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Song, Y.

Publications and source records attributed to Song, Y..

At least 73 records · Page 4Linked to original sources

ACE-2-like Enzymatic Activity in Anti-SARS-CoV-2 Spike Protein Monoclonal Antibodies

Many people with acute COVID-19 have clinical disease not clearly attributable to viral replication and many COVID-19 convalescents are affected by post-acute sequelae of COVID-19 (PASC, or long COVID, LC). LC has severely affected public health and economies worldwide. Features of LC including blood pressure dysregulation, coagulopathies, high levels of inflammation, and neuropsychiatric complaints. The mechanisms responsible for the pathogenesis of some of COVID-19s clinical features and LC have not been well established. The host cell receptor for SARS-CoV-2 is human angiotensin converting enzyme 2 (ACE2), which binds the SARS-CoV-2 spike protein receptor-binding domain (RBD) to initiate infection. We hypothesized that some people may produce anti-RBD antibodies that sufficiently resemble ACE2 structure to have ACE2-like catalytic activity after infection. Those antibodies, ACE2-like abzymes, may contribute to the pathogenesis of LC. Our previous studies showed that ACE2-like activity was associated with immunoglobulin in some acute and convalescent COVID-19 patients. ACE2-like catalytic activity correlated with blood pressure changes following a moderate exercise challenge in people convalescing from COVID-19. To further establish that ACE2-like activity could be attributed to antibodies, we screened human monoclonal antibodies (mAbs) against SARS-CoV-2 spike protein from 3 different research centers and others purchased from a commercial source for ACE2-like catalytic activity. We identified 4 human monoclonal antibodies with ACE2-like catalytic activity. The ACE2-like catalytic activity of these mAbs was not inhibited by MLN-4760, a compound that inhibits native human ACE2 catalytic activity, nor by EDTA, unlike native ACE2, a Zinc metalloprotease, but was inhibited by an overlapping pool of spike peptides. Enzyme kinetic studies showed that the mAbs had substantially lower Vmax and Km values than native ACE2. The data therefore suggested that the antibodies cleave ACE2 substrate via a different mechanism than native ACE2. The identification of specific mAbs with ACE2-like catalytic activity supports the hypothesis that antibodies induced by SARS-CoV-2 infection could help mediate the pathogenesis of COVID-19 and LC, and more generally, the hypothesis that catalytic antibodies induced by infectious agents can contribute to disease pathogenesis.

microbiology↗

Dynamic conformational ensembles of soluble Tau encode neuronal toxicity prior to aggregation

Tau aggregation is a defining feature of Alzheimers disease and related tauopathies, yet the conformational states of Tau in neurons prior to aggregation remain poorly understood. Existing structural models are derived largely from fibrillar assemblies and provide limited insight into the dynamic, soluble Tau species that initiate pathology. Here, we combine hydrogen-deuterium exchange mass spectrometry with super-resolution imaging and neuronal models to define the conformational ensemble of soluble Tau under physiological and disease-relevant conditions. We show that soluble Tau populates distinct, dynamic conformations characterized by regional stabilization and long-range intramolecular interactions that are invisible to fibril-based structures. Disease-associated perturbations selectively remodel these conformational ensembles, exposing aggregation-prone regions and altering Tau subcellular organization in neurons. Notably, these Tau species inhibit axonal transport, which is essential for neuronal health, linking specific ensemble states to neuronal toxicity. These findings establish soluble Tau conformation as a dynamic, regulatable state that precedes aggregation and encodes disease relevance. By defining the structural logic of Tau before fibril formation, this work provides a framework for understanding early tauopathy mechanisms and for targeting Tau pathology at its earliest stages. SUMMARYTau pathology is a hallmark of Alzheimers disease (AD) and related dementias (ADRDs). Although Tau is often described as intrinsically disordered, it is a dynamic protein with distinct but poorly defined conformations. Here we conduct a systematic time-resolved structure-function analysis of normal and pathologic Tau, including hyperphosphorylated, mutant Tau, and posttranslational-modification-mimetic Tau. To characterize dynamic conformational changes of Tau, we combined state-of-the-art hydrogen deuterium exchange mass spectrometry with structured illumination microscopy, demonstrating a novel Tau-MT binding mode: "dynamic oscillation". To correlate Tau structure with neuronal function, we evaluated axonal transport as a sensitive readout of neuronal health. Many toxic Tau forms share a common signature of increased exposure of the N-terminal phosphate activating domain (PAD) in vitro and in vivo. Aberrant exposure of PAD correlates with Tau pathology and axonal transport defects. Tau phosphorylation at S262 alone is sufficient to alter Tau-microtubule interactions beyond R1-R4 motifs, globally changing Tau conformation, disrupting "dynamic oscillation" on MTs, and inhibiting axonal transport. Frontotemporal dementia-associated P301L-Tau remains associated with microtubules but also inhibits axonal transport. Our results reveal a well-defined conformation of soluble WT Tau in neurons and its highly dynamic interaction with microtubules, altered by AD/ADRD-Tau forms. Our multidisciplinary approach comprising biochemical manipulations, innovative MS tools, advanced microscopy, cellular assays, and mouse and human data pair Tau conformations with distinct neuronal functions and pathologies in health and disease.

