Biology subjects

Hu, Y.

Publications and source records attributed to Hu, Y..

At least 199 records · Page 11Linked to original sources

bioRxiv2025

Title: Cell-autonomous and non-cell-autonomous effects of TRIM72 on ALS disease progression

Dysfunction of RNA-binding proteins, including TDP-43 and FUS, has been associated with amyotrophic lateral sclerosis (ALS); however, the underlying mechanisms are largely unknown. Here, we reported that a neuronal upregulation of TRIM72 (Tripartite Motif Containing 72) in FUS mutation knockin ALS models slows disease progression. TRIM72 interacts with Commander, a protein complex for recycling of membrane proteins, facilitating membrane repair and antioxidation. Exosomal TRIM72 is detected in ALS patient cerebrospinal fluid (CSF) and extracellular application of exosomal TRIM72 protects cell from membrane damage. In a sporadic ALS cohort, CSF TRIM72 level associates ALS disease progression. AAV-mediated neuronal expression of TRIM72 slows down the disease progressions in ALS models and in an ALS patient without adverse effects over a year treatment course. Taken together, our results suggest a universal neuronal protection of a TRIM family protein in cell-autonomous and non-cell-autonomous manners in ALS.

neuroscience↗

bioRxiv2025

Cell-death induced immune response and coagulopathy promote cachexia in Drosophila

Tumors can exert a far-reaching influence on the body, triggering systemic responses that contribute to debilitating conditions like cancer cachexia. To characterize the mechanisms underlying tumor-host interactions, we utilized a BioID-based proximity labeling method to identify proteins secreted by Ykiact adult Drosophila gut tumors into the bloodstream/hemolymph. Among the major proteins identified are coagulation and immune-responsive factors that contribute to the systemic wasting phenotypes associated with Ykiact tumors. The effect of innate immunity factors is mediated by NF{kappa}B transcription factors Relish, dorsal, and Dif, which in turn upregulate the expression of the cachectic factors Pvf1, Impl2, and Upd3. In addition, Ykiact tumors secrete Eiger, a TNF-alpha homolog, which activates the JNK signaling pathway in neighboring non-tumor cells, leading to cell death. The release of damage-associated molecular patterns (DAMPs) from these dying cells presumably amplifies the inflammatory response, exacerbating systemic wasting. Targeting the inflammatory response, the JNK pathway, or the production of cachectic factors could potentially alleviate the debilitating effects of cancer cachexia.

genetics↗

bioRxiv2024

The 1001G+ project: A curated collection of Arabidopsis thaliana long-read genome assemblies to advance plant research

Arabidopsis thaliana was the first plant for which a high-quality genome sequence became available. The publication of the first reference genome sequence almost 25 years ago was already accompanied by genome-wide data on sequence polymorphisms in another accession, or naturally occurring strain. Since then, inventories of genome-wide diversity have been generated at increasingly precise levels. High-density genotype data for A. thaliana, including those from the 1001 Genomes Project, were key to demonstrating the enormous power of GWAS in inbred populations of wild plants, and the comparison of intraspecific polymorphism with interspecific divergence has illuminated many aspects of plant genome evolution. Over the past decade, an increasing number of nearly complete genome sequences have been published for many more accessions. Here, we highlight the diversity of a curated collection of previously published and so far unpublished genome sequences assembled using different types of long reads, including PacBio Continuous Long Reads (CLR), PacBio High Fidelity (HiFi) reads, and Oxford Nanopore Technologies (ONT) reads. This 1001 Genomes Plus (1001G+) resource is being made available at http://1001genomes.org. We invite colleagues with yet unpublished genome assemblies from A. thaliana accessions to contribute to this effort.

