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Gong, R.

Publications and source records attributed to Gong, R..

At least 19 recordsLinked to original sources

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

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

bioengineering↗

The Gαi/o GPCR LPAR2 Acts as a Non-Classical Factor for Aldosterone Induced Injury in a Cardiomyocyte Model

Aldosterone is a key regulator of systemic sodium, potassium, and fluid homeostasis. Chronic elevation of aldosterone, as observed in primary aldosteronism, chronic heart and kidney diseases, promotes cardiac hypertrophy, inflammation, fibrosis, and heart failure, which are further enhanced in aging. Although these pathological effects are primarily attributed to the mineralocorticoid receptor (MR), emerging evidence suggests roles for nonclassical G protein-coupled receptor (GPCR) signaling. We identified lysophosphatidic acid receptor 2 (LPAR2) as a novel GPCR candidate that mediates aldosterone signaling in cardiomyocytes. Using AC16 human cardiomyocyte cells and reporter gene assays, we demonstrate that aldosterone activates a Gi/o-dependent GPCR pathway. Pharmacological inhibition of LPAR2 internalization confirms its specific reaction to aldosterone. Functional studies revealed that aldosterone-induced cardiomyocyte injury requires both MR and LPAR2, where specific antagonists to both receptors reduced the ability of aldosterone to induce collagen expression and cell death markers. These findings uncover a previously unrecognized non-classical mechanism of aldosterone action in the heart and highlight LPAR2 as a promising therapeutic target for aldosterone-driven cardiovascular disease.

systems biology↗

Satellite Glial Cells Drive Homeostatic Synaptic Structural Plasticity in Sympathetic Neurons

Sympathetic neuronal (SN) activity critically regulates the development and function of peripheral organs and tissues. The demonstration of activity-dependent modulation of SN output suggests that compensatory forms of plasticity could contribute to maintaining the stability of sympathetic circuits. Such plasticity mechanisms could act to restrain SN hyperactivity, a key driver of hypertension in humans and in the spontaneously hypertensive rat (SHR). In this study we examined how long-term changes in activity impact synaptic properties in postnatal sympathetic neuron cultures using chemogenetic and pharmacological manipulations and by examining the effects of enhanced activity of SHR neurons. We showed that bidirectional changes in neuronal activity resulted in homeostatic shifts in synaptic density to counteract long-term activity manipulations. In the absence of sympathetic satellite glial cells (SGCs) there was no synaptic compensation in the cultures. Direct chemogenetic activation of SGCs was sufficient to drive a decrease in synaptic sites and neuronal activity, while glial inhibition blocked activity-dependent synaptic compensation, demonstrating a role for the SGCs in homeostatic regulation of synaptic properties. We found that the SGCs responded to cholinergic signaling by downregulating the expression of the synaptic regulators NGF and TNF, suggesting that reciprocal signaling between SNs and SGCs acts to stabilize sympathetic output during long-term changes in circuit activity. Finally, we showed that these plasticity mechanisms are disrupted in postnatal SHR neurons, with an attenuated neuronal response to glia signaling during synapse formation and activity-dependent plasticity. Taken together, this work describes a new homeostatic activity-dependent plasticity mechanism in the peripheral nervous system.

neuroscience↗

A motif for domain-specific analysis applets that are easy to learn, reuse, test, and to compose into pipelines: application to vision science

