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Sun, W.

Publications and source records attributed to Sun, W..

At least 19 recordsLinked to original sources

Repetitive transcranial magnetic stimulation targeting motor cortical region induces cell-type-specific transcriptional reprogramming and behavioral recovery in non-human primate model of Rett syndrome

Rett syndrome (RTT), a severe neurodevelopmental disorder caused by mutations in the MECP2 gene, currently lacks effective treatments. The motor cortex is a pivotal hub in RTT and autism spectrum disorders, and its impairments contribute to motor, social, and cognitive deficits. Here we examined the effects of repetitive transcranial magnetic stimulation (rTMS) targeting motor area in non-human primate of RTT (MECP2-mutant monkey) and investigated neuromolecular basis underlying therapeutic effects. We identified a new treatment target, ventral premotor cortex (PMv), for RTT and found that following a 20-day rTMS course, several behavioral and functional connectivity measures showed directional changes. Neuroimaging analyses confirmed that rTMS induced reorganization of large-scale functional connectivity with enhanced functional integration between the somatomotor and the salience networks and normalized coupling between the motor cortex and both the thalamus and the anterior cingulate cortex. Notably, single-nucleus RNA sequencing revealed that rTMS triggered cell-type-specific transcriptional reprogramming: it rescued pathological hyperactivity of excitatory neurons by restoring the expression and regulatory networks of immediate early genes (e.g., FOS, EGR1) and corrected dysregulated intercellular signaling (e.g., NRG, WNT). These findings indicate that targeting motor cortical areas with brain stimulation may treat RTT, which warrants further clinical validation.

neuroscience↗

Microbial Reductive Dechlorination of Hexachlorobutadiene by Dehalococcoides

Hexachlorobutadiene (HCBD), a persistent organic pollutant (POP), poses a significant threat to ecological environments and human health. While anaerobic microbial transformation is a promising remediation strategy, the specific microorganisms and metabolic mechanisms involved have remained poorly understood. This study demonstrates the successful enrichment of an anaerobic microbial consortium from river sediment, with lactate as an electron donor, capable of transforming HCBD. Within 240 days, 62.5 mol of HCBD was sequentially dechlorinated through pentachlorobutadiene (PCBD), tetrachlorobutadiene (TeCBD), trichlorobutadiene (TCBD), and dichlorobutadiene (DCBD) to chlorobutadiene (CBD). Co-amendment with HCBD and trichloroethene (TCE) resulted in complete removal of both compounds. 16S rRNA gene sequencing and quantitative PCR showed enrichment of Dehalococcoides, linking its population growth to HCBD and TCE dechlorination. This study demonstrates that Dehalococcoides growth was associated with HCBD transformation in the enrichment cultures, broadens our understanding of the metabolic capabilities of Dehalococcoides, and identifies a candidate gene for this important environmental process, offering valuable insights for the bioremediation of sites contaminated with HCBD.

microbiology↗

A telomere-to-telomere genome of Holstein cattle resolves chromosome-end architecture and the genetic basis of telomere length

Telomeres safeguard chromosome-end integrity, yet population-scale dissection of telomere-length genetics has been largely restricted to humans. Here, we report a 3.01-Gb telomere-to-telomere (T2T) genome of Holstein cattle that resolves repeat-rich chromosome ends and centromeres and enables telomere-length quantification at single-chromosome-end resolution. Holstein chromosome ends show marked telomere-length asymmetry and end-specific variation in telomere variant repeats, subtelomeric tandem repeats, GC/CpG composition, and DNA methylation. Using sequencing-depth-corrected telomere-length phenotypes from 9,591 cows, teloGWAS identifies major loci encompassing RTEL1, CTC1, and TERT, while multi-tissue eQTL, sQTL, TWAS, and co-expression analyses prioritize CTC1 and implicate DNA replication, DNA repair, and stress-response networks. Together, these findings extend population-scale telomere genetics beyond humans and establish a sequence-resolved framework for chromosome-end biology and telomere-informed livestock genomics.

