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Yu, D.

Publications and source records attributed to Yu, D..

At least 19 recordsLinked to original sources

Sexual reproduction impacts vertebrate organ aging

Sexual reproduction is a central component of life. Yet, an unanswered question remains: how does sexual reproduction shape physiology and health across an individual's lifetime? Unlike other external factors such as diet and exercise, the impact of sexual reproduction on organ health during aging is far less studied, particularly in vertebrates. Here, we develop the short-lived killifish as a vertebrate model to study how lifelong mating affects organ aging. We discover that mating regulates liver aging in a cell-type and sex-specific manner. In old female livers, mating dampened hepatocyte inflammation and reduced myeloid cell levels, and machine-learning models predicted that mating led to a 'younger' transcriptomic age in several liver cell types. Functionally, mating reduced hepatic accumulation of several lipid classes and was associated with enhanced female resilience against the liver toxin acetaminophen. More broadly, mating induced anti-inflammatory and metabolic rewiring transcriptomic signatures in the brain and gut, indicating that mating may affect vertebrate organ aging more globally. Using publicly available human datasets and plasma proteomics aging clocks, we observed an association between sexual experience and a 'younger' plasma proteomic age of several cell types, including hepatocytes. Our work provides evidence that lifelong mating reshapes the physiological context during aging in a vertebrate, highlighting an understudied connection between vertebrate sexual history, health, and aging.

genomics↗

Reversion to the Meta Body Form of Life after Complete Cell Death in Pure Liquid Water

The prevailing view holds that simpler animate beings predating the dawn of cellular life once existed, yet they have long since vanished from the present-day Earth. Our hypothesis posits that these animate beings persist to this day. To this end, we devised a long-term experiment spanning over a decade, keeping Staphylococcus aureus (S. aureus) within a sealed aqueous system of pure water. The findings illustrated that, upon the complete cell death (CCD) of the S. aureus, as cellular remnants progressively succumbed to dissolution, the aqueous solution underwent self-purification, bringing forth a class of lipid bilayer membrane microspheres containing RNA and proteins. These structures maintained long-term sustainable stability within the thermodynamic storm of water molecules and underwent dynamic size fluctuations over time - collectively exhibited phenomena indicative of being "alive". This study reveals that the cell, upon complete cell death, undergoes reversion to a living entity simpler than the cell itself - the Meta Body (MB). The discovery of MB opens an entire re-conceptualization of what death ultimately brings.

biophysics↗

A PATHOGENIC NFKB2 VARIANT CAUSES COMBINED IMMUNODEFICIENCY WITH THYMIC AND PERIPHERAL LYMPHOID DEFECTS IN RATS

The non-canonical NF-kappa B pathway, in which NFKB2 plays a central role, is critical for lymphoid organ development and immune homeostasis. Pathogenic NFKB2 variants have been strongly associated with a broad spectrum of human pathologies, notably immunodysregulation syndromes, characterized by recurrent infections, autoantibody production and endocrine abnormalities. The mechanisms underlying the resulting immune defects remain incompletely understood. In the present study, we characterized the immune phenotype of a novel rat model harboring a Nfkb2 non-sense mutation located in the c-terminal region of the gene (c.2602T>A; p.Tyr867*, Nfkb2p.Tyr867*). This variant has been identified in patients with a familial form of common variable immunodeficiency (CVID) presenting with autoimmunity manifestations. Using this model, we demonstrate that mutated NFKB2 resulted in profound alterations of the thymic microenvironment, including reduced K5+ medullary thymic epithelial cells and decreased AIRE expression, accompanied by altered thymocyte development and impaired thymic regulatory T populations. Peripheral lymphoid organization was also profoundly affected, with absence of lymph nodes, defects in the splenic marginal zone, and alterations of CD4+ and CD8+ T-cell homeostasis, including impaired Treg populations and reduced ICOS expression on CD4+ T cells. The B-cell compartment was markedly altered, with impaired B-cell maturation, characterized by accumulation of IgM+IgD- transitional cells and a marked reduction of IgD+ mature B cells. These abnormalities were associated with impaired humoral immunity and complete absence of circulating immunoglobulins. Collectively, our findings define a systemic combined immunodeficiency phenotype in the Nfkb2-mutated rat, highlighting its utility for studying the role of non-canonical NF-kB signaling in immune system organization and adaptative immunity.