genomics↗

bioRxiv2024

Afadin Sorts Different Retinal Neuron Types into Accurate Cellular Layers

Neurons use cell-adhesion molecules (CAMs) to interact with other neurons and the extracellular environment: the combination of CAMs specifies migration patterns, neuronal morphologies, and synaptic connections across diverse neuron types. Yet little is known regarding the intracellular signaling cascade mediating the CAM recognitions at the cell surface across different neuron types. In this study, we investigated the neural developmental role of Afadin1-4, a cytosolic adapter protein that connects multiple CAM families to intracellular F-actin. We introduced the conditional Afadin mutant5 to an embryonic retinal Cre, Six3-Cre6-8. We reported that the mutants lead to the scrambled retinal neuron distribution, including Bipolar Cells (BCs), Amacrine Cells (ACs), and retinal ganglion cells (RGCs), across three cellular layers of the retina. This scrambled pattern was first reported here at neuron-type resolution. Importantly, the mutants do not display deficits for BCs, ACs, or RGCs in terms of neural fate specifications or survival. Additionally, the displayed RGC types still maintain synaptic partners with putative AC types, indicating that other molecular determinants instruct synaptic choices independent of Afadin. Lastly, there is a significant decline in visual function and mis-targeting of RGC axons to incorrect zones of the superior colliculus, one of the major retinorecipient areas. Collectively, our study uncovers a unique cellular role of Afadin in sorting retinal neuron types into proper cellular layers as the structural basis for orderly visual processing.

neuroscience↗

bioRxiv2024

CESA: Cross-species Epitope Sequence Analysis for discovery of existing antibodies useful for phospho-specific protein detection in model species

Signaling pathways play key roles in many important biological processes such as cell division, differentiation, and migration. Phosphorylation site-specific antibodies specifically target proteins phosphorylated on a given tyrosine, threonine, or serine residue. Use of phospho-specific antibodies facilitates analysis of signaling pathway regulation and activity. Given the usefulness of phospho-specific antibodies, a number of collections of these antibodies have been generated, typically for detection of phosphorylated mammalian proteins. Anecdotal evidence shows that some of these are also useful for detection of phosphorylated forms of orthologous proteins in model organisms. We propose that anti-phospho-mammalian protein antibody collections comprise an untapped resource for research in other species. To systematically analyze the potential utility of anti-phospho-mammalian protein antibodies in other species, we developed the Cross-species Epitope Sequence Analysis software tool (CESA). CESA identifies and aligns orthologous proteins in model species, then analyzes conservation of antibody target sites. We used CESA to predict what phospho-specific antibodies in a collection from Cell Signaling Technology (CST) might be useful for studies in Drosophila melanogaster and other species. CESA predicts that more than 232 sites on 116 Drosophila proteins can potentially be targeted by the antibodies initially developed at CST to detect human, mouse, or rat phosphoproteins.

bioinformatics↗

bioRxiv2024

CellMemory: Hierarchical Interpretation of Out-of-Distribution Cells Using Bottlenecked Transformer

Identifying the genetic and molecular drivers of phenotypic heterogeneity among individuals is vital for understanding human health and for diagnosing, monitoring, and treating diseases. To this end, international consortia such as the Human Cell Atlas and the Tabula Sapiens are creating comprehensive cellular references. Due to the massive volume of data generated, machine learning methods, especially transformer architectures, have been widely employed in related studies. However, applying machine learning to cellular data presents several challenges. One such challenge is making the methods interpretable with respect to both the input cellular information and its context. Another less explored challenge is the accurate representation of cells outside existing references, referred to as out-of-distribution (OOD) cells. The out-of-distribution could be attributed to various physiological conditions, such as comparing diseased cells, particularly tumor cells, with healthy reference data, or significant technical variations, such as using transfer learning from single-cell reference to spatial query data. Inspired by the global workspace theory in cognitive neuroscience, we introduce CellMemory, a bottlenecked Transformer with improved generalization capabilities designed for the hierarchical interpretation of OOD cells unseen during reference building. Even without pre-training, it exceeds the performance of large language models pre-trained with tens of millions of cells. In particular, when deciphering spatially resolved single-cell transcriptomics data, CellMemory demonstrates the ability to interpret data at the granule level accurately. Finally, we harness CellMemorys robust representational capabilities to elucidate malignant cells and their founder cells in different patients, providing reliable characterizations of the cellular changes caused by the disease.

bioinformatics↗

bioRxiv2024

Coupling CRISPR Scanning with Targeted Chromatin Accessibility Profiling using a Double-Stranded DNA Deaminase

