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Chen, H.

Publications and source records attributed to Chen, H..

At least 37 records · Page 2Linked to original sources

Reduced Control Over Pavlovian-to-Instrumental Transfer in Human Addiction: A Systematic Investigation Across Alcohol Use Disorder and Smoking Status

Pavlovian conditioned stimuli can compromise goal-directed behavior, particularly when they conflict with the required instrumental response. Previous research linked an increased impact of such Pavlovian-to-instrumental transfer (PIT) interference to risky drinking and alcohol dependence. However, it remained unclear whether the observed behavioral and neural alterations generalize to the substantially larger population of non-treatment-seeking individuals with predominantly mild-to-moderate alcohol use disorder (AUD) and to other substances like nicotine. We therefore studied 200 participants from the general population who were stratified by AUD and smoking status before completing a single-lever PIT task during functional imaging. PIT interference was measured as the difference in error rates between incongruent PIT trials, characterized by conflicts of Pavlovian and instrumental stimuli, and congruent trials. Associations with AUD and smoking status, as well as dimensional associations of behavioral PIT interference and neural responses to PIT conflicts with substance-related measures, were examined. As expected, participants with AUD showed greater PIT interference and reduced conflict-related activation in the lateral prefrontal, dorsomedial prefrontal, and anterior cingulate cortex than participants without AUD. The magnitude of these alterations also correlated with higher AUD severity and alcohol consumption, while being independent of smoking status and other smoking-related measures. These findings suggest that enhanced PIT interference generalizes to the broader AUD population but may not extend to other substances like nicotine. They further implicate a reduced recruitment of prefrontal control networks during PIT conflicts as a potential mechanism underlying enhanced PIT interference in AUD and its association with clinically relevant outcome measures.

neuroscience↗

Sum-h2, enabling genetic discovery for deep learning-derived phenotypes through a fast evaluation framework and arena of performance

In the recent growing interest of AI research toward biology, genetic association studies of AI- derived phenotypes from high-content modalities such as images emerges as a powerful means for biological discovery. However, such AI-phenotyping methods still lacks a good optimization target and an efficient evaluation framework. The number of discovered loci was the major criterion for evaluating the quality of AI-derived phenotypes. However, the time and computational resources required for running the GWAS and subsequent loci-clumping are substantial, limiting the rapid development and iteration of deep learning representation algorithms. Here we present a 1000x faster and lightweight framework, sum-h2, than traditional GWAS framework for evaluating genetic discovery through total heritability. We revisit tr(P^(-1) G), previously proposed in the context of evolutionary studies, as a measure of multi-phenotype heritability. We showed that sum-h2, the sum of heritability over phenotypic Principal Components (PCs), is equivalent to the linear transformation-invariant tr(P^(-1) G), through both theoretical proof and simulation studies. Moreover, sum-h2 can be estimated rapidly with minimal information loss over a relatedness-enriched sample, while preserving the relative ranking of endophenotypes by GWAS loci counts. Based on selected UKB data and sum-h2, we set up a Genetic Discovery Arena, enabling rapid and fair comparisons for the development and optimization of deep learning-derived phenotyping methods.

bioinformatics↗

Inflammation-induced of Clec18a inhibits immune responses via Trpm7-dependent Cbl activation

Innate immune responses must be tightly controlled to maintain immuno-homeostasis. However, the regulatory mechanisms underlying the activation and early stages of the innate immune response remain poorly defined. Here, we found the soluble C-type lectin Clec18a is up-regulated in multiple inflammatory diseases, including sepsis and influenza, and secreted within minutes upon activation in multiple immune cells, including macrophages, dendritic cells (DCs), and T cells. Clec18a-myeloid-knockout mice exhibited reduced survival and exacerbated inflammation than the wild-type. However, exogenous recombinant Clec18a administration alleviated inflammation both in vitro and in vivo. Mechanistically, we identified macrophage-inducible C-type lectin (Mincle) as the receptor of Clec18a. Clec18a-Mincle binding triggers Trpm7-dependent calcium influx, which activates the ubiquitin E3 ligase Cbl and leads to Mincle-Cbl-MyD88-Trpm7 complex formation and degradation. Cbl deficiency, calcium inhibition and Trpm7 knockdown abrogated Clec18a-mediated immune suppression. Thus, our study revealed Clec18a as a critical checkpoint on the initiation of innate immune response through an intrinsic crosstalk between CLR and TLR signaling.

immunology↗

Physiological Aging and Cardiovascular Disease Distinctly Remodel the Human Cardiac Lymphatic Endothelium