immunology↗

Single-cell transcriptomic and epigenomic analysis reveals X-linked sex differences in aging mouse hypothalamus

Sex differences contribute to brain aging, neurodegenerative diseases, and more broadly in determining rates of aging across species. The hypothalamus plays a central role in physiological homeostasis and healthy aging, yet how its cellular and molecular landscape diverges between males and females over the lifespan remains poorly understood. Here, we present a single-nucleus multi-omics analysis of the hypothalamus in young, middle aged, and aged male and female mice. We identified major hypothalamic cell types and characterized their sex- and age-dependent transcriptional and chromatin accessibility profiles. Notably, female-specific changes on the X chromosome (chrX) emerged as a prominent feature of aging, including changes to the X inactivation center and an overall increase in chrX gene expression and accessibility in immune cells and neurons. Pseudotime analysis of immune cells revealed an aging trajectory with sex-specific multi-omic programs, featuring increased inflammation in females compared to males. Delving deeper into the epigenetic signatures associated with these sex differences, we found that H3K27me3 - the repressive histone mark enriched on the inactive X in females - increased in abundance and underwent substantial genome-wide redistribution with age in both sexes, particularly on the inactive chrX in females. Collectively, these findings highlight distinct cell-type-specific aging trajectories in the male and female hypothalamus, identify female aging signatures associated with X-linked epigenetic regulatory programs, and provide a comprehensive resource for understanding the molecular basis of sex differences in brain aging.

genomics↗

A biologically supported global RNA architecture of cucumber mosaic virus satellite RNA

Satellite RNAs (satRNAs) are parasitic subviral agents whose biological activities are mediated largely by specific sequence determinants and structured RNA elements. Establishing biologically supported global RNA structures is therefore essential for understanding how RNA architecture underlies satRNA functions. Cucumber mosaic virus (CMV) satRNA is one of the best-characterized models for investigating satRNA structure-function relationships; however, a biologically supported global RNA architecture of CMV satRNA has yet to be established. Here, we applied AlphaFold3 modeling to predict the global structure of CMV satRNA T1 (sat-T1). Initial full-length structure modeling generated multiple long-distance interactions that lacked biological support. We therefore used fragment-based modeling, combined with chemical probing, evolutionary covariation, and compensatory mutagenesis, to derive a biologically supported global secondary structure. To determine whether structurally distant regions could interact in the context of the full-length RNA, we engineered a structure-guided T1-ZD mutant that preserved the supported secondary structure while reducing alternative base-pairing possibilities. Full-length AlphaFold3 modeling of T1-ZD largely recapitulated the proposed architecture, while one predicted model revealed a long-distance interaction that was subsequently supported by compensatory mutagenesis analysis. These findings suggest that the 3' terminus of sat-T1 may undergo conformational switching between alternative structural states. Together, our work establishes a biologically supported global RNA architecture for CMV sat-T1 and provides a structural framework for investigating the molecular basis of satRNA function.

microbiology↗

Spatial profiling of pooled mRNA-LNP delivery in vivo with NanoSTAMP

Existing pooled lipid nanoparticle (LNP) screens lack spatial information on formulation localization, cellular uptake, and associated multicellular tissue responses. Here we introduce NanoSTAMP, a spatially resolved, pooled in vivo screening platform for barcoded LNP libraries that uses fluorescence in situ hybridization (FISH)-based barcode readout and is compatible with spatial omics. NanoSTAMP links LNP formulation to cell-type specific uptake, cargo expression, and nearby multicellular neighborhoods within intact tissue, which enables spatially-informed design of RNA delivery, establishing tissue architecture as a dimension of LNP performance.