Genome editing enables sequence-function profiling of endogenous cis-regulatory elements, driving understanding of their mechanisms and the development of gene therapies. However, these approaches cannot be combined with direct scalable readouts of chromatin structure and accessibility across long single-molecule chromatin fibers. Here we leverage a double-stranded DNA cytosine deaminase to profile chromatin accessibility at high depth and resolution at endogenous loci of interest through targeted PCR and long-read sequencing, a method we term targeted deaminase-accessible chromatin sequencing (TDAC-seq). Powered by high sequence coverage at targeted loci of interest, TDAC-seq can be uniquely integrated with CRISPR perturbations to enable the functional dissection of cis-regulatory elements, where genetic perturbations and their effects on chromatin accessibility are superimposed on the same single chromatin fiber and resolved at single-nucleotide resolution. We employed TDAC-seq to parse CRISPR edits that activate fetal hemoglobin in human CD34+ hematopoietic stem and progenitor cells during erythroid differentiation as well as in pooled CRISPR and base editing screens tiling an enhancer controlling the globin locus. Together, TDAC-seq enables high-resolution sequence-function mapping of single-molecule chromatin fibers by genome editing.

molecular biology↗

bioRxiv2024

Sub-clustering, marker identification and multi-omics integration influenced by protoplasting in plant scRNA -seq data analysis

Single-cell RNA sequencing (scRNA-seq) technology is a powerful tool for exploring cell heterogeneity and lineage dynamics, revealing complex mechanisms driving tissue function and development. However, plant cells rigid cell walls require a protoplasing step, an enzymatic process that can introduce biases. The impact of protoplasting on plant scRNA-seq data remains poorly understood. In this study, we analyzed gene expression patterns from bulk RNA-seq of various plant tissues before and after protoplasting. Cell-type specific protoplasting effects were discovered in different plant tissues. Protoplasting-related biases were found to distort clustering, marker gene identification, and multi-omics integration. By calculating protoplasted scores based on gene expression, we identified and mitigated protoplasting effects, enabling the accurate clustering and annotation of tobacco BY-2 cells and identification of cell-cycle-related genes. Our findings underscore the importance of assessing and correcting for protoplasting biases in plant scRNA-seq data analysis, offering new insights for more accurate data interpretation and biological discovery.

bioinformatics↗

bioRxiv2024

Mechanistic Insights into Dengue Virus Inhibition by a Clinical Trial Compound NITD-688

Dengue, caused by the dengue virus (DENV), presents a significant public health challenge with limited effective treatments. NITD-688 is a potent pan-serotype DENV inhibitor currently in Phase II clinical trials. However, its mechanism of action is not fully understood. Here, we present the molecular details of how NITD-688 inhibits DENV. NITD-688 binds directly to the nonstructural protein 4B (NS4B) with nanomolar affinities across all four DENV serotypes and specifically disrupts the interaction between NS4B and nonstructural protein 3 (NS3) without significantly changing the interactions between NS4B and other viral or host proteins. NS4B mutations that confer resistance to NITD-688 reduce both NITD-688 binding to NS4B and disruption of the NS4B/NS3 interaction. Specifically, NITD-688 blocks the interaction of NS3 with a cytosolic loop within NS4B. This inhibits the formation of new NS4B/NS3 complexes and disrupts pre-existing complexes in vitro and DENV-infected cells, ultimately inhibiting viral replication. Consistent with this mechanism, NITD-688 retains greater potency in cellular assays with delayed treatment compared to JNJ-1802, another NS4B inhibitor that has been studied in Phase II clinical trials. Together, these findings provide critical insights into the mechanism of action of NITD-688, facilitating the development of novel flavivirus NS4B inhibitors and informing future clinical interventions against DENV.

microbiology↗

bioRxiv2024

Multimodal single-cell analyses reveal molecular markers of neuronal senescence in human drug-resistant epilepsy

