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Ding, J.

Publications and source records attributed to Ding, J..

At least 19 recordsLinked to original sources

Human brain white matter charts in international populations

Brain charts provide normative references for identifying neurodevelopmental milestones and clinically meaningful deviations. Existing white matter (WM) charts are derived predominantly from European and North American populations, limiting generalizability. Here, we established the first set of population-specific WM charts of 198 morphological and microstructural phenotypes for both Chinese (N=19,215) and Western (N=15,584) populations across the human lifespan. Developmental trajectories and spatial organization of WM maturation and degeneration were broadly conserved across the populations, whereas maturational timing varied across pathways and metrics. The Chinese population showed earlier maturation in several projection and sensorimotor pathways, but more protracted maturation in higher-order association and limbic pathways. Chinese population-matched charts more accurately predicted WM phenotypes and detected more extreme disease-related deviations in brain health in the Chinese population than Western-derived models. Individual deviation patterns further discriminated patients from healthy controls and predicted cognitive performance and plasma biomarkers. Our findings reveal population-specific WM maturation and show that reference-population mismatch can reduce the accuracy and clinical sensitivity of normative brain charts.

neuroscience↗

NeoOmni Atlas: an integrated database for pan-cancer neoantigen derived from proteogenomics analysis

Tumor neoantigens derived from diverse molecular aberrations are important targets for personalized cancer immunotherapy, but existing resources incompletely integrate mass-spectrometry-supported canonical and non-canonical antigen evidence across cancer types. NeoOmni Atlas is an interactive pan-cancer T-cell epitope resource, built via proteogenomic reanalysis of 7,561 immunopeptidomics datasets comprising 511 million raw spectra from 2,341 samples across 26 cancer types. The analysis yielded 872,414 eluted canonical peptides and 198,961 non-canonical peptides spanning 18 molecular alteration classes, along with 759,386 unique ligands presented by 322 human leukocyte antigen (HLA) alleles. Relative to existing repositories, NeoOmni Atlas covers a broader range of cancer types, includes 60 additional HLA alleles, and catalogs 369,781 novel ligands. A computational tumor-specific filtering framework identified 316,126 tumor-associated epitopes and 61,231 tumor-specific epitopes. Tumor-specific epitopes showed stronger predicted binding affinity than tumor-associated epitopes for HLA class I A and B alleles, and 65 conserved tumor-specific epitopes recurrent across more than 10 tumor types represent potential shared antigen candidates. NeoOmni Atlas also prioritizes candidate tumor-associated antigens including PMEL (gp100:209-217) and CSPG4, and supports browsing, searching, and downloading by cancer type, human leukocyte antigen allele, peptide sequence, and source event. NeoOmni Atlas is freely accessible at http://modinfor.com/NeoOmni-Atlas/.

bioinformatics↗

Molecular anatomy of the glomerular filtration barrier reveals topology-encoded albumin sieving

The kidney filters plasma rapidly while retaining albumin, yet where and how this selectivity is encoded within the glomerular filtration barrier remain unresolved. Here we combine cryo-electron tomography (cryo-ET) of vitrified mouse glomeruli with structure-resolved transport modelling to predict albumin passage from the native three-dimensional architecture of the barrier. Among the three barrier layers, endothelial fenestrae and the flexible Nephrin-Neph1 slit-diaphragm lattice are substantially permeable to albumin. The glomerular basement membrane (GBM) instead provides the dominant restriction through steric exclusion governed by void-network topology. In local GBM reconstructions, water traverses broadly connected void space, whereas narrow throats exclude albumin, leaving few accessible paths. To scale this mechanism to the tissue level, we combine structural statistics from local cryo-ET volumes with mesoscale measurements of GBM heterogeneity to generate representative ensembles. Integrating these ensembles with other layers predicts whole-barrier albumin sieving in close agreement with an independent measurement. The topology-driven mechanism also explains early filtration failure in Alport syndrome mice, in which collagen-IV disruption remodels the GBM network and opens albumin-accessible paths while cellular interfaces remain preserved. These findings identify the structural origin of glomerular albumin selectivity and establish a quantitative route from locally resolved architecture to tissue-scale physiology.

