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Biology subjects

Jiang, Y.

Publications and source records attributed to Jiang, Y..

At least 73 records · Page 4Linked to original sources

Microglial pruning of extinction-ensemble synapses preserves fear memory

Fear extinction suppresses learned fear without erasing the original memory, yet how competing fear and extinction ensembles are selectively updated remains unknown. Here, we show that microglia preserve fear memory by selectively editing extinction-ensemble synapses during retrieval. In medial prefrontal cortex, microglial processes, but not somata, expand, ramify, and tighten their engagement with extinction-ensemble dendrites and spines, where they preferentially engulf excitatory postsynaptic material and bias spine remodeling toward elimination. This selectivity is instructed by local find-me, eat-me, and dont-eat-me cues: purinergic signaling recruits microglial processes, phosphatidylserine exposure licenses engulfment of extinction-ensemble synapses, and CD47-SIRP protects fear ensembles from removal. Weakening microglial recruitment or engulfment, or removing this protection, accelerates extinction without impairing fear acquisition. These findings identify microglial processes as active gatekeepers of ensemble competition and reveal a neuroimmune mechanism that preserves fear memory by limiting extinction. In BriefDuring memory updating, microglial processes selectively engage extinction-ensemble synapses rather than globally pruning active circuits. Local recruitment, engulfment, and protection cues determine this choice, allowing microglia to preserve fear memory by limiting extinction. HighlightsO_LIExtinction retrieval selectively recruits microglial processes to extinction ensembles. C_LIO_LIMicroglia preferentially engulf excitatory postsynaptic material from extinction ensembles. C_LIO_LILocal "find-me," "eat-me," and "dont-eat-me" cues determine synapse selection. C_LIO_LIDisrupting microglial pruning facilitates extinction without impairing fear learning. C_LI

neuroscience↗

Vessel-Resolved Mapping of Perivascular Spaces Reveals Hierarchical Neurofluid Organization In Vivo

Perivascular spaces (PVS) are central to cerebrospinal fluid (CSF)-interstitial fluid (ISF) exchange in the brain, yet their brain-wide organization and in vivo accessibility remain poorly resolved due to limited spatial resolution and contrast specificity of existing imaging approaches. Prior gadolinium (Gd)-enhanced MRI studies demonstrate global tracer distribution but yield spatially diffuse signals that do not resolve PVS at the level of individual vessels. Here we introduce an ultra-high-resolution dual-contrast MRI framework that enables vessel-resolved mapping of PVS across the whole brain in vivo. This approach combines ultra-high-field imaging, an implantable radiofrequency coil for enhanced local sensitivity, and intraventricular Gd delivery to achieve sufficient contrast and spatial specificity for detecting vessel-associated perivascular signal. Using this framework, we show that PVS are hierarchically organized along vascular trees, extending from major surface arteries into deep cortical and subcortical regions. Signal patterns along arterial branches and junctions indicate that PVS follows vascular topology. Quantitative analysis reveals that only a subset of penetrating vessels ([~]6%) exhibits detectable PVS signal, indicating heterogeneous organization across vascular networks independent of vessel caliber. Widespread detection of PVS, including in the hippocampus, further demonstrates that ventricularly delivered tracers access a distributed, vessel-associated perivascular network in vivo. These results establish an anatomical framework for mapping perivascular transport pathways across the brain, bridging global tracer imaging with vessel-resolved organization, and enabling investigation of how vascular architecture and fluid dynamics shape CSF-ISF exchange.

neuroscience↗

DPLM: Dynamics-aware Protein Language Model via contrastive learning between sequence and molecular dynamics simulation trajectory