genomics↗

A robust and scalable image analysis framework for phenotyping human thoracic aorta

Large-scale phenotyping of the thoracic aorta requires a workflow in which every step, from segmentation to phenotype extraction, runs without manual intervention. We present a robust and scalable framework that converts contrast-enhanced CT into anatomical landmarks, a patient-specific quadrilateral mesh, a wall-stress field and regional phenotypes of the thoracic aorta. Four nnU-Net segmentation tasks delineate the aorta, its anatomical regions and two partitions of the aortic root. A surface-curve-point procedure derives the annulus, the sinotubular junction, the ostia of the supra-aortic branches, the cusp nadirs and the commissures from the interfaces between segmented regions. We fit a structured template of 24,882 quadrilateral elements to the segmented aortic surface by staged, differentiable mesh deformation and compute the transmural mean wall stress with PyTorch-FEA. The structured mesh provides node-to-node correspondence across patients, anchored to the anatomy by the landmarks, from which the framework extracts regional morphological and biomechanical phenotypes.

bioengineering↗

Allyl chloride respiration by Dehalobacter shapes the fate of 1,2,3-trichloropropane

The synthetic compound 1,2,3-trichloropropane (1,2,3-TCP) is a persistent groundwater contaminant and probable human carcinogen for which effective detoxification pathways remain limited. Under anoxic conditions, microbial transformation of 1,2,3-TCP typically stalls at the intermediate allyl chloride, preventing complete detoxification. Here, we report the enrichment and characterization of Dehalobacter restrictus strain XRTCP, a bacterium capable of coupling dichloroelimination of 1,2,3-TCP with subsequent hydrogenolysis of allyl chloride to propene. While dichloroelimination to allyl chloride has been previously observed, the ability to utilize allyl chloride as a respiratory electron acceptor represents a previously unrecognized metabolic capability. This transformation was linked to microbial growth, with cell densities increasing by up to 74-fold during 1,2,3-TCP reduction and 15.8-fold during allyl chloride transformation. Metagenomic and metaproteomic analyses revealed a diverse repertoire of reductive dehalogenases (RDases), with expression patterns that differed between 1,2,3-TCP and allyl chloride amendments. Notably, a tcpA-like RDase was expressed under both 1,2,3-TCP and allyl chloride conditions, while distinct RDases were preferentially expressed under each substrate, indicating functional specialization within the dechlorination pathway. Despite this metabolic capability, propene formation remained limited due to rapid abiotic transformation of allyl chloride, primarily via reactions with reduced sulfur species, highlighting a critical branching point between biotic and abiotic pathways. These findings demonstrate that allyl chloride can function as a growth-supporting respiratory electron acceptor. More broadly, this work reveals how interactions between microbial metabolism and geochemical processes govern contaminant fate, with implications for improving both monitored natural attenuation and engineered bioremediation strategies for chlorinated solvents.

microbiology↗

An Excelled Trifluorinated Probe for GPCR Conformational Quantification

G protein-coupled receptors (GPCRs) represent the largest membrane protein family in the human body and the major targets of FDA-approved medications. Unlike some other physiological proteins, GPCRs are highly plastic and often exist as collections of conformational ensembles in the environment to exert their function. Therefore, understanding how a GPCR adopts different conformational ensembles in response to ligands and signaling partners is essential for drug development. 19F-NMR has emerged as one of the most promising tools in this regard; however, a well-established 19F-labeling system is still lacking, including an effective 19F probe that meets both environmental susceptibility and NMR sensitivity requirements, even though progress has been made dramatically in recent years. Thus, this manuscript reports a novel conformational probe (4-(bromomethyl)-ethoxy-2-(trifluoromethyl)benzene, BTMB) that offers paramount benefits for future GPCR conformational dynamics studies. To rationalize the mechanism behind BTMB's superiority for future probe development, we performed MD simulations, referenced to the current state-of-the-art probe, BTFMA. Our study suggests that the spatial proximity of aromatic residues significantly influences the chemical shift dispersion and linewidths of related 19F-probe-profiled conformational states, as well as the rigidity and compactness of -CF3 in the target protein.

