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Huang, Y.

Publications and source records attributed to Huang, Y..

At least 181 records · Page 10Linked to original sources

New insights into the evolution of spider silk proteins illuminated by long-read transcriptomes

Spider silk has long fascinated scientists because of its exceptional mechanical properties, yet the evolutionary origins and diversification of spider silk proteins (spidroins) remain incompletely understood. By analyzing long-read spidroin transcripts from spiders representing key evolutionary lineages, we identify two ancestral proteins present in basal spiders: an alanine-serine-rich (AS-type) protein and a glycine-serine-rich (GS-type) protein. These ancestral proteins likely served as primary evolutionary templates for the diversification of modern spider silks. We show that the AS-type ancestral spidroin remained relatively conserved and ultimately gave rise to the specialized tubuliform spidroin (TuSp) used in eggcase silk. In contrast, the GS-type protein underwent extensive functional radiation, evolving into differentiated minor ampullate spidroins (MiSp) through the acquisition of distinct terminal domains and {beta}-sheet-associated structural innovations. Our results further suggest that major ampullate spidroins (MaSp) may have originated from MiSp, with the GS motif representing an evolutionarily favorable genetic substrate for the emergence of high-performance silk proteins. Finally, we propose a revised evolutionary trajectory for flagelliform spidroins (Flag), suggesting that they were co-opted as components of ampullate silk during functional degeneration in modern non-web-weaving RTA clade spiders. Together, these findings provide a high-resolution framework for understanding the genetic innovations that drove the diversification of spider silk.

evolutionary biology↗

cGAS-mediated IFN-I signaling contributes to disease progression in drug-refractory epilepsy

Epilepsy is a prevalent neurological disease with a third of patients becoming non-responsive to antiepileptic drugs and developing drug-refractory epilepsy (DRE). Here we report that DRE disease progression is contributed by overactive cyclic GMP-AMP synthase (cGAS), a double-stranded DNA sensor that induces type I interferon (IFN-I) signaling. In human DRE microglia, we observe a robust IFN-I signature and the activation of upstream cGAS-STING signaling. Further, in mouse models of Dravet syndrome, a genetic form of DRE, we observe the activation of the cGAS pathway. We show that microglial cGAS can be activated by DNA released from hyperexcitable neurons. Genetic reduction and pharmacological inhibition of cGAS reduces epileptic phenotypes, glial inflammatory signatures, and neuronal transcriptomic changes, underscoring the therapeutic potential of targeting cGAS for DRE treatment.

neuroscience↗

Near completely reversing the γ- to β-globin switch by enhancer release, retargeting and reinforcing

The {gamma}- to {beta}-globin switch is intricately regulated during human ontogeny, and this process is manipulated for therapeutic approaches to treat {beta}-hemoglobinopathies by activating {gamma}-globin expression. Several genetic strategies to reactivate HbF have partially reversed the {gamma}- to {beta}-globin switch and ameliorated the clinical symptoms of {beta}-hemoglobinopathies. However, whether the {gamma}- to {beta}-globin switch can be completely reversed remains unknown. Completely reversing the {gamma}- to {beta}-globin switch requires a thorough redirection of the locus control region (LCR) from interacting with the {beta}-globin gene (HBB) to interacting with the {gamma}-globin gene (HBG). Here, we found that disrupting the KLF1-mediated HBB-LCR interaction by mutating the CACCC motif in HBB leads to the release of the LCR and its retargeting to other {beta}-like globin genes. Moreover, simultaneously disrupting the KLF1-mediated HBB-LCR interaction and the epigenetic repression of HBG by combined editing of the CACCC motif in HBB and the TGACCA motif in HBG reinforces the HBG-LCR interaction, resulting in almost exclusive {gamma}-globin expression while nearly absent {beta}-globin expression, achieving near complete reversal of the {gamma}- to {beta}-globin switch. This finding demonstrates the comprehensive regulation of the {gamma}- to {beta}-globin switch by gene competition and gene silencing mechanisms. This finding also suggests that silenced genes can be fully activated through the redirection of enhancer-promoter contacts and that the specificity of enhancer-promoter contact within chromosomal domains is achieved through the transcription factor clusters binding to enhancers and promoters. Combined editing of the CACCC&TGACCA motifs also offer a more optimal therapeutic strategy for {beta}-hemoglobinopathies.