Protein dynamics play a critical role in protein function, yet such important information is missing in many protein language models (PLM). We introduce DPLM, a dynamics-aware protein language model that aligns sequence embeddings with molecular dynamics (MD) trajectory embeddings via contrastive learning. Using MD features encoded by a pretrained video model, DPLM learns sequence representations that correlate with residue-level flexibility and improve protein-level functional clustering compared to static sequence- and structure-based PLMs. Without task-specific training, DPLM outperforms ESM-based representations in zero-shot mutation-effect prediction on multiple deep mutational scanning datasets. When adapted with lightweight task-specific heads, DPLM further achieves top-tier performance on protein stability prediction and intrinsic disorder region identification, demon-strating that contrastive alignment with MD trajectories enables PLMs to capture biologically meaningful dynamic properties.

bioinformatics↗

Pharmacological rescue of cilia trafficking defects in IFT140 retinal organoid and RPE models of retinal dystrophy

Pathogenic variants in IFT140 are associated with a spectrum of syndromic and non-syndromic ciliopathies, with retinal degeneration as a common feature. Despite advances in understanding IFT140 function across various tissues, human retina-specific models are lacking. Here, we show that knock-in mice homozygous for the IFT140 patient variant c.932A>G (p.Y311C) did not develop retinal degeneration, while mice with the homozygous variant c.1451C>T (p.T484M), associated with non-syndromic retinal dystrophy, were embryonic lethal. Therefore, to understand the effect of these variants on retinal homeostasis, we generated novel human in vitro models of IFT140-associated retinal dystrophy, including CRISPR/Cas9 IFT140 knock-out (IFT140KO) induced pluripotent stem cells (iPSC) and patient-derived iPSC retinal pigment epithelium (iPSC-RPE) and retinal organoids (iPSC-ROs). IFT140KO iPSC-RPE cells display stubby cilia compared to isogenic controls, while IFT140T484M/T484Mpatient-derived iPSC-RPE cells exhibit slightly shorter cilia and cilia tip protein accumulation. Both IFT140KO and IFT140T484M/T484M iPSC-ROs show accumulation of cilia proteins at the connecting cilium and outer segment of photoreceptors, and mislocalization of rhodopsin to the inner segments and outer nuclear layer. Pharmacological screening of compounds previously reported to improve cilia structure identified the flavonoid eupatilin as the most effective molecule. Treatment with eupatilin improved cilium length and IFT traffic in iPSC-RPE, and IFT traffic and rhodopsin localization in iPSC-ROs. These findings emphasize the importance of human stem cell derived models to investigate tissue specific disease mechanisms and highlight the therapeutic potential of eupatilin to ameliorate cilia defects in retinal tissue.

neuroscience↗

CMS: Achieving Uniform and High-Quality Sequencing across Challenging Non-canonical Genomic Regions

High-throughput sequencing is essential in modern biological research, yet low-complexity sequences remain challenging as they form structurally complex, non-canonical (non-B) DNA conformations that impede sequencing enzyme read-through. This leads to a long-standing trade-off: maximizing coverage introduces false positives (FP), while stringent filtering causes coverage loss and false negatives (FN). To address this, we developed CMS (Cross Mountains and Seas) on GeneMind sequencing platforms by optimizing its chemistry and enzymatic systems to traverse these secondary structures with high fidelity. Benchmarking across whole-genome (WGS) and whole-exome (WES) sequencing demonstrates that CMS addresses the trade-off by simultaneously enhancing both coverage uniformity and accuracy, notably achieving an approximately 100-fold reduction in low-coverage bins for WGS and a 70% reduction in FN insertions/deletions (INDELs) within complex non-B regions. Specifically, a synthetic G-quadruplex (G4) motif sequencing experiment demonstrates that CMS maintains a 1:1 strand ratio, effectively handling G4-induced biases where benchmarked platforms exhibit extensive depletion. These findings establish CMS as a reliable technology for the precise characterization of structural-challenging but functional-essential genome regions.

genomics↗

Therapeutic Potential of Hypoxia-Preconditioned hiPSC-Epicardial Cell-Derived Exosomes in Mice with Myocardial Infarction