physiology↗

TRIM21 licenses pancreatic acinar fate by modulating BiP phase state through VCP-dependent retrotranslocation

The endoplasmic reticulum (ER) chaperone BiP/GRP78 sits at the center of the proteostasis network, coordinating unfolded protein response (UPR) signaling and supporting oncogenic programs of plasticity, metastasis, immune evasion, and chemoresistance. While BiP undergoes liquid-liquid phase separation in vitro, whether mammalian cells dynamically tune this physicochemical behavior to prevent functional exhaustion or pathological condensation under sustained ER stress has remained unclear. Here, we identify the E3 ubiquitin ligase TRIM21 as a phase-state regulator that suppresses BiP's liquid-to-solid phase separation, clearing, and preventing insoluble aggregates-thereby controlling BiP's localization and availability to sustain the adaptive UPR under ER stress. We found that during ER stress, BiP is prone to liquid-to-solid phase separation, a transition that renders the chaperone dysfunctional. TRIM21 is recruited to BiP, where it directly polyubiquitinates BiP at specific K547/553/554/556 sites with K6-, K27-, K33-, and K63-linked chains; VCP recognizes these marks and extracts BiP from the ER lumen via ER-associated degradation (ERAD), coupling ubiquitin tagging to retrotranslocation. This preserves chaperone availability and sustains adaptive UPR-a homeostatic mechanism broadly relevant to UPR-driven diseases. In vivo, genetic ablation of Trim21 in KrasG12D/+; Pdx1Cre/+ mice triggers aberrant BiP solidification while curtailing acinar-to-ductal transdifferentiation and tumorigenesis; notably, TRIM21 co-localizes with BiP condensates in pre-malignant human pancreatic lesions, underscoring the clinical relevance of this regulatory axis. Our findings define the TRIM21-BiP axis as a phase-control system at the interface of proteostasis and stress adaptation, offering a new framework with translational potential.

cell biology↗

Integration of cell-specific gene expression and chromatin accessibility facilitates localization of neurodegenerative risk in microglia

Genome-wide association studies (GWAS) have identified many loci that contribute to the risk of neurodegenerative diseases. However, a persistent challenge in interpretation of GWAS is to break loci down to specific genes, variants, and cell types, and thus nominate disease mechanisms. Here, we used iPSC-derived cells containing population-level variation to examine GWAS loci across NDDs including Alzheimer's disease, Parkinson's disease and Lewy body dementia. We differentiated a set of 135 iPSC donor lines into two cell types relevant to neurodegeneration, neurons and microglia, and completed single cell gene expression and chromatin accessibility profiling. Meta-analysis of these data with published human brain snRNAseq for QTL mapping identified multiple loci associated with NDDs that are restricted to either neurons or microglia. Colocalization of GWAS and these QTL supports microglia as having a strong contribution to disease risk. We tested peaks nominated at the BIN1 locus for enhancer activity using a perturb-seq-based method in microglia. Our results show one of the nominated peaks controls BIN1 expression in microglia but also modifies expression of other genes at the locus. These results support the hypothesis that common variants affecting gene expression specifically in microglia can contribute directly to NDD risk rather than functioning solely as a secondary response to neurodegeneration. These data also show that iPSC-derived cells are a useful model to experimentally dissect GWAS loci that colocalize with QTL.

genomics↗

SALRR: Scalable Analysis of Long-Read RNA-Seq Enables Comprehensive Transcriptome Profiling in Human Brain

Isoform-resolved transcriptomics is fundamental to decoding the molecular complexity of the human brain, yet population-scale long-read RNA sequencing has remained inaccessible due to labor-intensive library preparation, sensitivity to RNA degradation in postmortem tissue, and the absence of integrated, reproducible analysis pipelines. Here we present SALRR (Scalable Analysis of Long-Read RNA-seq), an integrated wet-lab and computational platform designed to overcome these barriers. Automated ONT long-read cDNA library preparation on the Hamilton Microlab NGS STAR platform reduces hands-on time by 67% and enables 24 libraries per operator per day while maintaining performance across RNA integrity values. A modular, Snakemake-based pipeline performs end-to-end processing from ONT signal data to isoform-level quantification, incorporating SIRV spike-in calibration, multi-stage quality control, and stringent isoform validation. Applied to 10 postmortem frontal cortex samples from the North American Brain Expression Consortium, SALRR identified 31,607 high-confidence isoforms from 10,075 genes, including 8,532 novel splice variants absent from GENCODE v49, and complex splicing events systematically missed by short-read sequencing at neurodegeneration-relevant loci, including GBA1, CCNF, CHCHD10, and TREM2. All protocols and code are openly available, providing a scalable, community-ready framework for isoform-resolved transcriptomics in neurodegeneration, aging, and complex brain disease.