Aims: Cardiac lymphatic endothelial cells (LECs) regulate tissue homeostasis, immune trafficking, and remodeling, but how human cardiac LEC heterogeneity changes with physiological aging and cardiovascular disease remains poorly defined. We sought to define age- and disease-associated LEC states, their regulatory and microenvironmental programs, and the functional relevance of selected pathways. Methods and results: We integrated human cardiac single-nucleus transcriptomic datasets spanning physiological aging, dilated and hypertrophic cardiomyopathy, doxorubicin-associated cardiomyopathy, and heart failure with preserved ejection fraction. Aging redistributed LECs among pre-existing states, with expansion of a homeostatic immune-surveillance state and loss of cytokine-responsive and polarity-associated states. Cardiovascular diseases showed a distinct trajectory, with depletion of a non-failing homeostatic state and expansion of shared and disease-associated remodeling states. SCENIC and NicheNet/MultiNicheNet identified state-specific regulatory programs and disease-dependent signaling networks, with recurrent BMP/TGF-{beta}/activin-family signaling. ACVR2A was prioritized in human doxorubicin-associated cardiomyopathy; endothelial Acvr2a deletion in aged doxorubicin-treated mice was associated with improved cardiac function and increased open cardiac lymphatic vessels. Independent human spatial transcriptomic analyses supported selected aging- and disease-associated programs. Conclusion: Physiological aging and cardiovascular disease remodel cardiac LECs through distinct changes in cellular state, transcriptional regulation, and microenvironmental signaling. Aging is associated with redistribution and reduced representation of specialized LEC programs, whereas cardiovascular diseases redirect LECs through disease-associated signaling environments, highlighting context-dependent remodeling of the cardiac lymphatic endothelium across aging and disease.

bioinformatics↗

Sleep Health in Lennox-Gastaut Syndrome impacts both Individuals with LGS and their Caregivers

Sleep disturbances are a significant but underrecognized burden for individuals with Lennox-Gastaut Syndrome (LGS) and their caregivers. We conducted a large LGS caregiver survey to assess sleep quality, duration, specific sleep-related issues, and management strategies. Quantitative analysis revealed a significant association between nocturnal seizures and overall seizure frequency, but general sleep metrics in individuals with LGS (e.g., sleep hours, sleep quality) were not associated with seizure burden. In contrast, caregiver sleep was frequently disrupted - particularly in families who co-slept or reported frequent seizures. Nearly 40% of caregivers experienced nightly sleep disturbances. Respondents reported a range of strategies to manage sleep problems, including medication, environmental adjustments, and behavioral routines. Many also expressed frustrations over the limited effectiveness of strategies and inadequate support for sleep issues. These findings underscore the dual impact of LGS-related sleep disturbances on patients and caregivers, and highlight the need for comprehensive, family-centered approaches to sleep health.

neuroscience↗

A prefrontal cortex-hypothalamus circuit for heart rate control in non-human primates

Humans exhibit changes in heart rate during cognitive and emotional events, and dysregulation of this brain-heart coupling is a hallmark of many psychiatric disorders. Yet, how circuits that regulate cognition exert direct control over heart physiology remains poorly understood, particularly in primates. Here, we identify a prefrontal-hypothalamic circuit that exerts powerful, bidirectional control over heart rate in monkeys. We show that electrical stimulation of a small ventral subregion within the ventrolateral prefrontal cortex (area 47/12; a12) evokes rapid and robust decreases in heart rate and increases heart rate variability, whereas neighboring prefrontal regions produce weaker or no effects. And a12 neurons are coupled to heart rate on a moment-by-moment basis. Anatomical tracing data reveal projections from a12 to a circumscribed region of lateral hypothalamus (LHA), and stimulation of this LHA target recapitulates the cardiac effects of prefrontal activation. Consistent with a prefrontal-to-hypothalamus system for heart rate control, stimulation of LHA produces faster, stronger, state-independent heart effects, whereas stimulation of a12 produces effects that are sensitive to internal states. Oppositely to its activation, chemogenetic inactivation of a12 or its projections to LHA increases heart rate, demonstrating that this pathway can provide tonic inhibitory control over cardiac function. To make steps towards a more cell-type-specific and minimally invasive causal control of this circuit, we developed a primate sonogenetic approach based on ultrasound activation of CaMKII+ neurons virally transduced with TRPV1. Sonogenetic stimulation of a12 produced increases in heart rate variability, and these effects were attenuated by inactivation of LHA. Finally, we found that sonogenetic and chemogenetic perturbation of the same prefrontal region during a value-based decision-making task bidirectionally alters risky decision making. Together, our work identifies how a12 regulates heart rate and cognition, revealing a mechanistic substrate for brain-body interactions and a potential therapeutic target for disorders of cognitive-autonomic dysregulation.