bioengineering↗

Cell type-resolved chromatin accessibility clocks for brain aging

Aging is a progressive decline in biological function that is proposed to be driven by the accumulation of epigenetic noise and the loss of epigenetic information. Among epigenetic readouts, DNA methylation has been extensively used to develop aging clocks, machine learning models that predict age from molecular data. However, DNA methylation clocks are relatively difficult to interpret and remain distant from gene regulatory networks, a gap that can be complemented by clocks built from another epigenetic layer: chromatin accessibility profiled by ATAC-seq. Existing chromatin accessibility clocks predict age from bulk ATAC-seq data, thereby averaging over the epigenetic heterogeneity across cells that drives aging. We hypothesized that a chromatin accessibility clock trained at the level of individual cell types, using pseudobulk profiles derived from single-nucleus ATAC-seq (snATAC-seq) data, would be particularly useful for characterizing cell type-specific aging. We focused on the brain, a highly heterogeneous tissue whose diverse cell types age asynchronously, and assessed how well cell type-specific accessibility clocks can predict chronological age, capture rejuvenation from genetic perturbation, and detect age acceleration in age-associated neurodegenerative disease. To this end, we introduce a set of cell type-specific and all-cell aging clocks built from snATAC-seq profiles of the prefrontal cortex (PFC) of 357 human donors (15 to 100 years), which generalize to accurately predict age across brain regions and species. Beyond healthy aging, these PFC clocks captured the rejuvenating effects of SIRT6 overexpression in mouse liver and cell type-specific age acceleration in Alzheimer's disease (AD) and Parkinson's disease, with microglial age acceleration correlating most strongly with pathology among major cell types, and with female oligodendrocytes and OPCs showing the largest sex differences in age acceleration. Interpreting the clocks further revealed the regulatory elements, genes, pathways, and motifs underlying these signals across species, disease, and perturbation, including repression of the NF-kB pathway in SIRT6 transgenic mice, upregulation of immune and inflammatory pathways in severe AD, and conserved age-predictive peaks related to histone regulation, metabolism, and neuronal survival across brain regions and species. Together, these results establish PFC snATAC-seq aging clocks as a generalizable tool that accurately predicts age and captures cell type-specific perturbation effects of rejuvenation and disease on the epigenetic landscape, providing both a means to evaluate perturbations and insight into the epigenetic mechanisms of aging and disease.

genomics↗

Fine tuning energy metabolism in skeletal muscle: Discovery of a novel autoinhibitory mechanism in the N-terminal extension of AMPKγ3

AMP-activated protein kinase (AMPK) regulates metabolism in response to metabolic stress that includes stimulating glucose uptake in skeletal muscle independently of the canonical insulin signalling pathway, positioning it as an attractive therapeutic target for insulin resistance and type 2 diabetes mellitus (T2DM). AMPK is an {beta}{gamma} heterotrimer, with multiple isoforms for each subunit enabling the formation of 12 different complexes with distinct tissue expression profiles. Among these, the 2{beta}2{gamma}3 complex is predominantly expressed in skeletal muscle, the major site of glucose disposal and a highly desirable therapeutic target for T2DM. Here, we characterise the functional role of a unique, 182 residue N-terminal extension (NTE) within {gamma}3 subunit. Deletion of the {gamma}3-NTE from 2{beta}2{gamma}3 complex increases basal AMPK activity without affecting activation by AMP or pharmacological AMPK activators, demonstrating the {gamma}3-NTE performs an autoinhibitory function. Using complementary biophysical techniques, including hydrogen-deuterium exchange-mass spectrometry, surface plasmon resonance, chemical crosslinking and co-pulldowns, we identified a 39-residue sequence in the {gamma}3-NTE (residues 129-168), that directly interacts with the C-helix of the AMPK kinase domain small lobe, a key regulatory element in many protein kinases. Using AlphaFold3, we probe the interaction predicted to take place between a {gamma}3-NTE -helix ({gamma}3-iHelix; [~]T142-E154) and the C-helix in the 2{beta}2{gamma}3 complex. These findings provide the groundwork for developing novel T2DM therapies that target AMPK activation selectively in skeletal muscle involving reversal of the {gamma}3 autoinhibition.

