Biology subjects

Wu, X.

Publications and source records attributed to Wu, X..

At least 271 records · Page 15Linked to original sources

bioRxiv2024

Macrophage WDFY3, a protector against autoimmunity

Efficient efferocytosis is essential for maintaining homeostasis. Excessive apoptotic cell (AC) death and impaired macrophage efferocytosis lead to autoantigen release and autoantibody production, immune activation, and organ damage. It remains unclear whether these immunogenic autoantigens are the sole cause of increased autoimmunity or if efferocytosis of ACs directly influences macrophage function, impacting their ability to activate T cells and potentially amplifying autoimmune responses. Additionally, it has not been established if enhancing macrophage efferocytosis or modulating macrophage responses to AC engulfment can be protective in autoimmune-like disorders. Our previous work showed WDFY3 is crucial for efficient macrophage efferocytosis. This study reveals that myeloid knockout of Wdfy3 exacerbates autoimmunity in young mice with increased AC burden by systemic injections of ACs and in middle-aged mice developing spontaneous autoimmunity, whereas ectopic overexpression of WDFY3 suppresses autoimmunity in these models. Macrophages, as efferocytes, can activate T cells and the inflammasome upon engulfing ACs, which are suppressed by overexpressing WDFY3. This work uncovered the role of WDFY3 as a protector against autoimmunity by promoting macrophage efferocytosis thus limiting autoantigen production, as well as mitigating T cell activation and inflammasome activation.

immunology↗

bioRxiv2024

Celastrol binds to pyruvate kinase and imitates the metabolic reprogramming of ATP

ATP is the final product of glycolysis and the TCA cycle. However, the counter-regulation of glycosis and TCA by ATP is poorly understood. Here we show that ATP analog celastrol (CLT) binds to the ATP binding pocket on pyruvate kinase PKM (PKM) while inducing allosteric regulation of PKM. Quantum calculation predicts hydrogen bond formation between CLT and asparagine. Liquid chromatography-mass spectrometry further identifies PKM as CLTs target. The inhibition of PKM is stronger and longer for CLT while weak and short for ATP. Notably, CLT-PKM interaction perfectly underlies the hypoglycemic effects by forming glucose carbon flux U turn before PKM. Besides, the PKM allostery induces a tricarboxylic acid (TCA) vortex which could promote amino acid and lipid degradation as the energy compensation, leading to a significant weight loss. Additionally, CLT exerts efficient antioxidant effects by altering the glucose flux to strengthen the pentose phosphate pathway. Consequently, the CLT-PKM interaction vividly reproduces the ATP-PKM interaction named "ATP resistance" in the diabetes pathogenesis.

pharmacology and toxicology↗

bioRxiv2024

Pertpy: an end-to-end framework for perturbation analysis

Advances in single-cell technology have enabled the measurement of cell-resolved molecular states across a variety of cell lines and tissues under a plethora of genetic, chemical, environmental, or disease perturbations. Current methods focus on differential comparison or are specific to a particular task in a multi-condition setting with purely statistical perspectives. The quickly growing number, size, and complexity of such studies requires a scalable analysis framework that takes existing biological context into account. Here, we present pertpy, a Python-based modular framework for the analysis of large-scale perturbation single-cell experiments. Pertpy provides access to harmonized perturbation datasets and metadata databases along with numerous fast and user-friendly implementations of both established and novel methods such as automatic metadata annotation or perturbation distances to efficiently analyze perturbation data. As part of the scverse ecosystem, pertpy interoperates with existing libraries for the analysis of single-cell data and is designed to be easily extended.

bioinformatics↗

bioRxiv2024

A Small Interfering Peptide Potentiates AMPA Receptor Diffusional Trapping and Prevents Social-Isolation-Induced Forgetting of Fear Memory