biophysics↗

Constructing Virtual Viruses in A Spatial Minimal Cell

Viral development links gene expression and genome replication to particle formation within a cell. Here we construct virtual viruses in a JCVI-syn3A-based spatial minimal cell. For mycoplasma virus P1, molecular events connect expression and replication to coarse-grained packaging, followed by a spatial reconstruction of membrane opening and particle release. Individual finite-size particles coexist, move across the boundary and undergo partial crossings and returns before complete exit. In contrast, Acholeplasma phage MV-L1 (L1) expresses its genes and accumulates genomes as the host continues to grow and develops a constricted shape. The coexistence of viral activity and continued host growth is qualitatively consistent with the non-lytic biology of group 1 acholeplasmaviruses. These reconstructions extend the virtual cell to the viruses that develop within it, linking molecular activity, particle behavior and host growth.

synthetic biology↗

Glutamine-regulated VCP acetylation creates a proteostasis vulnerability in RB1-deficient tumor

RB1 deficiency defines an aggressive tumor state with limited therapeutic options. Osteosarcoma represents a clinically relevant model of RB1 deficient malignancy, as RB1 alterations are among the most frequent genomic events in this tumor type. However, the non cell cycle vulnerabilities created by RB1 loss remain incompletely understood. We therefore used osteosarcoma to identify therapeutic dependencies associated with RB1 deficiency. Through high-throughput compound screening, we identified a selective vulnerability of RB1-deficient tumor cells to VCP inhibition. NMS-873 and other VCP-targeting compounds preferentially suppressed RB1 deficient cells across two-dimensional cultures, three-dimensional spheroids, patient-derived organoids, and in vivo tumor models. Mechanistically, VCP inhibition exacerbated proteostasis stress and activated endoplasmic reticulum stress responses in RB1-deficient cells. We further found that VCP function was regulated by glutamine-dependent acetylation, with lysine 615 serving as a dominant acetylation site that modulated sensitivity to VCP inhibition. Glutamine restriction phenocopied, whereas glutamine supplementation partially rescued, the effects of NMS-873 on VCP acetylation and tumor cell growth. Clinical and transcriptomic analyses further linked VCP expression and protein-folding stress programs to aggressive disease features. Together, these findings identify glutamine regulated VCP acetylation as a metabolic proteostasis dependency in RB1-deficient tumors and nominate VCP inhibition as a therapeutic strategy for this difficult-to-target tumor state.

cell biology↗

Alterations to the yeast chromatin landscape during hypoxia

When cells encounter low oxygen conditions, signaling events target key transcription factors to reprogram gene expression to promote cell survival and adaptation under this challenging environmental stress. The substantial metabolic changes that occur in hypoxia also drive changes to the chromatin environment due to altered cofactor availability and direct oxygen sensitivity of chromatin-modifying enzymes, among other factors. Given the links between hypoxic cellular environments and numerous pathophysiological processes, including tumor progression and metastasis, cardiovascular disorders, and aberrant development, it is critical to understand the chromatin states and chromatin-based regulatory mechanisms associated with cellular responses to hypoxia. Here, we used the model eukaryote Saccharomyces cerevisiae to interrogate the requirement for key transcription factors and chromatin regulators in survival during hypoxia and we assessed the distribution of major histone modifications associated with the response to stress, H3K9 acetylation and H3K4 methylation, throughout the genome during hypoxia. Our results show that only a small number of chromatin modifiers in yeast contribute to survival in hypoxia; however, there are substantial changes to the abundance and distribution of both H3K9ac and H3K4me3 during hypoxic growth. Specifically, H3K9ac levels are reduced throughout the genome though still maintain association with transcriptionally active genes. H3K4me3 has increased abundance genome-wide and shows a wider distribution with greater abundance in coding sequences particularly of genes upregulated in hypoxic conditions. Altogether, our data demonstrate substantial changes to the chromatin landscape in hypoxic conditions in the budding yeast model, providing key insights into physiological chromatin changes caused by limiting oxygen in the environment.