Scientific progress depends on the analysis of primary data, yet the small, domain-specific programs that perform most scientific analyses are typically poorly documented, narrowly tested, and difficult to reuse outside the lab that created them. General-purpose pipeline tools address the problem of running steps in order but do not enforce documentation, testing, or standardized outputs. We describe a motif for building domain-specific analysis applets, which we call calculators, that constrains developer choices in order to produce code that is readable, tested, and reusable almost as a byproduct of following the template. Calculators operate on a typed, searchable database of documents, eliminating the need to explicitly wire inputs and outputs together; instead, each calculator searches the database for documents it can operate on and adds its results as new typed documents. Calculators must provide documentation in a standard location, self-tests that can be run and inspected interactively, adjustable input parameters, a single well-defined output document type, and a default plotting method. Sets of calculators compose naturally into pipelines whose outputs satisfy FAIR principles at every stage. We demonstrate the motif by implementing calculators for common analyses in vision science, including orientation and direction selectivity, contrast tuning, spatial and temporal frequency tuning, speed tuning, and Hartley reverse correlation. These calculators have been used in published work and are in active use across collaborating laboratories. We discuss the design principles of the motif, its advantages and limitations, and its applicability to domain-specific computation across neuroscience and beyond. Significance StatementScientists often must write small programs to analyze their own data. These programs are usually poorly documented, lightly tested, and hard for other labs to reuse. Mistakes in this kind of code have even caused well-known papers to be retracted. We describe a simple pattern for writing these programs, which we call a calculator. The pattern requires the programmer to include clear documentation, built-in tests, adjustable settings, and a standard form of output. Calculators work by searching a shared database for data they know how to handle, so many calculators can be chained together into a pipeline without extra setup. We show how this works by building calculators for common visual neuroscience analyses that other labs are already using.

neuroscience↗

Evolutionarily Conserved Decline of tRNA Mannosyl-Queuosine Links Translational Regulation to Aging and Is Reversed by Queuine

Aging arises from interconnected molecular defects, yet upstream regulatory mechanisms that coordinate these hallmarks remain incompletely defined. While epitranscriptomic regulation has emerged as a critical layer of gene control, the contribution of tRNA-specific modifications to aging remains largely unexplored. Here, we systematically profile tRNA modifications across multiple organs, species, and senescence models and identify mannosyl-queuosine (manQ), a wobble-position modification of tRNAAsp, as the first tRNA-specific modification that consistently declines with age. ManQ depletion is evolutionarily conserved and tightly correlates with functional deterioration. Mechanistically, loss of manQ impairs translational fidelity, leading to proteome imbalance, collapse of proteostasis, and aberrant expression of senescence-associated proteins, including GPNMB. These translational defects intersect with established aging hallmarks and accelerate cellular and organismal aging. We further demonstrate that circulating queuine, a microbiota-derived precursor required for manQ biosynthesis, declines with age in rodents and humans. Queuine deficiency promotes senescence, whereas supplementation restores manQ levels, improves translational accuracy, suppresses p16/p21-driven senescence programs, and re-establishes proteostatic balance. Across species, queuine supplementation extends lifespan and enhances healthspan. In Drosophila, it increases median lifespan by 47% and improves stress resistance and memory. In naturally aging mice, long-term oral administration extends lifespan by 15.3%, reduces DNA methylation age, improves cognitive and motor performance, strengthens antioxidant defenses, remodels the gut microbiota, and alleviates inflammation and metabolic dysfunction without detectable toxicity. Collectively, these findings establish tRNA epitranscriptomic remodeling as a previously unrecognized layer of aging regulation and identify restoration of manQ through queuine supplementation as a multi-system strategy to delay aging.

pharmacology and toxicology↗

Oxidation-Driven mtDNA B-Z Transition Activates ZBP1 to Mediate Acetaminophen Hepatotoxicity

Acetaminophen (APAP) overdose induces mitochondrial damage in hepatocytes, leading to secondary toxicity that resists to N-acetylcysteine (NAC) treatment and culminates in hepatocyte death and acute liver failure (ALF)1. The underlying mechanisms remain poorly understood, often necessitating liver transplantation2. Here, we identify oxidative modification-driven B-to-Z transitions in mtDNA as the central pathological driver of APAP-induced ALF. Upon APAP exposure, oxidized mtDNA fragments leak into the cytosol, activating ZBP1 signaling via its Z domain. Genetic inhibition of ZBP1 mitigates liver damage and improves survival. Using synthetic 12-bp dGdC duplexes, we demonstrate that 8-oxoG substitution, even under physiological salt concentrations, is sufficient to induce Z-DNA formation, enabling specific ZBP1 binding through its Z domain. The 8-oxoG repair enzyme OGG13, activated by TH107854, removes 8-oxoG modifications and reverses Z-DNA to B-DNA conformation. In mice with lethal APAP toxicity, delayed NAC treatment results in 50% mortality. In contrast, TH10785 monotherapy increases survival to 90%, while its combination with NAC achieves 100% survival. These results define the oxidized mt Z-DNA-ZBP1 axis as a critical driver of APAP hepatotoxicity, providing fundamental insights into DNA conformational dynamics and therapeutic opportunities in drug-induced liver failure.