Synaptic trapping of AMPA receptors (AMPARs) is a key mechanism regulating excitatory synaptic transmission and activity-dependent plasticity underlying learning and memory. Destabilization of synaptic AMPARs is increasingly implicated in cognitive dysfunction across neurological and neuropsychiatric disorders, yet strategies to directly modulate this process in vivo remain limited, constraining both mechanistic insight and therapeutic development. Here we present a peptide-based strategy to enhance AMPAR synaptic trapping by targeting the interaction between transmembrane AMPA receptor regulatory proteins (TARPs) and activity-regulated cytoskeleton-associated protein (ARC/Arg3.1). We designed a 21-amino-acid TAT-fused peptide (TARP-pep) mimicking the TARP C-terminal motif that binds the ARC N-lobe. TARP-pep disrupted the TARP-ARC interaction and increased the stabilization of AMPARs at synaptic surfaces in cultured hippocampal neurons. In vivo, acute intrahippocampal infusion of TARP-pep enhanced perforant path-evoked synaptic transmission in the rat dentate gyrus (DG) and strengthened the interaction between TARPs and postsynaptic density protein 95 (PSD-95), a key mechanism underlying AMPAR anchoring. Consistent with a long-term potentiation (LTP)-like synaptic state, TARP-pep increased basal phosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) and occluded further chemical LTP (cLTP)-induced increases in phosphorylated CaMKII (p-CaMKII). Notably, a 7-day regimen of daily bilateral DG injections of TARP-pep prevented social isolation (SI)-induced impairment of fear memory in mice. Together, these findings identify the TARP-ARC interaction as a druggable regulator of AMPAR diffusional trapping and highlight synaptic AMPAR stabilization as a promising therapeutic strategy for preserving cognitive function under conditions of circuit vulnerability.

neuroscience↗

bioRxiv2024

Uncovering Individualized Cerebellar Atrophy Pattern and Behavioral Links in Children with Brainstem Tumor

Background and PurposeBrainstem tumors are rare but cause enduring behavioral issues, challenging patients and surgeons. Research on cerebellar changes in these patients limited, despite symptoms similar to cerebellar injuries. This study aims to investigate cerebellar damage pattern resulting from brainstem tumors and its association with behavioral disorders. MethodsIn this study, a U-Net-based segmentation algorithm was used to divide the cerebellum into 26 lobules, which were then used to build a normative model for assessing individual structural deviations. Furthermore, a behavior prediction model was developed using the total outlier count (tOC) index and brain volume as predictive features. ResultsMost patients were found to have negative deviations in cerebellar regions, particularly in anterior lobules like Left V. Higher tOC was significantly associated with severe social problems (r = 0.31, p = 0.001) and withdrawal behavior (r = 0.28, p = 0.001). Smaller size of cerebellar regions strongly correlated with more pronounced social problems (r = 0.27, p = 0.007) and withdrawal behavior (r = 0.25, p = 0.015). Notably, lobules Right X, V, IV, VIIB, Left IX, VIII, and X influenced social problems, while Left V, Right IV, Vermis VI, and VIII impacted withdrawal behavior. ConclusionsOur study revealed cerebellar damage patterns in patients with brainstem tumors, emphasizing the role of both anterior and posterior cerebellar lobes in social problems and withdrawal behavior. This research sheds light on the brain mechanisms underlying complex behavioral disorders in brainstem tumor patients.

neuroscience↗

bioRxiv2024

Nuclear FAK aggravates CD8+ T cell exhaustion via the SP1-IL-6 axis in colorectal cancer

Nuclear abnormalities such as nuclear deformation are hallmarks of many diseases, including cancer. Accumulating evidence suggests that the dense and mechanically stiff tumor microenvironment promotes nuclear deformation in cancer cells. However, little is known about how nuclear deformation in neoplastic cells regulates immune exhaustion in the tumor microenvironment. Here, we found that lamin A/C-mediated nuclear stiffening in neoplastic cells promotes the nuclear translocation of phosphorylated focal adhesion kinase (pFAK), which is strongly correlated with the heterogeneity and exhaustion of CD8+ T cells within the spatial context of the tumor microenvironment in human colorectal cancer. Mechanistically, we revealed that increased nuclear tension within tumor cells promotes pFAK nuclear translocation, where nuclear pFAK was found to regulate SP1/IL-6-mediated T-cell exhaustion and the transcription of proinflammatory cytokines/chemokines. Pharmacological inhibition or disruption of pFAK nuclear translocation enhanced antitumor immune responses and synergistically potentiated PD-1 and TIM-3 immunotherapy by increasing CD8+ T-cell cytotoxicity and restoring exhaustion in preclinical models of colorectal cancer. These findings highlight the pivotal role of nuclear tension-mediated pFAK translocation into the tumor cell nucleus in regulating CD8+ T-cell exhaustion, suggesting that pFAK is a promising target for advancing cancer immunotherapy.