The histopathological neurons in the brain tissue of drug-resistant epilepsy exhibit aberrant cytoarchitecture and imbalanced synaptic circuit function. However, the gene expression changes of these neurons remain unknown, making it difficult for the diagnosis or to dissect the mechanism of drug-resistant epilepsy. By integrating whole-cell patch clamp recording and single-cell RNA sequencing approaches, we identified a transcriptionally distinct subset of cortical pyramidal neurons. These neurons highly expressed genes CDKN1A (P21), CCL2 and NFKBIA that associated with mTOR pathway, inflammatory response and cellular senescence. We confirmed the expression of senescent marker genes in a subpopulation of cortical pyramidal neurons with enlarged soma size in the brain tissue of drug-resistant epilepsy. We further revealed the expression of senescent cell markers P21, P53, COX2, {gamma}-H2AX, {beta}-Gal and reduction of nuclear integrity marker Lamin B1 in histopathological neurons in the brain tissue of drug-resistant epilepsy patients with different pathologies, but not in control brain tissue with no history of epilepsy. Additionally, chronic, but not acute, epileptic seizures induced senescent markers expression in cortical neurons in mouse models of drug-resistant epilepsy. These results provide important molecular markers for histopathological neurons and new insights into the pathophysiological mechanisms of drug-resistant epilepsy.

neuroscience↗

bioRxiv2024

Evolution of Salmonella Chromosomes and Its Influence on Gene Expression and Chromosomal Conformation

Salmonella is one of the most important bacterial pathogens in the world, causing an estimated 120 million infections each year. There is considerable diversity, with [~]2,600 serovars, but it remains unclear how the genomes have evolved as the species and subspecies of Salmonella differentiate. Here, we have reconstructed the ancient orthologous chromosomes of each major Salmonella lineage and traced their evolutionary process. In total, 911 rearrangement events were identified, with 64% of events occurring in a locus-specific way. Using RNA sequencing and multi-strain association analysis, we demonstrate that genetic rearrangements have a significant effect on gene expression across Salmonella lineages. Moreover, we perform chromosome conformation capture (3C) sequencing analysis, which demonstrates large variations for the organization of ter chromosomal interaction domains among Salmonella lineages. In conclusion, our work delineates the evolutionary trajectory of Salmonella chromosomes, and demonstrates the influence of rearrangements on gene expression profiles and chromosomal conformation. ImportanceThis study reconstructed the ancient orthologous chromosomes of the Salmonella genus, species and well-recognized subspecies, by which the trajectory of gene flow caused by genetic rearrangements was delineated chronologically. The rearrangements show apparent hotspot distribution property and are enriched with genes important for bacterial fitness. Correlation analysis further disclosed the general influence of the rearrangements on gene expression and the organization and conformation of chromosome interaction domains. The results provide new insights on the evolution of Salmonella chromosomes, especially the genetic rearrangements and their epigenetic consequences.

microbiology↗

bioRxiv2024

Mapping of Multilineage Tumor Cell Populations in Mouse Bladder Cancer

In bladder cancer (BLCA), the cellular expression of lineage markers with predictive biomarker function can have important implications for tumor progression, treatment response, and survival. However, tumor heterogeneity and the coexistence of distinct tumor subpopulations can complicate the utility of using a primary, clinically assigned tumor signature. In this report, we have applied the reference atlas, Tabula Sapiens, and deep learning model, UniCell, to conduct in-depth transcriptional analysis of unique lineage marker-defined cell clusters in a carcinogen (BBN) induced bladder cancer model. UniCell deconvolution has identified tumor populations, including urothelial, adenocarcinoma, squamous cell carcinoma, and mesenchymal tumor populations, each with cell-intrinsic gene expression signatures relevant to human BLCA progression. The identified tumor clusters contain uniquely basal, luminal, stromal, or hybrid cells in cell lineage marker expression. To understand the significance of these populations during progression, we used trajectory and pseudo-time analysis to show that cells uniquely basal are plastic in lineage identity and can evolve to form tumor populations composed of other lineage marker-defined signatures. Finally, pathway and drug enrichment analysis of tumor cell clusters were used to identify therapeutics that may preferentially target the identified tumor cell populations. These data collectively define a molecular template that may uniquely profile molecular plasticity occurring during progression and response to therapy with important implications for human disease. SignificanceTumor heterogeneity is a mechanism for treatment resistance. Our study defines unique tumor subpopulations having differential therapeutic sensitivities and potential for lineage plasticity. Our modeling may impact the treatment of BLCA patients.

cancer biology↗

bioRxiv2024

Abnormal eNK cells contribute to endometrial fibrosis in intrauterine adhesions patients