cell biology↗

BRD8 Disruption Unlocks Retrotransposon-Driven Tumor-Intrinsic Immunogenicity via Redistribution of Histone Acetylation in Liver Cancer

Overall response rate for immune checkpoint blockade (ICB) therapy remains limited in advanced hepatocellular carcinoma (HCC). Epigenetic perturbation has been shown to enhance tumor-intrinsic immunogenicity and thus reverse resistance to immunotherapy in multiple cancer types. Here, through domain-focused CRISPR/Cas9 genetic screens targeting chromatin regulators, we identified the bromodomain-containing protein 8 (BRD8) as a novel epigenetic factor that functions to suppress tumor-intrinsic immunity through BRD8/EP400 chromatin remodeling complex in HCC. Depletion of BRD8 potently induces anti-tumor immune responses and sensitizes tumors to ICB therapy in mouse tumor models. Mechanistically, BRD8 knockout leads to partial redistribution of H3K27ac to repetitive elements, activating double-stranded RNA (dsRNA) accumulation and subsequent type I interferon (IFN) response, leading to tumor rejection via remodeling the tumor microenvironment. The first-in-class selective chemical probe DN02 targeting the bromodomain of BRD8 also exhibits immunomodulatory and anti-tumor effects. In line with these findings, low BRD8 expression correlated with enriched interferon signatures, elevated immune cell infiltration, and prolonged survival in HCC patients. Together, this study reveals BRD8 as a selective epigenetic vulnerability for promoting tumor immunogenicity, and its bromodomain as a druggable target to overcome immunotherapy resistance in liver cancer patients. SignificanceThe induction of viral mimicry by epigenetic interference could trigger tumor-intrinsic immune response and enhance immunotherapy efficacy. Here, through domain-focused CRISPR/Cas9 screening, we identify BRD8 complex as a regulator involved in the suppression of repetitive elements by controlling H3K27ac distribution and propose BRD8 as a novel target to enhance anti-tumor immunity.

cancer biology↗

Epithelial FOXP3 Drives Pancreatic Fibrosis through O-glycosylated IL-6

BACKGROUND & AIMSThe transcription factor FOXP3, known for specifying regulatory T cell fate, is unexpectedly expressed in the epithelium of precancerous pancreatic lesions. Here we investigate its non-immune role in initiating pancreatic fibrosis, a process driving therapeutic resistance and organ failure in pancreatic ductal adenocarcinoma (PDAC) with unknown origins in early neoplasia. METHODSUsing human tissues and genetically engineered mouse models, we analysed FOXP3 expression in premalignant lesions. We employed epithelial-specific FOXP3 knockout and knock-in strategies to determine its functional impact on fibrogenesis and neoplasia progression. Mechanistic studies included chromatin immunoprecipitation, glycomic analyses, and signalling assays. RESULTSFOXP3 was consistently expressed in the epithelial compartment of human and murine precancerous pancreas. Epithelial-specific deletion of FOXP3 attenuated pancreatic fibrosis and delayed neoplasia, whereas its knock-in induced spontaneous stromal activation and accelerated PanIN progression. Mechanistically, epithelial FOXP3 directly transactivated the glycosyltransferase GALNT1. GALNT1, in turn, mediated O-glycosylation of interleukin (IL)-6, which was essential for its rapid secretion. CONCLUSIONSOur study establishes epithelial-derived FOXP3 as a master regulator of early pancreatic fibrocarcinogenesis. It drives a glycosylation-dependent amplification loop for IL-6 signalling, orchestrating sustained stromal activation. This pathway represents a promising target for intercepting pancreatic fibrosis and carcinogenesis at its origin.

