs are commonly used for vaccination, immune stimulation, and gene therapy, but their use in cancer still remains limited. One of the reasons is that systemic delivery to tumor-associated antigen-presenting cells (dendritic cells and macrophages) is often inefficient, while off-target nucleic acid-sensing immune pathways can stimulate systemic immune responses. Conversely, certain carbohydrate nanoparticles with small molecule payloads have been shown to target these cells efficiently in the tumor microenvironment. Yet, nucleic acid incorporation into such carbohydrate-based nanoparticles has proven challenging. Methods: We developed a novel approach using cross-linked bis succinyl-cyclodextrin (b-s-CD) nanoparticles to efficiently deliver nucleic acids and small-molecule immune enhancer to phagocytic cells in tumor environments and lymph nodes. Our study involved incorporating these components into the nanoparticles and assessing their efficacy in activating antigen-presenting cells. Results: The multi-modality immune stimulators effectively activated antigen-presenting cells and promoted anti-tumor immunity in vivo. This was evidenced by enhanced delivery to phagocytic cells and subsequent immune response activation in tumor environments and lymph nodes. Conclusion: Here, we describe a new approach to incorporating both nucleic acids and small-molecule immune enhancers into cross-linked bis succinyl-cyclodextrin (b-s-CD) nanoparticles for efficient delivery to phagocytic cells in tumor environments and lymph nodes in vivo. These multi-modality immune stimulators can activate antigen-presenting cells and foster anti-tumor immunity. We argue that this strategy can potentially be used to enhance anti-tumor efficacy.
PMID:38773971 | PMC:PMC11103498 | DOI:10.7150/thno.95267
Disease-specific prioritization of non-coding GWAS variants based on chromatin accessibility
HGG Adv. 2024 May 20:100310. doi: 10.1016/j.xhgg.2024.100310. Online ahead of print.
ABSTRACT
Non-protein-coding genetic variants are a major driver of the genetic risk for human disease; however, identifying which non-coding variants contribute to diseases and their mechanisms remains challenging. In-silico variant prioritization methods quantify a variant's severity, but for most methods the specific phenotype and disease-context of the prediction remain poorly defined. For example, many commonly used methods provide a single, organism-wide score for each variant, while other methods summarize a variant's impact in certain tissues and/or cell-types. Here we propose a complementary disease-specific variant prioritization scheme, which is motivated by the observation that variants contributing to disease often operate through specific biological mechanisms.
PMID:38773771 | DOI:10.1016/j.xhgg.2024.100310
The Contribution and Mechanism of Hypoxia /USP19/Beclin-1 Feed-Forward Loop in Cervical Cancer
Biophys J. 2024 May 20:S0006-3495(24)00328-X. doi: 10.1016/j.bpj.2024.05.014. Online ahead of print.
ABSTRACT
Cervical cancer ranks fourth in female mortality. Since the mechanisms for pathogenesis of cervical cancer are still poorly understood and the effective treatment options are lacking. Beclin-1 exhibits an inhibitory role in cervical cancer via suppressing the proliferation, invasion, and migration of cervical cancer cells. It is reported that the USP19 removes the K11-linked ubiquitination of Beclin-1 to protect Beclin-1 from proteasomal degradation. Interestingly, we found that hypoxia induced significant decrease of both Beclin-1 and USP19, suggesting that hypoxia could dually inhibit the protein level of Beclin-1 through a type 2 coherent feed-forward loop (C2-FFL, hypoxia ⊸ Beclin-1 integrating with hypoxia ⊸ USP19 → Beclin-1) to promote the occurrence and development of cervical cancer. Furthermore, mathematical modeling revealed that under the hypoxic environment of solid tumor, the hypoxia/ USP19/ Beclin-1 coherent feed-forward loop could significantly reduce the protein level of Beclin-1, greatly enhance the sensitivity of Beclin-1 to hypoxia, strikingly restrict the heterogeneity of Beclin-1, and contribute to the low positive rate of Beclin-1 in cervical cancer. It is expected to have significance for elucidating the underlying mechanisms of the occurrence and development of cervical cancer, and provide novel targets and strategies for prevention and treatment of cervical cancer.