neuroscience↗

Clocks and Dominoes: Timing Mechanisms of Embryogenesis

How developmental timings are regulated is a fundamental open question. Two widely considered mechanisms are the clock, in which an internal timer determines when each stage occurs, and the domino, in which the completion of each stage triggers the next. It is often unclear how to establish either mechanism. Here, we construct a quantitative framework that uses the correlation structure of developmental timings to test the clock and domino mechanisms. We apply this framework to human pre-implantation development by using ~1 million images of 2946 embryos acquired during IVF treatment, establishing mathematical models of developmental rate. We find that a domino mechanism governs the cleavage timings, while a pronuclei fade-triggered clock mechanism governs the morula and blastocyst timings. These results are consistent with the cell cycle oscillator governing the cleavage timings and the accumulation of embryonic gene products or the degradation of maternally deposited factors governing the morula and blastocyst timings. We next investigate the physiological regulators of developmental timing by analyzing how the timings are statistically associated with the clinical pregnancy outcome. While embryos that result in a clinical pregnancy tend to exhibit shorter cleavage timings, this association is primarily driven by patient-specific properties. In contrast, embryo-specific properties independently influence the pregnancy outcome and the cleavage timings, so that factors directly determining implantation potential, such as aneuploidy, can only weakly impact the cleavage timings. Taken together, this work provides a robust framework for decoding developmental timing mechanisms, with significant implications for fundamental biology and clinical practice.

developmental biology↗

Lung-Targeting Interleukin-10 mRNA Lipid Nanoparticles Ameliorate Acute Lung Injury

Acute respiratory distress syndrome (ARDS) is the most severe manifestation of acute lung injury (ALI), characterized by diffuse pulmonary inflammation, impaired gas exchange, and high morbidity and mortality. Despite its clinical significance, no specific or effective pharmacological therapies are currently available for its treatment. In this study, we developed a lung -targeted mRNA-sulfonium lipid nanoparticle (mRNA/sLNP) delivery system for the treatment of ALI in a mouse model. We first optimized sulfonium lipid structures, and the optimized sLNP was comprehensively characterized and subsequently loaded with interleukin-10 (IL-10) mRNA. In a lipopolysaccharide (LPS)-induced ALI mousemodel, IL-10/sLNPdemonstrated both prophylactic and therapeutic efficacy, significantly attenuating pulmonary and systemic inflammation, restoring barrier integrity, and reducing tissue injury.

bioengineering↗

Optimizing broadly neutralizing antibodies via all-atom interaction modeling and pre-trained language models

