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Biology subjects

Han, W.

Publications and source records attributed to Han, W..

At least 19 recordsLinked to original sources

Moving object generates topographic responses in the majority of entorhinal neurons

Vision is crucial in generating a complex array of responses in rodents during spatial exploration and in humans during memory tasks. These tasks involve other variables too, e.g. multisensory cues in rodents and complex memories in humans. Further, there are major differences between the medial and lateral entorhinal cortical (MEC and LEC) functional cell types. To understand the contribution of purely visual information to entorhinal responses, we presented a simple, moving vertical bar of light to head-fixed mice, without any task or reward. Surprisingly, 66% (2391/3601) of the MEC broad spiking neurons were significantly modulated by the bar position on the screen. Visual tuning in MEC had a pronounced dorsoventral topography --the tuning strength dropped from 79% in the dorsal most quartile to 40% in the ventral most quartile. Unlike major differences in spatial and other codes between MEC and LEC during free foraging experiments, LEC cells showed very similar visual tuning (392/606, 65%), including the dorso-ventral gradient in LEC5. Additionally, the majority of putative interneurons, from MEC as well as LEC, showed similar, widespread visual tuning, unlike spatial tasks. Neurons also encoded the object motion direction (naso-temporal vs. temporo-nasal visual motion) with changes in mean rate, tuning strength and/or tuning location. Such directional nature of visual tuning indicates significant history-dependence or sequence encoding. Consistently, replacing the continuous motion by randomly flashing bar of light abolished bar-tuning in two-thirds of continuous bar-tuned cells and substantially altered tuning in the rest. These results reveal the contribution of purely visual inputs in generating anatomically organized responses in the majority of entorhinal neurons. The prevalence and similarity of visual tuning across all layers of MEC as well as LEC exceeds that of other known functional cell types (like grid cells in MEC or egocentric object tuning/time-cells in LEC) during spatial navigation tasks and could be foundational in understanding entorhinal complexity.

neuroscience↗

Psilocybin collapses visual change detection and drives cortical dynamics toward a state of surprise

Psilocybin profoundly alters visual perception, yet the neuronal mechanisms underlying these effects remain unclear. Here we combined large-scale Neuropixels recordings with cell-type specific optogenetics in head-fixed mice performing a visual change-detection task. Psilocybin severely impaired task performance without overt motor deficits. In cortex, the drug modestly suppressed activity of layer 5 neurons while preserving representations of image identity. By contrast, psilocybin imposed a 4-Hz oscillation on visually evoked activity that preferentially affected neurons encoding image change rather than image identity. Under psilocybin, expected image repetitions aberrantly recruited change-encoding ensembles and shifted cortical population dynamics towards trajectories normally evoked by genuine stimulus changes. These effects were strongest in somatostatin-expressing (SST) interneurons in visual cortex. The strength of this modulation depended on image structure and was greatest for images with clear, continuous contours, which preferentially recruited change-encoding ensembles. These findings demonstrate that psilocybin drives internally generated cortical surprise signals, providing a circuit mechanism for altered perception in the acute psychedelic state.

neuroscience↗

Isl1+ Central Amygdala Neurons Coordinate Control of the Jaw and Stomach During Ingestion