PMID:38773770 | DOI:10.1016/j.bpj.2024.05.014
Single-Cell Patch-Clamp/Proteomics of Human Alzheimer's Disease iPSC-Derived Excitatory Neurons Versus Isogenic Wild-Type Controls Suggests Novel Causation and Therapeutic Targets
Adv Sci (Weinh). 2024 May 21:e2400545. doi: 10.1002/advs.202400545. Online ahead of print.
ABSTRACT
Standard single-cell (sc) proteomics of disease states inferred from multicellular organs or organoids cannot currently be related to single-cell physiology. Here, a scPatch-Clamp/Proteomics platform is developed on single neurons generated from hiPSCs bearing an Alzheimer's disease (AD) genetic mutation and compares them to isogenic wild-type controls. This approach provides both current and voltage electrophysiological data plus detailed proteomics information on single-cells. With this new method, the authors are able to observe hyperelectrical activity in the AD hiPSC-neurons, similar to that observed in the human AD brain, and correlate it to ≈1400 proteins detected at the single neuron level. Using linear regression and mediation analyses to explore the relationship between the abundance of individual proteins and the neuron's mutational and electrophysiological status, this approach yields new information on therapeutic targets in excitatory neurons not attainable by traditional methods. This combined patch-proteomics technique creates a new proteogenetic-therapeutic strategy to correlate genotypic alterations to physiology with protein expression in single-cells.
PMID:38773714 | DOI:10.1002/advs.202400545
Development and evaluation of Fusarium wilt-resistant and high-yielding chickpea advanced breeding line, KCD 11
Plant Genome. 2024 May 21:e20460. doi: 10.1002/tpg2.20460. Online ahead of print.
ABSTRACT
Fusarium wilt (FW) is the most severe soil-borne disease of chickpea that causes yield losses up to 100%. To improve FW resistance in JG 11, a high-yielding variety that became susceptible to FW, we used WR 315 as the donor parent and followed the pedigree breeding method. Based on disease resistance and yield performance, four lines were evaluated in station trials during 2017-2018 and 2018-2019 at Kalaburagi, India. Further, two lines, namely, Kalaburagi chickpea desi 5 (KCD 5) and KCD 11, which possesses the resistance allele for a specific single-nucleotide polymorphism marker linked with FW resistance, were evaluated across six different locations (Bidar, Kalaburagi, Raichur, Siruguppa, Bhimarayanagudi and Hagari) over a span of 3 years (2020-2021, 2021-2022 and 2022-2023). KCD 11 exhibited notable performance, showcasing yield advantages of 8.67%, 11.26% and 23.88% over JG 11, and the regional checks Super Annigeri 1 (SA 1) and Annigeri 1, respectively, with enhanced FW resistance in wilt sick plot. Further, KCD 11 outperformed JG 11, SA 1 and Annigeri 1 in multi-location trials conducted across three seasons in the North Eastern Transition Zone, North Eastern Dry Zone, and North Dry Zones of Karnataka. KCD 11 was also tested in trials conducted by All India Coordinated Research Project on chickpea and was also nominated for state varietal trials for its release as a FW-resistant and high-yielding variety. The selected line is anticipated to cater the needs of chickpea growers with the dual advantage of yield increment and disease resistance.
PMID:38773690 | DOI:10.1002/tpg2.20460
Biologically informed NeuralODEs for genome-wide regulatory dynamics
Genome Biol. 2024 May 21;25(1):127. doi: 10.1186/s13059-024-03264-0.