neuroscience↗

A naturally occurring Tat R52W variant in brain-derived HIV attenuates transcription and may contribute to reservoir persistence

HIV-1 persistence under suppressive antiretroviral therapy (ART) remains a major barrier to eradication, yet the contribution of naturally occurring viral variation to transcriptional regulation is incompletely understood. Here, we identify an HIV-1 Tat variant (R52W) that attenuates viral transcription through the disruption of the Tat-TAR RNA interaction. Full-length HIV-1 genomes derived from the brain microglia of a Last Gift donor, together with peripheral viral sequences obtained during suppressive ART, revealed the presence of the R52W variant in vivo. The same R52W variant was found in another virally suppressed donor within the same cohort. Additional analysis of 3,440 clinical blood isolates from people with HIV identified R52W in 73 sequences (2.12%) of individuals, including three on ART and a therapy controller, and across diverse viral subtypes. Structural modeling demonstrated that R52W destabilizes Tat-TAR binding, while functional assays showed markedly reduced Tat-mediated transcriptional activity, which was restored upon tryptophan-to-arginine reversion (W52R) in Tat. These findings establish a direct molecular mechanism by which a naturally occurring HIV-1 variant modulates viral transcriptional output. Together, our results identify transcriptionally attenuated HIV-1 variants in treated individuals and suggest that modulation of Tat-dependent transcription may represent an underappreciated determinant of viral persistence under suppressive ART.

microbiology↗

A binuclear copper enzyme platform for enantioconvergent radical (pseudo)halogenation

Despite their intriguing native metalloenzymology, naturally occurring copper enzymes remain largely underexploited for new-to-nature biocatalytic reactions. Herein, we report the systematic investigation and reprogramming of natural copper enzymes to catalyze unnatural free radical (pseudo)halogenation reaction in a highly enantioselective fashion. Evaluating Cu enzymes in the decarboxylative azidation of redox-active esters revealed activity across multiple Cu enzyme families, with type III binuclear Cu enzymes, particularly the Bacillus megaterium tyrosinase (BmTyr), exhibiting superior activity and enantioselectivity across both stabilized and unstabilized alkyl radicals upon further engineering. The strong halide binding affinity of the binuclear Cu system also enabled challenging enantioconvergent bromination, chlorination and isothiocyanation reactions, which remained inaccessible to repurposed nonheme Fe enzymes. Further EPR and UV-visible spectroscopic analyses confirmed the coupled binuclear nature of wild-type and engineered bacterial tyrosinases and provided insights into the origin of their enhanced activity. Collectively, this study establishes binuclear copper enzymes as a powerful platform for new-to-nature stereoselective radical reactions, expanding the scope of metalloenzyme catalysis beyond mononuclear systems.

biochemistry↗

NeuralRNN: a unified framework for recurrent neural network methods in cognitive neuroscience

Recurrent neural networks (RNNs) provide a central tool in neuroscience to optimize cognitive tasks and reconstruct dynamical systems. Around these two paradigms, many RNN model variants have been tailored to capture specific computations of the brain. In practice, however, this methodological diversity remains difficult to exploit, because different paradigms and model variants are mostly implemented in idiosyncratic, study-specific code. Here we introduce NeuralRNN, an open-source Python framework that unifies these paradigms and model variants in a general-purpose pipeline. NeuralRNN brings task optimization, dynamical system reconstruction, and biological constraints into a single objective interface. It also provides an integrated and extensible model library spanning generic, structure-constrained, gain-modulated, and gated RNNs. Furthermore, data, models, and training are constructed through a shared automated pipeline and are equipped with a suite of tools for dynamical systems analysis. Together, NeuralRNN lowers the barrier to implementing, comparing, and extending RNN methods in neuroscience.

neuroscience↗

SERINC1-dependent lipid preservation gates neocortical synaptogenesis and remote memory

Systems memory consolidation reorganizes episodic memories from the hippocampus into neocortical networks such as the anterior cingulate cortex (ACC), yet the localized molecular programs supporting this process remain unknown. Here, we show that the transmembrane lipid regulator Serinc1 is selectively induced in the ACC during neocortical memory consolidation. Loss of Serinc1 reduces ACC synapse density, blocks learning-induced de novo callosal synaptogenesis, and selectively abolishes remote memory. Lipidomic profiling reveals that SERINC1 prevents activity-dependent depletion of inner-leaflet anionic phospholipids-specifically docosahexaenoic acid (DHA) bearing-phosphatidylserine and arachidonic acid (AA) bearing-phosphatidylinositol-safeguarding signaling cascades required for structural plasticity. Targeted viral restoration of SERINC1 in the ACC rescues cortical synapse density and remote memory. Thus, long-term memory is gated by a localized program of activity-dependent neuro-lipidomic remodeling.

