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At least 19 recordsLinked to original sources

Network oscillatory dynamics accompany cerebral bioenergetic defence in hypoxia.

A network physiology framework investigated how coordinated interactions among multiple organ systems collectively support the preservation of cerebral bioenergetic function and better distinguish adaptive from maladaptive responses to hypoxia. Twelve healthy males were passively exposed to 6 h of normoxia (21% O2) and hypoxia (12% O2) in a randomised, single-blind, crossover design. Venous blood was assayed for oxidative-nitrosative stress (OXNOS, spectroscopy/chemiluminescence) and neurovascular unit (hs-ELISA) biomarkers. Global cerebral delivery of O2 and glucose were determined by duplex ultrasound. Clinical acute mountain sickness (AMS+) was diagnosed in five participants. Cerebral substrate delivery was well maintained in both hypoxia and AMS+ (p < 0.05 vs normoxia and AMS-) despite marked arterial hypoxemia. Bioenergetic defence coincided with pronounced elevations in the spectral amplitude and phase synchronisation of very low-frequency oscillations (VLFOs, 0.03-0.06 Hz), which were evident across multiple organ systems and most prominent within the cerebral network. Systemic VLFOs were further exaggerated and more functionally connected in AMS+ in the absence of exaggerated systemic OXNOS or structural damage/destabilisation of the neurovascular unit (both p < 0.05 vs normoxia and AMS-). Collectively, these findings suggest that AMS, while characterised by debilitating symptomatology, may reflect a neuroprotective adaptive as opposed to pathologically maladaptive phenotype.

Humans

The subcellular location, maturation and response to increased plasma glucagon of ruthenium red-insensitive calcium-ion transport in rat liver.

1. The subcellular distribution and maturation of Ruthenium Red-insensitive Ca(2+) transport activity were determined in livers of rats ranging in age from 3 days pre-term to 10 weeks of adult life and compared with those of glucose 6-phosphatase, 5'-nucleotidase and Ruthenium Red-sensitive Ca(2+) transport. Initial rates of Ruthenium Red-insensitive Ca(2+) transport were highest in those fractions enriched in glucose 6-phosphatase, i.e. the microsomal fraction; this fraction was devoid of Ruthenium Red-sensitive Ca(2+) transport activity. Although the heaviest fraction (nuclear) contained significant amounts of 5'-nucleotidase activity it was devoid of Ruthenium Red-insensitive Ca(2+) transport activity. 2. Foetal rat liver contain minimal amounts of Ruthenium Red-insensitive Ca(2+) transport activity, glucose 6-phosphatase and 5'-nucleotidase activities. These begin to be expressed concomitantly soon after birth; Ruthenium Red-insensitive Ca(2+) transport is maximal by 3 to 4 days and remains so for up to at least 10 weeks of adult life. Glucose 6-phosphatase also reaches a peak at 3-4 days, but then rapidly decreases to approach adult values. Maximal activity of 5'-nucleotidase in the microsomal and nuclear fractions is seen about 4-6 days after birth; this enzyme activity remains increased for up to about 10 days and then falls, but not as rapidly as glucose 6-phosphatase. It is tentatively suggested that the bulk of the Ruthenium Red-insensitive Ca(2+) transport is attributable to the system derived from the endoplasmic reticulum. 3. Administration of glucagon to adult rats enhances by 2-3-fold the initial rate of Ruthenium Red-insensitive Ca(2+) transport in the intermediate but not the microsomal fraction. The hormone-induced effect is fully suppressed by co-administration of puromycin, is dose-dependent with half-maximal response at approx. 1mug of glucagon/100g body wt. and time-dependent exhibiting a half-maximal response about 1h after administration of the hormone. 4. Ruthenium Red-insensitive Ca(2+) transport in the post-mitochondrial fraction of foetal liver also responds to the administration in situ of glucagon. The response, which also is prevented by co-administration of puromycin, is maximal in those foetuses nearing term. The suggestion is made that these effects of the hormone on Ruthenium Red-insensitive Ca(2+) transport are an integral part of the physiological network in the liver cell.

Animals

Integrative Multidimensional Profiling of Individuals Recovered from Mild COVID-19 Reveals Immune-Metabolic-Oxidative Network Interactions.

