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Biology subjects

Miao, Q.

Publications and source records attributed to Miao, Q..

15 recordsLinked to original sources

SGFP-Grid Split GFP Graphene Grids

Affinity graphene grids provide a promising approach for selective protein capture in cryo-EM. Here, we introduce a split-GFP graphene grid platform(SGFP-G), in which graphene-conjugated GFP 1-10 selectively captures GFP11 tagged proteins from low concentration samples or cell lysates. This platform enables rapid assessment of target protein enrichment and particle distribution before vitrification via fluorescence imaging, while the grid design positions captured proteins away from the graphene surface and air-water interface. We also introduce a unique strategy to minimize nonspecific protein adsorption, thereby improving the selective enrichment of target proteins on this grid. Using GFP11-tagged apoferritin, we demonstrate fluorescence guided protein capture and obtain a 2.58 [A] cryoEM reconstruction, establishing SGFP-G as an affinity grid platform for high resolution structural studies with reduced sample requirements.

biochemistry↗

NgBR controls hepatic adiponectin signaling competence through KAT7-dependent chromatin regulation

Adiponectin signaling is essential for hepatic glucose homeostasis, yet the molecular basis of adiponectin receptor responsiveness remains incompletely understood. Here, we identify the Nogo-B receptor (NgBR; NUS1) as a regulator of hepatic adiponectin sensitivity. Across human, cynomolgus monkey, and mouse datasets, hepatic NgBR expression is consistently reduced in obesity-associated diabetes, indicating a conserved metabolic signature. Hepatocyte-specific NgBR deletion abolishes the metabolic effects of the adiponectin agonist AdipoRon, resulting in impaired AMPK activation, persistent gluconeogenesis, and ceramide accumulation. Mechanistically, NgBR loss suppresses KAT7 expression and reduces histone acetylation at AdipoR1 and AdipoR2 promoters, thereby limiting receptor expression. Adeno-associated virus (AAV)-mediated restoration of hepatic NgBR reinstates KAT7-dependent chromatin activation, adiponectin receptor expression, and glucose homeostasis. These findings support a hepatocellular mechanism in which NgBR maintains adiponectin receptor competence and suggest a potential therapeutic strategy for restoring adiponectin responsiveness in metabolic disease. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=115 SRC="FIGDIR/small/726643v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@117fa66org.highwire.dtl.DTLVardef@1385297org.highwire.dtl.DTLVardef@b64369org.highwire.dtl.DTLVardef@3dd55_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

Chemoproteomic Characterization of GPX4 Covalent Ligands and Targeted Degradation

Despite intensive efforts, the ferroptosis gatekeeper glutathione peroxidase 4 (GPX4) remains difficult to selectively target due to stringent structural constraints surrounding its catalytic selenocysteine, which impose tight requirements on warhead reactivity and geometry. Here, leveraging a chemoproteomic approach, we characterize a potent and selective covalent GPX4 inhibitor featuring a pyrimidinylmethyl isourea warhead and define the chemical features underlying its proteome-wide selectivity. This chemotype enables tunable electrophile reactivity through steric and electronic modulation of leaving group ability, suggesting potential broader utility for targeting other recalcitrant proteins. Building on this scaffold, we further develop two selective GPX4 degraders - one CRBN-dependent and the other CRBN-independent - enabling complementary modulation of GPX4 through both inhibition and degradation. Together, these molecules expand the GPX4 chemical toolbox for more nuanced interrogation of GPX4 biology.

cancer biology↗

EGR3 Deletion Rescues Developmental and Epileptic Encephalopathy in Kcna1-null Mice