molecular biology↗

Morphological bias of the MNI152 brain

The MNI152 template is widely treated as a representative average brain in neuroimaging, computational modeling, and neuromodulation research, yet its fidelity to true population morphology has not been systematically evaluated. In this study, we compared the MNI152 template to 430 individual MRI scans from a publicly available dataset spanning Asian, Black, and White participants. We additionally generated an alternative template using ANTsPy to assess whether a modern diffeomorphic approach yields a more anatomically representative average. We conducted affine registrations and deformation-based morphometry to detect and quantify gross morphological differences as well as local voxel-level deformations. Across all racial groups, the MNI152 template required consistent global contraction, and its Jacobian fields revealed spatially heterogeneous deformations, indicating systematic mismatches in both size and shape. In contrast, the ANTsPy template showed mean scaling and deformation values near 1.0, reflecting closer correspondence to real human anatomy. These findings demonstrate that the MNI152 template does not accurately represent the morphology of the studied population and that linear registration alone cannot correct its inherent biases. Reliance on MNI152 may therefore introduce unintended distortions in applications requiring anatomically realistic head models. More robust, unbiased template-generation pipelines, and potentially demographic-specific templates, may be necessary for improved accuracy.

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↗

Synaptopodin enables directional mechanoadaptation of integrin-based adhesions

The attachment of cells to their substrate through adhesion complexes is fundamental to tissue architecture and function. These adhesions are inherently optimized to resist shear forces parallel to the substrate, yet certain specialized cells must also withstand substantial perpendicular forces. How cells adapt their adhesion machinery to resist forces in different directions has remained unclear. In the kidney, podocytes experience perpendicular forces from pressurized filtrate flow while maintaining attachment to the glomerular basement membrane through integrin-based adhesions. Here we show that synaptopodin converts adhesions from shear-resistant to perpendicular force-resistant structures through coordinated reorganization of the actin cytoskeleton and adhesion complexes. Using an inertial force application system, we demonstrate that synaptopodin triggers force-dependent redistribution of {beta}1-integrin to the cell periphery specifically in response to perpendicular loading, while synaptopodin-deficient cells lack this directional adaptation and detach. This mechanism operates in multiple cell types and is physiologically essential: synaptopodin-null mice subjected to elevated glomerular pressure develop significant proteinuria and podocyte foot process effacement. These findings reveal a molecular basis for directional mechanoadaptation, whereby a single protein enables cells to reconfigure their adhesion architecture in response to the direction of applied force.

biophysics↗

Genome-wide CRISPRi screen identifies basigin loss as protective in cardiac hypoxia

Cardiac function depends on continuous oxidative metabolism, rendering cardiomyocytes highly vulnerable to oxygen deprivation. Here, we performed a genome-wide CRISPR interference (CRISPRi) screen in human iPSC-derived cardiomyocytes to identify genes that modulate survival during chronic hypoxia. This screen revealed that knockdown of basigin (BSG), a chaperone for the monocarboxylate transporters MCT1 and MCT4, confers robust protection. Canonically, hypoxic cells suppress pyruvate dehydrogenase (PDH) activity to reduce the oxidation of major fuel sources, thereby limiting TCA cycle flux, lowering oxygen consumption, and minimizing reactive oxygen species generated by an overly reduced electron transport chain (ETC). In contrast, we found that BSG inhibition reverses this response, prioritizing ATP maintenance during hypoxia and enhancing cardiomyocyte survival. Mechanistically, BSG loss restricts lactate efflux, leading to decreased PDH phosphorylation and increased glucose uptake for oxidation. Consistent with this, ETC subunits are more essential under hypoxia, highlighting cardiomyocytes unusual reliance on aerobic ATP production even when oxygen is limited. These findings challenge prevailing models of hypoxic adaptation by revealing cardiomyocyte-specific bioenergetic requirements and motivating future therapeutic efforts.