neuroscience↗

Accurate and scalable decontamination of imaging-based spatial transcriptomics via optimal transport

Imaging-based spatial transcriptomics enables molecule-resolved profiling of gene expression and tissue organization in situ. However, segmentation errors, transcript spillover and three-dimensional cell overlap can introduce misassigned transcripts into cell-level expression profiles, compromising biological interpretation and obscuring genuine signals. Existing methods either remove suspect expression at the cost of signal loss or lack a biologically grounded criterion for transcript assignment. Here we present CellDot, an optimal-transport framework that determines the fate of each transcript by retaining it in its host cell, reassigning it to a plausible neighboring cell or removing it as background. By integrating reference-guided expression compatibility with spatial information and data-adaptive constraints, CellDot enables accurate and traceable molecule-level correction while preserving biologically meaningful variation. In evaluations across multiple human tumor datasets, CellDot exhibited superior performance compared to existing decontamination methods, successfully restoring spatial expression patterns that matched independent cross-platform measurements. Moreover, it significantly enhanced the recovery of cellular states, intercellular communication, and spatial niche programs. Our experiments using real data demonstrated CellDot's scalability and established it as the only method applicable to a whole-transcriptome Atera dataset, underscoring its distinct advantages in the field of spatial transcriptomics.

bioinformatics↗

Adhesion-clutch drives three-dimensional axon outgrowth

Axon outgrowth requires forces generated by the growth cone. A key model explaining this force generation is the adhesion-clutch mechanism, in which adhesion and clutch molecules convert backward movement of actin filaments into the force that drives axon outgrowth. However, this mechanism has not been validated in three-dimensional (3D) environments. Additionally, a recent study reported that inhibiting actin dynamics or the cell adhesion molecule integrin did not affect axon outgrowth in a 3D collagen gel, challenging the adhesion-clutch paradigm. Here, we show that the adhesion molecule N-cadherin and the clutch molecule shootin1a form a non-integrin adhesion-clutch in a 3D environment containing an appropriate adhesive substrate, N-cadherin. We detected forces produced by growth cones when N-cadherin was present. Furthermore, inhibition of N-cadherin, shootin1a or actin dynamics suppressed 3D axon outgrowth. Our findings demonstrate that the adhesion-clutch is critical machinery for 3D neural network formation under the regulation of specific adhesions.

neuroscience↗

CellART: a unified framework for extracting single-cell information from high-resolution spatial transcriptomics

Understanding how different cell types assemble into tissues and organs, as well as how they interact to transmit and receive biological signals, is essential for advancing biomedical and biological research. Recent advancements in spatial transcriptomics (ST) technologies have opened new avenues for investigating biological systems by achieving subcellular spatial resolution. Since cells are the fundamental units of life, extracting single-cell information from high-resolution ST data is crucial. However, existing ST platforms often capture sparse transcript counts per spot or measure only a limited number of genes, complicating the extraction of comprehensive single-cell information. In this study, we introduce CellART, a unified framework designed to extract single-cell information across diverse high-resolution ST platforms, including VisiumHD, Xenium, MERFISH, and Stereo-seq. By leveraging multimodal data, such as staining images, spatial transcriptomics data, and single-cell RNA sequencing references, CellART simultaneously performs cell segmentation and cell type annotation through a seamless integration of deep learning and probabilistic modeling. We demonstrate the efficiency, generalizability, and robustness of CellART across various high-resolution spatial transcriptomics platforms, capable of processing datasets containing millions of spots. Comprehensive experiments validate the biological relevance and accuracy of the recovered cellular information within spatial configurations. Notably, we highlight the utility of CellART in breast and colorectal cancer datasets, showcasing its ability to fully leverage high-resolution ST data. By enhancing cellular resolution, CellART facilitates the identification of transient cancer cell states and immune cell subtypes. Furthermore, CellART enables investigations into cancer-immune cell communication, uncovering both established interactions and novel ligand-receptor pairs. The outputs of CellART are compatible with widely used community tools, facilitating a variety of downstream analyses.

bioinformatics↗

SPP1+ Microglia Are Associated with Neuroimmune Rewiring and Glutamatergic Neuronal Injury in ART-Suppressed People Living with HIV