Antibody optimization is a fundamental challenge, and the identification of antibody-antigen interactions is crucial in the optimization process. However, current methods cannot accurately predict antibody-antigen interactions, providing limited functional guidance to improve the time-consuming and costly traditional optimization techniques. Here, we present InterAb and InterAb-Opt, a unified computational framework that integrates all-atom modeling with antibody language models to predict antibody-antigen interactions and enable antibody optimization. Leveraging the proposed all-atom modeling approach, AtomInter, and pre-trained antibody language models, InterAb outperforms existing methods in predicting antibody specificity and antibody-antigen binding affinity. InterAb successfully identified influenza A virus-binding antibodies from an antibody library and accurately detected high-affinity antibodies in the AIntibody competition. Empowered by the robust functional insights from InterAb, InterAb-Opt was developed to optimize broadly neutralizing antibodies. For R1-32 antibody, biolayer interferometry results reveal that 85%, 80%, 90%, and 67.5% of the 40 InterAb-Opt-optimized antibodies exhibit enhanced binding affinities to wild-type SARS-CoV-2, Lambda, BQ.1.1, and EG.5.1, respectively, with a maximum improvement of up to 96-fold. For the newly emerging BA.2.86 and KP.3, 55% and 52.5% of the optimized antibodies notably transition from non-binding to binding. Neutralization assays demonstrated that the optimized antibodies exhibited enhanced neutralization activity across multiple targets, highlighting the capability of InterAb-Opt in engineering broadly neutralizing antibodies. This technology enables precise analysis of antibody-antigen interactions and optimization of broadly neutralizing antibodies, holding promise for addressing challenges in immune evasion and vaccine design.

bioinformatics↗

Compartment-specific core microbiomes in potato tubers are associated with plant health across genotypes, soils, and years

Harnessing plant microbiomes for sustainable agriculture requires understanding not only whether they can boost crop performance, but also how they assemble, persist, and support plant growth and health across environments. While we previously showed that seed tuber microbiomes can predict potato vigour using machine learning, it remained unclear how ecological processes shape tuber microbiome stability and functionality across host genotypes, tuber compartments, soil types, and years. Here, we analyzed the national-scale dataset of 240 field-collected potato seedlots, spanning six genotypes, two soil types, and two growing years, with a focus on the spatially distinct heel and eye compartments of the potato tuber. By profiling over 1,200 bacterial and fungal communities and linking microbiome composition to plant performance using leaf area as a health proxy, we show that plant genotype and tuber compartment are the strongest determinants of microbial diversity and composition. Compartment-specific enrichment of functional traits was observed, with organic compound conversion and nitrogen cycling dominant in the heel, and energy metabolism enriched in the eye. Using a macroecological abundance-occupancy framework, we identified a stable core microbiome of bacterial and fungal taxa that persisted across environments and years. Core members were more strongly associated with plant performance than non-core taxa, and pathogen-suppressive functions were spatially structured, with distinct protective taxa dominating in the heel versus the eye. Together, our findings demonstrate that tuber compartments act as selective microbial filters, shaping persistent microbiomes with specialized functions. By providing an ecological and functional framework for compartment-resolved, stable core microbiomes, this study complements our predictive modelling work and highlights persistent microbial partners as promising targets for improving potato resilience and productivity.

ecology↗

On-virion structural dynamics reveal temperature- and receptor-coordinated activation of an alphacoronavirus spike

Human alphacoronaviruses primarily infect the human upper respiratory tract, yet how physiological temperature and receptor-binding coordinate viral spike (S) protein activation remain unclear. Using cryo-electron tomography and subtomogram averaging, we directly visualized the structural dynamics of S on human coronavirus 229E (HCoV-229E) virions under physiologically relevant temperatures and in the presence of the host receptor human aminopeptidase N (hAPN). We identified two prefusion S2 conformations, compact and loose, that interconvert reversibly by temperature, revealing intrinsic S2 "breathing" on virions. Receptor-binding domain (RBD)-up conformations are rare on apo virions but are promoted at physiological temperature and stabilized upon receptor binding. hAPN can bind bivalently to neighboring S, forming Gemini S-hAPN complexes. Receptor incubation further promotes conversion from prefusion to postfusion S, an effect enhanced at 33. Together, our results demonstrate an optimized temperature for the HCoV-229E viral fitness, establish temperature and receptor binding as synergistic regulators of alphacoronavirus S activation and define an integrated, on-virion model of S conformational transitions during viral entry. These findings provide a structural framework for understanding alphacoronavirus infectivity.