molecular biology↗

A combined program of induced stemness and differentiation in response to interferon gamma drives acute myeloid leukaemia growth

How inflammation shapes acute myeloid leukaemia (AML) has come under scrutiny, as it may explain the disease resistance to immunotherapy approaches. IFNg has emerged as a key cytokine with paradoxical roles in suppressing and supporting AML growth, and the fundamental question of how leukemic stem cells (LSCs) respond to IFNg and whether IFNg signaling influences LSC quiescence and their capacity to regenerate disease over the long term remains unanswered. Here, we study primary human AML cells and murine models and combine bioinformatics analyses and functional assays to show that AML hierarchical heterogeneity is responsive to IFNg challenge. We uncover that IFNg triggers parallel stemness and differentiation programs; HSC/MPP-like cells enter deeper stemness, associated with quiescence and high leukaemia regeneration potential, while the surviving pool of progenitor-like cells divides faster but produces progeny that is quickly lost. Finally, with murine models we show that exposure to inflammation in vivo results in only transient impairment of leukaemia propagating capacity. This mechanism is driven by a previously unrecognised intraclonal fate bifurcation, relevant for the development of more effective therapeutic approaches.

cancer biology↗

Large-Scale Network Embedding Predicts Opposing Functions of Adjacent Regions Within Human Prefrontal Cortex

Prefrontal regions are hypothesized to be organized hierarchically in support of cognitive control. Using precision functional MRI in three independent cohorts of intensively scanned participants (N=37), we consistently identified a lateral prefrontal cortex (LPFC) region linked to a canonical control network separate from a nearby rostral LPFC region linked to the action-mode network. Despite their spatial juxtaposition, the two regions were differentially coupled to the caudate and ventral putamen, suggesting they are components of segregated networks. Working memory demands activated the canonical LPFC control region but not the adjacent region. Contrasting go and no-go trials during target detection revealed a robust functional double dissociation during goal-directed behavior. The canonical LPFC control region activated when responses were withheld, while the putamen-coupled LPFC region increased activity during executed responses. These findings demonstrate that adjacent LPFC regions participate in opposing functions predicted by their embedding within distinct parallel large-scale networks.

neuroscience↗

AI-driven framework modeling perturbation in brain organoids reveals candidate genes for autism

Autism gene discovery is constrained by the rarity and heterogeneity of damaging variants, requiring large cohorts to identify susceptibility genes. Neural organoids and single-cell foundation models enable perturbation modeling in neurodevelopmental contexts. Here, we show that perturbation-informed foundation modeling of neural organoids can provide functional context for prioritizing candidate genes with genomic and clinical support. We constructed a 3.6-million-cell organoid atlas and trained models to predict genome-wide perturbation responses. Benchmarking 17 models identified a telencephalic neuron-specific model best preserving autism-relevant perturbation structure. Genome-wide profiling revealed two clusters associated with mid-fetal synaptic neuronal processes and early radial glia ubiquitin signaling. These clusters were supported by damaging-variant enrichment and clinical phenotypes across 89,916 family-based samples. Logistic-regression prioritization identified 343 candidates, including 167 in the key clusters, with convergence across TADA signals and recurrent evidence for NBEA and KLHDC10. This framework integrates predicted perturbation effects with genomic evidence to support autism candidate prioritization.

bioinformatics↗

Dietary iron overload enhances susceptibility to Yersinia enterocolitica infection