The COVID-19 pandemic underscored the need to better characterize immune and molecular responses following SARS-CoV-2 infection and vaccination. Beyond antibody and cellular immunity, COVID-19 involves oxidative stress and DNA damage, affecting repair mechanisms and metabolic adaptation linked to immune resilience. Here, we present a multidimensional analysis of 20 individuals who recovered from mild COVID-19, integrating clinical features with humoral and cellular immune responses, T cell and myeloid phenotypes, oxidative stress, DNA damage, and metabolomic and lipidomic profiles. Although most individual parameters fell within physiological ranges, network modeling revealed structured associations spanning multiple biological domains. A central finding was a coherent cluster organized around vaccine dose number, linking anti-Spike antibody titers, oxidative stress, bioenergetic signatures, and granulocyte activation. Higher vaccination was associated with stronger humoral responses, lower oxidative stress, and a more balanced myeloid-metabolic profile, suggesting a potential protective role extending beyond antibody induction. Additional associations linked symptom patterns to T cell differentiation states, anti-nucleocapsid responses to systemic inflammation, and anaerobic signatures to DNA damage markers, revealing interconnections between immunometabolism, clinical expression, and genomic stress. Despite the small sample size, these findings offer a preliminary systems-level perspective on mild COVID-19 recovery and illustrate the value of integrative exploratory frameworks in infectious disease research, laying the groundwork for validation in larger longitudinal cohorts.

Humans

The genomic alchemist's arsenal: A comprehensive review of gene recruitment, regulatory rewiring, and the evolutionary arms race in snake envenomation.

Snake venom represents a striking example of evolutionary innovation, in which ancestral physiological gene networks have been co-opted into potent biochemical weapons. Advances in multi-omics, single-cell genomics, and structural bioinformatics have catalyzed a conceptual shift from descriptive toxin cataloging to a systems-level understanding of venom evolution, regulation, and function. This Review integrates genomic, cellular, and structural perspectives to delineate the molecular architecture underpinning venom diversification and target-site co-evolution. Emphasis is placed on regulatory mechanisms driving rapid expression plasticity, including super-enhancer activity, transposable element insertion, spatial heterogeneity within the venom gland, and non-coding RNA-mediated modulation. At the protein level, the review examines how hypervariable toxins engage in structural arms races with prey targets, and how multi-toxin complex formation, functional synergy, and molecular dynamics simulations inform models of lethality and resistance. A comparative framework is provided by contrasting high-potency predatory snake venoms with low-potency defensive venoms of hymenopterans such as bees and wasps, revealing how ecological selective pressures shape toxin potency, composition, and target specificity across taxa. Finally, current translational strategies are evaluated, with a focus on the relative merits of recombinant human monoclonal antibodies versus catalytic-site small-molecule inhibitors as deployable interventions for snakebite. By synthesizing evolutionary genomics, structural biology, comparative toxinology, and synthetic antivenomics, this Review outlines a predictive framework for anticipating venom evolutionary trajectories and for designing broad-spectrum, next-generation therapeutics.

Animals

Pattern generation in the lobster (Panulirus) stomatogastric ganglion. II. Pyloric network simulation.

1. Results from the companion paper were incorporated into a physiologically realistic computer model of the three principal cell types (PD/AB, LP, PY) of the pyloric network in the stomatogastric ganglion. Parameters for the model were mostly calculated (sometimes estimated) from experimental data rather than fitting the model to observed output patterns. 2. The initial run was successful in predicting several features of the pyloric pattern: the observed gap between PD and LP bursts, the appropriate sequence of the activity periods (PD, LP, PY), and a substantial PY burst not properly simulated by an earlier model. 3. The major discrepancy between model and observed patterns was the too-early occurrence of the PY burst, which resulted in a much shortened LP burst. Motivated by this discrepancy, additional investigations were made of PY properties. A hyperpolarization-enabled depolarization-activated hyperpolarizing conductance change was discovered which may make an important contribution to the late phase of PY activity in the normal burst cycle. Addition of this effect to the model brought its predictions more in line with observed patterns. 4. Other discrepancies between model and observation were instructive and are discussed. The findings force a substantial revision in previously held ideas on pattern production in the pyloric system. More weight must be given to functional properties of individual neurons and less to properties arising purely from network interactions. This shift in emphasis may be necessary in more complicated systems as well. 5. An example has been provided of the value quantitative modeling can be to network physiology. Only through rigorous quantitative testing can qualitative theories of how the nervous system operates be substantiated.

Animals

Dynamic and non-additive gene regulation shapes maize responses to simultaneous salt and cold stress.