biochemistry↗

Progranulin deficiency perturbs lipid metabolism in white matter microglia

Progranulin (PGRN) deficiency is a common hallmark in frontotemporal dementia (FTD) patients with granulin (GRN) mutations (FTD-GRN). Previous studies by our group and others have observed that reduced PGRN perturbs lysosomal function and microglial activation, which is believed to accelerate neurodegeneration in FTD-GRN patients. Lysosomal function is intrinsically linked to lipid metabolism, and evidence suggests that GRN deficiency can alter lipid profiles in the brain. Unfortunately, studies to date have focused on whole brain or cortical extracts, limiting our ability to assess cell type-dependent changes in lipid metabolism under disease conditions. Here, we employed lipidomic analysis specifically within the pontine microglia of Grn knock-out (KO) mice, a cell population that was previously linked to disease phenotypes in this model. We observed a significant reduction in the endolysosomal lipid bis(monoacylglycero)phosphate (BMP) and the lipid metabolite phosphatidylethanolamine (PE); these microglial-specific lipid alterations mirror previous whole-brain findings, suggesting that similar changes may occur across multiple cell types in the brain. We also detected a significant increase in the myelin-composing factor galactosylceramide (GalCer), which may reflect an aberrant accumulation of myelin debris within microglia that arises due to defective lysosomal clearance. Notably, lipid perturbations were exacerbated with age within Grn KO microglia, suggesting that changes in lipid metabolism are both age- and genotype-dependent in this model. Together, our results support our hypothesis that PGRN acts as a master regulator of critical microglial processes - including lysosomal function, lipid metabolism, and the regulation of myelination - in an age-dependent manner.

neuroscience↗

Hidden genetic diversity in 320 nearly-complete East Asian genome assemblies

East Asian populations, representing over 20% of the global population, remain critically underrepresented in human genomic studies, limiting our understanding of population-stratified genetic variation and its implications for health and disease. Here we present the first phase of the Asian Pan-Genome project (APG), comprising 320 nearly complete, fully phased haploid genome assemblies from 160 East Asian individuals. These assemblies achieve unprecedented quality, with an average contig N50 of 144.3 megabase pairs and an average quality value of 64.5. Leveraging these superior assemblies, we reveal previously uncharacterized diversity in human repeatome, including population-stratified patterns in centromere satellites and rDNA arrays. Compared to existing global human genome assemblies, the newly generated genomes supplement 152 million base pairs of novel sequences, 355 gene gains, 18,300 structural variation loci and 26 large euchromatic inversions missing from current human pangenomes. We perform population stratification analyses of structural variations, and further resolve the structural haplotypes of complex genomic regions such as Major Histocompatibility Complex and Survival Motor Neuron loci across global pangenomes, exemplifying tandem-duplicate and inversion-rich complex locus architectures in the human genome, respectively. This resource provides a critical foundation for human genetic studies, especially for East Asian populations, promoting more accurate variant discovery, reducing bias, and ultimately advancing the equity and efficacy of genomic medicine.

genomics↗

Multidimensional variation and population stratification across 8000 complete human centromeres

Human centromeres are indispensable for the faithful segregation of chromosomes during cell division, yet their highly repetitive nature has historically precluded comprehensive characterization, leaving fundamental questions about their sequence diversity, evolution trajectories and function dynamics unresolved. Here, we generated 6,312 complete human centromere sequences from 320 phased genome assemblies in Asian Pan-Genome project phase 1. By integrating the assemblies from the Human Pangenome Reference Consortium (HPRC) and Human Genome Structural Variation Consortium (HGSVC), we constructed a multidimensional genetic variation map encompassing over 8,000 gapless centromeres. Centromeric satellite arrays account for 4.19% to 6.01% of the whole genome, with substantial variations in size and architecture across chromosomes. Using a refined alpha satellite clustering approach that captures global diversity, we identified 195 higher-order repeat (HOR) arrays, 56.4% of which are absent from the T2T-CHM13 reference genome. Extensive structural variations across multiple dimensions exhibit population stratification, including centromeric haplotypes (CenHaps), ultra-large pericentric inversions spanning up to 36.6 Mbp, and inter-chromosomal HOR sharing that reflects sequence exchange among chromosomes. Integrating CENP-A CUT&Tag experiments and long-read-based DNA methylation profiles, we demonstrate that 16.8% of centromeres harbor multiple potential kinetochore assembly sites, and CenHap-specific local HOR homogenization is associated with kinetochore positioning. Despite global suppression of recombination at centromeres, we observed asymmetric linkage disequilibrium flanking centromeres and an ancient recombination event within the centromere of chromosome 19. Furthermore, contrary to the prevailing assumption of high mutation rates in centromeres, our estimates based on stringent orthology reveal no significantly higher single-base substitution rates for centromeres relative to flanking pericentromeric regions with substantial variations across chromosomes, despite extraordinary structural plasticity. Collectively, these multi-scale centromeric variations provide a global view of human centromere diversity and population stratification, fundamentally redefine centromere evolution through a dual-track model balancing structural innovation with mutational constraint, and establish an essential resource for investigating centromere biology and a baseline reference for diagnosing centromere-associated disorders.