Central Amygdala neurons expressing Isl1 (CeAIsl1+) project to brainstem regions involved in control of the jaw and the stomach, including the parabrachial nucleus (PBN), the nucleus of the tractus solitary (NTS), and the parvocellular reticular nucleus (PCRt). Stimulation of CeAIsl1+ cells elicits fictive feeding, particularly biting. Activation of these neurons can rate dependently set the amplitude of bite force and inhibition dramatically reduces bite force. Findings suggest this force generation depends on modulation of a jaw closing reflex involving tooth sensory neurons in the mesencephalic trigeminal nucleus (Me5). Anatomical tracing studies show Me5 neurons receive synaptic input from CeAIsl1+ neurons. Patch clamp recordings of Me5 neurons indicate this synapse is mediated by GABA yet depolarizing. Activation of CeAIsl1+ neurons is capable of dramatically potentiating the periodontal jaw closing reflex, a reflex whereby Me5 tooth sensory neurons activate jaw closing muscles. In addition to controlling the actions of the jaw, CeAIsl1+ neuron stimulation is sufficient to reduce gastric pH. Inhibition experiments show these cells are necessary for lowering gastric pH in mice anticipating a meal. Finally, CeAIsl1+ neurons can modulate gastric motility, stimulation transiently suppresses gastric motility, an effect also observed when animals chewed food. Subdiaphragmatic vagotomy eliminated the transient suppression of gastric motility otherwise observed with CeAIsl1+ neuron stimulation or food chewing. Taken together, this molecularly and anatomically defined population generates specific motor patterns of ingestion that involve not only release of oromotor patterns, but also modulation of gastric functions.

physiology↗

HiFi-ST: High-Fidelity Reconstruction of Continuous Spatial Transcriptomic Expression Fields via Conditional Neural Fields

Spatial transcriptomics characterizes tissue-scale gene expression patterns, yet its observations are sparse discrete samples of an underlying continuous molecular field, leading to spatial aliasing and sub-resolution information loss. Existing methods usually formulate this task as spot-level point regression, making it difficult to capture both expression continuity and the regional nature of observation. Here, we propose HiFi-ST, a conditional neural field framework for continuous spatial transcriptomics modeling. HiFi-ST formulates spatial gene expression prediction as continuous expression field learning, models each spot as a regional observation over a finite support domain, approximates local integration through Monte Carlo sampling, and integrates multiscale tissue feature extraction with FiLM-based conditional modulation to improve modeling of complex spatial heterogeneity and consistency with the underlying measurement process. Systematic evaluation on three independent datasets (HER2+, cSCC, and Alex_NatGen) showed that HiFi-ST outperformed mclSTExp, BLEEP, THItoGene, His2ST, and HisToGene on key metrics. On HER2+, HiFi-ST achieved an average PCC improvement of 65.1% and an average MSE reduction of 40.9%; on cSCC, PCC improved by 10.2% and MSE decreased by 51.2%; on Alex_NatGen, PCC improved by 80.0% and MSE decreased by 16.3%. In addition, the learned multiscale tissue representations supported downstream spatial immunoanalysis, including assisted identification of candidate TLS regions. Overall, HiFi-ST provides a unified framework bridging discrete measurements and continuous expression field reconstruction for tumor microenvironment analysis and spatial immune structure characterization.

genomics↗

From hotspot dependence to distributed robustness in resistance-aware lead optimization

Drug resistance remains a recurrent failure mode in targeted anticancer and antiviral therapy, and resistance evidence often enters only after compound selection. ResistAgent is an evidence-constrained framework that converts mutational liabilities into design-time objectives through site- and combo-aware resistance mapping, deterministic mechanism diagnosis and robust counter-design. In EGFR-Erlotinib and HIV-RT-Rilpivirine, the framework separated residue-level liabilities from observed HIV combination liabilities and linked prioritized mutations to anchor loss, pocket rearrangement, electrostatic shifts and contact redistribution. Same-budget paired searches showed that robust objectives changed lower-tail mutant-panel behavior and interaction-dependence profiles while prioritizing robustness over average-affinity behavior. Under predefined liability panels, robust-objective trajectories shifted support away from mutable hotspot contacts toward more distributed interaction networks. Supplementary physical summaries and ranking-first benchmarks support the validation envelope of this resistance-aware design strategy.