immunology↗

bioRxiv2024

A new alignment-free method: Subsequence Correlation Coefficient Vector(SCCFV) for influenza A comparison using virus genomes

Withdrawal StatementThe authors have withdrawn their manuscript because I discovered some important missing data that is crucial for supporting my viewpoint and research findings. Although I tried to supplement this data through other means, I was unable to complete it before the deadline. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

bioinformatics↗

bioRxiv2024

SlNAP2 promoted fruit ripening by directly binding the ACS2 promoter and interacting with EIL3

The ripening process of tomato fruit is affected by a variety of environmental factors and genetic regulators. NAC transcription factors (TFs) function in a multitude of biological processes, while the current knowledge on the participation of NAC TFs in the regulatory network of fruit ripening is relatively limited. In this study, we isolated a NAC TFs, NAP2, which acts as a positive transcription activator in tomato fruit ripening. We also observed a notable delay in the ripening process of SlNAP2 silenced and knockout mutant fruit. In particular, ethylene production was obviously inhibited in SlNAP2 mutant fruit. Y1H and DLR assays showed that SlNAP2 directly binds to the promoter of SlACS2 and activates its transcriptional activity. Furthermore, SlNAP2 and SlEIL3 physically interaction was demonstrated by yeast two-hybrid (Y2H), luciferase complementation (LUC), bimolecular fluorescence complementation (BiFC) and coimmunoprecipitation analysis (CoIP) assays. Meanwhile, the pigment content, firmness and the transcript levels of genes associated with carotenoid and chlorophyll metabolism and cell wall metabolism were also potentially affected by the SlNAP2 deletion; however, it has remained unclear whether these genes are also directly regulated by SlNAP2. Therefore, our findings indicate that SlNAP2 directly binds to SlACS2 promoter to activate its expression and promote ethylene generation, which in turn interacts with EIL3 to enhance the function of ethylene in tomato fruit ripening. Collectively, our data contribute to understanding the interaction of NAC TFs and ethylene in tomato fruit ripening, thereby enhancing our knowledge of the ripening regulatory network that governs tomato fruit maturation.

biochemistry↗

bioRxiv2024

Frontal-posterior loop integrating captured attention into visual consciousness in the human brain

We usually perceive what we are attending to. How goal-directed attention contributes to conscious perception remains yet elusive. Here we combined a novel psychophysical paradigm with intracranial electroencephalography data to investigate this issue in the human brain. Relative to unattended conditions, goal-directed attention modulated early activity and inter-regional connectivity, even though this part of attention failed to predict image detectability. Later, the coupling between the frontal and posterior brain got established and maintained but the signals exchanged did not inform fine-grained image contents but instead reflect success or failure of attentional capture. This part of captured attention proportionally predicted image detectability. These results attribute consciousness to attention-based coupling between the frontal and posterior brain as a whole, rather than activity of either part alone.

neuroscience↗

bioRxiv2024

Break-induced replication is activated to repair R-loop-associated double-strand breaks in SETX-deficient cells

The primary role of break-induced replication (BIR) is to repair single-ended double-strand breaks (seDSBs) generated at broken replication forks and eroding telomeres. In this study, we demonstrated that when senataxin (SETX), an RNA/DNA helicase, is defective, hyper-recombination using the BIR mechanism is induced at R-loops/hybrids-accumulated double-ended DSBs (deDSBs), uncovering a role for BIR in repair of R-loops/hybrids-associated deDSBs. Intriguingly, the loss of SETX not only triggers non-canonical hyper-end resection requiring RAD52 and XPF, but also stalls Pol-primase-initiated end-fill DNA synthesis due to the accumulation of RNA/DNA hybrids on single-strand DNA (ssDNA) overhangs at deDSBs. This conflict between fill-in DNA synthesis and accumulated hybrids induces PCNA ubiquitination and PIF1 loading, thereby initiating the BIR mechanism at deDSBs. Hyper-resection further enhances PCNA ubiquitination and PIF1 loading, driving BIR-mediated hyper-recombination. Moreover, SETX is synthetic lethal with PIF1, RAD52, and XPF, offering new strategies for targeted treatment of SETX-deficient tumors.