genomics↗

Deciphering complete archaic introgression sequences in modern human genomes

Genetic introgression from archaic hominins has profoundly reshaped the genetic diversity and adaptive potential of modern humans, yet the full catalog of introgressed sequences, particularly those residing in structurally complex regions has remained elusive. Here, we present ASMaid (ASseMbly-based archaic introgression detector), a Hidden Markov Model-based framework that leverages haplotype-resolved pangenome assemblies to identify archaic-derived sequences with unprecedented completeness. By integrating both single-nucleotide genotype and structural variation (SV) signals, ASMaid captures significantly more intact archaic segments than conventional reference-based approaches. Applying ASMaid to a global panel of 610 phased human genome assemblies, we show that non-African individuals carry approximately 79.8 Mbp of Neanderthal and 8.3 Mbp of Denisovan sequences, representing substantial increases over previous estimates, respectively. Notably, we detected several centromere-spanning archaic segments, including EAS-specific calls on chromosomes 5 and 7. Our assembly-based approach uncovered 1,701 archaic-derived SVs, revealing a previously overlooked layer of archaic functional legacy. High-frequency introgressed loci are enriched in pathways associated with metabolism, immunity, and nervous system (e.g. CTNNA2 linked to early-onset schizophrenia risk), underscoring the fundamental role of introgression in modulating modern human traits. Notably, we identified dozens of loci potentially facilitating local adaptation, such as PRDM16 involved in adipocyte differentiation and cold tolerance, and CSGALNACT2 associated with chondroitin sulfate synthesis. Furthermore, our analysis delineates three distinct Denisovan introgression pulses in Eastern Eurasian genomes, in which the first two pulses are shared across East Eurasian and Oceanian populations, while the third remain primarily exclusive in East Asians. Reflecting these complex introgression events, 31 Denisovan-derived segments, including the TBX15-WARS2 locus, are inferred to have been introduced via at least two events. This comprehensive map of archaic introgression provides a fundamental resource for understanding how ancient gene flow continuously shapes human phenotypic diversity and adaptation.

evolutionary biology↗

Chemogenetic Inhibition of the Ventrolateral Orbitofrontal Cortex Disrupts Prediction Error and Salience-Guided Memory-Updating at the Hippocampal Engram Level