bioinformatics↗

Biosynthetic allene and alkyne formation by enzymatic prenyl demethylation

Allenes and alkynes are versatile functional groups in total synthesis, medicinal chemistry, and bioorthogonal conjugation. The biosynthetic logic of how Nature installs allene or alkyne in natural products, especially that of allenes, is not well understood. Here we uncovered allenes and alkynes can be formed enzymatically through oxidative C(sp2)-demethylation of the common five-carbon prenyl group. Two fungal cytochrome P450 monooxygenases, PpnB and NseB, from the penipratynolene and sinuxylamide biosynthetic pathways, respectively, were shown to catalyze oxidative removal of a C(sp2)-methyl group in O-prenyl-L-tyrosine to afford O-homoallenyl-L-tyrosine and O-but-2-ynyl-L-tyrosine, respectively. Combining density functional theory calculations, heterologous expression, biotransformation and enzymatic assays with isotopically labeled substrates, a mechanism involving selective C-C bond cleavage followed by product-determining hydrogen atom abstraction is presented. An additional P450 enzyme from the penipratynolene pathway, PpnD, acts as an oxidative isomerase that converts the four-carbon terminal allene into a terminal alkyne. This unprecedented enzymatic editing strategy to install allene and alkyne expands the catalytic repertoire of P450 enzymes. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=100 SRC="FIGDIR/small/727785v1_ufig1.gif" ALT="Figure 1"> View larger version (21K): org.highwire.dtl.DTLVardef@54a57dorg.highwire.dtl.DTLVardef@13cb5d0org.highwire.dtl.DTLVardef@c4a2b7org.highwire.dtl.DTLVardef@196b357_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

UP-REGULATION OF SYNAPTOBREVIN-2 TO DELAY AGE-RELATED COGNITIVE IMPAIRMENT

The slowing of executive function and memory impairment are the leading hallmarks of cognitive decline with age. The exact cause of this change is unknown and is the focus of aging research. Expression levels of Vesicle Associated Membrane Protein 2 (VAMP2)/Synaptobrevin-2 (syb2) are decreased with age. Here we report results from a novel transgenic mouse model (TgV2) that overexpresses syb2. We hypothesized that overexpression of syb2 improves synaptic function during aging, thus it delays dementia. Aged TgV2 mice, which maintained syb2 levels, performed better in spatial memory tests than 2-year-old WT control mice, which had lost half of syb2 due aging. In hippocampal CA1 synapses of aged TgV2 mice, long-term potentiation was increased. These effects of maintained syb2 levels were beneficial for both males and females providing improved synaptic plasticity. These results indicate that overexpression of syb2 supports cognitive function throughout the aging process and better resist age-related synaptic dysfunction.

neuroscience↗

A Fungal Natural Product that Targets Cellulose Synthase Complex and Inhibits Plant Cellulose Biosynthesis

Cellulose, a primary component of plant cell walls, is synthesized by cellulose synthase complexes (CSCs) at the plasma membrane. Targeting this process with cellulose biosynthesis inhibitors (CBIs) has significantly advanced our understanding of plant cell wall formation and provided valuable compounds for herbicide development. Here, we identified a fungal natural product, 8-methyldichlorodiaporthin (MDD), as a broad-spectrum plant CBI. Structure-activity relationship analyses demonstrate that methylation modifications on the isocoumarin ring and chlorination of side chain are crucial for MDD-induced growth inhibition. A chemical forward genetic screen in Arabidopsis thaliana revealed two semi-dominant CESA1 mutations, causing A903T and H1024Y substitutions, that confer insensitivity to MDD. Both mutations locate to transmembrane domains of CESA1, and we show that MDD depletes CSCs from the plasma membrane and reduces cellulose content. Further genetic analyses indicate that the cesa1mddi1-1 A903T mutant also confers resistance to CBIs quinoxyphen and C17, but not to CBIs isoxaben, indaziflam, or ES20. Stacking additional point mutations conferring resistance to other CBIs, cesa3ixr1-1 G998D, and cesa6es20-r3 G935E into the cesa1mddi1-1 A903T background yields multiple-drugs resistant lines that maintain normal growth. These findings establish MDD, as a novel, natural CBI that likely targets CESA1, thereby extending our understanding of CSC regulation and abilities to develop multi-drugs resistant crop varieties. These findings offer new perspectives for weed management and plant biotechnology. Significance StatementCellulose, a fundamental structural component of plant cell walls, is synthesized by cellulose synthase complexes (CSCs) and represents a critical herbicide target. While synthetic cellulose biosynthesis inhibitors (CBIs) like isoxaben and quinoxyphen have helped in the elucidation of CSC function and aided in weed control, natural CBIs remain largely undiscovered. Here, we identify 8-methyldichlorodiaporthin (MDD), a fungal-derived isocoumarin natural product, as a CBI that inhibits plant growth by depleting CSCs from the plasma membrane. Genetic screens reveal MDD-resistant cesa1 mutations, and combining these with other CBI-resistant alleles yields multi-herbicide resistant plants that can grow normally. This research enhances our understanding of cellulose biosynthesis and paves the way for multi-herbicide resistant crops with agricultural benefits.