cancer biology↗

The Brain/MINDS 3D Digital Marmoset Brain Atlas Version 2.0: Population-based Cortical Region Parcellations with Multi-Modal Standard Templates

We present our new Brain/MINDS 3D digital marmoset brain atlas version 2.0 (BMA2.0), a population-based 3D digital brain atlas of the common marmoset (Callithrix jacchus), designed to overcome the limitations of previous single subject atlases that are prone to structural biases arising from individual variation. Here, manually delineated cortical regions from 10 myelin-stained brains were used to create a generalized cortical parcellation. Newly refined subcortical regions from a previous atlas and a completely new cerebellum parcellation were also incorporated, resulting in a comprehensive whole brain parcellation for both hemispheres. To facilitate multimodal data analysis, the atlas package includes co-registered average templates for myelin and Nissl staining from the same individuals, ex vivo MRI T2 (91 individuals), and in vivo MRI T2 (446 individuals). Cortical flat maps and pial, cortical mid-thickness, and white matter surfaces are also provided. BMA2.0 provides a central brain space for multimodal data integration, spatial analysis, and comparative neuroscience. Standard formats and transformations are provided for easy integration into existing workflows and interoperability with existing atlases.

neuroscience↗

Geometrically encoded positioning of introns, intergenic segments, and exons in the human genome

Human tissues require a mechanism to generate durable, yet modifiable, transcriptional memories to sustain cell function across a lifetime. Previously, we demonstrated that nanoscale packing domains couple heterochromatin (cores) and euchromatin (outer zone) into unified reaction volumes that can generate transcriptional memory. In prior work, this framework demonstrated that RNA synthesis occurred within the ideal zone (intermediate density) portions of the domain. Naturally, this creates a question of where genes are positioned in relation to the packing domain architecture and which genetic material fills the domain core to sustain transcription. Here we propose that this could be solved by the encoded positioning of introns, intergenic segments, and exons as a projection of the functional packing layers of domains. This suggests that introns and intergenic segments are coupled to adjacent exons to generate coherent packing domain volumes. We illustrate how this organization would reconcile contradictions in epigenetic patterns, non-randomness in oncogenic mutations, and produce durable transcriptional memory. We conclude by showing that this genome geometry might have coincided with the rapid evolution of body-plan complexity, suggesting that chromatin geometry could be fundamental to metazoan evolution.

biophysics↗

Dual function of DOT1L suppresses tumor intrinsic immunogenicity in hepatocellular carcinoma

Immune checkpoint inhibitor (ICB) therapy for many cancers remains limited in patients overall response rate. Discovery and development of more effective combinatorial approaches is urgent. Here, through CRISPR/Cas9 genetic screens, we identify DOT1L as a versatile epigenetic factor that functions to suppress tumor-intrinsic immunity through a dual mechanism. Depletion of DOT1L induces the expression of transposable elements and subsequent type I interferon (IFN) response, and meanwhile lowers ZEB1 levels to further unleash the expression of immune-related genes. In turn, we demonstrate that DOT1L loss or treatment with the clinical stage inhibitor EPZ-5676 sensitizes tumors to ICB with increased immune infiltration in mice. More importantly, EPZ-5676 treatment alone is sufficient to enhance antitumor immunity in humanized mice. TCGA data analysis reveals an inverse correlation between DOT1L expression and IFN signatures across multiple cancer types. These findings provide a rationale for targeting DOT1L to improve tumor immunogenicity and overcome immunotherapy resistance. One Sentence SummaryCRISPR genetic screens identified DOT1L as a potential suppressor of tumor intrinsic immunogenicity

cell biology↗

Afadin mediates cadherin-catenin complex clustering on F-actin linked to cooperative binding and filament curvature