genomics↗

Cross-chemistry single-nucleus RNA-seq identifies gene length and CpG-island promoters as determinants of transcriptional noise.

Cell-to-cell transcriptional heterogeneity, or noise, is an intrinsic property of the transcriptome with implications for development, disease progression, and aging. Bulk RNA-seq masks this variability by averaging gene expression across cells, whereas single-cell RNA sequencing (scRNA-seq) resolves it. Nevertheless, separating biological noise from technical variance remains challenging, particularly across platforms with different chemistries. We benchmarked two widely adopted technologies, Evercode WT (SPLiT-seq, Parse Biosciences) and Chromium (10x Genomics), on human lymphoblastoid nuclei. Evercode WT achieved targeted sequencing depth and nuclei number far more reliably, and its random-hexamer priming yielded more intronic reads and non-coding RNA genes; Chromium recovered more cells and detected polyadenylated transcripts and cell-line markers more sensitively. Despite these opposing biases, the platforms showed comparable gene detection and strongly correlated expression profiles. Using datasets from both platforms, we defined a noise metric detrended from mean expression and showed that per-gene estimates were reproducible across chemistries. Noise was lower in G2M than in G1 and was most strongly associated with gene length rather than exonic length. Expression of genes with CpG-island promoters was less variable than that of those without. This study establishes a platform-independent basis for quantifying transcriptional noise and a framework for selecting an appropriate scRNA-seq platform.

genomics↗

Irregular nucleosome positioning governs a crystalline to liquid-like phase transition and tunes chromatin accessibility

Chromatin must fold tightly enough to protect the genome while being sufficiently accessible for DNA dependent processes such as transcription. The physical rules that balance these competing roles remain unclear, as DNA sequence encodes both biochemical information such as transcription factor binding sites, and biophysical cues that shape chromatin structure. Here, using synthetic chromatin fibres assembled from physiologically relevant DNA sequences, we show that nucleosome positioning dictates the material state of chromatin. Heterochromatin-like sequences produce compact fibres stabilised by nucleosome stacking, whereas euchromatin-like sequences generate irregular nucleosome positioning that yields disrupted, heterogeneous, and mechanically deformable fibres. Quantitative polymer modelling reveals that these irregular arrays are highly dynamic, continually sampling a broad ensemble of conformations as nucleosome stacking breaks down. We identify two previously unrecognised thresholds encoded by nucleosome positioning: minimal positional irregularity (2-3 bp) triggers a transition from an ordered paracrystalline state to a liquid-like phase, whereas an order of magnitude greater irregularity (~18 bp) is required to generate accessibility and mechanical fragility permissive for transcription factor binding. Euchromatin-like arrays reside at this accessibility threshold. These findings indicate that nucleosome positioning tunes chromatin toward or away from critical structural states that couple genome protection, chromatin dynamics, and transcriptional potential, providing a physical mechanism that helps connect DNA sequence to gene expression.

molecular biology↗

ITPKB is a conserved regulator of natural killer cell desensitization/education that constrains antitumor immunity