Endometrial natural killer cells (eNK) at the proliferative phase are one of the major lymphocytes in the endometrium, but their phenotype and function remain elucidated. Here, we demonstrated that eNK cells had three subtypes and were different from peripheral blood NK (pbNK) and decidual NK (dNK) cells. They played an important role in maintaining the homeostasis of the endometrium through preventing endometrial stromal cells (ESCs) from the differentiation into myofibroblasts physiologically. However, in the fibrotic endometria of patients with intrauterine adhesions (IUA), eNK cells were significantly decreased and highly negatively correlated with an increase in myofibroblasts. In vitro experiments showed that eNK cells could inhibit the differentiation of ESCs into myofibroblasts and promote the dedifferentiation of myofibroblasts, in which the main effector molecules from eNK cells was Prostaglandin D2 (PGD2). PGD2 downregulated the expression of ZNF521 to decrease profibrotic protein synthesis. Furthermore, we confirmed the anti-endometrial fibrosis effect of eNK cells and its mechanism in an IUA-like murine model. These findings reveal an important role of eNK cells in endometrial homeostasis and provide potential therapeutic approaches for IUA patients.

immunology↗

bioRxiv2024

A CRISPR/SpCas9M-reporting system for efficient and rapid genome editing in Caulobacter crescentus

As members of the -proteobacteria group, Caulobacter crescentus and its relatives are known for their asymmetric life cycle and comprehensive applications in gene delivery, agricultural biotechnology, and the production of high-value compounds. However, genetic manipulations of these bacteria are often time-consuming and labor-intensive due to the lack of efficient genome editing tools. Here, we report a practical CRISPR/SpCas9M-reporting system that overcomes the limitations of SpCas9 expression, enabling efficient, markerless, and rapid genome editing in C. crescentus. As a demonstration, we successfully knocked out two genes encoding the scaffold proteins, achieving apparent editing efficiencies up to 80%. Key components, including the Cas protein, Cas inducer, sgRNA, homologous arms, and reporter, were systematically analyzed and optimized to enhance the editing efficiency or decrease the cell lethality. A nearly zero off-target ratio was observed after the curing of the editor plasmid in editing strains. Furthermore, we applied the CRISPR/SpCas9M-reporting system to two C. crescentus relatives, Agrobacterium fabrum and Sinorhizobium meliloti, establishing it as an efficient and reliable editing strategy. We anticipate that this system could be applied to other hard-to-edit organisms, accelerating both basic and applied research in -proteobacteria.

bioengineering↗

bioRxiv2024

BPMs regulate Arabidopsis seedling development by promoting auxin-independent degradation of the Aux/IAA protein IAA10

After germination, seedlings undergo etiolated development (skotomorphogenesis), enabling them to grow towards the soil surface. In Arabidopsis, etiolated seedlings exhibit rapid hypocotyl elongation, apical hook formation and closed cotyledons to protect the meristem. In this study, we found that high-order mutants in the BPM gene family displayed defects in seedling development, characterized by a shorter hypocotyl, early apical hook opening, and opened cotyledons in the dark. BPM1, BPM2, BPM4, and BPM5 exhibit distinct expression patterns and subcellular localization in etiolated seedlings. In a hypocotyl segment assay the bpm mutants showed defects in auxin response indicating impaired auxin signaling in the hypocotyl. Expression of the auxin reporter DR5:GFP was also altered in the bpm1,4,5 mutant in various tissues compared to the wild type. Furthermore, we showed that BPM1 and IAA10 interact in yeast two-hybrid, BiFC, and Co-IP assays. Experiments in protoplasts indicated that BPM1 promotes ubiquitylation and degradation of IAA10, and the level of IAA10 protein is greater in the bpm1,4,5 mutant. In addition, IAA10 over-expression resulted in phenotypes similar to the bpm mutants. These results indicate that the BPMs target the Aux/IAA proteins for ubiquitylation and degradation. Overall, our findings shed light on the key roles of the BPMs in auxin signaling during seedling development.

plant biology↗

bioRxiv2024

Polarized ATP synthase in synaptic mitochondria induced by learning and plasticity signals