The E-cadherin-{beta}-catenin-E-catenin (cadherin-catenin) complex couples the cytoskeletons of neighboring cells at adherens junctions (AJs) to mediate force transmission across epithelia. Mechanical force and auxiliary binding partners converge to stabilize the cadherin-catenin complexs inherently weak binding to actin filaments (F-actin) through unclear mechanisms. Here we show that afadins coiled-coil (CC) domain and vinculin synergistically enhance the cadherin-catenin complexs F-actin engagement. The cryo-EM structure of an E-cadherin-{beta}-catenin-E-catenin-vinculin-afadin-CC supra-complex bound to F-actin reveals that afadin-CC bridges adjacent E-catenin actin-binding domains along the filament, stabilizing flexible E-catenin segments implicated in mechanical regulation. These cooperative binding contacts promote the formation of supra-complex clusters along F-actin. Additionally, cryo-EM variability analysis links supra-complex binding along individual F-actin strands to nanoscale filament curvature, a deformation mode associated with cytoskeletal forces. Collectively, this work elucidates a mechanistic framework by which vinculin and afadin tune cadherin-catenin complex-cytoskeleton coupling to support AJ function across varying mechanical regimes.

biophysics↗

mRNA expression is co-regulated by non-nucleolar RNA polymerase I

The relationship between gene transcription and chromatin organization is an area of active study. Due to its role in mRNA synthesis, many studies have focused on the regulaton of RNA polymerase II (Pol-II) function by supranucleosomal structure and vice-versa. In contrast, there is little work on the function of RNA polymerase I (Pol-I) in non-nucleolar chromatin. Prior work has shown that Pol-I engages with components of Pol-II on rDNA, but its role in global transcription and chromatin structure beyond the nucleolus has largely been ignored. By pairing auxin-inducible degron technology with nanoscopic imaging, RNA-Seq, and Hi-C, we found that Pol-I and Pol-II co-regulate conformationally defined chromatin domains and mRNA synthesis. Mechanistically, Pol-I maintains the positioning of intronic and intergenic chromatin within domains for the proper expression of exon elements. Consequently, Pol-I loss disrupts genome connectivity, in situ chromatin domains, and the expression of mRNA, genome-wide.

genomics↗

Three-color single-molecule localization microscopy in chromatin

Super-resolution microscopy has revolutionized our ability to visualize structures below the diffraction limit of conventional optical microscopy and is particularly useful for investigating complex biological targets like chromatin. Chromatin exhibits a hierarchical organization with structural compartments and domains at different length scales, from nanometers to micrometers. Single molecule localization microscopy (SMLM) methods, such as STORM, are essential for studying chromatin at the supra-nucleosome level due to their ability to target epigenetic marks that determine chromatin organization. Multi-label imaging of chromatin is necessary to unpack its structural complexity. However, these efforts are challenged by the high-density nuclear environment, which can affect antibody binding affinities, diffusivity and non-specific interactions. Optimizing buffer conditions, fluorophore stability, and antibody specificity is crucial for achieving effective antibody conjugates. Here, we demonstrate a sequential immunolabeling protocol that reliably enables three-label studies within the dense nuclear environment. This protocol couples multiplexed localization datasets with a robust analysis algorithm, which utilizes localizations from one target as seed points for distance, density and multi-label joint affinity measurements to explore complex organization of all three targets. Applying this multiplexed algorithm to analyze distance and joint density reveals that heterochromatin and euchromatin are not-distinct territories, but that localization of transcription and euchromatin couple with the periphery of heterochromatic clusters. This work is a crucial step in molecular imaging of the dense nuclear environment as multi-label capacity enables for investigation of complex multi-component systems like chromatin with enhanced accuracy.

bioengineering↗

Curved light sheet microscopy for centimeter-scale cleared tissues imaging

Imaging large cleared tissues requires scaling the throughput of imaging techniques. Here we introduce curved light sheet microscope to perform optical sectioning with curved light sheets. This concept addresses the long-standing field curvature problem and lowers the barriers in designing high-throughput objectives. Leveraging a customized objective, the curved light sheet microscope achieves diffraction-limited resolution (1.0 m laterally and 2.5 m axially) and uniform contrast over a field of view of more than 1 x 1 cm2 and is compatible with various tissue clearing techniques. Imaging an entire intact cleared mouse brain at 0.625 x 0.625 x 1.25 m3 voxel size takes less than 3 hours and image tiling is not required. We share full optics description of the objective and report imaging neuronal and vascular networks and tracing brain-wide long-distance axonal projections in intact mouse brains.