BackgroundIt has been demonstrated that stem cell transplantation promotes healing of the infarcted heart through paracrine effects. However, the therapeutic potential of exosomes secreted by hiPSC-derived epicardial cells (hEP-Exos) for treating infarcted hearts remains unclear. Myocardial infarction (MI) can trigger EP activation, increasing EP paracrine function. Therefore, this study aims to determine and compare the cardioprotective effects of exosomes secreted by hEPs under normoxic (Exo-N) and hypoxic (Exo-H) conditions in MI mice and to explore the underlying mechanisms. MethodsTwo types of exosomes were collected by ultracentrifugation and delivered via intramyocardial injection in a murine MI model. The protective effects of Exo-N and Exo-H on the infarcted heart were assessed using echocardiography, histological examination, and immunofluorescence analysis. Additionally, microRNA sequencing, luciferase activity assays, and miRNA gain-and loss-of-function experiments were performed to identify enriched miRNAs and investigate their roles in different exosome populations. ResultsIn vitro, both Exo-N and Exo-H enhanced the migration and tube-formation capacities in human umbilical vein endothelial cells (HUVECs) and reduced the apoptosis in hiPSC-derived cardiomyocytes (hCMs) under oxygen-glucose deprivation (OGD), with Exo-H exhibiting a stronger effect. In vivo, both Exo-N and Exo-H significantly improved contractile function, reduced infarct size, and mitigated adverse remodeling in mouse hearts with MI, accompanied by increased cardiomyocyte survival and angiogenesis, with Exo-H showing superior efficacy. Mechanistically, miRNA sequencing revealed distinct cargo profiles between Exo-N and Exo-H. miR-214-3p was identified as a key mediator of the enhanced therapeutic potency of Exo-H. miR-214-3p promoted EC angiogenesis by suppressing vasohibin-1 and attenuated cardiomyocyte mitochondrial fission and apoptosis by suppressing mitochondrial elongation factor 2 (MIEF2). ConclusionsThis study demonstrates that administration of hEP-Exos, particularly Exo-H, provides robust cardioprotection by enhancing cardiomyocyte survival and angiogenesis, potentially mediated by miR-214-3p. These findings suggest that conditioned hEP-Exos could be a promising and effective acellular therapeutic option for treating MI.

cell biology↗

Adulthood depletion of Integrator extends lifespan and healthspan via defective pre-mRNA processing

Identifying strategies to mitigate age-related physiological decline remains a central challenge. During ageing, the transcriptome undergoes extensive remodelling, but how this affects organismal health and lifespan is not well understood. The Integrator complex plays a central role in RNA polymerase II transcription and RNA 3' end processing. Surprisingly, we find that depletion of most Integrator subunits specifically in adults extends lifespan and healthspan in the nematode C. elegans. We show that loss of the catalytic subunit INTS-11 disrupts 3' end formation of small nuclear and spliced leader RNAs, impairing trans-splicing and promoting outron retention in a subset of transcripts enriched for spliceosomal and nucleocytoplasmic transport genes. These RNA-processing defects lead to altered levels of endogenous siRNAs, which are required for the longevity and healthspan benefits of INTS-11 depletion. In parallel, outron retention disrupts nuclear-encoded mitochondrial gene expression and protein production, inducing mitochondrial dysfunction and promoting lifespan extension. We also demonstrate that loss of INTS-11 perturbs transcription elongation at genes where Integrator is present at promoters, and that upregulation of enhancer elements within intragenic regions can affect the expression and isoform usage of nearby genes. Together, our findings identify Integrator as a key upstream regulator of non-coding RNA transcription, which in turn impacts protein-coding gene expression and mitochondrial function to shape the ageing process.

cell biology↗

Detecting misfolded non-covalent lasso entanglements in protein structures, simulation trajectories, and mass spectrometry data