Salt and cold stresses often occur together in nature and severely impact crop productivity, yet their transcriptional regulation remains poorly understood. Here, we conducted a time-series transcriptomic analysis of maize under salt, cold, and their combination at 0, 6, 12, and 24&#xa0;h. Differential expression analysis revealed dynamic, condition-specific gene responses grouped into eight distinct temporal patterns. Promoter motif analysis of genes within each pattern identified 5-39 significantly enriched motifs, with over 40% lacking known counterparts, suggesting the involvement of previously uncharacterized cis-regulatory elements in stress-responsive transcriptional regulation. By comparing combined stress responses to the sum of single-stress effects, we found that about 74% of DEGs showed non-additive patterns, suggesting that combined stress triggers a distinct transcriptional program. Evolutionary analysis showed that additive DEGs tend to be more recently evolved, subject to weaker purifying selection, and enriched in transposed duplications, contrasting with the stronger constraint observed in non-additive DEGs. WGCNA identified 24 co-expression modules, among which 65 hub DEGs were detected in modules significantly correlated with specific stress conditions. Furthermore, we reconstructed 228, 20, and 200 sequential transcription factor cascades spanning 6&#xa0;h, 12&#xa0;h, and 24&#xa0;h under cold, salt, and combined stress, respectively, with no cascade shared across all three conditions. Together, these results reveal that maize responses to combined salt and cold stress are largely non-additive and temporally dynamic, with distinct evolutionary patterns underlying different response types, offering insights and candidate regulators for enhancing crop stress resilience.

Zea mays

Autoimmunity and the immunologic network.

Recent developments in autoimmunity suggest that there are three stages in the response to self, which can be called autorecognition, autoimmunity, and autoimmune disease. The first is physiologic and fundamental to a network theory of immunologic control that is based upon recognition of idiotypes and antigens related to the major histocompatibility complex. Many foreign antigens may be recognized immunologically only if they can be imposed upon an existing network of immunologic communication. The existence of anti-receptor autoimmune diseases (such as myasthenia gravis and Grave's disease) leads to the postulate that the immune network may normally function to help regulate hormone and other nonimmune cell surface receptors. Chronic autoimmune diseases may be caused either by genetically determined abnormalities in the immune network or by an antigenic perturbation of the network that results in unresponsiveness and tolerance of an offending agent.

Animals

Transcriptomics reveals species-specific adaptive strategies to calorie restriction in two Argopecten scallops with distinct lifespans.

Calorie restriction (CR) is a well-established non-genetic intervention for lifespan extension in multiple model organisms. Seasonal food shortage in cold and temperate seas may mimic CR, inducing in bivalves a response similar to that in vertebrates and thereby prolonging life expectancy. However, the relationship and the mechanism underlying the food availability and lifespan in bivalves remain largely unexplored. Two closely related scallop species the short-lived warm-water Argopecten irradians (lifespan <2&#xa0;years) and the longer-lived cold-water Argopecten purpuratus (7-10&#xa0;years) provide an ideal comparative system to investigate species-specific adaptive strategies. In this study, we subjected both species to CR for 30 and 56&#xa0;days and performed comparative transcriptomic profiling, weighted gene co-expression network analysis (WGCNA), and physiological assays to elucidate their distinct molecular responses. Transcriptomic analysis revealed that A. purpuratus exhibited substantially more DEGs than A. irradians at both time points under CR, with both species showing downregulation of metabolic pathways but to different extents. A. irradians mounted an early nutrient-sensing response at 30&#xa0;days (IGF1R, PIK3R3, INSR suppression), indicating acute sensitivity to limitation; by contrast, A. purpuratus displayed delayed FoxO activation at 56&#xa0;days, along with its downstream effectors NFKBIA, CREB3L4, and SMAD4, suggesting a gradual adaptive program may link to its extended lifespan. WGCNA identified three negatively correlated modules in each species, with coral2 being the most prominent in A. irradians and darkolivegreen in A. purpuratus. The former was dominated by ciliary motility genes, whereas the latter featured coordinated repression of oxidative phosphorylation. Additionally, both species exhibited conserved suppression of mTOR/S6K growth signaling and activation of cellular maintenance programs. Collectively, these findings expand the understanding of CR-mediated longevity regulation in bivalves and provide candidate gene resources for future functional studies and breeding programs.

Pectinidae

Cooperative anaerobic catabolism of chlorinated organic compounds: implications for sustainable bioremediation.