microbiology↗

Colibactin produced by a honeybee symbiont defends against pathogens and shapes the gut community

Colibactin is a bacterial genotoxin that is linked to colorectal cancer and implicated in interbacterial competition; however, its role in natural communities remains unknown. Frischella perrara, a symbiont living only in honeybee guts, produces colibactin and causes DNA damage. Here, we found that F. perrara mono-colonization reduces bee lifespan but increases survivorship following challenge with an opportunistic pathogen. F. perrara reduces pathogen loads by causing colibactin-dependent DNA damage and prophage induction. clbS, a gene conferring protection from colibactin, is ubiquitous among bacteria restricted to bee guts but is absent from opportunistic colonizers including bee pathogens. Our findings provide evidence that colibactin functions in interbacterial competition, exerts selective pressure on community members, and confers protection against pathogens, while permitting co-evolved gut symbionts to persist.

microbiology↗

Guam amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS/PDC) features CTE-like tau seeds in brain and spinal cord

Amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS/PDC) is a fatal neurodegenerative disorder that was once hyperendemic in the island of Guam (Mariana Islands, US) and a few other Pacific locales. Despite extensive investigations into its origins, the etiology of ALS/PDC remains unclear. ALS/PDC is, at the neuropathology level, characterized by tau-dominant multiple proteinopathy in brain and spinal cord. It was recently reported that Guam ALS/PDC brain extracts exhibit tau seeding activity in fluorescence resonance energy transfer (FRET)-based biosensor cells. To build upon those findings and explore the nature of tau seeds in ALS/PDC in more detail, we used an alanine mutational scanning (Ala scan) approach to determine the seeding profile of tau in nervous tissues of Guam ALS/PDC cases. First, we confirmed the detection of tau seeding activity in ALS/PDC brain samples in tau biosensor cells. Notably, we could also detect potent tau seeding activity in spinal cord. Subsequent Ala scan assays demonstrated that ALS/PDC tau displays an aggregate incorporation pattern that resembles that of chronic traumatic encephalopathy (CTE)-type tau. This result is consistent with recent electron cryo-microscopy studies of tau, which revealed that ALS/PDC tau filaments are predominantly of the CTE-type. The structural characteristics and seeding behavior of ALS/PDC tau, as well as the regional distribution of tau pathology at post-mortem, suggest that ALS/PDC is a CTE-like tauopathy. Significance StatementNeurodegenerative tauopathies are characterized by proteinaceous deposits containing microtubule-associated tau in nervous tissue. Emerging evidence suggests that disease-associated tau proteins adopt abnormal, self-propagating conformations characteristic of prions. Here, we employed alanine mutational scanning (Ala scan) to determine the nature of prion-like tau seeds in ALS/PDC, a mysterious disorder that occurred formerly in high incidence in certain regions in the western Pacific. We show that the Ala scan incorporation profile of ALS/PDC tau is similar to that of abnormal tau proteins in chronic traumatic encephalopathy (CTE). The findings lend support to the idea that ALS/PDC can be classified structurally as a CTE-like tauopathy. This work may have important implications for our understanding of ALS/PDC as well as common neurological disorders beyond the Pacific.

neuroscience↗

Spatial Navigation Training Enhances Large-Scale and Small-Scale Spatial Abilities through Different Neural Mechanisms

Elucidating the relationship between large-scale and small-scale spatial abilities is fundamental to advancing our understanding of spatial cognition, with training transfer effects across tasks offering a direct means of exploration. This study investigated how large-scale spatial navigation training influences both large- and small-scale spatial abilities and their underlying neural mechanisms. Participants completed 20 days of real-world campus navigation training and performed large-scale (distance judgment) and small-scale (paper folding) spatial tasks before and after training. The training group showed significant improvements in both tasks, whereas the control group did not. Brain imaging revealed increased activation in the right middle frontal gyrus (MFG) and bilateral posterior cingulate cortex (PCC) during large-scale task performance after training. In contrast, improvements in the small-scale task were associated with reduced deactivation in the right postcentral gyrus (PoCG), right precuneus, and left superior temporal gyrus (STG). Overall, these findings indicate that large-scale navigation training enhances spatial ability across scales through distinct neural mechanisms, supporting the partial dissociation model and highlighting the contribution of negatively activated regions to spatial processing.

