Biology subjects

Wang, J.

Publications and source records attributed to Wang, J..

At least 1,189 records · Page 66Linked to original sources

bioRxiv2024

Rice OsPLATZ3 controls ROS homeostasis by inhibiting ROS-Scavenging Activity during Tapetum Degeneration

OsPLATZ3, a transcription factor of rice (Oryza sativa) belonging to the PLATZ family, is involved in the repression of transcriptional activity. PLATZ3 exhibits preferential expression in the tapetal cells during anthers development, regulating tapetum degeneration by controlling the dynamics of reactive oxygen species (ROS) in rice male reproductive processes. The Osplatz3 exhibits enlarged tapetum with delayed degeneration, significantly lower ROS levels from S5 to S12 in anthers compared to the wild-type, resulting in complete male sterility. In the anthers of Osplatz3, there are significant changes in the regulators of programmed cell death (PCD)-induced tapetal degradation, such as TDR, EAT1, and their effectors OsCP1, OsC6, OsAP25, and OsAP37. These findings indicate that OsPLATZ3 is a new addition to the tapetum PCD regulatory network. In the late stages of anthers development, Osplatz3 exhibits phenotypes associated with oxidative stress. Transcriptome analysis revealed significant differential expression in 229 genes associated with maintaining ROS homeostasis. Furthermore, Electrophoretic Mobility Shift Assay (EMSA) demonstrate that OsPLATZ3 can bind to the promoter region of OsAPX9, a gene encoding a plant ascorbate peroxidase domain protein with putative ROS scavenging capabilities. These findings suggest that OsPLATZ3 serves as a crucial regulatory factor in tapetum PCD by suppressing ROS scavenging activity.

plant biology↗

bioRxiv2024

Fertilization-induced synergid cell death by RALF12-triggered ROS production and ethylene signaling

Fertilization-dependent elimination of the persistent synergid cell is essential to block supernumerary pollen tubes and thus to avoid polyspermy in flowering plants. Little is known about the molecular mechanisms ensuring timely induction and execution of synergid cell death. We analysed manually isolated maize synergid cells along their degeneration and show that they are gland cells expressing batteries of genes encoding small secreted proteins under control of the MYB98 transcription factor. This network is down-regulated after fertilization, while genes involved in reactive oxygen species (ROS) production, ethylene biosynthesis and response, senescence, and oxidative stress regulation are induced before synergid elimination and its ultimate fusion with the endosperm. We further show that fertilization-induced RALF12 peptide specifically triggers mitochondrial ROS and apoptosis, while ethylene promotes synergid degeneration. In conclusion, this study sheds light on developmental programmed cell death (dPCD) in plants and provides a unique resource to discover novel PCD regulators.

cell biology↗

bioRxiv2024

Cas1 mediates the interference stage in a phage-encoded CRISPR-Cas system

CRISPR-Cas systems are prokaryotic adaptive immune systems against invading phages and other mobile genetic elements, which function in three stages: adaptation, expression and interference. Interestingly, phages were also found to encode CRISPR-Cas systems to antagonize their hosts and establish infection. The Vibrio cholerae-infecting ICP1 phage was the first discovered phage with a functional CRISPR-Cas system against an antiphage region in the host genome. Nevertheless, this system lacks a domain essential for recruitment of helicase-nuclease Cas2/3 during target DNA cleavage, and how this system accomplishes the interference stage remains unknown. Here, surprisingly, we found that Cas1, a highly conserved component known to exclusively work in the adaptation stage, also mediates the interference stage through connecting Cas2/3 to the DNA bound-Cascade (Csy) complex of the ICP1 CRISPR-Cas system. A series of structures of Csy, Csy-dsDNA, Cas1-Cas2/3 and Csy-dsDNA-Cas1-Cas2/3 complexes collectively reveal the whole process of Cas1-mediated target DNA cleavage by the ICP1 CRISPR-Cas system. Together, these data support an unprecedented model in which Cas1 mediates the interference stage in a phage-encoded CRISPR-Cas system and also shed light on a unique model of primed adaptation.

microbiology↗

bioRxiv2024

On the identification of differentially-active transcription factors from ATAC-seq data