Biodegradation research historically followed a reductionist approach focused on axenic (pure) cultures capable of catabolizing the specific contaminant(s) of interest. While this approach has substantially advanced our understanding of the microbiology, physiology, biochemistry, and genetics of contaminant degradation under laboratory conditions, it does not capture the complexity of natural and engineered environments. During in situ bioremediation, microbiomes are exposed to mixtures of contaminants, and microbial interactions profoundly influence contaminant transformation and fate. In anoxic environments, degradation of chlorinated compounds is often sustained by metabolic cooperation among taxonomically and physiologically distinct microorganisms. Through the exchange of metabolites such as hydrogen, formate, acetate, and other nutrients, microbial populations establish interdependent networks that overcome thermodynamic and physiological constraints, enabling self-sustaining systems of contaminant transformations that would be inefficient or impossible with individual organisms. We highlight examples of microbial interactions that underpin anaerobic catabolism of chlorinated contaminants, including systems resulting in self-sustained anaerobic bioremediation.

Biodegradation, Environmental

A generalized higher-order correlation analysis framework for multi-omics network inference.

Multiple -omics (genomics, proteomics, etc.) profiles are commonly generated to gain insight into a disease or physiological system. Constructing multi-omics networks with respect to the trait(s) of interest provides an opportunity to understand relationships between molecular features but integration is challenging due to multiple data sets with high dimensionality. One approach is to use canonical correlation to integrate one or two omics types and a single trait of interest. However, these types of methods may be limited due to (1) not accounting for higher-order correlations existing among features, (2) computational inefficiency when extending to more than two omics data when using a penalty term-based sparsity method, and (3) lack of flexibility for focusing on specific correlations (e.g., omics-to-phenotype correlation versus omics-to-omics correlations). In this work, we have developed a novel multi-omics network analysis pipeline called Sparse Generalized Tensor Canonical Correlation Analysis Network Inference (SGTCCA-Net) that can effectively overcome these limitations. We also introduce an implementation to improve the summarization of networks for downstream analyses. Simulation and real-data experiments demonstrate the effectiveness of our novel method for inferring omics networks and features of interest.

Genomics

CRISPR screens for the discovery of novel ferroptosis targets: progress and perspectives.

Ferroptosis is a distinct, iron-dependent form of regulated cell death characterized by lipid peroxidation. Despite its growing significance in physiology and disease, the molecular networks that govern ferroptosis are not yet fully understood. Genome-wide CRISPR screens have broadened the regulatory landscape of ferroptosis by revealing both conserved and context-dependent mechanisms. In this review, we summarize recent advances in CRISPR-based ferroptosis screens, highlighting a transition from in vitro CRISPR screens to in vivo platforms and single-cell CRISPR screens. We also discuss the potential translation of key targets, focusing on their structural druggability and therapeutic potential. By outlining objective-driven screening strategies, this review seeks to provide options for exploring the distinct mechanisms of ferroptosis and to accelerate its translation into therapeutic opportunities for various diseases.

CRISPR screens

Evolutionary Reorganization of Transcriptomic Architecture Across a UVB Tolerance Gradient in Fish.

Environmental stressors such as ultraviolet radiation impose strong selective pressures on organisms, yet how adaptation to such stressors shapes transcriptomic responses at the network level remains poorly understood. Although stratospheric ozone is recovering globally, substantial regional variation in UV exposure persists, particularly in high-altitude environments where extreme UV levels can occur. Here, we compared three fish models representing distinct biological responses to UVB exposure: wild-type zebrafish (Danio rerio), a melanin-deficient zebrafish mutant (nacre) lacking a major protective mechanism against UVB damage, and the high-altitude Andean killifish Orestias ascotanensis, a species naturally exposed to extreme UVB radiation. Together, these models define a gradient spanning physiological protection, impaired protection, and evolutionary adaptation to UVB stress. Using RNA-seq and protein-protein interaction networks, we show that transcriptomic responses differ markedly across this gradient. Wild-type and nacre zebrafish exhibited relatively limited transcriptomic changes (&#x223c;2%-2.4% of genes changing), whereas O. ascotanensis displayed a large-scale and highly coordinated response (&#x223c;21.6% of genes changing) characterized by functionally specialized networks enriched in DNA repair pathways. These differences involved not only transcriptomic magnitude but also marked reorganization of transcriptomic architecture. Integration with positive selection analyses revealed that positively selected genes were concentrated within highly interconnected regions of transcriptomic networks, consistent with adaptation involving network reorganization. Furthermore, ortholog-based analyses suggest that adaptive responses involve differential reorganization of a conserved functional background. Together, our results support a model in which adaptation to environmental stress is associated with the reorganization of conserved transcriptomic networks across physiological and evolutionary contexts, providing a systems-level perspective on the molecular basis of adaptation.

UVB radiation

Competition and cooperation: The plasticity of bacterial interactions across environments.