plant biology↗

AAV-mediated delivery of leptin but not adiponectin improves metabolic health in a mouse model of congenital generalised lipodystrophy

Lipodystrophies are a group of disorders featuring reduced adipose tissue mass or function, which often leads to significant metabolic disease, reduced lifespan and impaired quality of life. Individuals with congenital generalised lipodystrophy (CGL) have severely reduced adipose tissue mass. The loss of healthy systemic lipid storage typically causes hepatic steatosis and lipoatrophic diabetes. In addition, adipocyte-secreted hormones including leptin and adiponectin are dramatically reduced. Leptin has critical roles regulating appetite and broader effects on lipid and glucose metabolism. Daily injection with recombinant leptin is currently the only specific, approved treatment for CGL. The consequences of adiponectin loss in these patients are not fully understood. Likewise, the potential therapeutic benefit of adiponectin delivery is unclear. Here we examine the effect of delivering leptin or adiponectin by adeno-associated virus (AAV) as potential gene therapy treatment for metabolic disease in CGL using a well-characterised murine model of the condition. AAV-mediated leptin delivery significantly improved hepatic steatosis and hyperinsulinemia. However, adiponectin delivery did not lead to any observed beneficial effects. This demonstrates the potential of gene therapy approaches for long-term delivery of leptin in individuals with lipodystrophy, without the need for continuous supply of perishable therapeutics and painful daily injections.

physiology↗

TRiC folds the giant ciliary protein IFT172 via a non-canonical open-state mechanism

The eukaryotic chaperonin TRiC/CCT is essential for folding complex proteins, yet how it folds substrates that exceed its closed chamber capacity remains a longstanding paradox. Here, we define the folding pathway of IFT172, the largest subunit ([~]200 kDa) of the intraflagellar transport (IFT) machinery, and uncover a "divide-and-conquer" mechanism. TRiC and HSP70 engage IFT172 concurrently but on distinct domains: TRiC captures the N-terminal WD40 {beta}-propellers within its chamber, whereas HSP70 independently stabilizes the C-terminal TPR domain in the cytosol. To accommodate this oversized client, specific TRiC subunits (CCT4, CCT2, and CCT7) undergo pronounced Z-shaped outward bending, thereby expanding the chamber. Unexpectedly, the first WD40 domain reaches a near-folded state within the open, ATP-bound chamber, and subsequent TRiC ring closure triggers substrate ejection rather than encapsulation. This non-canonical "fold-and-eject" mechanism challenges the classical view that the closed chamber is an obligate folding cage. We further demonstrate that this pathway is essential for ciliary functions in vivo, and reveal a conserved mode of chaperonin recognition among IFT components bearing tandem WD40-TPR architectures. Together, our findings establish a new paradigm for the folding of oversized, multi-domain proteins and identify TRiC as a central proteostasis hub in ciliary biogenesis, with direct implications for ciliopathy pathogenesis.