ATAC-seq has emerged as a rich epigenome profiling technique, and is commonly used to identify Transcription Factors (TFs) underlying given phenomena. A number of methods can be used to identify differentially-active TFs through the accessibility of their DNA-binding motif, however little is known on the best approaches for doing so. Here we benchmark several such methods using a combination of curated datasets with various forms of short-term perturbations on known TFs, as well as semi-simulations. We include both methods specifically designed for this type of data as well as some that can be repurposed for it. We also investigate variations to these methods, and identify three particularly promising approaches (a chromVAR-limma workflow with critical adjustments, monaLisa and a combination of GC smooth quantile normalization and multivariate modeling). We further investigate the specific use of nucleosome-free fragments, the combination of top methods, and the impact of technical variation. Finally, we illustrate the use of the top methods on a novel dataset to characterize the impact on DNA accessibility of TRAnscription Factor TArgeting Chimeras (TRAFTAC), which can deplete TFs - in our case NFkB - at the protein level. Author summaryTranscription factors regulate gene expression by binding sites in the genome that often harbor a specific DNA motif. The collective accessibility of these motif-matching regions, measured by technologies such as ATAC-seq, can be used to infer the activity of the corresponding transcription factors. Here we use curated datasets of 11 TF-specific perturbations as well as 116 semi-simulated datasets to benchmark various methods for identifying factors that differ in activity between experimental conditions. We investigate important variations in the analysis and make recommendations pertaining to such analysis. Finally, we illustrate the application of the top methods to characterize the effects of a novel method for perturbing transcription factors at the protein level.

bioinformatics↗

bioRxiv2024

Modeling the genomic complexity of human cancer using Cas12a mice

Somatic genome editing in mouse models has increased our understanding of the in vivo effects of genetic alterations in areas ranging from neuroscience to cancer biology and beyond. However, existing models are limited in their ability to create multiple targeted edits. Thus, our understanding of the complex genetic interactions that underlie development, homeostasis, and disease remains incomplete. Cas12a is an RNA-guided endonuclease with unique attributes that enable simple targeting of multiple genes with crRNA arrays containing tandem guides. To accelerate and expand the generation of complex genotypes in somatic cells, we generated transgenic mice with Cre-regulated and constitutive expression of enhanced Acidaminococcus sp. Cas12a (enAsCas12a). In these mice, enAsCas12a-mediated somatic genome editing robustly generated compound genotypes, as exemplified by the initiation of diverse cancer types driven by homozygous inactivation of trios of tumor suppressor genes. We further integrated these modular crRNA arrays with clonal barcoding to quantify the size and number of tumors with each array, as well as the efficiency of each crRNA. These Cas12a alleles will enable the rapid generation of disease models and broadly facilitate the high-throughput investigation of coincident genomic alterations in somatic cells in vivo.

cancer biology↗

bioRxiv2024

Antigenicity assessment of SARS-CoV-2 saltation variant BA.2.87.1

The recent emergence of a SARS-CoV-2 saltation variant, BA.2.87.1, which features 65 spike mutations relative to BA.2, has attracted worldwide attention. In this study, we elucidate the antigenic characteristics and immune evasion capability of BA.2.87.1. Our findings reveal that BA.2.87.1 is more susceptible to XBB-induced humoral immunity compared to JN.1. Notably, BA.2.87.1 lacks critical escaping mutations in the receptor binding domain (RBD) thus allowing various classes of neutralizing antibodies (NAbs) that were escaped by XBB or BA.2.86 subvariants to neutralize BA.2.87.1, although the deletions in the N-terminal domain (NTD), specifically 15-23del and 136-146del, compensate for the resistance to humoral immunity. Interestingly, several neutralizing antibody drugs have been found to restore their efficacy against BA.2.87.1, including SA58, REGN-10933 and COV2-2196. Hence, our results suggest that BA.2.87.1 may not become widespread until it acquires multiple RBD mutations to achieve sufficient immune evasion comparable to that of JN.1.

immunology↗

bioRxiv2024

Coronavirus Nucleocapsid Protein Enhances the binding of p-PKCα to RACK1: Implications for Inhibition of Nucleocytoplasmic Trafficking and Suppression of the Innate Immune Response