A previously overlooked class of protein entanglements, non-covalent lasso entanglements (NCLEs), has been found to play a role in widespread protein misfolding. However, understanding the influence NCLEs have on biological processes is hindered by the absence of dedicated algorithms and computational tools to detect and characterize these geometries in protein structures, molecular dynamics simulations, and in comparison to experimental data from limited proteolysis (LiP) and cross-linking (XL) mass spectrometry (MS). Here, we present EntDetect, a software tool designed to: (1) identify non-redundant NCLEs in protein structures, (2) detect misfolded states by comparing NCLE changes through pairwise comparisons of structures, (3) extract structural ensembles consistent with experimental signals from LiP-MS and XL-MS, and (4) investigate proteome-wide protein misfolding using high-throughput MS data. We demonstrate the utility of EntDetect on a simulated structural ensemble of phosphoglycerate kinase (PGK), alongside corresponding LiP- and XL-MS experimental data. Additionally, we detail the application of EntDetect to detect misfolding associated with native NCLEs on a proteome-wide MS dataset and select candidate proteins for further investigation. This protocol is intended for biophysicists, structural biologists, and molecular biologists with domain knowledge of protein structure, mass spectrometry proteomics data, and beginner experience with Python who want to interpret their experimental observations and computer simulations results through the presence and potential misfolding of NCLE topologies. EntDetect is open-source and freely available (https://github.com/obrien-lab-psu/EntDetect). NCLEweb is also available which is a webserver that identifies NCLEs within a given user-uploaded structure (https://www.ncleweb.org/).

molecular biology↗

Multiscale transcriptomic organization of the human brain with DigitalBrain

The human brain varies across anatomical regions, cell types, development, aging and disease states, yet existing single-cell transcriptomic resources remain fragmented and difficult to integrate into a unified biological model. Here we present DigitalBrain, a human brain-specific atlas and foundation-model framework for organizing diverse and fragmented human brain transcriptomic data across scales. We first built DigitalBrain-Atlas, a harmonized whole-brain single-cell resource comprising 16.35 million transcriptomes from 2,143 donors across 165 brain regions, spanning the human lifespan and multiple neurological and clinical conditions. We then developed DigitalBrain-M1, a Transformer-based model that jointly encodes gene identity and expression magnitude to learn a shared embedding space for cells and genes. Across held-out datasets, DigitalBrain supported robust single-cell integration, clustering and cell-type annotation while preserving major biological structure and reducing technical fragmentation. Beyond these benchmarks, the learned embeddings revealed emergent large-scale hierarchical organization of the human brain, linking anatomically distinct regions into higher-order patterns consistent with known functional systems. Applied to human hippocampal aging, DigitalBrain identified cell-type-specific aging sensitive gene sets, highlighted dentate gyrus granule cells as a particularly age-sensitive population, and discovered selective reorganization of gene programs related to synaptic transmission, postsynaptic structure, membrane excitability and axon guidance during aging. Cross-dataset convergence was strongest at the level of functional modules and recurrent aging sensitive genes. Together, these results demonstrate that DigitalBrain is a brain-specific framework for mapping human brain organization across scales, and as an early step towards a complete virtual organ for the human brain.

bioinformatics↗

Protein entanglement misfolding determines divergent fates: proteasomal degradation or persistence in near-native misfolded states

A novel class of protein misfolding, involving changes in entanglement status, occurs across the cytosolic proteome of a bacterium and likely occurs in many other organisms. Here, we examine if this class of misfolding has measurable downstream consequences for protein homeostasis. Specifically, we test the hypothesis that proteins that misfold in this way are more likely to be degraded by the ubiquitin-proteasome system immediately after synthesis. We do this by cross-referencing protein structural information with ubiquitin mass spectrometry (Ubq-MS) data from human fibroblast cells. Ubq-MS identifies proteins that have been covalently modified with ubiquitin in a particular pattern and is a cellular signal for that protein to be degraded by the proteasome. We find that nascent proteins with native entanglements, which were previously shown to be twice as likely to misfold, are 93% (95% Confidence Interval: [44%, 160%]) more likely to be tagged with ubiquitin and targeted to the proteasome compared to proteins that do not contain such entanglements. Simulating the folding of these proteins using a coarse-grained model, we find that the ubiquitin-tagged proteins containing native entanglements are four times more likely to misfold than the non-ubiquitinated proteins that are devoid of entanglements. These results indicate that entanglement misfolding, primarily involving a failure to form native entanglements, leads to an increased likelihood that those proteins will be degraded in human cells. Finally, we estimate that approximately one-third of the globular proteome likely misfolds in this way but bypasses proteasomal degradation because their misfolded states are structurally similar to their native ensemble. These consequences for protein degradation are likely common across organisms as entanglement misfolding is inherent to the polymeric nature of proteins.