KCNA1 encodes the -subunit of the voltage-gated potassium channel KV1.1. Mutations in KV1.1s pore domain result in developmental and epileptic encephalopathy (DEE), where early life seizures and a culprit lesion synergistically disrupt neurodevelopmental trajectories, resulting in intellectual disability that often presents with disturbances in sleep, sociability and sensory processing. Abnormalities in the subcellular localization of Kv1.1, via mutations in/autoantibodies against LGI1 and CNTNAP2, also give rise to syndromes of epilepsy and neuropsychiatric impairment. Mice with deletions of Kcna1("-/-") display spontaneous seizures at 2-3 weeks of age and premature mortality. In this study, we applied instrumented home-cage monitoring to examine how aberrations in KCNA1 expression may result in pervasive alterations in spontaneous behavior. Compared to wildtype, Kcna1-/- mice displayed a robust multifaceted behavioral syndrome featuring marked nocturnal hyperactivity, insomnia, reduced sheltering, fragmented feeding/drinking rhythms, sensory over-responsivity and diminished wheel-running. In identical recordings, Kcna1+/- mice only displayed increased sheltering, Lgi1+/- mice displayed mild insomnia and Cntnap2-/- mice showed home-cage hypoactivity. Kcna1 loss in parvalbumin-positive interneurons (Pv-Cre) resulted in a subtle phenocopy, with mild insomnia accompanied by reduced sheltering behavior, while similar deletions in forebrain pyramidal neurons (Emx1-Cre) or dopaminergic neurons (DAT-Cre) were asymptomatic. Adult-onset conditional deletions of Kcna1 also produced only mild insomnia 6 weeks later. To survey the molecular landscape in Kcna1-/- mice, we conducted a mass spectrometry proteomic analysis of dissected hippocampal tissue (a predominant seizure onset zone and where astrogliosis is observed). This revealed significant upregulations in BDNF (brain-derived neurotrophic factor) and the immediate early transcription factor EGR3 (early growth response-3), which is necessary for the induction of BDNF following electroconvulsive seizures. Heterozygous or homozygous deletions of Egr3 in Kcna1-/- mice resulted in significant survival prolongation, a partial neurobehavioral rescue, and a significant improvement in the frequency of spontaneous seizures and spreading depolarization events. These clinical improvements were associated with an amelioration of BDNF induction, hippocampal astrogliosis and proteomic disturbances. Together, these data illustrate how an ion channel that governs excitability at millisecond scales also shapes the spatiotemporal structure of spontaneous behavior at meso- or macroscopic time scales. Our results provide a model and a set of precision endpoints to understand how ictal and interictal features of DEE may be ameliorated by inhibiting the long-term downstream transcriptional alterations imparted by early life seizures.

neuroscience↗

Granular component sub-phases direct ribosome biogenesis in the nucleolus

The hierarchical, multiphase organization of the nucleolus underlies ribosome biogenesis. Ribonucleoprotein particles that regulate ribosomal subunit assembly are heterogeneously disposed in the granular component (GC) of the nucleolus. However, the molecular origins of the GCs spatial heterogeneity and its association with ribosomal subunit assembly remain poorly understood. Here, using super-resolution microscopy, we uncover that key GC biomolecules, including nucleophosmin (NPM1), surfeit locus protein 6 (SURF6), and ribosomal RNA (rRNA), are heterogeneously localized within sub-phases in the GC. In vitro reconstitution showed that these GC biomolecules form multiphase condensates with SURF6/rRNA-rich core and NPM1-rich shell, providing a mechanistic basis for GCs spatial heterogeneity. SURF6s association with rRNA is weakened upon ribosome subunit assembly, enabling NPM1 to extract assembled subunits from condensates--suggesting an assembly-line-like mechanism of subunit efflux from the GC. Our results establish a framework for understanding the heterogeneous structure of the GC and reveal how its distinct sub-phases facilitate ribosome subunit assembly.

biochemistry↗

FerroEnrich: An Interactive web tool for computing Ferroptosis index and gene enrichment.