The hallmark of coronavirus infection lies in its ability to evade host immune defenses, a process intricately linked to the nuclear entry of transcription factors crucial for initiating the expression of antiviral genes. Central to this evasion strategy is the manipulation of the nucleocytoplasmic trafficking system, which serves as an effective target for the virus to modulate the expression of immune response-related genes. In this investigation, we discovered that infection with the infectious bronchitis virus (IBV) dynamically impedes the nuclear translocation of several transcription factors such as IRF3, STAT1, STAT2, NF-{kappa}B p65, and the p38 mitogen-activated protein kinase (MAPK), leading to compromised transcriptional induction of key antiviral genes such as IFN{beta}, IFITM3, and IL-8. Further examination revealed that during the infection process, components of the nuclear pore complex (NPC), particularly FG-Nups (such as NUP62, NUP153, NUP42, and TPR), undergo cytosolic dispersion from the nuclear envelope; NUP62 undergoes phosphorylation, and NUP42 exhibits a mobility shift in size. These observations suggest a disruption in nucleocytoplasmic trafficking. Screening efforts identified the IBV nucleocapsid protein (N) as the agent responsible for the cytoplasmic distribution of FG-Nups, subsequently hindering the nuclear entry of transcription factors and suppressing the expression of antiviral genes. Interactome analysis further revealed that the IBV N protein interacts with the scaffold protein RACK1, facilitating the recruitment of activated protein kinase C alpha (p-PKC) to RACK1 and relocating the RACK1-PKC complex to the cytoplasm. These observations are conserved across pan-coronaviruses N proteins. Concurrently, the presence of both RACK1 and PKC/{beta} proved essential for the phosphorylation and cytoplasmic dispersion of NUP62, the suppression of antiviral cytokine expression, and efficient virus replication. These findings unveil a novel, highly effective, and evolutionarily conserved mechanism. Author summaryCoronaviruses employ diverse strategies to suppress the host innate immune defense. In this study, we uncovered a novel and highly effective strategy utilized by pan-coronaviruses to inhibit the innate immune response. Specifically, we found that the coronavirus N protein facilitates the binding of p-PKC to RACK1, leading to the phosphorylation of NUP62 and the cytoplasmic redistribution of multiple FG-Nups. This phenomenon is accompanied by the disruption of nuclear translocation of several innate immune response-related transcription factors and suppression of antiviral/pro-inflammatory genes expression. Our research represents the first elucidation of how the N protein targets and impairs NPC function through the promotion of RACK1-PKC interaction and NUP62 phosphorylation/disassembly. This discovery unveils a novel mechanism employed by pan-coronaviruses to counteract the host immune response.

microbiology↗

bioRxiv2024

Spatial Transcriptomics of Spinal Ependymoma in NF2-related Schwannomatosis

Spinal ependymoma (SP-EPN) is a central nervous system (CNS) tumor that is associated with high morbidity. The only effective treatment for end-stage SP-EPN is surgery, but this is associated with high risk of injury to the sensorimotor spinal tracts and paralysis. There is a critical need to understand the cellular origins of this tumor so that disease models of tumor progression can be generated for drug development. Recent genomic studies with bulkRNA sequencing suggest the molecular signature of SP-EPN matches that of ependymal cells (EPCs). However, large-scale genomic studies can often misrepresent rare cancer stem cell populations within the tumor. In this study, we performed spatial transcriptomics (ST) on a SP-EPN resected from a patient with NF2-related neurofibromatosis to examine the spatial heterogeneity within the tumor. The SP-EPN sample exhibited cellular heterogeneity with diffuse expression of astrocytic and EPC markers, and smaller pockets with RGC or stem cell markers, as well as overlap between progenitor cell and mature cell markers. These findings suggest that there may be a developmental hierarchy within the EPC lineage in SP-EPN tumors, which may stem from aberrant radial glia cells.

cancer biology↗

bioRxiv2024

Gut Microbiome-Driven Metabolites Influence Skin Pigmentation in TYRP1 Mutant Oujiang Color Common Carp