Natural Killer (NK) cell desensitization induced by persistent stimulation limits durable antitumor immunity, yet the molecular mechanisms governing this dysfunctional state remain poorly defined. To identify conserved regulators of NK cell desensitization, we performed comparative transcriptomic analyses across multiple murine models of persistent activation and dysfunction. This approach defined a shared transcriptional program of desensitization and identified Itpkb to be upregulated across multiple distinct contexts. Genetic and pharmacological inhibition of ITPKB enhanced degranulation, cytokine production, and cytotoxicity in both murine and human NK cells under multiple desensitization settings. Mechanistically, ITPKB regulated signaling downstream of persistent activation through the IP3/IP4 axis, limiting calcium mobilization and NFAT-dependent transcriptional responses in desensitized NK cells. Furthermore, inhibition or deletion of ITPKB enhanced NK-cell mediated tumor control in vivo and improved the efficacy of adoptively transferred CAR-NK cells, underscoring the translational potential of targeting this pathway. Together, these findings identify ITPKB as a cell-intrinsic regulator of NK cell desensitization and support targeting the IP3/IP4 signaling axis to enhance NK cell-mediated antitumor immunity.

immunology↗

Integrated multi-omics profiling of gut bacterial extracellular vesicles links cargo composition to host transcriptional responses

Bacterial extracellular vesicles (bEVs) enable gut microbiota to deliver bioactive cargo to host cells, yet the specific bacterial producers have not been systematically identified. Here, we profiled stool-derived bEVs from healthy individuals using metaproteomic profiling, revealing that vesiculation is widespread across gut bacterial phyla. We selected a subset of vesiculating species, showing that bEVs localize to distinct tissues in vivo, including extraintestinal sites such as lung, liver, kidney, and bone, suggesting roles beyond the gastrointestinal tract. We profiled intestinal epithelial cells and macrophages after endocytosing bEVs from various species, uncovering pronounced, cell-type-specific responses. For example, Bacteroides fragilis bEVs promote anti-inflammatory mitochondrial-telomeric regulation, while a set of commensal-derived bEVs contribute to epithelial survival and structural renewal. By combining proteomic, lipidomic, and metabolomic cargo profiling with transcriptional output, we find that specific Bacteroidota-derived protein cargo activates cytoprotective stress defenses while attenuating inflammatory signaling. Together, these findings establish a multi-layered comparative atlas of bEV composition, uptake, and host response, providing a framework for understanding bEV-mediated microbiome-host communication.

microbiology↗

Super-Resolution Visual ProteomEx for Hard Tissues and Clinical Samples

Correlating nanoscale tissue architecture with unbiased molecular composition within the same specimen remains a fundamental challenge in spatial biology. Current spatial proteomics methods either lack the imaging resolution required to resolve nanoscale tissue architecture or achieve only limited proteome coverage, and untargeted approaches capable of deep protein identification have yet to be integrated with super-resolution imaging within a single workflow. Here, we present microProteomEx, an integrated platform that combines hydrogel-assisted tissue expansion with mass spectrometry-compatible fluorescence imaging, laser capture microdissection, and bottom-up proteomics to achieve simultaneous three-dimensional super-resolution imaging (effective lateral resolution down to [~]47 nm on conventional diffraction-limited microscopes) and spatially resolved proteomics at a scalable lateral resolution of 29-100 {micro}m (0.02-0.28 nL volumetric resolution). By optimizing fixation, protein anchoring, and a secondary re-embedding strategy, we extend the method to mechanically resilient tissues, including mouse kidney and heart, as well as to formalin-fixed, paraffin-embedded clinical specimens. We demonstrate single-glomerulus and single-plaque proteomics (450-1,000 proteins per structure), resolve proteomic differences between malignant melanoma and giant congenital melanocytic nevus in a rare pediatric case, and characterize the morphology-resolved molecular heterogeneity of cored versus diffuse amyloid-beta plaques in a mouse model of Alzheimers disease across two disease stages. microProteomEx establishes a broadly accessible framework for correlating tissue ultrastructure with deep spatial proteomics, with direct implications for disease biology, biomarker discovery, and precision medicine.

biochemistry↗

Structural and Dynamic Basis of TREM2--DAP12 Stabilization by Small-Molecule Agonist VG-3927