molecular biology↗

bioRxiv2024

The Ptch methylase installs an m3U modification on 28S rRNA for efficient protein synthesis in flies and men

The ribosomal RNA (rRNA) is one of the most heavily modified RNA species in nature. Although we have advanced knowledge of the sites, functions and the enzymology of many of the rRNA modifications from all kingdoms, we lack basic understanding on many of those that are not universally present. A single N3 modified Uridine base (m3U) was identified on the 28S rRNA from human and frog over thirty years ago, which is absent in bacteria or yeast. Here we show that the equivalent m3U is present in Drosophila, and that the Ptch enzyme and its human homolog are both necessary and sufficient for carrying out the modification. The Ptch-modified U is at a functional center of the large ribosome, and consistently ptch-mutant cells suffer loss of ribosomal functions. Ptch, proposed to be the most druggable RNA methyltransferases in human, represents a unique target where ribosomal functions could be specifically compromised in cancer cells.

genetics↗

bioRxiv2024

Phase-Separating Peptide Coacervates with Programmable Material Properties for Universal Intracellular Delivery of Macromolecules

Phase-separating peptides (PSPs) self-assembling into coacervate microdroplets (CMs) are a promising new class of intracellular delivery vehicles that can release macromolecular modalities deployed in a wide range of therapeutic treatments. However, the molecular grammar governing intracellular uptake and release kinetics of CMs remains elusive. Here, we systematically manipulated the sequence of PSPs to unravel the relationships between their molecular structure, the physical properties of the resulting CMs, and their delivery efficacy. We show that a few amino acid alterations are sufficient to modulate the viscoelastic properties of CMs towards either a gel-like or a liquid-like state as well as their binding interaction with cellular membranes, collectively enabling to tune the kinetics of intracellular cargo release. Our findings provide molecular guidelines to precisely program the material properties of PSP CMs and achieve tunable cellular uptake and release kinetics depending on the cargo modality, with broad implications for therapeutic applications.

bioengineering↗

bioRxiv2024

IDH1 regulates human erythropoiesis by eliciting chromatin state reprogramming in a metabolic enzyme independent manner

Isocitrate dehydrogenase 1 (IDH1) is the key enzyme that was involved in the modulation of cellular metabolism, epigenetic modification and redox states homeostasis. Gain-of-function mutations and decreased expression of IDH1 have been demonstrated to be tightly associated with the pathogenesis of various myeloid malignancies characterized by ineffective erythropoiesis, such as acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). However, the function and mechanism of IDH1 in human erythropoiesis still remains to be further explored. Here, utilizing the human erythropoiesis system, we present an evidence of IDH1-mediated chromatin state reprogramming besides its well-characterized metabolism effects. We showed that knockdown of IDH1 induced chromatin reorganization and subsequently led to abnormalities of various key biological events in erythroid precursors, which could not be rescued by addition of reactive oxygen species (ROS) scavengers or supplementation of -ketoglutarate (-KG). We further revealed that deficiency of IDH1 induces genome-wide changes in distribution and intensity of multiple histone marks, among which H3K79me3 was identified as a critical factor in chromatin state reprogramming. Integrated analysis of ChIP-seq, ATAC-seq and RNA-seq recognized that SIRT1 was the key gene affected by IDH1 deficiency. Thus, our current work provided novel insights for further clarifying fundamental biological function of IDH1 which has substantial implications for an in-depth understanding of pathogenesis of diseases with IDH1 dysfunction and accordingly development of therapeutic strategies. Key PointsO_LIIDH1 deficiency impaired terminal erythropoiesis; C_LIO_LIIDH1 deficiency leads to chromatin states reprogramming by causing aberrant accumulation and genome-wide re-distribution of H3K79me3; C_LIO_LIDyserythropoiesis is caused by upregulation of SIRT1 induced by H3K79me3 accumulation. C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=81 SRC="FIGDIR/small/599556v2_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@328986org.highwire.dtl.DTLVardef@1e2e8a0org.highwire.dtl.DTLVardef@166885org.highwire.dtl.DTLVardef@1283261_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2024