RationaleAdaptive behavior requires revising memories when outcomes deviate from expectations. The orbitofrontal cortex (OFC) is implicated in representing outcome expectancies, but its role in memory-updating, beyond value-based learning, remains unclear. ObjectivesWe tested whether the ventrolateral OFC (VLO) contributes to hippocampal-dependent memory-updating in the Objects in Updated Locations (OUL) task, where novelty-driven exploration provides a behavioral readout consistent with successful updating of spatial information MethodsUsing inhibitory DREADDs, in male and female (Swiss Webster and C57BL/6) mice, we suppressed VLO activity during the Updating session, when new object-location information was introduced. ResultsControl mice preferentially explored the updated object-location configuration during Updating and discriminated between updated and novel object-location configurations at Test, whereas VLO-inhibited mice did not. VLO inhibition when no updating demand was present did not alter exploration of novel object-location configurations or memory for the original spatial configuration at Test. ConclusionsThese results indicate that VLO activity is selectively required when novelty must be interpreted relative to prior experience, implicating this region in evaluating change rather than detecting it. To assess hippocampal ensemble dynamics, we tagged neuronal ensembles, in the dorsal dentate gyrus (dDG) recruited during Updating, followed by quantification of overlap between Updating-tagged cells and ensembles reactivated at Test. We found that VLO inhibition reduced reactivation of Updating-tagged dDG ensembles, paralleling the behavioral impairments observed in the OUL task. These findings support a role for the VLO in hippocampal-dependent memory-updating and extend OFC models beyond reward contexts to include predictive updating of spatial memory representations. Significance StatementUsing a spatial paradigm that distinguishes detection of changed information from incorporation of that information into an updated hippocampal representation, we found that ventrolateral orbitofrontal cortex (VLO) activity is required for memory-updating when new information is present. We found behavioral deficits accompanied by impairments in hippocampal ensemble representations, indicating VLO activity is necessary for memory-updating at the hippocampal engram level. Through this mechanism, the OFC supports the flexible updating of expected outcomes when environmental conditions shift, allowing for the re-evaluation of previously learned associations. These findings extend models of orbitofrontal cortex function beyond reward-guided behavior and identify a cortical contribution to predictive spatial memory processes. Disruption of this computation may contribute to the cognitive rigidity observed in neuropsychiatric disorders.

neuroscience↗

scWeave: A deep learning model that bidirectionally translates between gene expression and chromatin structure at single cell resolution

Chromatin structure and gene expression are intimately linked, yet characterizing how the two covary has proven challenging, primarily because the two modalities are rarely measured in the same cells. Recently, single-cell co-assay protocols have enabled simultaneous profiling of both modalities within the same cells, but these experiments remain costly and technically challenging. To better characterize the relationship between 3D chromatin architecture and gene expression and to enable cross-modality inference from single-modality measurements, we developed a model called scWeave that bidirectionally translates between gene expression (scRNA-seq) and 3D chromatin architecture (scHi-C) at single-cell resolution. The scWeave model employs dual autoencoders to extract separate cell-level latent representations and learns to translate between these representations using dedicated translation modules. We evaluate scWeave on six publicly available co-assay datasets spanning mouse embryonic development, mouse cortex, mouse olfactory epithelium, and human bone marrow. On held-out mouse cells, scWeave outperforms a nearest-neighbor baseline and existing methods adapted to single-cell resolution, achieving a 57% improvement in median Spearman correlation when predicting gene expression from chromatin structure and an 18.8% improvement in median HiCRep similarity in the reverse direction relative to the next-best baseline. We further show that scWeave learns cross-modally aligned latent representations at single-cell resolution, enabling cells profiled in one modality to be matched to their counterparts in the other. Finally, scWeave generalizes to entirely held-out developmental timepoints in mouse olfactory epithelium and performs well on held-out human bone marrow cells despite limited human training data. By predicting the unmeasured chromatin architecture or transcriptional state from a single measured modality, scWeave offers a route to extend the benefits of costly co-assays to the many cell types, developmental stages, and species that are currently profiled with only one modality.

genomics↗

Sustained epigenetic rejuvenation of serially engrafting human iPSC-derived HSCs

Hematopoietic stem cell (HSC) function declines with age, contributing to immunosenescence and inferior transplantation outcomes. Here, we generated iPSC-derived HSCs (iHSCs) from multiple adult donors and performed integrated epigenetic, transcriptional, telomeric, and functional analyses to see if they retain youthful identity across differentiation and serial transplantation. Longitudinal DNA methylation profiling revealed that, independent of donor age, epigenetic age was reset to near zero in iPSCs and remained under seven years across differentiation and transplantation. In contrast, hematopoietic identity was established through a two-phase process: directional remodeling during in vitro differentiation extinguished pluripotency programs and initiated hematopoietic regulatory networks, while long-term engraftment was associated with a second wave of promoter methylation differences that converged toward primary adult HSCs. Notably, methylation at age-associated sites and global entropy remained stable across both phases, and single-cell telomere analysis demonstrated restoration of telomere length in iHSCs compared to primary adult HSCs. Youthful epigenetic features were maintained through secondary transplantation. These findings demonstrate that long-term HSC identity can be achieved independently of epigenetic aging and establish a framework for evaluating rejuvenated stem cell-derived grafts in regenerative medicine.