biochemistry↗

A Cross-Species Enhancer-AAV Toolkit for Cell Type-Specific Targeting Across the Basal Ganglia

The mammalian basal ganglia (BG) orchestrate motor, cognitive, and affective functions, yet cell type-specific genetic access remains limited, especially beyond rodents. Key structures implicated in movement and psychiatric disorders, including pallidum, subthalamic nucleus, and dopaminergic midbrain, lack scalable tools for cross-species targeting. Here, we present a comprehensive enhancer-AAV library enabling selective labeling and manipulation of major BG neuronal populations: striatal projection neuron subtypes, pallidal and subthalamic neurons, and midbrain dopaminergic and GABAergic populations. Using an evolutionarily informed discovery pipeline, we identified enhancers targeting canonical, non-canonical, and disease-relevant cell types, with validation demonstrating robust cross-species conservation of specificity between mouse and macaque. Computational modeling revealed sequence features predictive of in vivo performance, including motif grammar, chromatin accessibility, and evolutionary conservation, and identified distinct regulatory architectures across glial, projection, and interneuron lineages. This work establishes a comprehensive cross-species viral toolkit for the BG, unlocking previously inaccessible cell types for circuit dissection.

neuroscience↗

A human-in-the-loop explanation framework for morphologically transparent AI predictions from whole-slide images

Deep learning models enable the prediction of clinical endpoints from whole-slide images (WSIs), but many such models function as "black boxes", lacking transparency about whether and which histomorphological patterns drive their predictions, hindering interpretability and clinical adoption. Here we propose a human-in-the-loop explanation framework, MorphoXAI, which provides both local and global interpretability for deep learning models by incorporating human-expert interpretations. At the global level, it reveals the histomorphological patterns on which the model consistently relies to distinguish between classes of WSIs, as well as the patterns associated with confusion between classes. At the local level, it indicates which of these patterns are used in the prediction of an individual WSI and which regions within the slide correspond to such patterns. We validated our method on a deep learning model trained for ovarian tumor histologic subtype prediction. The results show that our framework generates explanations that accurately reflect the histomorphology underlying the models predictions at both global and local levels. For interpretability and clinical utility in diagnostic contexts, human evaluation results showed that our explanations were easy to interpret, rich in diagnostic features, and directly helpful for diagnostic decision-making, thereby enhancing pathologist-AI collaboration. Our work highlights that unifying global and local explanations and grounding them in expert-interpreted morphology enhances the interpretability and verifiability of deep learning models, thereby facilitating the transparent deployment of such models in clinical practice.

pathology↗

Adipocyte-related genes analysis contributes to the prognosis of atrial fibrillation

BackgroundPatients with mild left atrial appendage fibrosis have a significantly lower rate of atrial fibrillation (AF) recurrence after 5 years compared to those with moderate or severe fibrosis, which presented a significantly increased positive area of cellular senescence. MethodsGSE135445, a RNA-sequencing dataset between epicardial adipose tissue (EAT) from patients with persistent non-valvular AF and sinus rhythm (SR), was downloaded and analyzed and hub genes were obtained. To obtain the abundance of immune cells, the CIBERSORT algorithm with 100 permutations was applied. The senescent hub genes were obtained and validated using human blood samples. ResultsA total of 164 up-regulated and 317 down-regulated DEGs was obtained between EAT from subjects with AF and SR. Using immune infiltration analysis in whole PAT related DEGs, the abundance of M0 macrophages was significantly different between PAT and SAT and 22 M0 macrophages-related DEGs were also obtained, such as MMP7, APOE, CCND1, MMP12 and APOC1. Venn diagram was utilized to obtain the same transcripts between senescence datasets and DEGs and PPI network was used to 94 overlapping genes. The top15-degree senescence adipicytes hub genes were explored. To investigate senescence-related hub genes effects on AF progression, we collected the blood samples of patients with paroxysmal atrial fibrillation and persistent atrial fibrillation. There were no significant differences at baseline characteristics and laboratory examinations at 1d after admission except heart failure history and function examinations, for instance, ALT, LDL, LVEF and LA diameters. Using univariate analysis and multivariate analysis, heart failure history, ALT and LA diameters can be prognostic factors for AF progression. BMP7, COL4A3, COL4A4, CHRD, IRX1, SPON1, ALPL, TCF19 and SIX2 were validated to be highly expressed in persistent atrial fibrillation compared to paroxysmal atrial fibrillation. ConclusionBased on our current study, BMP7, COL4A3, COL4A4, CHRD, IRX1, SPON1, ALPL, TCF19 and SIX2 were validated to be highly expressed in persistent atrial fibrillation compared to paroxysmal atrial fibrillation, which may be potential therapeutic targets to treat AF progression and improve patients prognosis.