Nitrous Oxide Formation and Consumption in Thawing Permafrost: A Microcosm Study

Nitrous oxide (N2O) emissions contribute to stratospheric ozone depletion and global warming. Climate warming causes permafrost thawing and decomposition of the dormant nitrogenous compounds, releasing N2O; however, understanding of the microbial formation and consumption of N2O in permafrost is still limited. Permafrost soils collected at two depths (5.4 m and 16.9 m) from the East Siberian Sea coast of Russia were used to establish microcosms assessing N2O formation and consumption in the presence of either nitrate (NO3-, 1 mM) or N2O (1 mM), respectively, during incubation at 4 and 20{degrees}C. Rapid N2O formation was observed in NO3--amended microcosms, but N2O consumption was slow and incomplete over a 1-year incubation period in all microcosms. Twenty-six quality-filtered metagenome-assembled genomes (MAGs) harboring genes involved in the reduction of NO3- and/or N2O were recovered from 16 metagenomes obtained from duplicate NO3-- and N2O-amended microcosms. None of the MAGs carried a complete set of genes to perform canonical denitrification (i.e., NO3-[->]N2) indicating N2O formation and consumption is likely driven by non-denitrifying bacteria. While coastal permafrost microbiomes harbor nosZ genes, activity monitored in the microcosms indicates N2O formation exceeds N2O consumption, emphasizing the need for integrated approaches to assess and predict N turnover in thawing permafrost.

microbiology↗

bioRxiv2024

Multi-step engineered adeno-associated virus enables whole-brain mRNA delivery

Adeno-associated viruses (AAVs) are commonly used vectors for DNA delivery in gene therapy. Here we developed a system that enables the AAV shell to package mRNAs by multi-step introduction of RNA-packaging components and modification of AAV Rep proteins. The resultant mRNA-carrying AAVs (RAAVs) retained most properties of conventional AAVs, including capsid composition, virus morphology, and tissue tropism. These RAAVs could mediate mRNA transfer into target cells and tissues, leading to transient expression of the functional protein. Importantly, intravenously injected RAAVs efficiently crossed the blood-brain barrier (BBB) and infected the whole mouse brain. Thus, the DNA viral vector could be modified for RNA delivery, and our RAAV represents the first highly efficient BBB-crossing mRNA delivery system that could be used for therapeutic purposes via whole-brain infection.

bioengineering↗

bioRxiv2024

RF coil design strategies for improving SNR at theultrahigh magnetic field of 10.5 Tesla

PurposeTo develop multichannel transmit and receive arrays towards capturing the ultimate-intrinsic-SNR (uiSNR) at 10.5 Tesla (T) and to demonstrate the feasibility and potential of whole-brain, high-resolution human brain imaging at this high field strength. MethodsA dual row 16-channel self-decoupled transmit (Tx) array was converted to a 16Tx/Rx transceiver using custom transmit/receive switches. A 64-channel receive-only (64Rx) array was built to fit into the 16Tx/Rx array. Electromagnetic modeling and experiments were employed to define safe operation limits of the resulting 16Tx/80Rx array and obtain FDA approval for human use. ResultsThe 64Rx array alone captured approximately 50% of the central uiSNR at 10.5T while the identical 7T 64Rx array captured [~]76% of uiSNR at this lower field strength. The 16Tx/80Rx configuration brought the fraction of uiSNR captured at 10.5T to levels comparable to the performance of the 64Rx array at 7T. SNR data obtained at the two field strengths with these arrays displayed [Formula] dependent increases over a large central region. Whole-brain high resolution T2* and T1 weighted anatomical and gradient-recalled echo EPI BOLD fMRI images were obtained at 10.5T for the first time with such an advanced array, illustrating the promise of >10T fields in studying the human brain. ConclusionWe demonstrated the ability to approach the uiSNR at 10.5T over the human brain with a novel, high channel count array, achieving large SNR gains over 7T, currently the most commonly employed ultrahigh field platform, and demonstrate high resolution and high contrast anatomical and functional imaging at 10.5T.