bioengineering↗

A drought stress-responsive metabolite malate modulates stomatal responses through G-protein-dependent pathway

Drought stress is a significant environmental threat to global agricultural production and distribution. Plant adaptation to dehydration stress involves intricate biological processes with substantial changes in metabolite composition. In this study, we investigated the role of tricarboxylic acid (TCA) cycle metabolites in drought tolerance in grapevine and Arabidopsis by metabolome, live cell imaging, electrophysiological and pharmacological approaches. Metabolome analysis revealed that amount of malate, citrate, and isocitrate increased over time in detached grapevine leaves. Ca2+ imaging and ion channel measurements indicated that fumarate, malate, and -ketoglutarate induced cytosolic free Ca2+ concentration ([Ca2+]cyt) elevation in guard cells and directly activated a guard-cell anion channel SLAC1. However, only malate induced stomatal closure, which required increases in [Ca2+]cyt in guard cells and activation of SLAC1. Through pharmacological experiments and reverse genetics analyses, G-proteins were identified as essential components of malate signaling by regulating second messenger production. These results indicate that TCA cycle metabolites are sensed individually by guard cells and that malate plays a key role in connecting metabolic regulation and drought tolerance through G-protein-dependent signal cascades.

plant biology↗

Nuclear blebs are associated with destabilized chromatin packing domains

Disrupted nuclear shape is associated with multiple pathological processes including premature aging disorders, cancer-relevant chromosomal rearrangements, and DNA damage. Nuclear blebs (i.e., herniations of the nuclear envelope) have been induced by (1) nuclear compression, (2) nuclear migration (e.g., cancer metastasis), (3) actin contraction, (4) lamin mutation or depletion, and (5) heterochromatin enzyme inhibition. Recent work has shown that chromatin transformation is a hallmark of bleb formation, but the transformation of higher-order structures in blebs is not well understood. As higher-order chromatin has been shown to assemble into nanoscopic packing domains, we investigated if (1) packing domain organization is altered within nuclear blebs and (2) if alteration in packing domain structure contributed to bleb formation. Using Dual-Partial Wave Spectroscopic microscopy, we show that chromatin packing domains within blebs are transformed both by B-type lamin depletion and the inhibition of heterochromatin enzymes compared to the nuclear body. Pairing these results with single-molecule localization microscopy of constitutive heterochromatin, we show fragmentation of nanoscopic heterochromatin domains within bleb domains. Overall, these findings indicate that translocation into blebs results in a fragmented higher-order chromatin structure. SUMMARY STATEMENTNuclear blebs are linked to various pathologies, including cancer and premature aging disorders. We investigate alterations in higher-order chromatin structure within blebs, revealing fragmentation of nanoscopic heterochromatin domains.

bioengineering↗

Fascin structural plasticity mediates flexible actin bundle construction

Fascin crosslinks actin filaments (F-actin) into bundles that support tubular membrane protrusions including filopodia and stereocilia. Fascin dysregulation drives aberrant cell migration during metastasis, and fascin inhibitors are under development as cancer therapeutics. Here, we use cryo-electron microscopy, cryo-electron tomography coupled with custom denoising, and computational modeling to probe fascins F-actin crosslinking mechanisms across spatial scales. Our fascin crossbridge structure reveals an asymmetric F-actin binding conformation that is allosterically blocked by the inhibitor G2. Reconstructions of seven-filament hexagonal bundle elements, variability analysis, and simulations show how structural plasticity enables fascin to bridge varied inter-filament orientations, accommodating mismatches between F-actins helical symmetry and bundle hexagonal packing. Tomography of many-filament bundles and modeling uncovers geometric rules underlying emergent fascin binding patterns, as well as the accumulation of unfavorable crosslinks that limit bundle size. Collectively, this work shows how fascin harnesses fine-tuned nanoscale structural dynamics to build and regulate micron-scale F-actin bundles.

biophysics↗