neuroscience↗

AI Identifies Broadly Neutralizing Antibodies from an IGHV1-69 Public Antibody Class Exerting Continued Selection Over SARS-CoV-2

R1-32-like public antibodies, characterized by shared IGHV1-69/IGLV1-40 usage, are elicited in more than 50% of individuals with COVID-19 and have been implicated in driving recurrent mutations at L452SARS2 and F490SARS2 within their convergent epitope in the SARS-CoV-2 spike receptor-binding domain. These mutations effectively mediate escape from non-affinity-matured R1-32-like antibodies with germline-like sequences. Here, we characterize four affinity-matured R1-32-like antibodies, C092, C807, BD56-104, and BD56-597, that tolerate L452SARS2 and F490SARS2 mutations. We show that this tolerance arises from residues introduced by somatic hypermutation at convergent positions across multiple CDR loops and surrounding regions, thereby creating additional contacts that reinforce epitope binding. An unusual N354SARS2 glycosylation site, which emerged in BA.2.86 and became fixed in its descendants, is linked to escape from affinity-matured R1-32-like antibodies, implying ongoing selection by this public antibody class. Using an AI model trained on integrated structural, neutralization, and binding data, we further identified ZL525, an ultrapotent R1-32-like antibody with pan-SARS-CoV-2 variant activity, including against the highly evasive KP.3 variant carrying the N354SARS2 glycosylation, and broad sarbecovirus cross-reactivity extending to SARS-CoV-1. Together, these findings show how affinity maturation enables public antibodies to adapt to viral antigenic drift, reveal their role in shaping SARS-CoV-2 antigenic evolution, and demonstrate the potential of AI-empowered strategies for discovering broadly neutralizing antibodies.

immunology↗

A K27-linked Ubiquitin Checkpoint Controls NOTCH Homeostasis

Cell surface receptors such as NOTCH1 must be tightly regulated to ensure developmental fidelity and prevent pathological activation. Although the proteolytic steps culminating in nuclear NOTCH1 signaling are established, how cells prevent excessive or uncontrolled activation has remained unresolved. Here we identify the autophagy-related protein UVRAG as a negative regulator of NOTCH1. Upon receptor activation, UVRAG, acting independently of autophagy, recruits and activates the E3-ligase ITCH to catalyze K27-linked ubiquitination of membrane-tethered NOTCH1, thereby licensing ESCRT-dependent lysosomal degradation. Disruption of the UVRAG-ITCH-ESCRT axis stabilizes activated NOTCH1 intermediates and amplifies oncogenic signaling. In T-cell leukemia models driven by constitutive NOTCH1 activity, restoring UVRAG expression reinstates receptor turnover, suppresses disease progression, and improves therapeutic response. These findings define a ubiquitin-directed safeguard circuit that enforces NOTCH1 signaling homeostasis and reveals a tunable axis for intervention in NOTCH1-driven cancers.

molecular biology↗

AI recognizes convergent somatic hypermutation signatures to allow the discovery of variant-resilient broadly neutralizing antibodies