Triggering receptor expressed on myeloid cells 2 (TREM2) is an important microglial receptor implicated in Alzheimers disease, but the structural basis of small-molecule TREM2 agonism remains poorly understood. In particular, the clinical-stage agonist VG-3927 has been reported to promote TREM2-DAP12 complex formation, suggesting a mechanism distinct from conventional recognition at the ectodomain surface. Here, we propose that VG-3927 binds within a membrane-embedded interfacial cavity formed by the transmembrane helices of TREM2, DAP12A, and DAP12B. Our simulations support a stable and reproducible cavity-bound pose that is maintained across independent trajectories and is anchored by a persistent hotspot network dominated by hydrophobic and van der Waals interactions. Rather than merely occupying a pre-existing pocket, VG-3927 reshapes the surrounding transmembrane assembly by reinforcing selected interhelical contacts, strengthening receptor-adaptor hydrogen-bond coupling, and biasing the three-helix bundle toward a more compact, more upright, and more conformationally focused state. Importantly, the ligand-bound ensemble remains within a subdomain of the apo conformational landscape, consistent with stabilization of a pre-existing but less populated signaling-relevant state. Together, these findings support a membrane-asscosiated mechanism in which VG-3927 acts as a transmembrane interfacial molecular glue, biasing the TREM2-DAP12 complex toward a more compact, ordered, and signaling-competent state. This finding can provide a structural framework for understanding small-molecule TREM2 agonism.

Molecular Biology↗

Liver-to-Atria Inflammatory Axis Driving Arrhythmia

BackgroundMetabolic dysfunction-associated steatohepatitis (MASH) is emerging as a risk factor of cardiometabolic diseases, including the atrial fibrillation (AF) - the most common sustained arrhythmia. Given that the liver is a major source of inflammatory mediators, lipids, and hepatokines under metabolic stress, we hypothesized that hepatocyte-derived factors in MASH may accelerate atrial remodeling and arrhythmogenesis. MethodsAnalysis of the Atherosclerosis Risk in Communities (ARIC) visit 5 cohort was performed to determine the association between the FIB-4 index - a classic indicator of liver fibrosis, and AF risk, with multivariable adjustment for common comorbidities. A murine model of MASH was induced using the GAN (Gubra-Amylin NASH) diet. Programmed intracardiac stimulation and echocardiography were performed to assess AF susceptibility and cardiac function. Calcium imaging, histology, flow cytometry, plasma proteomics, and single-nucleus RNA sequencing (snRNA-seq) analyses were employed to elucidate the role of recruited inflammatory macrophages via hepatocyte-derived osteopontin (OPN) in MASH-induced atrial remodeling. ResultsAnalysis of the ARIC cohort confirmed a higher cumulative incidence of AF and an elevated adjusted hazard ratio (HR) in patients with intermediate and high FIB-4 indices compared to individuals with low FIB-4 scores. MASH mice exhibited increased susceptibility to pacing-induced AF, accompanied by enhanced proarrhythmic calcium release events, atrial enlargement, and fibrosis, independent of ventricular dysfunction. Proteomics and snRNA-seq revealed that the hepatocyte-secreted OPN under MASH conditions promoted the differentiation and recruitment of TGFBR1+ inflammatory macrophages to the atria, leading to gasdermin D (GSDMD) activation - an effector of inflammasome signaling and consequent proarrhythmic atrial remodeling. Activation of the monocyte-derived pro-inflammatory TGFBR1+ macrophages was dependent on the OPN receptor CD44. Furthermore, the MASH-induced atrial fibroinflammatory milieu and enhanced AF susceptibility were mitigated through several strategies, including hepatocyte-specific Spp1 (encoding OPN) deletion, neutralization of circulating OPN, ablation of CD44 or GSDMD. ConclusionsThese findings establish a pathogenic role of the hepatokine osteopontin in driving activation and recruitment of TGFBR1+ inflammatory macrophages into the atria, leading to proarrhythmic atrial remodeling under MASH. Osteopontin-targeted therapy or GSDMD inhibition prevents AF, indicating a novel therapeutic strategy for liver disease-related atrial arrhythmogenesis. Clinical PerspectiveO_ST_ABSWhat is new?C_ST_ABSO_LIIn the ARIC cohort, metabolic dysfunction-associated steatohepatitis (MASH) is associated with increased risk of atrial fibrillation (AF) after adjusting for common comorbidities. Elevated levels of circulating osteopontin (encoded by SPP1) predict an increased risk of AF in patients with MASH-induced liver fibrosis. C_LIO_LIMASH enhances hepatocyte secretion of osteopontin, leading to expansion of myeloid cells and recruitment of inflammatory macrophages into atria. This liver-to-atrial inflammatory circuit promotes the development of a substrate conducive to AF, which can be attenuated by hepatocyte-specific Spp1 deletion or neutralizing anti-anti-osteopontin antibody treatment to eliminate the mediator, or ablation of inflammasome effector gasdermin D to correct the atrial response. C_LI What are the clinical implications?O_LIOsteopontin may serve as a biomarker for AF in MASH cohorts. C_LIO_LIAnti-osteopontin therapy through neutralizing antibodies may serve as a novel therapeutic strategy for liver disease-related atrial arrhythmia. C_LI