cell biology↗

Reconfiguration of Premotor Excitation and Inhibition Drives Behavior-Specific Protopodium Dynamics in Drosophila Larvae

Animals use shared muscles and motor neurons to generate distinct movements, but how premotor circuits differentially recruit these neuromuscular components remains unclear. Drosophila larvae crawl forward and backward using overlapping motor pools, yet the timing of ventral oblique (VO) muscle activity differs between these behaviors. Here, we show that VO muscles are major contributors to the movement of protopodia, limb-like structures that help larvae interact with the crawling surface. Muscle imaging, perturbation, and modeling indicate that VO activity is particularly important for protopodium folding, whereas contractions of both VO and ventral longitudinal (VL) muscles contribute to protopodium stride length and crawling efficiency. We identify a tri-segmental premotor motif--comprising excitatory (A27h, A18b3) and inhibitory (A06c) neurons--that shapes VO timing during forward crawling. A06c exhibits two activity peaks during forward fictive locomotion, defining a constrained window of VO MN activation, whereas during backward locomotion the early A06c peak is absent and the excitatory PMNs A27h and A18b3 are inactive. Disrupting this motif shifts VO activity earlier, reduces intersegmental timing delays, increases temporal overlap of VO activity, and impairs forward protopodium folding, stride, and crawling efficiency. These findings show how premotor excitation and inhibition coordinate muscle timing to shape locomotor mechanics.

neuroscience↗

Orthogonal Force Balance Between Contractility and Shear Stress Governs Podocyte Dynamics

Maintenance of tissue barriers under mechanical stress represents a fundamental biological challenge across organ systems. In the kidney, podocyte cells withstand highly variable hemodynamic forces while preserving a tensioned, nanostructured filtration barrier. Dysregulation of this barrier leads to significant pathology, but the mechanical principles underlying homeostasis of cells against flow of filtrates have not yet been identified. Here, we uncover a counterintuitive mechanical homeostasis mechanism whereby podocyte attachment depends on a dynamic balance between external fluid shear stress and internal cellular contractility. Integrated biomechanical modeling and experiment reveal a previously unrecognized mechanosensing circuit that optimizes integrin distribution at foot process peripheries. Our mathematical framework for cell-matrix adhesion stability reveals, surprisingly, that reducing blood pressure can worsen outcomes when cell contractility is impaired, contrary to clinical belief that lowering blood pressure universally benefits cellular adhesion and kidney function. We validated this principle through mouse models with manipulated blood pressure and myosin inhibition, demonstrating that concurrent reduction of both shear stress and contractility worsens podocyte injury and proteinuria. Super-resolution microscopy confirms our predicted integrin redistribution patterns under these mechanical perturbations. These findings establish a fundamental mechanobiological principle applicable beyond nephrology, and suggest potential treatment pathways targeting non-equilibrium steady states.

cell biology↗

SparseAEH: Scalable autoregressive expression histology discovery in spatial transcriptomics via sparse Gaussian kernels

SummarySpatial clustering of genes is an effective way to elucidate histological or spatial patterns of marker expressions or ligand-receptor interactions. However, its computational complexity hinders its application to the advanced spatial transcriptomics (ST) technologies with high resolution and throughput. Here, we present SparseAEH, a highly scalable algorithm and implementation of the Gaussian process mixture model, by leveraging block-wise sparse covariance for approximating the likelihood. This acceleration enables the analysis of dense ST datasets within practical time constraints while maintaining accuracy. Benchmarking on both simulated and experimental data demonstrates that our method achieves significantly less computational time with comparable accuracy to previous methods, highlighting its potential as a powerful tool for the exploration of high-resolution ST data. Availability and implementationSparseAEH is implemented in Python and is publicly available at https://github.com/jackywangtj66/SparseAEH.