neuroscience↗

bioRxiv2024

Covalent DNA-Encoded Library Workflow Drives Discovery of SARS-CoV-2 Non-structural Proteins Inhibitors

The global coronavirus disease 2019 (COVID-19) pandemic persists, with the ongoing mutation of the virus. Consequently, the development of inhibitors with diverse binding modes and mechanisms of action, along with the elucidation of novel binding sites is of paramount importance. The 3-chymotrypsin-like protease (3CLpro) and papain-like protease (PLpro) are two validated cysteine proteases that cleave the viral polyprotein and are essential for viral replication. In this study, we utilized covalent DNA-Encoded libraries (CoDELs) workflow to identify two series of triazine-based covalent inhibitors targeting 3CLpro and PLpro. Molecular docking facilitated the identification of optimization pathways, further refined through medicinal chemistry efforts, leading to the development of the non-peptide 3CLpro inhibitor LU9, which exhibited an IC50 value of 0.34 M, and crystal structure of LU10 revealed a unique binding mode within the active site. Additionally, the X-ray cocrystal structure of SARS-CoV-2 PLpro with XD5 uncovered a previously unexplored binding site, adjacent to the catalytic pocket, providing an opportunity for further development of PLpro inhibitors. Overall, these novel compounds serve as valuable chemical probes for target validation and represent promising drug candidates for the continued development of SARS-CoV-2 antivirals.

biochemistry↗

bioRxiv2024

Peripheral B Lymphocyte Serves as A Reservoir for The Persistently Covert Infection of Mandarinfish Siniperca chuatsi Ranavirus

Genus Ranavirus in family Iridoviridae is composed of large members with various genomic sizes and viral gene contents, infecting a variety of ectothermic vertebrates including reptile, amphibians and bony fish worldwide. Mandarinfish ranavirus (MRV) is a very distinctive member among genus Ranavirus. Persistently convert infection of MRV were previously observed in natural outbreak of MRV, but the underlying mechanism remains unclear. We here evidenced that mandarinfish peripheral B lymphocytes are implemented as viral reservoirs to maintain persistent and covert infection. When mandarinfish were infected with sublethal dosage of MRV under nonpermissive temperature (19 {o}C) and permissive temperature (26 {o}C), respectively, all fish in 19 {o}C group survived and entered persistent phase of infection characterized with very low viral load in white blood cell, whereas partial fish died of MRV infection in 26 {o}C group, and the survivals then initiated persistent status. Gradually raising temperature, vaccination and dexamethasone treatment can reactivate the quiescent MRV to replicate and result in partial mortality. The viral reservoir investigates showed that IgM+-labelled B lymphocytes but not CD3{Delta}+-labelled T lymphocytes and MRC-1+-labelled macrophages are target cells for the persistent infection of MRV. Moreover, the quiescent MRV could not be reactivated by heat-killed Escherichia coli, indicating a very different reactivation mechanism from that of other known rannaviral member. Collectively, we are the first to confirm the presence of B cell-dependent persistent and covert infection of ranavirus, and provide a new clue for better understanding the complex infection mechanism of vertebrate iridovirus, especially regarding ranavirus. IMPORTANCEViruses known as HIV, HBV and EBV etc. evade host immune clearance by establishing long-term even lifelong persistent or latent infection. In vertebrate iridovirus, FV3, the type species of genus Ranavirus was evidenced to establish persistent infection by using Xenopus peritoneal macrophages as reservoirs. MRV is a very distinctive ranavirus from FV3 with very different genomic content and host species. We here uncovered MRV establishes persistent and covert infection by using peripheral B lymphocytes as virus reservoirs. During persistent infection, very low copies of quiescent MRV were harbored in peripheral B lymphocytes. Water temperature stress, vaccination stimulation, and dexamethasone treatment can reactivate quiescent MRV to replicate in abundance via a non-TLR5-mediated manner, and results in recurrence of MRV disease. Our finding suggests the diversity and complexity of the pathogenic mechanisms among ranaviruses, and also has important scientific significance for in-depth understanding of the infection and immunity interaction of vertebrate iridoviruses.

microbiology↗