Bacteria live in diverse communities, forming complex networks of interacting species. A central question in bacterial ecology is whether species engage in cooperative or competitive interactions. But this question often neglects the role of the environment. Here, we use genome-scale metabolic networks from two different open-access collections (AGORA and CarveMe) to assess pairwise interactions of different microbes in varying environmental conditions (provision of different environmental compounds). By computationally simulating thousands of environments for 10,000 pairs of bacteria from each collection, we found that most pairs were able to both compete and cooperate depending on the availability of environmental resources. This modeling approach allowed us to determine commonalities between environments that could facilitate the potential for cooperation or competition between a pair of species. Namely, cooperative interactions, especially obligate, were most common in less diverse environments. Further, as compounds were removed from the environment, we found interactions tended to degrade towards obligacy. However, we also found that on average at least one compound could be removed from an environment to switch the interaction from competition to facultative cooperation or vice versa. Together our approach indicates a high degree of plasticity in microbial interactions in response to the availability of environmental resources.

Microbial Interactions

A hypothetical explanation of saccadic oscillations.

Eye movements in a patient with saccadic oscillations (ocular flutter) were recorded and analyzed. Findings were related to recent microelectrode studies in the monkey pontine reticular formation which have identified three types of premotor neurons related to saccadic eye movements: burst, tonic, and pause cells. We incorporated these cell types into a hypothetical circuit that generates saccades by rapidly driving the eye to a designated orbital position rather than preprogramming a distance for movement. Physiological measurements suggest that this neural network is unstable and that the burst neurons must be tonically inhibited to prevent saccadic oscillations during periods of fixation. Pause cells, which discharge tonically except during saccades, when they pause, appear to inhibit burst cells and prevent such saccadic oscillations. Analysis of our patient's behavior indicates that many types of saccadic oscillations can be explained and classified by assuming an abnormality of pause cell control over saccadic burst neurons.

Adult

Stepping out of the dark: how metabolomics shed light on fungal biology.

Metabolomics, a critical tool for analyzing small-molecule metabolites, integrates with genomics, transcriptomics, and proteomics to provide a systems-level understanding of fungal biology. By mapping metabolic networks, it elucidates regulatory mechanisms driving physiological and ecological adaptations. In fungal pathogenesis, metabolomics reveals host-pathogen dynamics, identifying virulence factors like gliotoxin in Aspergillus fumigatus and metabolic shifts, such as glyoxylate cycle upregulation in Candida albicans. Ecologically, it highlights fungal responses to abiotic stressors, including osmolyte production like trehalose, enhancing survival in extreme environments. These insights highlight metabolomics' role in decoding fungal persistence and niche colonization. In drug discovery, it aids target identification by profiling biosynthetic pathways, supporting novel antifungal and nanostructured therapy development. Combined with multi-omics, metabolomics advances insights into fungal pathogenesis, ecological interactions, and therapeutic innovation, offering translational potential for addressing antifungal resistance and improving treatment outcomes for fungal infections. Its progress shed light on complex fungal molecular profiles, advancing discovery and innovation in fungal biology.

Metabolomics

Ultrastructural basis for alveolar-capillary permeability to protein.

The intravenous injection into mice of small volumes (less than 0.1 ml) of peroxidatic enzymes of molecular weight of 40 000 daltons or greater results in little if any penetration of these probe molecules into endothelial junctions. The injection of cytochrome c (12 000 daltons), on the other hand, results in the localization of this tracer in some but not all endothelial junctions. When horseradish peroxidase (EC 1.11.1.7) is injected in a large volume of saline (0.5 ml), reaction product is present in endothelial junctions and basement membrane, but is prevented from entering the alveolar space by zonulae occludentes between epithelial cells. These experiments indicate that although endothelial junctions, under physiological conditions, are largely impermeable to molecules the size of horseradish peroxidase, and presumably most serum proteins, they are labile and susceptible to stretching if intravascular pressure is increased. Freeze-fracture studies show that pulmonary capillary endothelial junctions are composed of one or at the most two strands which show areas of discontinuity. Epithelial junctions, by contrast, are composed of a continuous, complex network of anastomosing fibres. These observations confirm physiological experiments which indicate that it is the pulmonary epithelium rather than the endothelium which determines the permeability properties of the alveolar-capillary membrane to lipid-insoluble molecules. Bidirectional pinocytic transport is an additional mechanism whereby lipid-insoluble molecules are transported across both endothelial and epithelial layers. The relative contribution of this transport mechanism to the total amount transported remains to be established.

Animals