bioinformatics↗

Polymorphic 3D genome architecture mediated by transposable elements

The three-dimensional (3D) folding of the genome plays a crucial role in genome regulation. However, how 3D genome structure varies between individuals and consequently influences genome function and evolution remains poorly understood. One potential source of this variation is transposable elements (TEs), genomic parasites whose location and composition vary between species and individuals. Hosts typically silence TEs through enriching them with repressive epigenetic marks, turning euchromatic TEs into heterochromatin islands, which were shown to spatially interact with pericentromeric heterochromatin (PCH). Because most TE insertions are present in only a few individuals within Drosophila populations, we asked whether polymorphism in the presence/absence of TEs drives varying 3D structures through TE-PCH spatial interactions. We performed deep-coverage Hi-C of two wild-type Drosophila strains and developed a Hi-C analysis framework enabling allelic comparisons of spatial interactions with PCH. Supporting our hypothesis, nearly 40% of strain-specific euchromatic TEs cause their adjacent euchromatic regions to be spatially closer to PCH than TE-free homologous alleles. These interactions are not limited to specific TE families, and, surprisingly, telomere-proximal TEs show a similar propensity as centromere-proximal TEs to enhance PCH interactions. The most defining feature of TEs involved in PCH interactions is H3K9me3 enrichment, revealing a chromatin-based mechanism for TE-mediated 3D genome organization broadly applicable across TE families and genome locations. Importantly, TEs involved in PCH interactions reduce the expression of adjacent genes and are evolutionarily young, indicating stronger selection against them. Our study reveals a previously uncharacterized mechanism by which TEs influence the function and evolution of host genomes by generating polymorphic 3D genome organization.

genomics↗

Medea: An omics AI agent for therapeutic discovery

Therapeutic hypotheses can transfer across diseases but their relevance depends on biological context. The same target, perturbation, or treatment can produce different effects across cell types, disease states, genetic backgrounds, and patients. Therapeutic reasoning therefore requires methods that preserve context, test when evidence supports transfer, and identify where context-specific effects limit it. Although AI agents can perform therapeutic analyses, existing systems often fail to preserve biological context over long workflows, verify intermediate computational steps, or reconcile conflicting evidence across datasets and literature. Here, we present Medea, an AI agent for therapeutic reasoning across biological contexts. Medea executes multi-step analyses using biological tools, machine learning models, and literature retrieval while enforcing verification during planning, execution, and evidence synthesis. We evaluate Medea across 5,673 open-ended analyses in three domains: cell type specific therapeutic target nomination in five diseases and 29 cell types, synthetic lethality prediction in 7 cancer cell lines, and immunotherapy response prediction from multimodal patient profiles. Using a previously unpublished epistatic miniarray profiling screen performed under two DNA-damaging treatments, we evaluate Medea on predicting synthetic lethality among 238,046 gene-gene pairs in yeast. Medea predicts these experimentally measured synthetic lethal interactions, indicating that its performance reflects biological relevance rather than information leakage from benchmark datasets. Across these evaluations, Medea improves performance over large language models, reasoning models, biomedical agents, and specialized machine learning models while maintaining low failure rates and calibrated abstention. These results show that verifiable AI agents can perform therapeutic analyses across biological contexts.

bioinformatics↗

Monitoring Gene Expression in Retina with Synthetic Serum Markers

Gene expression underlies retinal development, function, and pathogenesis. However, monitoring retinal gene expression in vivo is challenging. In this study, we apply synthetic serum markers, called Released Markers of Activity, or RMAs, to quantify gene expression in an intact retina through a simple blood test. We show that RMAs can quantify transduction of multiple retinal cell-types and monitor cell implantation or cell loss. We found RMAs are sensitive enough to measure transduction of rare cell populations, such as retinal ganglion cells and could detect transplantation of as few as 100 stem cells. Expression of RMAs showed no evidence of cell loss or immune activation in the retina. Overall, these findings demonstrate that RMAs are highly sensitive, tissue non-destructive gene expression reporters that can continuously track gene delivery and cell survival in intact retina through a simple blood test.

bioengineering↗

Dual Engram Architecture within a Single Striatal Cell Type Distinctly Controls Alcohol Relapse and Extinction