biophysics↗

End-to-end evaluation of pipelines for metagenome-assembled genomes reveals hidden performance gaps

The generation of Metagenome Assembled Genomes (MAGs) has become a standard and basic step in the analysis of metagenomic data. This multi-step process, which includes assembly, binning, refinement, and quality control, has many alternative approaches, algorithms, and parameters. Determining the ideal approach for a given ecosystem and study, or highlighting algorithmic gaps in need of additional research and development, requires rigorous benchmarking. We present MAG-E (MAG pipeline Evaluator), a generalizable and expandable framework for end-to-end evaluation of entire MAG pipelines: from assembly, through binning, to quality control and filtering. MAG-E relies on simulations that are built to match an ecosystem of interest and provide a ground truth for accurate evaluation. To demonstrate the capabilities of MAG-E, we benchmark two assemblers, six binning algorithms, three binning modes, and three quality control and refinement methods in the context of the human gut microbiome. Our findings offer multiple insights into optimal MAG generation in this context. We find that metaSPAdes consistently outperforms MEGAHIT in terms of recall (completeness), and that COMEBin overall outperforms alternative binning algorithms, but has lower precision than SemiBin2. While multi-sample binning results in higher precision, as previously shown, single-sample binning has higher recall and leads to better overall performance with modern binners. Binning refinement, which combines bins from multiple different algorithms, leads to reduced performance. We further show that CheckM2 systematically overestimates completeness and underestimates contamination, and that this is partially ameliorated when using GUNC. Finally, we analyze performance at the contig level, and demonstrate that binning algorithms systematically underperform for prophages and fail to bin contigs that are shared between genomes. Overall, MAG-E offers deep insights into successes and gaps in this important analytic process.

bioinformatics↗

Curvature-mediated prewetting organize mitochondrial nucleoid

The emergence of spatiotemporal order in diffusive cellular environments requires physical mechanisms to overcome the entropic drive toward disorder. While the organizing role of chemical signaling is well characterized, how complex membrane curvature regulate soluble molecular organization remains a fundamental open question. Here, we establish membrane curvature as a thermodynamic control parameter for the condensation of soluble proteins through prewetting. Using the mitochondrial transcription factor TFAM, we demonstrate that intrinsic membrane curvature locally drives a prewetting transitiona surface-mediated phase separation distinct from bulk condensation. By combining in vitro reconstitution, live-cell super-resolution imaging, cryo-electron tomography, and thermodynamic theory, we show that negatively high-curvature regions lower the nucleation energy barrier of Tfam, driving localized protein condensation at physiological concentrations. These results reveal that membrane curvature does not merely scaffold cellular machinery but manipulates the local free energy landscape, establishing a geometric principle for the spatial control of biological processes.

biophysics↗

MolClaw: An Autonomous Agent with Hierarchical Skills for Drug Molecule Evaluation, Screening, and Optimization

Computational drug discovery, particularly the complex workflows of drug molecule screening and optimization, requires orchestrating dozens of specialized tools in multi-step workflows, yet current AI agents struggle to maintain robust performance and consistently underperform in these high-complexity scenarios. Here we present MolClaw, an autonomous agent that leads drug molecule evaluation, screening, and optimization. It unifies over 30 specialized domain resources through a three-tier hierarchical skill architecture (70 skills in total) that facilitates agent long-term interaction at runtime: tool-level skills standardize atomic operations, workflow-level skills compose them into validated pipelines with quality check and reflection, and a discipline-level skill supplies scientific principles governing planning and verification across all scenarios in the field. Additionally, we introduce MolBench, a benchmark comprising molecular screening, optimization, and end-to-end discovery challenges spanning 8 to 50+ sequential tool calls. MolClaw achieves state-of-the-art performance across all metrics, and ablation studies confirm that gains concentrate on tasks that demand structured workflows while vanishing on those solvable with ad hoc scripting, establishing workflow orchestration competence as the primary capability bottleneck for AI-driven drug discovery.