genetics↗

Leveraging defense system modularity to discover anti-phage systems

Bacterial exposure to constant phage attack drives rapid diversification of anti-phage defense systems, often through the exchange of modular defensive domains. Here, we leverage this modularity signature to identify new defense systems by systematically searching for operons encoding defensive domains in non-canonical configurations. We identified 214,164 candidate defense operons in E. coli genomes, representing a [~]2.2-fold expansion over defense systems detected by DefenseFinder. Experimental testing of 9 candidates validated 6 with anti-phage activity. These include DarTG and ietAS system variants that have acquired helicase modules, and a Gabija system in which a MazF-like protein replaces GajA, implying novel anti-phage mechanisms. We also identified a new clade of Pycsar and show that it synergizes with type IV Thoeris to broaden phage protection. Our findings demonstrate that mining modular defensive domains provides a powerful strategy to predict and characterize new anti-phage systems, expanding the known repertoire of bacterial immunity. TeaserModular domains of anti-phage defense systems are harnessed to predict novel defense systems

microbiology↗

Effects of biological fixation methods on stimulated Raman scattering microscopy signal

Stimulated Raman Scattering (SRS) microscopy enables label-free imaging of cells and tissues in their native state with chemical specificity. However, there are often experimental advantages of chemical fixation of samples prior to imaging, which can introduce perturbations that may alter the native state of the samples, and possibly impact the SRS signal. In this study, we systematically characterize the effects of common fixatives (Paraformaldehyde, Formalin, Glutaraldehyde, Methanol, Ethanol) on the preservation of cellular integrity and molecular composition in a Hela cell model as observed by SRS microscopy. We demonstrate how the different fixatives can influence lipid and protein content, and overall cell morphology, with significant implications for the accuracy of quantitative SRS microscopy. Our findings indicate that Paraformaldehyde (PFA) imposes minimal disruption to cellular and molecular states compared to the other fixatives tested, and suggest Glutaraldehyde (GA) as a suitable alternative for SRS imaging. This study provides insights for the choice of the optimal sample preparation, enabling more reliable SRS-based studies for the evaluation of cellular processes and disease mechanisms where fixation is used.

cell biology↗

Unify: Learning Cellular Evolution with Universal Multimodal Embeddings

Integrating single-cell RNA-sequencing (scRNA-seq) data across species is hindered by evolutionary divergence, technical batch effects, and the reliance on one-to-one orthologs. We present Unify, a transfer learning methodology that learns universal cell embeddings by defining functionally coherent, multi-modal macrogenes. This is achieved by combining RNA expression with embeddings from protein language models and general-purpose language models. Unify transcends species boundaries, enabling cross-species comparisons beyond strict gene-level homology. Unify corrects batch effects while preserving conserved biological signals across vast evolutionary distances and enables more accurate prediction of perturbation responses across species, such as from mouse to human. Applied to species separated by over 700 million years, Unify reconstructs more accurate multi-species cell-type evolutionary trees and uncovers convergent gene programs. Together, these results establish Unify as a powerful method for comparative single-cell genomics and evolutionary biology.