ABSTRACT
BACKGROUND: Gene regulatory network (GRN) models that are formulated as ordinary differential equations (ODEs) can accurately explain temporal gene expression patterns and promise to yield new insights into important cellular processes, disease progression, and intervention design. Learning such gene regulatory ODEs is challenging, since we want to predict the evolution of gene expression in a way that accurately encodes the underlying GRN governing the dynamics and the nonlinear functional relationships between genes. Most widely used ODE estimation methods either impose too many parametric restrictions or are not guided by meaningful biological insights, both of which impede either scalability, explainability, or both.
RESULTS: We developed PHOENIX, a modeling framework based on neural ordinary differential equations (NeuralODEs) and Hill-Langmuir kinetics, that overcomes limitations of other methods by flexibly incorporating prior domain knowledge and biological constraints to promote sparse, biologically interpretable representations of GRN ODEs. We tested the accuracy of PHOENIX in a series of in silico experiments, benchmarking it against several currently used tools. We demonstrated PHOENIX's flexibility by modeling regulation of oscillating expression profiles obtained from synchronized yeast cells. We also assessed the scalability of PHOENIX by modeling genome-scale GRNs for breast cancer samples ordered in pseudotime and for B cells treated with Rituximab.
CONCLUSIONS: PHOENIX uses a combination of user-defined prior knowledge and functional forms from systems biology to encode biological "first principles" as soft constraints on the GRN allowing us to predict subsequent gene expression patterns in a biologically explainable manner.
PMID:38773638 | DOI:10.1186/s13059-024-03264-0
The Evolution of Mouse Models of Cancer: Past, Present, and Future
Cold Spring Harb Perspect Med. 2024 May 21:a041736. doi: 10.1101/cshperspect.a041736. Online ahead of print.
ABSTRACT
In the nearly 50 years since the original models of cancer first hit the stage, mouse models have become a major contributor to virtually all aspects of cancer research, and these have evolved well beyond simple transgenic or xenograft models to encompass a wide range of more complex models. As the sophistication of mouse models has increased, an explosion of new technologies has expanded the potential to both further develop and apply these models to address major challenges in cancer research. In the current era, cancer modeling has expanded to include nongermline genetically engineered mouse models (GEMMs), patient-derived models, organoids, and adaptations of the models better suited for cancer immunology research. New technologies that have transformed the field include the application of CRISPR-Cas9-mediated genome editing, in vivo imaging, and single-cell analysis to cancer modeling. Here, we provide a historical perspective on the evolution of mouse models of cancer, focusing on how far we have come in a relatively short time and how new technologies will shape the future development of mouse models of cancer.
PMID:38772706 | DOI:10.1101/cshperspect.a041736
Lineage-specific splicing regulation of MAPT gene in the primate brain
Cell Genom. 2024 May 13:100563. doi: 10.1016/j.xgen.2024.100563. Online ahead of print.
ABSTRACT
Divergence of precursor messenger RNA (pre-mRNA) alternative splicing (AS) is widespread in mammals, including primates, but the underlying mechanisms and functional impact are poorly understood. Here, we modeled cassette exon inclusion in primate brains as a quantitative trait and identified 1,170 (∼3%) exons with lineage-specific splicing shifts under stabilizing selection. Among them, microtubule-associated protein tau (MAPT) exons 2 and 10 underwent anticorrelated, two-step evolutionary shifts in the catarrhine and hominoid lineages, leading to their present inclusion levels in humans. The developmental-stage-specific divergence of exon 10 splicing, whose dysregulation can cause frontotemporal lobar degeneration (FTLD), is mediated by divergent distal intronic MBNL-binding sites. Competitive binding of these sites by CRISPR-dCas13d/gRNAs effectively reduces exon 10 inclusion, potentially providing a therapeutically compatible approach to modulate tau isoform expression. Our data suggest adaptation of MAPT function and, more generally, a role for AS in the evolutionary expansion of the primate brain.
PMID:38772368 | DOI:10.1016/j.xgen.2024.100563
REM sleep: Out-dreaming fear
Curr Biol. 2024 May 20;34(10):R510-R512. doi: 10.1016/j.cub.2024.04.033.