Elucidating the mechanisms by which broadly neutralizing antibodies (bnAbs) develop to confer durable immunity in humans is pivotal for the rational design of next-generation vaccines and therapeutics. VH3-53/3-66-encoded public antibodies are widely elicited in the population after the COVID-19 pandemic. Here, we isolated 15 VH3-53/3-66-encoded bnAbs from elite neutralizers who experienced sequential SARS-CoV-2 Omicron breakthrough infections. These bnAbs exhibit exceptional potency and breadth against circulating variants and, as members of a long-lived public antibody lineage, likely contribute to durable humoral protection. Genetic analysis of VH3-53/3-66-encoded bnAbs reveals a convergent somatic hypermutation pattern at seven positions in and around the CDR loops that emerges with repeated viral exposures and distinguishes them from non-bnAbs. Grafting these combined mutations onto clinically escaped antibodies broadens their breadth and restores neutralization activity. Structural analysis shows that these convergent mutations cooperatively remodel CDRs to bind and tolerate virus receptor-binding domain mutations. Using an AI-based antibody language model trained on data linking somatic hypermutations to binding affinity and neutralization, the model is able to identify mutational patterns predictive of breadth, enabling the discovery of a rare bnAb with protective activity against the latest variants from early-pandemic antibody repertoires. This demonstrates the feasibility of establishing an AI-empowered pipeline to identify mutation-tolerant bnAbs from early-pandemic antibody repertoires to fight fast-evolving newly introduced viruses.

immunology↗

Warming makes 20 boreal species grow earlier but not always taller

Climate warming is altering the timing of seasonal growth in cold-temperate and boreal ecosystems, with potential consequences for forests on multiple continents. It has been hypothesized that in a warming climate, earlier growth in spring might lead to a longer growing season and thus higher annual total growth. However, whether the period of active growth is longer in a warming climate is unclear, as is whether changes in growth rate might reinforce or offset the effect of changing growing season length in modulating annual total growth. Understanding responses in growth to warming is crucial to projecting forest dynamics under future climate change. To address this, we experimentally warmed (by +1.62 and 3.26 {degrees}C on average) open-air southern boreal forest plots for 14 years (2010 to 2023) and measured juvenile height growth from spring until fall for 20 tree and shrub species, with a total of 11,565 individual-year growth trajectories. Across all species and in various canopy (open, closed) and rainfall (ambient, reduced) contexts, experimental warming consistently advanced the timing of height growth (4.32 days per 3 {degrees}C warming). However, species differed in their annual total growth responses. Evergreen gymnosperms such as spruce, fir, and pine tended to exhibit suppressed annual total growth under warming (-15.8% per 3 {degrees}C warming), driven by a shorter duration of active growth, despite an earlier start, with little change in relative growth rate. In contrast, deciduous angiosperms and non-native shrubs often show enhanced annual total growth under warming (19.3 and 37.4% per 3 {degrees}C warming), driven by faster rate, longer duration, or a combination of both. More broadly, species with a more conservative lifestyle responded less positively in the duration and rate of growth, thus placing them at a disadvantage under warming. These contrasting responses challenge assumptions that an earlier start of the growing season universally enhances growth and highlight how warming may shift both the timing and pace of growth and thus alter community composition within mixed-species forests.

ecology↗

GPTAnno: Ontology-tree-guided hierarchical cell type annotation based on GPT models for single-cell data

Cell type annotation is critical for interpreting single-cell transcriptomic data but remains challenging due to uncertain cellular clustering granularity and inconsistent labeling across studies. Here we present GPTAnno, an automated, ontology-tree-guided, uncertainty-aware, hierarchical cell type annotation method based on GPT models. GPTAnno directly handles gene expression matrices, integrates multi-resolution clustering with large language model reasoning constrained by the cell ontology to produce standardized, ontology-aware, and reproducible annotations with automatic resolution selection. GPTAnno selects optimal clustering resolutions based on the annotation distance on the ontology tree and quantifies annotation uncertainty to flag ambiguous clusters for expert review. Benchmarking across twelve large-scale datasets demonstrates GPTAnnos superior accuracy on annotating cell types across various species, tissues, and disease contexts against existing methods. Implemented in R and Python with Seurat and Scanpy compatibility, GPTAnno allows simple inputs to streamline the reproducible annotation, considerably reducing human efforts in repeated reclustering, assigning and examining the labels.

genomics↗

Susceptibility to Task-irrelevant Auditory Distractors in Relation to Visual Working Memory in Children With and Without ADHD