bioinformatics↗

Genotoxic antibody-drug conjugates combined with Bcl-xL inhibitors enhance therapeutic efficacy in metastatic castration-resistant prostate cancer

Metastatic castration-resistant prostate cancer (mCRPC) is an aggressive subtype of prostate cancer (PC) without curative treatments. Antibody-drug conjugates (ADCs) emerged as promising cancer therapeutics that selectively deliver cytotoxic agents (payloads) to the tumors. Although ADCs have been successfully applied in the treatment of hematological and solid tumors, ADC monotherapy has not demonstrated durable responses in mCRPC and the mechanisms of PC resistance to ADCs have not been thoroughly investigated. Our study aimed to improve ADC efficacy using a new integrated approach for custom ADC design and multiplexing. To nominate rational combinations of ADC targets and ADC payloads, we (1) examined protein co-expression of three clinically relevant surface antigens-- B7 homolog 3 (B7-H3), prostate specific membrane antigen (PSMA), and six-transmembrane epithelial antigen of prostate-1 (STEAP1)--in a series of human mCRPC samples and (2) screened established ADC payloads and their combinations in mCRPC cell lines with different phenotypes. We identified synergistic interactions between DNA-damaging payloads and Bcl-xL inhibitor A-1331852 as well as their coordinated induction of the intrinsic apoptosis pathway. The functional relevance of isolated p53 loss and impaired PC responses to three genotoxic ADCs (B7-H3-seco-DUBA, PSMA-SG3249, and STEAP1-DXd) and their combinations with A-1331852 was established using genetic knockout models. Lastly, we found enhanced in vivo antitumor activity in mCRPC by combining the clinically relevant agents B7-H3-seco-DUBA (vobramitamab duocarmazine) and A-1331852. Collectively, our findings provide rationale for the development of ADC therapies combining genotoxic payloads with Bcl-xL inhibitors for mCRPC. SignificanceB7-H3, PSMA, and STEAP1 targeted ADC therapies combining genotoxic payloads with Bcl-xL inhibitors induce p53-dependant apoptotic cell death in mCRPC, providing a clinically viable strategy for the treatment of advanced prostate cancer.

cancer biology↗

JARID2 Inhibition Reprograms Human Hematopoietic Progenitor Cells To Enhance Bone Marrow Transplantation

Hematopoietic stem cell transplantation is a common treatment for many blood disorders and can be a life-saving therapy for patients with leukemias, lymphomas and multiple myeloma. Umbilical cord blood (UCB) serves as a valuable source of hematopoietic stem and progenitor cells (HSPCs) for transplantation, particularly for patients lacking a matched donor. However, the limited number of repopulating cells in UCB units restricts its clinical utility. Our prior studies showed that genetic deletion of the polycomb repressive complex 2 (PRC2) co-factor Jarid2 in mouse multipotent progenitors (MPPs) conveyed ectopic self-renewal capacity. Here, we hypothesized that the function of human HSPCs could be enhanced through JARID2 inhibition. In this study, we demonstrate that both constitutive and transient knockdown of JARID2 increases the number and enhances the functionality of human HSPCs both in vitro and in vivo. This phenotype was distinct from inhibition of EZH2 in UCB cells, suggesting the mechanism was independent of PRC2 co-factor activity of JARID2. Mechanistically, JARID2 knockdown promotes a quiescent, long-term self-renewal gene expression program governed by upregulating STAT1 and characterized by an MHC class II immunophenotype. Analogous to mice, these mechanisms conferred HSC-like potential to human MPPs in vivo. Taken together, these findings highlight JARID2 inhibition as a novel and reversible approach to expand functional UCB-derived HSPCs ex vivo, potentially improving access to stem cell transplantation for a wider patient population. One Sentence SummaryGenetic inhibition of JARID2 enhances repopulating activity of human hematopoietic stem and progenitor cells in vivo via STAT1 upregulation.

developmental biology↗