Ferroptosis is an iron-dependent form of controlled cell death and is characterized by the formation of lipid peroxides. Understanding gene expressions associated with ferroptosis is critical for determining its function in illnesses and potential therapeutic approaches. Despite its significance, no computational model is currently available to accurately quantify the ferroptosis incident. FerroEnrich is a sophisticated web-based tool built using R Shiny application to enumerate the occurrence of ferroptosis based on the relevant gene expressions. This tool available at https://ferroenrich.shinyapps.io/ferroenrich/ processes the input gene expression file to identify genes that are resistant or prone to ferroptosis, calculates ferroptosis index value with dynamic colored heatmap and gene network plot. This manuscript describes the design, operation and usability of FerroEnrich, including examples and a discussion of its potential impact on ferroptosis research. FerroEnrich is a vital tool for researchers, allowing them to explore and analyze complicated gene expression data related to ferroptosis.

bioinformatics↗

Overlapping and Distinct Mechanisms of Effective Neoantigen Cancer Vaccines and Immune Checkpoint Therapy

The goal of therapeutic cancer vaccines and immune checkpoint therapy (ICT) is to eliminate cancer by expanding and/or sustaining T cells with anti-tumor capabilities. However, whether cancer vaccines and ICT enhance anti-tumor immunity by distinct or overlapping mechanisms remains unclear. Here, we compared effective therapeutic tumor-specific mutant neoantigen (NeoAg) cancer vaccines with anti-CTLA-4 and/or anti-PD-1 ICT in preclinical models. Both NeoAg vaccines and ICT induce expansion of intratumoral NeoAg-specific CD8 T cells, though the degree of expansion and acquisition of effector activity was much more substantial following NeoAg vaccination. Further, we found that NeoAg vaccines are particularly adept at inducing proliferating and stem-like NeoAg-specific CD8 T cells. Single cell T cell receptor (TCR) sequencing revealed that TCR clonotype expansion and diversity of NeoAg-specific CD8 T cells relates to their phenotype and functional state associated with specific immunotherapies employed. Effective NeoAg vaccines and ICT required both CD8 and CD4 T cells. While NeoAg vaccines and anti-PD-1 affected the CD4 T cell compartment, it was to less of an extent than observed with anti-CTLA-4, which notably induced ICOS+Bhlhe40+ Th1-like CD4 T cells and, when combined with anti-PD-1, a small subset of Th2-like CD4 T cells. Although effective NeoAg vaccines or ICT expanded intratumoral M1-like iNOS+ macrophages, NeoAg vaccines expanded rather than suppressed (as observed with ICT) M2-like CX3CR1+CD206+ macrophages, associated with the vaccine adjuvant. Further, combining NeoAg vaccination with ICT induced superior efficacy compared to either therapy in isolation, highlighting the utility of combining these modalities to eliminate cancer. HighlightsO_LINeoAg cancer vaccines utilize distinct mechanisms from CTLA-4 or PD-1 ICT C_LIO_LINeoAg vaccines induce TCF1+ stem-like and proliferating NeoAg-specific CD8 T cells C_LIO_LICD8 TCR clonotype expansion relates to phenotype and functional state associated with immunotherapy C_LIO_LINeoAg vaccines induce partially distinct macrophage remodeling from ICT C_LIO_LINeoAg vaccines synergize with ICT, exceeding combination CTLA-4/PD-1 ICT efficacy C_LI