systems biology↗

STRIP2 Stabilizes LCN2 to Suppress Ferroptosis and Drives Colorectal Cancer Malignancy

Colorectal cancer (CRC) presents a significant global health challenge with high incidence rates, mortality, and poor five-year survival rates, particularly in advanced cases, despite the availability of existing treatments. This study investigates the role of Striatin-interacting protein 2 (STRIP2) in CRC progression and the underlying mechanisms. To evaluate the impact of STRIP2 on CRC, we conducted in vitro experiments to assess cell proliferation, migration, invasion, and apoptosis in CRC cell lines. Furthermore, in vivo studies were performed utilizing nude mouse models. Transcriptomic analysis, Western blotting, co-immunoprecipitation assays, and ferroptosis validation were employed to elucidate the role of STRIP2 in CRC. The findings indicate that STRIP2 is overexpressed in CRC and drives malignant behaviors in both in vitro and in vivo settings. Overexpressing STRIP2 (oe-STRIP2) suppresses ferroptosis, leading to increased cell proliferation and reduced oxidative stress, whereas silencing STRIP2 (si-STRIP2) has the opposite effect. Mechanistically, STRIP2 stabilizes LCN2, an effector downstream of IL-17, by preventing its K48-linked ubiquitination and subsequent degradation. This stabilization enhances the anti-ferroptosis capacity of CRC cells, thereby promoting cell survival and facilitating malignant progression in CRC. These findings suggest STRIP2 as a promising diagnostic biomarker and therapeutic target for CRC intervention and warrant further investigation.

cancer biology↗

Intranuclear polyglycine aggregation drives neurodegeneration through epigenetic repression of chromatin accessibility and transcription

Polyglycine (polyG) proteins translated from expanded GGC trinucleotide repeats are implicated in a growing group of neuromuscular degenerative disorders characterized by intranuclear inclusions, yet the pathogenic importance of aggregate localization and the mechanisms underlying polyG-induced neurodegeneration remain unclear. Here we show that intranuclear polyG aggregates are markedly more pathogenic than cytoplasmic aggregates in cellular and mouse models. Intranuclear aggregation causes greater cell death, more severe behavioral deficits and neuropathology, and earlier mortality. Mechanistically, intranuclear polyG aggregates impair nascent RNA synthesis and are associated with a transcriptionally repressive chromatin state marked by globally reduced chromatin accessibility, decreased H3K27 acetylation, and increased HDAC3 expression across cellular, mouse, and human disease tissue. Using a light-inducible system, we further show that this transcriptional impairment depends on insoluble intranuclear aggregate formation rather than diffuse polyG alone. Pharmacological HDAC inhibition partially restores histone acetylation and transcriptional output and ameliorates behavioral and pathological abnormalities. Together, these findings identify intranuclear polyG aggregates as the more pathologically relevant species and uncover epigenetic repression of chromatin accessibility and transcription as a potentially common mechanism underlying polyG diseases.

neuroscience↗

δ-catenin controls layer-specific transcriptional maturation of astrocytes via Zbtb20