Abstract Antiretroviral therapy (ART) effectively suppresses systemic HIV replication but does not eradicate viral reservoirs in the brain, where their identity and contribution to neurological injury remain poorly defined. Using bulk, single-cell, and single-nucleus transcriptomics of postmortem human brain tissue, we identify an activated SPP1 microglial population that expands 5.8-fold during ART and serves as the primary central nervous system (CNS) reservoir, preferentially harboring HIV transcripts. These reservoir microglia adopt a distinct, immune-evasive reprogramming state marked by chronic type I interferon signaling and inflammasome activation, which we recapitulate in primary human microglia via prolonged interferon-{beta} exposure. We show that viral transcription in ART-suppressed brains is dominated by nef, which may sustain the viral reservoir by disrupting host HLA-A and HLA-E presentation machinery. This persistent, immune-evasive state is associated with TREM2-C1QC complement-mediated synaptic pruning and severe DNA damage response dysregulation, culminating in a profound loss of VGLUT1 and GAD67 glutamatergic neurons that persists despite viral suppression. Our findings establish SPP1 microglia as an active, pathogenic CNS reservoir, identifying the SPP1, MHC-I, and complement pathways as therapeutic targets to eliminate viral persistence and reverse HIV-associated neurocognitive dysfunction.

neuroscience↗

Why woodiness repeatedly evolves--and disappears

Derived woodiness--the evolution of woody growth from herbaceous ancestors--has arisen hundreds of times across flowering plants, yet the environmental conditions associated with its repeated evolution remain poorly understood. Here, we analyse woodiness evolution in the mustard family (Brassicaceae; ~4,150 species) using a time-calibrated phylogeny of 2,927 species, including 374 of the 385 known woody species, together with global growth-form and climatic niche data. We infer 231 independent origins of woodiness alongside 176 reversals to herbaceousness, indicating that woodiness evolves repeatedly but remains evolutionarily unstable. Although woody species are enriched on islands, most occur on the mainland, where woodiness is consistently associated with drought and reduced frost. Correlated-evolution analyses reveal that drought is associated primarily with the persistence of woodiness, whereas reduced frost is associated with gains of woodiness and increased frost with its loss. These findings identify distinct climatic associations with the gain, persistence, and loss of woody growth forms.

evolutionary biology↗

Extrachromosomal Circular DNA Function as Mobile Elements to Alter the Mammalian Germline Genome

The viability of any species including the human requires that the germline genome is kept stable as it is transmitted across generations by the germ cells. Failure to safeguard the genome integrity and stability would lead to inherited diseases and infertility. Thus, a better understanding of the mechanisms that alter the germline genome is crucial to ensure human health and our continuation as a species. Here, we show that the extrachromosomal circular DNA (eccDNA) in the mouse and human male germline represents a new mechanism in altering the mammalian germline genome. To enable the tracking of germline eccDNA in vivo, we established a novel mouse model that allows the generation of a reporter eccDNA in a cell type-specific manner. Using this mouse model, we showed that eccDNA formed in the developing male germ cells can integrate into the germline genome. Using eccDNA-containing sperm for in vitro fertilization led to the eccDNA sequence being inherited by the embryos. By analyzing a large cohort of long-read whole genome sequencing data, we showed that eccDNA-mediated germline genome insertions represent an important source of human genome structural variations. Finally, by leveraging human sperm samples, we found that diabetes induces an increase in sperm eccDNA quantity, which is mediated at least in part through poly (ADP-ribose) polymerases. Together, our results provide new insights into how the mammalian germline genome can be altered, with important implications for human health and genome evolution.

developmental biology↗

Pharmacologic Targeting of ZNF281 Suppresses Metastatic Prostate Cancer Beyond Androgen Receptor Dependence

Metastatic prostate cancer remains a lethal disease, with most treatments focusing on the androgen receptor (AR) axis. We identified the zinc finger protein 281 (ZNF281) as a previously unrecognized driver of metastatic prostate cancer that promotes both AR-related transcriptional output and distinct AR-independent tumor-promoting pathways. It increases AR expression and acts as a coactivator to promote AR transcriptional activity. Independent of AR, ZNF281 promotes prostate cancer by upregulating SMURF1 to sustain tumor growth and by promoting SNAIL-mediated metastasis. We developed an orally bioavailable, ZNF281 Interfering Molecule (Oral ZIM) that disrupts its DNA binding and AR protein interaction. Knockout of ZNF281 as well as treatment with oral ZIM potently inhibited prostate cancer growth and metastasis in orthotopic xenograft models of castration-sensitive and castration-resistant prostate cancers (without detectable systemic toxicity), and ZIM outperformed enzalutamide treatment in patient-derived prostate cancer organoids.

cancer biology↗