immunology↗

The response mechanism of oreorchis patens (Lindl.) Lindl. to cold stress

Cold stress, a major environmental factor, has an important impact on the production of landscape plants and crop yield, and its stress and resistance mechanisms have always been hot research issues. Oreorchis patens (Lindl.) Lindl., an important germplasm resource, has strong frost resistance and can resist low temperatures of -40 {degrees}C. However, the mechanism by which O. patens responds to cold stress remains poorly understood. Here, we examined the adaptation to the low-temperature environment of O. patens by changing the leaf tissue structure, while the synergistic effect of osmotic regulation, reactive oxygen scavenging and protein improved the resistance to cold stress. In addition, analysis of the photosynthetic system showed that cold stress changes the photosynthetic capacity of O. patens leaves to affect cold resistance. Analysis by nonparametric transcriptome sequencing revealed 2402 genes that were differentially expressed, most of which were related to resistance. Simultaneously, quantitative real-time polymerase chain reaction (qRT-PCR) analysis obtained results consistent with the transcriptome. These results indicated that O. patens could alter leaf structure and physiological and biochemical metabolic processes by initiating resistance-related molecular regulatory networks to improve the ability to resist cold stress. This study was the first to discuss the physiological, biochemical and molecular regulatory mechanisms of O. patens resistance to cold stress, which laid a foundation for revealing the biological and molecular mechanisms of overwintering of O. patens and breeding cold-resistant horticultural crops in northern China.

plant biology↗

Single-Cell Manifold Preserving Feature Selection (SCMER)

1AO_SCPLOWBSTRACTC_SCPLOWA key challenge in studying organisms and diseases is to detect rare molecular programs and rare cell populations (RCPs) that drive development, differentiation, and transformation. Molecular features such as genes and proteins defining RCPs are often unknown and difficult to detect from unenriched single-cell data, using conventional dimensionality reduction and clustering-based approaches. Here, we propose a novel unsupervised approach, named SCMER, which performs UMAP style dimensionality reduction via selecting a compact set of molecular features with definitive meanings. We applied SCMER in the context of hematopoiesis, lymphogenesis, tumorigenesis, and drug resistance and response. We found that SCMER can identify non-redundant features that sensitively delineate both common cell lineages and rare cellular states ignored by current approaches. SCMER can be widely used for discovering novel molecular features in a high dimensional dataset, designing targeted, cost-effective assays for clinical applications, and facilitating multi-modality integration.

bioinformatics↗

Generation of glucocorticoid resistant SARS-CoV-2 T-cells for adoptive cell therapy

Adoptive cell therapy with viral-specific T cells has been successfully used to treat life-threatening viral infections, supporting the application of this approach against COVID-19. We expanded SARS-CoV-2 T-cells from the peripheral blood of COVID-19-recovered donors and non-exposed controls using different culture conditions. We observed that the choice of cytokines modulates the expansion, phenotype and hierarchy of antigenic recognition by SARS-CoV-2 T-cells. Culture with IL-2/4/7 but not other cytokine-driven conditions resulted in >1000 fold expansion in SARS-CoV-2 T-cells with a retained phenotype, function and hierarchy of antigenic recognition when compared to baseline (pre-expansion) samples. Expanded CTLs were directed against structural SARS-CoV-2 proteins, including the receptor-binding domain of Spike. SARS-CoV-2 T-cells could not be efficiently expanded from the peripheral blood of non-exposed controls. Since corticosteroids are used for the management of severe COVID-19, we developed an efficient strategy to inactivate the glucocorticoid receptor gene (NR3C1) in SARS-CoV-2 CTLs using CRISPR-Cas9 gene editing.

immunology↗

Optogenetic control of small GTPases reveals RhoA-mediated intracellular calcium signaling

Rho/Ras family small GTPases are known to regulate numerous cellular processes, including cytoskeletal reorganization, cell proliferation, and cell differentiation. These processes are also controlled by Ca2+, and consequently, crosstalk between these signals is considered likely. However, systematic quantitative evaluation is not yet reported. Thus, we constructed optogenetic tools to control the activity of small GTPases (RhoA, Rac1, Cdc42, Ras, Rap, and Ral) using an improved light-inducible dimer system (iLID). Using these optogenetic tools, we investigated calcium mobilization immediately after small GTPase activation. Unexpectedly, we found that a transient intracellular calcium elevation was specifically induced by RhoA activation in RPE1 and HeLa cells. These findings were confirmed in all the cell lines tested in this study. Of note, molecular mechanisms were identified to be different among cell types. In RPE1 and HeLa cells, RhoA activated phospholipase C epsilon (PLC{varepsilon}) at the plasma membrane, which in turn induced Ca2+ release from the endoplasmic reticulum (ER). The RhoA-PLC{varepsilon} axis induced calcium-dependent NFAT nuclear translocation, suggesting it does activate intracellular calcium signaling.