Coordinated maturation of diverse neural cell types drives mammalian cortical circuit development. Disruption of this coordination is a hallmark of human neurodevelopmental disorders, yet mechanisms that synchronize transcriptional maturation across cell types remain poorly understood. Here, we identify {delta}-catenin (Ctnnd2), a component of adherens junctions, that links cell-cell interactions to transcriptional regulation. Using single-nucleus and spatial transcriptomics, we show that {delta}-catenin loss disrupts transcriptional maturation across neural cell types, particularly in astrocytes. {delta}-catenin loss impairs acquisition of layer-specific astrocyte identities and prolongs ocular dominance plasticity, indicating impaired circuit stabilization. Mechanistically, we identify the BTB/POZ transcription factor Zbtb20, which is enriched in glial cells, as a key regulator of this process. {delta}-catenin loss increases Zbtb20 expression, redistributes its genome-wide binding, and dysregulates its target genes. Together, these findings support a model in which {delta}-catenin regulates Zbtb20-dependent transcriptional programs to establish layer-specific astrocyte identities in coordination with developing cortical circuits. SUMMARYSejourne et al report that loss of the adherens junction protein {delta}-catenin prolongs ocular dominance plasticity and disrupts astrocyte and oligodendrocyte transcriptional identity. The underlying mechanism seems to rely on the glia-enriched transcription factor Zbtb20, which is upregulated and redistributed upon {delta}-catenin loss, resulting in altered expression of its target genes.

cell biology↗

G4 Eurasian avian-like H1N1 swine influenza viruses exhibit enhanced pathogenicity potential in mice and pigs

Currently circulating swine influenza viruses (SIVs) mainly include H1N1, H1N2, and H3N2 subtypes. In this study, two G4 genotype Eurasian avian-like (EA) H1N1 SIVs were isolated from 556 samples collected between 2023 and 2026. A systematic analysis was conducted on the two EA H1N1 isolates (FYD30 and YZF69) to assess their pandemic potential. The hemagglutinin (HA) proteins of both H1N1 viruses possessed residues 225E and 228S, indicating enhanced affinity for human-like -2,6-linked sialic acid receptors, which was confirmed by receptor-binding assays. Polymerase activity tests demonstrated that the two SIVs exhibited significantly higher activity in mammalian cells, relative to avian cells, which is consistent with the efficient replication in mammalian cells. Challenge experiments revealed that both H1N1 caused significant pathogenicity in mice and pigs, with YZF69 exhibited higher virulence than FYD30. The higher virulence of YZF69 may be attributed to its molecular features, including the NP Q357K mutation, and an additional glycosylation site in HA. In conclusion, currently circulating EA H1N1 SIVs have acquired key molecular signatures of mammalian adaptation, exhibit enhanced virulence in mammals, and continue to undergo extensive reassortment driven by international swine trade. These findings highlight the potential pandemic risk of SIVs and underscore the urgent need for strengthened surveillance.

microbiology↗

Sex-Dependent Effects of Glutamatergic Disruption on Dopaminergic Neuron Subtype Vulnerable in Parkinson's Disease

Aldehyde dehydrogenase 1A1-positive (ALDH1A1+) dopaminergic neurons (DANs) are preferentially vulnerable in Parkinsons disease (PD), yet how their activity is modulated by presynaptic inputs remains poorly defined. Here we investigated the role of glutamatergic input by conditionally deleting Grin1, which encodes a critical NMDA receptor (NMDAR) subunit, in ALDH1A1+ DANs. Grin1 conditional knockout (cKO) mice displayed normal locomotion and motor learning; however, females exhibited enhanced operant reward acquisition and excessive feeding with transient weight gain following food restriction. To determine regional contributions, Grin1 was selectively knocked down in ALDH1A1+ DANs of either the ventral tegmental area (VTA) or substantia nigra pars compacta (SNc). VTA-specific knockdown in females was sufficient to reproduce the post-restriction feeding and weight gain phenotype. Bulk whole-brain mRNA sequencing revealed pronounced sex-dependent transcriptional changes, primarily in female Grin1 cKO mice after food restriction. Many differentially expressed genes were associated with mitochondrial function, energy metabolism, and synaptic signaling. Together, these findings reveal a sex-specific role for NMDAR-mediated glutamatergic input to ALDH1A1+ VTA DANs in regulating feeding behavior, providing mechanistic insight into how dysfunction of this vulnerable subpopulation may contribute to PD-associated compulsive eating disorders. Key FindingDisrupted NMDA receptor-mediated glutamatergic input to ALDH1A1+ DANs drives sex-specific feeding abnormalities relevant to PD-associated compulsive eating disorders.

neuroscience↗