cell biology↗

Placental invasion mismatch underlines pregnancy disorders and cancers

Mammalian placentas vary dramatically in invasiveness, parallel aggressive cancers, and are dysregulated in pregnancy disorders, yet whether they share regulatory architecture remains unclear. We investigated single-cell transcriptomes of the maternal-fetal interface across nine mammals spanning all major placental morphotypes and integrated it with thirteen cancers and five pregnancy complications. A conserved cellular framework is deployed through three discrete regulatory programs: a cancer-like program in hemochorials, endothelial-cooperation program in endotheliochorials, and collagen-rich invasion-suppressing program in epitheliochorials. Aggressive cancers selectively converge on hemochorial program, and we functionally validated share invasion regulators including the VGLL3-TEAD1 interaction and APOE. Pregnancy disorders are partially, mismatched deployments of these programs; placental APOE knockdown in mice phenocopies preeclampsia with concurrent collapse of both M1/M2 macrophage programs. These findings unify placental diversity, cancer convergence, and obstetric disorders under a regulatory-mismatch principle, whereby evolved placental invasion programs becomes pathological when deployed outside their evolutionary context.

evolutionary biology↗

Zinc coordination by the wheat rust effector AvrSr33 provides a structural scaffold required for immune recognition

Abstract/SummaryInteractions between plants and pathogens drive long-term co-evolution through cycles of effector diversification and immune recognition. Effectors play central roles in this molecular interplay, and zinc-binding folds have been identified in a subset of pathogen effectors, yet the contribution of zinc coordination to effector stability and immune recognition remains unclear. Here, we investigated the structure and recognition of the AvrSr33 effector from the wheat stem rust fungus (Puccinia graminis f. sp. tritici, Pgt). Structural and biochemical analyses show that AvrSr33 adopts a fold containing two zinc-binding sites. Transient expression assays in Nicotiana benthamiana show that AvrSr33 directly interacts with Sr33, and comparison of recognised and non-recognised AvrSr33 variants identifies a polymorphic loop associated with recognition. This loop is positioned adjacent to one of the zinc-binding sites with its orientation constrained by zinc coordination. Reciprocal mutations of key surface residues within this region alter recognition, whereas mutation of the zinc-binding site abolishes recognition. Our data suggest that zinc coordination in AvrSr33 provides a structurally constrained scaffold that supports the surface features associated with Sr33 recognition. These findings provide a mechanistic framework for understanding how zinc coordination contributes to effector recognition and may influence the evolutionary trajectories of pathogen effectors.

Plant Biology↗

FALCON: Closed-Loop Multi-Objective Optimization of Lipid Nanoparticles for Cell-Selective mRNA Delivery

Efficient, cell type-selective delivery of genetic payloads remains a central challenge in the development of gene and cell therapies. Lipid nanoparticles (LNPs) offer a versatile delivery platform, but their optimization is hindered by reliance on brute-force screening methods that are laborious, resource-intensive, and focus on single targets. Here, we present FALCON (Framework for Active Learning-driven Compositional Optimization of Nanoparticles), a closed-loop pipeline that leverages iterative screening, surrogate modeling, and multi-objective optimization to accelerate LNP compositional design. In B cell-targeted validation experiments, FALCON-optimized LNPs achieved a 1.8-fold increase in splenic B cell transfection in vivo compared with reference compositions. When optimized for selectivity, FALCON LNPs displayed an 84-fold improvement in selective transfection of splenic B cells over off-target liver populations and enabled spleen-tropic behavior across factorial panels of varying ionizable and helper lipid chemistries. In vaccine studies, these LNPs induced higher IgG2c antibody titers and a more Th1-biased immune profile. FALCON was also deployed to optimize LNPs for myeloid cell-selective delivery, achieving enhanced in vivo selectivity following systemic administration both across and within spleen and liver compartments. Our results establish FALCON as a useful tool for data-driven design of LNP compositions for precision gene delivery.

bioengineering↗