ObjectiveAttention-deficit/hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder in children and is often associated with increased distractibility. Previous research has reported that susceptibility to task-irrelevant visual distractions is associated with visual working memory (WM) capacity. However, how neural responses to task-irrelevant auditory distractors are related to visual WM capacity in children with and without ADHD remains poorly understood. MethodsIn this study, we collected electroencephalography (EEG) signals from 72 children with ADHD and 88 typically developing (TD) children across two experiments, during which they performed visual tasks of varying difficulty while task-irrelevant auditory distractors were presented. The mismatch negativity (MMN) amplitude was measured as a neural index of susceptibility to auditory distractors, and the K score was assessed as a behavioral indicator of visual WM capacity. ResultsTD children showed opposite patterns across the two experiments: under low audiovisual competition, those with higher visual working memory capacity were more susceptible to task-irrelevant sounds, whereas under high competition, children with lower capacity showed greater susceptibility to distraction. In contrast, children with ADHD showed a stable association, with lower visual WM capacity consistently predicting higher susceptibility to task-irrelevant auditory distractors regardless of competition level. ConclusionsThese findings provide novel evidence that susceptibility to task-irrelevant auditory distraction is closely related to visual WM capacity in both children with and without ADHD, but the patterns of this relationship differ between typical and atypical neurodevelopment and are modulated by audiovisual competition.

neuroscience↗

Developmental Trajectories of Addition and Subtraction in Early School-aged Children

Mastering basic arithmetic lays the foundation for lifelong mathematical achievement, yet how the neural mechanisms underlying addition and subtraction calculations develop during childhood remain unclear. This study investigated the developmental trajectories of addition and subtraction calculations in school-aged children, and explored how arithmetic-specific neural responses in the right parieto-occipital region are related to age-related improvements in behavioral performance. Here, we recorded electroencephalography (EEG) signals from 115 typically developing children divided into three age groups (7-8-, 9-10-, and 11-12-year-olds) during an arithmetic task involving addition and subtraction calculations. We analyzed the P300 component from the original waveforms and the {Delta}P300 component from the difference waveforms, which were generated by subtracting the event-related potentials (ERPs) elicited by the first operand from those elicited by the second operand to isolate arithmetic-specific neural processes. The results revealed that, in both calculations, older children showed better behavioral performance (faster reaction time and larger PI) and greater right parieto-occipital {Delta}P300 amplitudes, with a key developmental stage at 11-12 years. Furthermore, all groups of children exhibited greater right parieto-occipital P300 and {Delta}P300 amplitudes in subtraction, whereas the smaller right parieto-occipital {Delta}P300 amplitudes in addition significantly mediated the relationship between age and PI. These findings reveal distinct patterns for addition and subtraction calculations over development, highlighting the right parieto-occipital {Delta}P300 amplitude as a neural marker of arithmetic performance, particularly for addition calculation.

neuroscience↗

β-Nicotinamide mononucleotide: a novel broad-spectrum CRISPR inhibitor

CRISPR-Cas systems have revolutionized genome editing with their precision and versatility, enabling transformative applications in various fields, especially in the treatment of genetic diseases. However, the clinical translation of this technology is hindered by challenges such as off-target effects and uncontrolled nuclease activity. At the same time, it has the possibility of causing biosecurity risks, underscoring the urgent need for reliable regulatory tools. Existing CRISPR inhibitors, primarily anti-CRISPR protein or exogenously synthesized small molecules, are limited by their specificity or bioavailability and long research period, unable to address the diverse CRISPR nucleases used in research and therapy. Based on the phenomena obtained from various in vitro and cell experiments, combining molecular dynamics simulation and bio - layer interferometry (BLI) analysis, here we report a naturally occurring small-molecule {beta}-nicotinamide mononucleotide (NMN), the first known endogenous metabolite with broad-spectrum inhibitory activity against multiple CRISPR-associated proteins (Cas9, Cas12, and Cas13) through various mechanisms. Our findings establish NMN as a dual-purpose tool, which reduces cell damage caused by gene editing and mitigates risks of unintended genetic modifications in research and clinical settings. This discovery further shortens the distance between basic medicine and translational medicine, providing a new approach for developing endogenous regulatory molecules in genome engineering.

genetics↗