cell biology↗

Ab initio Spillover Compensation in CyTOF Data

Signal intensity measured in a mass cytometry (CyTOF) channel can often be affected by the neighboring channels due to technological limitations. Such signal artifacts are known as spillover effects and can substantially limit the accuracy of cell population clustering. Current approaches reduce these effects by using additional beads for normalization purposes known as single-stained controls. While effective in compensating for spillover effects, incorporating single-stained controls can be costly and require customized panel design. This is especially evident when executing large-scale immune profiling studies. We present a novel statistical method, named CytoSpill that independently quantifies and compensates the spillover effects in CyTOF data without requiring the use of single-stained controls. Our method utilizes knowledge-guided modeling and statistical techniques, such as finite mixture modeling and sequential quadratic programming, to achieve optimal error correction. We evaluated our method using five publicly available CyTOF datasets obtained from human peripheral blood mononuclear cells (PBMCs), C57BL/6J mouse bone marrow, healthy human bone marrow, chronic lymphocytic leukemia patient, and healthy human cord blood samples. In the PBMCs with known ground truth, our method achieved comparable results to experiments that incorporated single-stained controls. In datasets without ground-truth, our method not only reduced spillover on likely affected markers, but also led to the discovery of potentially novel subpopulations expressing functionally meaningful, cluster-specific markers. CytoSpill (developed in R) will greatly enhance the execution of large-scale cellular profiling of tumor immune microenvironment, development of novel immunotherapy, and the discovery of immune-specific biomarkers. The implementation of our method can be found at https://github.com/KChen-lab/CytoSpill.git.

bioinformatics↗

Nucleolin is essential for rabbit hemorrhagic disease virus replication by providing a physical link in replication complex formation

Rabbit hemorrhagic disease virus (RHDV) is an important member of the Caliciviridae family and cannot be propagated in vitro, which has greatly impeded progress of investigating its replication mechanism. Construction of an RHDV replicon system has recently provided a platform for exploring RHDV replication in host cells. Here, aided by this replicon system and using two-step affinity purification, we purified the RHDV replicase and identified its associated host factors. We identified rabbit nucleolin (NCL) as a physical link required for the formation of RHDV replication complexes (RCs), by mediating the interaction between other host proteins and the viral RNA replicase, RNA-dependent RNA polymerase (RdRp). We found that RHDV RdRp uses an amino acid (aa) region spanning residues 448-478 to directly interact with NCLs RNA-recognition motif 2. We also found that the viral p16 protein uses a highly conserved region (35Cys-Ile-Arg-Ala38 or CIRA motif) to specifically bind the N-terminal region of NCL (aa 1-110) and that RHDV p23 uses a specific domain (aa 90-145) to bind NCLs RNA-recognition motif 1. Disrupting these protein-protein interactions severely weakened viral replication. Furthermore, NCL overexpression or knockdown significantly increased or severely impaired, respectively, RHDV replication. Collectively, these results indicate that the host protein NCL is essential for RHDV replication and plays a key role in the formation of RHDV RCs. The mechanisms by which NCL promotes viral replicase assembly reported here shed light on viral RC biogenesis and may inform antiviral therapies. Author summaryRabbit hemorrhagic disease virus (RHDV) is the causative agent of highly contagious and lethal hemorrhagic disease in the European rabbit, but the host factors involved in RHDV replication remain poorly understood. In the present study, we isolated RHDV replication complex (RC) for the first time and identified its main components. We found that nucleolin (NCL) plays a key role in the formation of the RHDV RC. NCL not only interacts with viral replicase (RdRp), it also specifically binds to other important host factors. In addition, we proved that NCL is necessary for RHDV replication because the level of RHDV replication is significantly affected by knocking down the NCL gene in cells. Together, our data suggest that RHDV completes its replication by hijacking NCL to recruit other viral proteins and host factors, thereby assembling the RC of RHDV.