bioinformatics↗

Sharp cell type boundaries emerge from coordinated morphogen signaling

Classic models of the French flag problem depict sharp cell-type boundaries emerging from threshold responses to morphogen gradients. How discrete cell-type boundaries arise from morphogen signals that vary continuously across developing tissues is not completely understood. We use hair follicle dermal condensate formation to study a sharp developmental transition in which proliferative progenitors undergo cell-cycle exit concurrent with molecular differentiation. Using genetic and genomic approaches, we show that Wnt and Hedgehog signaling interact to coordinate the timing of these two processes. We identify a division of labor between the pathways: Wnt signaling promotes cell-cycle exit by regulating chromatin binding of the Hedgehog mediator GLI3, while Hedgehog signaling induces differentiation genes in a Wnt-dependent manner and simultaneously elevates Wnt activity. When Wnt and Hedgehog activities are temporally aligned, differentiation and cell-cycle exit occur within the same developmental window, restricting both the duration and abundance of intermediate states and producing a sharp cell-type boundary. When these signals are misaligned, intermediate states persist and expand, producing fuzzy boundaries. These findings reveal a mechanism in which interacting morphogen signals regulate the duration and abundance of intermediate states during a developmental transition, thereby controlling how continuous cell-state progression is translated into discrete tissue patterning.

developmental biology↗

Structure-guided discovery and engineering of miniature CRISPR-Cas12m for epigenome editing

CRISPR-based epigenome editing represents a programmable strategy to precisely modulate gene expression, holding immense promise for therapeutic applications. However, the large size of the dCas proteins substantially impedes the delivery via adeno-associated virus (AAV) vectors. Here, through iterative bioinformatics analysis, structure-guided predictions, and functional assays, we identified and characterized PmCas12m, a novel miniature subtype V-M CRISPR-Cas12m. PmCas12m exhibited flexible 5-YTN-3 PAM-dependent recognition and robust double-stranded DNA binding properties, while lacking DNA cleavage activity, thus positioning it as an ideal tool for epigenome editing. Cryogenic electron microscopy (cryo-EM) structures of PmCas12m unveiled its unique molecular mechanism of DNA binding facilitating interference. Guided by these structural insights, we employed deep mutational scanning (DMS) and protein engineering to develop xCas12m, a hypercompact variant with highly potent and specific epigenome editing capabilities in human cells. We further constructed the xCas12m-CRISPRoff platform in a single AAV vector, which achieved durable epigenetic silencing and effective inhibition of hepatitis B virus (HBV) infection in a mouse model. Collectively, these findings establish xCas12m as a versatile epigenome editing platform with transformative potential for treating diseases, paving the way for clinical translation of epigenetic therapies.

bioengineering↗

Isoform-resolved spatial transcriptomics on a lab-made high-density array via a single-chip NGS-TGS workflow

High-resolution spatial transcriptomics is still cost-prohibitive and dominated by short-read sequencing, limiting in situ detection of transcript structures. Here we present a low-cost, lab-made, high-density bead-in-microwell chip assembled by routine centrifuge and decoded by a tri-part combinatorial long-barcode strategy. The design provides 5.6x107 barcode combinations across 4.1x10{square} capture sites, reducing collisions while remaining tolerant to third-generation sequencing raw errors. Using a single-chip, dual-platform workflow, we split full-length cDNA for next-generation and third-generation sequencing within the same spatial coordinates. In an incompatible tomato-pepper graft, we identified interface-associated splicing reprogramming, including thousands of unannotated isoforms, enriched novel CaGRP1 isoforms, and SlPIP2 intron retention, supported by individual long-read sequences. In mouse embryos, we further demonstrate cross-species applicability by resolving unannotated Col1a2 isoforms in oligodendrocyte progenitors and spatially restricted Dalrd3 intron retention. This cost-efficient system broadens access to spatial full-length transcriptomics and may support diverse biological studies.