The gut microbiome is one of the major regulators of the gut-skin axis and is partly regulated by host genetics. In the present study, using comparative high-throughput omics data on CRISPR/Cas9-mediated TYRP1 mutant and wild-color common carp populations, we quantified the proportion of inter-individual variation in the skin transcriptome and blood metabolome by genetic architecture and gut microbiomes. We found 525 differential metabolites (DMs) and 45 differential gut microbial genera in TYRP1 mutant fishes relative to the wild type. Through interaction analysis and causal mediation analyses, we revealed that the TYRP1-mutant derived genetic background may exert an inflammatory Acinetobacter - Leukotrience-C4 and - Spermine metabolic pathway under the regulation of an anti-inflammatory cardio-vascular genetic network underlying the upregulating expression of COMT, PLG, C2, C3, F10, TDO2, MHC1, and SERPINF2 gene for evolving unusual coffee-like color phenotype. This unique network appears to underlie the "coffee-like" color phenotype. We propose that the COMT-mediated causal effect of the unusual gut microbiome on the atypical skin gene expression patterns through the gut-skin metabolic pathway. Article SummaryR.N. Mandal et al. report on the causal effect of gut microbiome-driven metabolites on the expression pattern of regulatory genes underlying an unusual color phenotype. It suggests that TYRP1 Mutation may rise an unusual inflammatory gut microbiome-skin metabolic pathway that may be balanced by an anti-inflammatory cardio-vascular genetic network leading to unique coloration in Oujiang Color Common Carp.

genetics↗

bioRxiv2024

Targeting GFPT2 to reinvigorate immunotherapy in EGFR-mutated NSCLC

In the evolving field of cancer immunotherapy, EGFR-mutated NSCLC presents a significant challenge, demonstrating marked innate resistance to established treatments. An effective method to counter this resistance remains elusive. Through comprehensive genetic and pharmacological analyses across various models, we have identified glutamine fructose-6-phosphate transaminase 2 (GFPT2) as a key facilitator of immune evasion in EGFR-mutated NSCLC. Mechanistically, under EGFR mutation condition, GFPT2 expression, which is typically low in normal tissues, is highly induced via EGFR/IRE1/Xbp1s signaling axis, leading to a significant increase in intracellular UDP-GlcNAc and consequently, an altered N-glycosylation profile. GFPT2 escalates the expression and glycosylation of PD-L1, PVR and CD276, bolstering their interactions with CD8+T cells, and amplifies CD73 glycosylation, thereby intensifying adenosine-mediated CD8+T cells suppression. These actions collectively reduce tumor cell vulnerability to CD8+T cell-mediated death. Moreover, GFPT2 regulates EGFR glycosylation, which consequentially modulates the EGFR-dependent secretion of CXCL10 and VEGF, thus impeding CD8+T cell infiltration within tumors. We further identified a GFPT2 isoform-specific inhibitor that potentiates PD-1 blockade therapy beyond that of existing strategy, corroborated by results in xenografts and patient-derived organoids. Together, these findings illuminate the promising therapeutic potential of GFPT2 as a metabolic checkpoint, offering an innovative approach to invigorate immunotherapy in NSCLC with EGFR mutations.

cancer biology↗

bioRxiv2024

pTAC3 and pTAC14 are required for binding of plastid-encoded RNA polymerase to DNA

Plastid-encoded RNA polymerase (PEP) is a bacterial-type multisubunit RNA polymerase responsible for the majority of transcription in chloroplasts. PEP consists of four core subunits, which are orthologs of their cyanobacterial counterparts. In Arabidopsis thaliana, PEP associates with 12 PEP-associated proteins (PAPs), which serve as peripheral subunits of the RNA polymerase. The exact contributions of PAPs to PEP function are still poorly understood. We use ptChIP-seq to show that PAP1/pTAC3, a peripheral subunit of PEP, binds to the same genomic loci as RpoB, a core subunit of PEP. The pap1/ptac3 mutant shows a complete loss of RpoB binding to DNA throughout the genome, indicating that PAP1/pTAC3 is necessary for RpoB binding to DNA. A similar loss of RpoB binding to DNA is observed in the pap7/ptac14 mutant, which is defective in another peripheral PEP subunit. We propose that the peripheral subunits of PEP are required for the recruitment of core PEP subunits to DNA. KEY MESSAGEThe peripheral subunits of plastid-encoded RNA polymerase play a crucial role in recruiting the core PEP subunits to DNA in Arabidopsis chloroplasts.

plant biology↗

bioRxiv2024

Single-cell multiomics reveals a gene regulatory circuit promoting leukemia cell differentiation