Relapse is a major obstacle in the treatment of alcohol and drug addiction and is thought to be driven by persistent drug-associated memories formed during their use. Behavioral therapies such as extinction training can reduce relapse and are proposed to work by creating a competing memory trace. However, where and how these opposing memories are stored in the brain is unknown. Here, we show that two anatomically and functionally distinct engram ensembles within the same genetically defined striatal cell type, direct-pathway medium spiny neurons (dMSNs), encode these opposing memories. Using engram-tagging tools in mice, we found that the acquisition of operant alcohol learning recruits a dMSN ensemble enriched in the striatal matrix compartment that stores alcohol-associated memories and whose activation selectively promotes relapse. Conversely, extinction of alcohol seeking recruits a dMSN ensemble enriched in the striosome compartment that stores extinction-related memories and whose activation suppresses relapse. Furthermore, we reveal that the physical memory trace storing the relapse-promoting memory is embedded within persistently strengthened corticostriatal synapses engaged during learning, and that artificially reproducing this plasticity is sufficient to trigger relapse-like behavior. These findings uncover a dual-engram architecture within dMSNs that governs relapse and extinction, providing a mechanistic framework for understanding how competing memories regulate drug-seeking behavior. HighlightsO_LIAcquisition and extinction of alcohol learning recruits distinct dMSN ensembles. C_LIO_LIAcquisition recruits matrix-enriched dMSN ensembles to promote relapse. C_LIO_LIExtinction recruits striosome-enriched dMSN ensembles to suppress relapse. C_LIO_LIEngram dMSNs show lasting synaptic potentiation and mimicking this potentiation triggers relapse. C_LI

neuroscience↗

Early-Stage Corticostriatal Circuit Hyperactivity Impairs Cholinergic Function and Cognitive Flexibility in an Alzheimer's Model

Cognitive flexibility deficits are a hallmark of early-stage Alzheimers disease (AD), but the underlying circuit mechanisms remain poorly understood. Here, we show that the 5xFAD mouse model of AD neuropathology exhibited early deficits in instrumental reversal learning, indicating cognitive inflexibility preceding spatial memory deficits. This impairment was associated with excessive neuronal reactivation in the medial prefrontal cortex (mPFC) and dorsomedial striatum (DMS), key regions for goal-directed behavior. Electrophysiological recordings revealed that mPFC neurons in young 5xFAD mice were hyperexcitable and received elevated excitatory input. Moreover, the mPFC-to-direct pathway medium spiny neuron (dMSN) circuit and the dMSNs themselves were selectively hyperactive. These hyperactive dMSNs exerted increased inhibitory control over cholinergic interneurons (CINs) in the DMS, coinciding with reduced CIN firing and diminished striatal acetylcholine (ACh) release. Critically, sustained chemogenetic inhibition of the mPFC-to-DMS circuit in 5xFAD mice reduced cortical A{beta} accumulation, normalized glutamatergic transmission in both the mPFC and DMS, restored striatal ACh levels, and rescued reversal learning deficits. Together, these findings identify a hyperactive mPFC-to-DMS circuit that disrupts corticostriatal and cholinergic signaling, contributing to cognitive inflexibility in 5xFAD mice. Targeting this circuit may offer a therapeutic strategy to preserve cognitive function in the early stages of AD. HighlightsO_LI5xFAD mice exhibit early cognitive deficits in instrumental reversal learning. C_LIO_LImPFC neurons and corticostriatal circuits are hyperactive, while cholinergic neurons are hypoactive in 5xFAD mice. C_LIO_LISustained inhibition of mPFC-to-DMS circuit hyperactivity normalizes glutamatergic transmission and slows A{beta} accumulation in 5xFAD mice. C_LIO_LISustained inhibition of the mPFC-to-DMS circuit rescues reversal learning deficits in 5xFAD mice. C_LI

neuroscience↗

Quantitative Full-length transcriptome analysis by nanopore sequencing with Error-Aware UMI mapping