Hemochromatosis and hemosiderosis are iron overload disorders that cause immune dysfunction and increase susceptibility to bacterial infections. There have been numerous case studies reporting septic-like outcomes for hemochromatosis patients infected with enteric Yersiniae; however, research regarding hemosiderosis and Yersinia infection is limited. Here, we have established a mouse model of hemosiderosis by feeding C57BL/6 mice a high-iron diet. These mice exhibit several indicators of iron overload that are seen clinically, including elevated serum iron levels and iron deposition in various tissues. Characterization of the iron overload mouse model shows that a high-iron diet induces local inflammation in the small intestine and systemic inflammation in a time-dependent manner. Oral infection with Yersinia enterocolitica causes complete mortality in the iron-overloaded mice, while wild-type mice all survive and effectively clear the infection. Lastly, we have observed that iron chelation therapies such as Deferoxamine and Deferisarox are detrimental to iron-overloaded mice during Yersinia infection. This work provides a model to further study iron overload disorders and Yersinia infection.

immunology↗

Multiple Nested Distributed Language Networks in the Human Brain

Brain regions specialized for language have been extensively described, yet their arrangement into one or multiple networks remains debated. Using precision functional mapping across three independent cohorts of intensively scanned individuals (22 individuals scanned over 216 separate MRI sessions), we dissociated two nested left-lateralized perisylvian networks: an intermediate language network (intLANG) and an anatomically distinct association language network (aLANG). intLANG is anchored to precentral speech areas and the Sylvian parietal-temporal area (Spt), whereas aLANG surrounds intLANG and extends into higher-order prefrontal and temporal association cortices. The two networks can be fully recapitulated by functional connectivity from adjacent cerebellar regions, indicating that they are segregated, brain-wide networks. Task-based analyses further reveal that intLANG and aLANG are functionally distinct: intLANG responds robustly during rhyme judgments and nonword reading that emphasize phonology, whereas aLANG is preferentially recruited during meaning-based sentence processing. These findings indicate that human language engages nested distributed networks each specialized for distinct components of language processing: a lower-order network biased toward phonology, and a surrounding association network that subserves higher-order syntax and semantics. This nested organization is similar to other brain systems suggesting a shared hierarchical motif that may give rise to specialized cognitive functions across the human brain.

neuroscience↗

Spatial multi-omics and single-cell transcriptomics uncover senescence-associated cellular programs during colon adenoma to cancer progression

Colorectal cancer develops through a normal-adenoma-carcinoma sequence, yet only 5-10% of adenomas progress to malignancy, and the cellular programs governing that sequence remain poorly defined. Here we generate a spatial multi-omics atlas of human colon adenomas, combining Visium CytAssist and protein co-detection across 24 nonadvanced and advanced tubular adenomas with single-cell resolution Xenium Prime 5K profiling of 101 patient-matched normal, adenoma, and carcinoma cores from 16 patients. Integrating whole-transcriptome and 31-plex protein data identifies nine spatial clusters and two dysplastic epithelial populations that co-express stemness, proliferation, and senescence programs. These programs occupy a shared, spatially confined epithelial niche that expands from adenoma to carcinoma. Spatial analysis revealed GDF15, a senescence-associated secretory factor, mediated the coupling between senescence and stemness in advanced adenomas, and that GDF15-high epithelium locally excludes CD8+ T cells in adenoma and, more broadly, in carcinoma. These findings position senescence as a spatially instructive rather than merely tumor-suppressive program during colorectal carcinogenesis and suggest GDF15 might be a potential candidate target for cancer prevention and interception in the colon.

cancer biology↗

Ischemia-reperfusion and acidosis induce retrotransposon derepression in the mouse brain