MINFLUX represents a state-of-the-art single-molecule localization microscopy technology that surpasses the conventional diffraction limit, enabling the visualization and analysis of nanostructures with exceptional precision. Despite its potential, the utilization of MINFLUX has been primarily confined to in vitro cultured cell environments. In this research, we have refined the sample preparation protocols to facilitate 3D MINFLUX imaging in fixed brain tissue sections, focusing on the mitochondrial distribution within dendritic spines and engram cells of the dentate gyrus. Probing single molecules in vivo reveals an interesting finding: the reorganization of mitochondrial inner membrane proteins during synaptic plasticity within dendritic spines of engram cells. Utilizing 3D MINFLUX nanoscopy, we identified a significant redistribution of -F1-ATP synthase, which correlates with learning related activities. This redistribution implies a pivotal function for polarized ATP synthesis in the vicinity of the postsynaptic zone, which may modulate both short-term and long-term synaptic modifications, thereby influencing synaptic plasticity and memory consolidation. Furthermore, dual-color 3D MINFLUX imaging has uncovered distinct patterns of mitochondrial reorganization involving both the inner and outer membranes within dendritic spines. These patterns, induced by plasticity signals, persist for up to 12 hours in neuronal cultures. This distinction highlights the presence of distinct regulatory mechanisms governing mitochondrial proteins during synaptic plasticity. These results offer new insights into the molecular mechanisms underlying synaptic plasticity and underscore the transformative potential of 3D MINFLUX imaging for studying neuronal processes in the brain.

neuroscience↗

bioRxiv2024

Cross-tissue Graph Attention Networks for Semi-supervised Gene Expression Prediction

High-throughput biotechnologies have significantly advanced precision medicine by enabling the exploitation of global gene expression patterns to enhance our understanding of disease etiology, progression, and treatment options. However, the tissue-specific nature of gene expression presents a challenge, particularly for less accessible tissues such as the brain, underscoring the need for computational methods to accurately impute gene expression in these critical but hard-to-reach tissues. While several attempts to impute gene expression in tissue-specific contexts have shown promising results, their reliance on regression analysis faces limitations due to the inability to capture complex, nonlinear relationships in gene expression patterns. In contrast, modern machine learning techniques, particularly graph neural networks, have demonstrated superior performance by efficiently modeling the intricate interactions among genes across different tissues. Therefore, we introduce gene expression imputation with Graph Attention Networks (gemGAT), a novel approach leveraging Graph Attention Networks (GATs) to enhance gene expression prediction across different tissues. gemGAT distinguishes itself by predicting the expression of all genes simultaneously, utilizing the full spectrum of genomic data to account for gene co-expressions and non-linear relationships. Validated through extensive experiments with Genotype-Tissue Expression (GTEx) data and a case study from the Alzheimers Disease Neuroimaging Initiative (ADNI), gemGAT demonstrates superior performance over existing methods by efficiently capturing non-linear gene co-expressions. This advancement underscores gemGATs potential to significantly contribute to precision medicine, showcasing its utility in advancing our understanding of gene expression in less accessible tissues.

bioinformatics↗

bioRxiv2024

Intestinal stem cells enhance local mucosal immunity through apoptotic body phagocytosis

Modulation of immune tone at mucosal surfaces is critical to maintain homeostasis while facilitating the handling of emerging threats. One dynamic component of immune modulation is the phagocytosis and clearance of apoptotic bodies known as efferocytosis that inhibits inflammation by promoting its resolution. Here, we evaluated the effects of apoptotic body phagocytosis by intestinal epithelial stem and progenitor cells (ISCs). Unexpectedly, instead of immunomodulation through efferocytosis, this process elevated local immune system activity. To achieve this result, ISCs actively engaged apoptotic bodies in a unique fashion, leading to their engulfment and ultimate delivery to lysosomes for processing. We found that ISCs were capable of actively recruiting inert material such as apoptotic bodies by using actin-based intrinsic biomechanical processes. Uptake of apoptotic bodies was facilitated by complement factor C3 produced by apoptotic bodies themselves. ISCs in turn generated signals heightening T cell activity that was driven in part by ISC-generated TNF. Taken together, uptake of apoptotic bodies by ISCs produced a local inflammatory alert to specific immune cells. This altered paradigm for the response to phagocytosed apoptotic bodies fits the needs of active mucosal surfaces and demonstrates that efferocytosis as currently defined is not a universal response of all cell types.

cell biology↗