Comprehensive transcriptome profiling is essential for understanding RNA diversity and regulation, yet accurate identification and quantification of full-length transcript isoforms remain challenging with short-read sequencing technologies. Nanopore sequencing enables direct sequencing of long cDNA molecules and thus offers a powerful solution for full-length transcriptome analysis, but its application to quantitative transcriptomics is limited by PCR amplification bias and the difficulty of unique molecular identifier (UMI) recognition under high sequencing error rates. Here, we developed UMImap, a dedicated pipeline for robust UMI identification, error correction, and deduplication in nanopore data. By integrating transcript-aware UMI correction with long-read isoform assembly, UMImap substantially improves UMI recognition accuracy compared with existing methods and effectively mitigates PCR-induced duplication bias. Using this framework, we identified tens of thousands of full-length transcript isoforms, including a large fraction of previously unannotated isoforms that are significantly longer than reference annotations. Quantitative analyses demonstrate the reliability of UMImap for transcript-level quantification. Functional and pathway enrichment analyses of highly expressed novel isoforms revealed coherent and biologically meaningful patterns, including strong enrichment in RNA processing, splicing, and translation pathways. Our results establish UMImap as an effective solution for UMI-based quantification in nanopore full-length transcriptome sequencing and highlight the potential of long-read sequencing to simultaneously achieve accurate isoform discovery and expression analysis in complex transcriptomes.

bioinformatics↗

Assessing suitability of ultra-low-field MRI for TES electric field models

ObjectiveRecent ultra-low-field (ULF) MRI systems provide an option for more accessible and cost-effective imaging to widely used higher field (HF, usually 3T) systems. However, it remains uncertain whether ULF scans can be used for reliable TES current-flow modeling as opposed to using 3T MRI. MethodsWe used raw anatomical scans of 23 healthy adults from 64 mT and 3T systems. We enhanced the 64 mT scans using SynthSR. Using our established current-flow modeling pipeline we determined the electric fields (EF) for the ULF and 3T scans induced by the classic M1-SO electrode montage. We quantified the differences in EF at three regions of interest (ROI): left motor cortex (LMC), anterior commissure (AC), and left hippocampus (LHC). ResultsAt the cortical ROI (LMC), the individual mean EF based on a 3T scan was found to be 27% higher than the corresponding ULF scan. The average mean relative error was found to be 40%. At AC, the individual mean EF based on a 3T scan continued to be elevated by about 13% in magnitude with respect to the corresponding ULF scan with a mean error range of 31-34%. At LHC, comparison of the induced individual mean EF magnitudes indicated no clear bias between 3T-based and ULF-based models. The average mean relative error at this level dropped to [~]20%. DiscussionThe substantial decrease in cortical EF when using an ULF scan is predominantly explained by the overestimation of cerebrospinal fluid (CSF) noted by prior morphological comparison studies. Scaling up EF magnitude to match predicted cortical values to a 3T scan may be considered depending on the modeling question being addressed. While preliminary, our results suggest an "equalizing" effect between ULF and 3T predictions with increasing depth within the brain.

bioengineering↗

Periplasmic gatekeeping of phage DNA entry by rSAM enzyme-mediated maturation of an effector with His-X-Ser repeats

In the relentless arms race between bacteria and phages, bacteria have evolved a variety of defense strategies to combat phage infection. However, no bacterial system has been identified that specifically target the phage DNA entry phase. Here, we present a novel bacterial antiphage system, termed HXS, which provides broad-spectrum and robust antiphage activity by interfering with phage DNA entry. The HXS system consists of two radical S-adenosylmethionine (rSAM) enzymes (HxsB and HxsC), a small protein (HxsD), and the effector HxsA with a peptidoglycan-binding domain and five His-Xaa-Ser (HXS) repeats. HxsB/HxsC catalyze rSAM enzyme-dependent maturation of HxsA, including N-terminal processing and a site-specific +8 Da modification, thereby producing a periplasmic effector required for HXS defense. Biochemical evidence supports a model in which the matured effector likely engages incoming DNA electrostatically to arrest entry, establishing an rSAM enzyme-modified protein effector in antiphage defense.

microbiology↗