microbiology↗

Inhibition of the av integrin-TGF-b axis improves natural killer cell function against glioblastoma stem cells

Glioblastoma, the most aggressive brain cancer, often recurs because glioblastoma stem cells (GSCs) are resistant to all standard therapies. Here, we show that patient-derived GSCs, but not normal astrocytes, are highly sensitive to lysis by healthy allogeneic natural killer (NK) cells in vitro. In contrast, single cell analysis of autologous, tissue infiltrating NK cells isolated from surgical samples of high-grade glioblastoma patient tumors using mass cytometry and single cell RNA sequencing revealed an abnormal phenotype associated with impaired lytic function compared with peripheral blood NK cells from GBM patients or healthy donors. This immunosuppression was attributed to an integrin-TGF-{beta} mechanism, activated by direct cell-cell contact between GSCs and NK cells. Treatment of GSC-engrafted mice with allogeneic NK cells in combination with inhibitors of integrin or TGF-{beta} signaling, or with TGF-{beta} receptor 2 gene-edited NK cells prevented GSC-induced NK cell dysfunction and tumor growth. Collectively, our findings reveal a novel mechanism of NK cell immune evasion by GSCs and implicate the integrin-TGF-{beta} axis as a useful therapeutic target to eliminate GSCs in this devastating tumor.

immunology↗

Correlation between the epigenetic modification of histone H3K9 acetylation of NR2B gene promoter in rat hippocampus and ethanol withdrawal syndrome

Our results showed that, in rat hippocampus, the ethanol withdrawal syndrome score was increased at 2 h, peaked at 6 h after withdrawal of ethanol, and reduced to the level parallel to the normal control group at day 3 after ethanol withdrawal. The NR2B mRNA expression and protein levels of rat hippocampus region showed similar patterns. Further correlation analyses indicted that both histone H3K9 acetylation in NR2B gene promoter and the expression levels of NR2B were positively associated with ethanol withdrawal syndrome. Chronic ethanol exposure may result in epigenetic modification of histone H3K9 acetylation in NR2B gene promoter in rat hippocampus, and the expression levels of NR2B were found to be positively correlated with EWS.\n\nAbstractPrevious studies showed that an epigenetic modification of N-methyl-D-aspartate (NMDA) receptor, especially NMDA receptor 2B subunit (NR2B), was involved in the pathological process of ethanol withdrawal syndrome (EWS). However, the relationship between the epigenetic regulation of the NR2B gene in the rat hippocampus region and EWS were inconsistent. A rat model of chronic ethanol exposure was established. EWS score and the behavioral changes were recorded at different points in time. The NR2B expression levels and the histone H3K9 acetylation level in the NR2B gene promoter region were measured using qRT-PCR, Western blot, immunofluorescence and chromatin immunoprecipitation, respectively. Finally, the relationships between the epigenetic modification of histone H3K9 acetylation of NR2B gene promoter and EWS were examined. Our results showed that the EWS score was increased at 2 h, peaked at 6 h after withdrawal of ethanol, and reduced to the level parallel to the normal control group at day 3 after ethanol withdrawal. The NR2B mRNA expression and protein levels showed similar patterns. Further correlation analyses indicted that both histone H3K9 acetylation in NR2B gene promoter and the expression levels of NR2B were positively associated with EWS. Chronic ethanol exposure may result in epigenetic modification of histone H3K9 acetylation in NR2B gene promoter in rat hippocampus, and the expression levels of NR2B were found to be positively correlated with EWS.

neuroscience↗