ABSTRACT
The ability to forget fear-inducing situations is essential for adapting to our environment, but the neural mechanisms underlying 'fear forgetting' remain unclear. Novel findings reveal that the activity of the infralimbic cortex - specifically during REM sleep - contributes to the extinction of fear memory.
PMID:38772341 | DOI:10.1016/j.cub.2024.04.033
Plant-fungus symbiosis: One receptor to switch on the green light
Curr Biol. 2024 May 20;34(10):R507-R509. doi: 10.1016/j.cub.2024.04.013.
ABSTRACT
Arbuscular mycorrhiza, an ancient symbiosis with soil fungi, support mineral nutrition in most plants. How roots recognize such symbiotic fungi has long been debated. Recent research identifies a Medicago truncatula receptor as a key player in triggering symbiont accommodation responses.
PMID:38772340 | DOI:10.1016/j.cub.2024.04.013
A chemical probe to modulate human GID4 Pro/N-degron interactions
Nat Chem Biol. 2024 May 21. doi: 10.1038/s41589-024-01618-0. Online ahead of print.
ABSTRACT
The C-terminal to LisH (CTLH) complex is a ubiquitin ligase complex that recognizes substrates with Pro/N-degrons via its substrate receptor Glucose-Induced Degradation 4 (GID4), but its function and substrates in humans remain unclear. Here, we report PFI-7, a potent, selective and cell-active chemical probe that antagonizes Pro/N-degron binding to human GID4. Use of PFI-7 in proximity-dependent biotinylation and quantitative proteomics enabled the identification of GID4 interactors and GID4-regulated proteins. GID4 interactors are enriched for nucleolar proteins, including the Pro/N-degron-containing RNA helicases DDX21 and DDX50. We also identified a distinct subset of proteins whose cellular levels are regulated by GID4 including HMGCS1, a Pro/N-degron-containing metabolic enzyme. These data reveal human GID4 Pro/N-degron targets regulated through a combination of degradative and nondegradative functions. Going forward, PFI-7 will be a valuable research tool for investigating CTLH complex biology and facilitating development of targeted protein degradation strategies that highjack CTLH E3 ligase activity.
PMID:38773330 | DOI:10.1038/s41589-024-01618-0
RNA-binding protein PTENα blocks RIG-I activation to prevent viral inflammation
Nat Chem Biol. 2024 May 21. doi: 10.1038/s41589-024-01621-5. Online ahead of print.
ABSTRACT
A timely inflammatory response is crucial for early viral defense, but uncontrolled inflammation harms the host. Retinoic acid-inducible gene I (RIG-I) has a pivotal role in detecting RNA viruses, yet the regulatory mechanisms governing its sensitivity remain elusive. Here we identify PTENα, an N-terminally extended form of PTEN, as an RNA-binding protein with a preference for the CAUC(G/U)UCAU motif. Using both in vivo and in vitro viral infection assays, we demonstrated that PTENα restricted the host innate immune response, relying on its RNA-binding capacity and phosphatase activity. Mechanistically, PTENα directly bound to viral RNA and enzymatically converted its 5'-triphosphate to 5'-monophosphate, thereby reducing RIG-I sensitivity. Physiologically, brain-intrinsic PTENα exerted protective effects against viral inflammation, while peripheral PTENα restricted host antiviral immunity and, to some extent, promoted viral replication. Collectively, our findings underscore the significance of PTENα in modulating viral RNA- and RIG-I-mediated immune recognition, offering potential therapeutic implications for infectious diseases.
PMID:38773328 | DOI:10.1038/s41589-024-01621-5
Recognition of antiepileptic brivaracetam by synaptic vesicle protein 2A
Cell Discov. 2024 May 21;10(1):56. doi: 10.1038/s41421-024-00686-9.
NO ABSTRACT
PMID:38773074 | DOI:10.1038/s41421-024-00686-9