plant biology↗

A generalized life-motion mechanism supports invariant directional coding of local biological kinematics in humans

Humans can detect biological motion (BM) from sparse local kinematic cues, yet whether the visual system encodes directional information in a category-invariant manner remains unresolved. Here we combined a visual adaptation paradigm with computational modelling to reveal direction-sensitive neural mechanisms specialized for local biological kinematics. Adapting to a side-view scrambled point-light walker produced a robust repulsive aftereffect in the perceived direction of an intact human walker near the frontal view. Notably, this aftereffect generalized across different terrestrial vertebrates (pigeon, cat, dog) and across various actions (running, crawling, cycling), demonstrating a high degree of kinematic invariance. Crucially, the effect disappeared when biological kinematics were disrupted (inversion or removal of gravitational acceleration cues) or when the test stimulus was replaced with non-biological object motion. Individuals direction-discrimination abilities were also highly correlated across diverse local BM patterns, indicating a shared underlying mechanism. Drift-diffusion modeling further revealed that adaptation primarily altered the efficiency of sensory evidence accumulation rather than decision-level processes, and individual drift-rate changes strongly predicted the magnitude of perceptual aftereffects. These findings provide compelling evidence for a generalized, direction-sensitive neural system tuned to local biological kinematics, extending the life-motion detector theory and revealing a fundamental principle of biological motion perception. Significance StatementHumans possess an exceptional ability to detect and interpret the movements of living beings--an ability fundamental to survival, social interaction, and adaptive behavior. But how does the visual system extract "life motion" so adeptly amidst the complexity of natural scenes? Using visual adaptation and computational modelling, we provide direct evidence for direction-sensitive neural mechanisms specialized for local biological kinematics. These mechanisms operate robustly across species and actions, and remain selective for natural biological dynamics. Our findings advance the life-motion detector theory by demonstrating that the human visual system encodes directional information in a highly invariant manner, revealing a fundamental computational strategy for detecting animate agents.

neuroscience↗

Synergistic Inhibition of Notch Signaling and Forced Cell Cycle Re-entry Drive Müller Glia Reprogramming in Uninjured Mouse Retina

In regenerative species, such as teleost fish, Muller glia (MG) autonomously re-enter the cell cycle after injury and give rise to functional retinal neurons. In contrast, the loss of retinal neurons in mammals is irreversible due to the limited proliferative and regenerative ability of MG. Various strategies have been developed to induce proliferation of mature mouse MG with or without injury, yet most MG daughter cells retain glial cell fate. Here, we found that MG progenies maintain high Notch signaling, which may constrain their neurogenic potential. Conditional deletion of Rbpj, the central transcriptional effector of Notch, induced limited MG-to-neuron conversion in mature MG without proliferation. However, Rbpj deletion, combined with forced MG proliferation by overexpressing cyclin D1 and suppressing p27Kip1, significantly promoted MG dedifferentiation and ectopic expression of the neuronal marker Otx2 in MG daughter cells in uninjured mouse retina. Combining Notch inhibition with MG cell cycle re-activation not only increased the numbers of bipolar- and amacrine-like cells generated from MG but also promoted the further differentiation toward ON-cone, OFF-cone, and rod-bipolar subtypes. Single-nucleus RNA and ATAC sequencing data revealed that Notch inhibition facilitated the formation of MG-derived progenitor-like cells while MG proliferation increased chromatin accessibility of neurogenic genes. Notably, most MG-derived cells survived long term despite incomplete maturation. Together, our findings delineate how Notch inhibition and MG proliferation, alone or in combination, influence the regenerative potential of MG in the mammalian retina.

cell biology↗