Retrotransposons are repetitive DNA elements normally suppressed through epigenetic mechanisms. In aging and neurodegenerative diseases, abnormal retrotransposon activation occurs and leads to neurotoxicity. However, whether ischemic stroke induces retrotransposon activation remains unclear. Here, we investigated whether cerebral ischemia triggers dysregulation of retrotransposon in the brain. Since brain ischemia leads to tissue acidosis, we further examined whether acidosis contributes to this response. We performed 45 min of transient middle cerebral artery occlusion (tMCAO) followed by reperfusion on adult wild-type mice, then measured expression of retrotransposons LINE-1, IAP, ETn2 and SINE B2 in ipsilateral brain tissue using RT-qPCR. Retroviral GAG protein expression was examined by Western blotting. In vitro, we exposed neuro-2a (N2A) cells to acidic extracellular pH (6.4 or 6.0) and retrotransposon transcripts were analyzed. We found that ischemia-reperfusion increased expression of IAPEz-gag and ETn2 in ipsilateral ischemic brain tissue at 24 h, with stronger induction of LINE-1 Orf1, IAPEz-gag and B2 in infarct than peri-infarct brain regions. Western blotting analysis revealed dynamic changes in GAG proteins, with no detectable changes at 6 h of reperfusion followed by reduced levels of the precursor Pr65 and mature capsid p30 products at 24 h. In N2A cells, extracellular acidosis induced time-dependent increases in LINE-1 Orf1, IAPEz-gag and B2 transcripts. These findings identify retrotransposon dysregulation as a molecular feature of ischemic brain injury and provide a framework for further investigating its role in stroke pathology.

neuroscience↗

Ligand-Specified Signaling Efficacy Defined by Unique Transitions in G Protein Conformations

Despite decades of research into the signaling efficacy of G protein-coupled receptors (GPCRs), including the resolution of numerous receptor structures in complex with nucleotide-free G proteins1,2, mini-G proteins3,4, and G protein carboxyl-terminal peptides5-7, our understanding of the underlying mechanisms remains elusive, because a fluidic, dynamic view of the conformational transitions during GPCR activation is still missing. Benefiting from its supersensitization to microenvironmental changes, recent advances in 19F-quantitative NMR (19F-qNMR)8 enable the dissection and quantification of the conformational energy landscape and dynamics of receptors and their signaling partners, offering new perspectives for deciphering the signaling machinery through a novel lens. Herein, we first established a 3-state model of Gs conformational landscape and then quantitatively investigated the conformational transitions and dynamics of Gs proteins in response to different ligand-bound receptors. Our research demonstrated that Gs substates are not only differentially populated in a ligand-dependent manner but also undergo distinct conformational-cycling kinetics across sub-states in response to different ligand bindings. These discoveries enable us to propose a novel GPCR model that integrates quantitative G protein conformational dynamics at the atomic level to explain GPCR pharmacological efficacy, emphasizing that unique equilibrium and transitions of G protein conformational states in response to ligands are critical determinants of signaling specificity.

biophysics↗

Evolutionary dynamics of sex chromosomes and candidate sex-determining genes across the beetle phylogeny

The evolutionary dynamics of beetle sex chromosomes remain poorly understood. Using synteny analyses of 163 chromosome-level genome assemblies, we examine sex chromosome evolution across the beetle phylogeny. Beetles retain a highly conserved ancestral X chromosome region, even in superfamilies with extensive autosomal rearrangements and in species with enlarged neo-X chromosomes formed by fusions of autosomal segments. In contrast, Y chromosomes vary greatly in presence, size and gene content, driven by degeneration of ancestral regions and addition of neo-Y segments in some species. Neo-X and neo-Y chromosomes frequently occur and generally evolve independently, highlighting a flexible neo-sex chromosome dynamics. We identify putative sex-determining genes and propose a novel candidate, the highly conserved and sexually differentially expressed X-linked gene ELAV-like. Our results uncover conserved X elements, fragile Y chromosomes, and independent neo-X and neo-Y formation across 300 million years of beetle genome evolution.

genomics↗