Cancer differentiation therapy aims to induce maturation of neoplastic cells, yet how cell fate is determined in oncogenic cellular contexts is poorly understood. Here we integrate chromatin accessibility and transcriptome analysis at single-cell levels to investigate the mechanism driving the differentiation trajectory of the PML/RAR+ acute promyeloid leukemia (APL) cell line model, NB4, under the induction of all-trans-retinoid acid (ATRA). We show that differentiating NB4 cells navigate through an intermediate cell fate decision point that leads to either terminal granulopoiesis or a transient immature-lymphocyte-like state. Functional perturbation studies indicate that ATRA signaling activates discrete PML/RAR-target enhancers to induce a positive feedforward gene regulatory circuit involving two myeloid-lineage transcription factors, SPI1 and CEBPE, which is both necessary and sufficient to activate a myelocytic gene expression program in NB4. Further, ectopic expression of SPI1 and CEBPE also promotes myelocytic differentiation in non-APL leukemia cell lines HL60 and K562. Together, these results shed light on the differentiation trajectory of therapy-induced cell decisions of APL and suggest a gene regulatory circuit that may be broadly exploited to promote terminal differentiation of leukemia.

cancer biology↗

bioRxiv2024

Super Pangenome of Grapevines Empowers Improvement of the Oldest Domesticated Fruit

Grapevine (Vitis) is the oldest domesticated fruit crop with great cultural and economic importance. Here, we assemble and annotate haplotype-resolved genomes of 72 Vitis accessions including 25 wild and 47 cultivated grapevines, and a haplotype-resolved complete genome of V. vinifera. Coalescent phylogenomics of 142 haplotype genomes disentangles the mysterious hybridization history of grapevines, revealing enormous genetic diversity among species. Pangenome analysis together with phenotyping data reveals that European cultivars, more susceptible to the most destructive disease downy mildew (DM), had a smaller repertoire of disease resistance genes of NLR family. Through extensive structural variation (SV) characterization, phenotyping, transcriptome profiling of 113 Vitis accessions, and SV-eQTL analysis, we have identified over 79 SVs and their relevant genes significantly associated with DM resistance, exemplified by a lysine histidine transporter, VvLHT8. This haplotype-resolved complete genome and pangenome of Vitis genus will accelerate grapevine breeding and enrich our understanding of the evolution and biology of grapevines.

plant biology↗

bioRxiv2024

Armored Bicistronic CAR T Cells with Dominant-negative TGF-β Receptor II to Overcome Resistance in Glioblastoma.

Chimeric antigen receptor (CAR) T cells have shown significant efficacy in hematological diseases. However, CAR T therapy has demonstrated limited efficacy in solid tumors, including glioblastoma (GBM). One of the most important reasons is the immunosuppressive tumor microenvironment (TME), which promotes tumor growth and suppresses immune cells to eliminate tumor cells. The human transforming growth factor-beta (TGF-{beta}) plays a crucial role in forming the suppressive GBM TME and driving the suppression of the anti-GBM response. In order to mitigate TGF-{beta} mediated suppressive activity, we combined a dominant-negative TGF-{beta} receptor II (dnTGF{beta}RII) with our previous bicistronic CART-EGFR-IL13R2 construct, currently being evaluated in a clinical trial, to generate CART-EGFR-IL13R2-dnTGF{beta}RII, a tri-modular construct we are developing for clinical application. We hypothesized that this approach would more effectively subvert resistance mechanisms observed with GBM. Our data suggests that CART-EGFR-IL13R2-dnTGF{beta}RII significantly augmented T cell proliferation and enhanced functional responses, particularly in a TGF{beta}-rich tumor environment. Additionally, in vivo studies validated the safety and efficacy of the dnTGF{beta}RII cooperating with CARs in targeting and eradicating GBM in a NSG mouse model.

cancer biology↗

bioRxiv2024

Rapid in situ mutation detection in extracellular vesicle-DNA

A PCR- and sequencing-free mutation detection assay facilitates cancer diagnosis and reduces over-reliance on specialized equipment. This benefit was highlighted during the pandemic when high demand for viral nucleic acid testing often sidelined mutation analysis. This shift led to substantial challenges for patients on targeted therapy in tracking mutations. Here, we report a 30-minute DNA mutation detection technique using Cas12a-loaded liposomes in a microplate reader, a fundamental laboratory tool. CRISPR-Cas12a complex and fluorescence-quenching (FQ) probes are introduced into tumor-derived extracellular vesicles (EV) through membrane fusion. When CRISPR-RNA hybridizes with the DNA target, activated Cas12a can trans-cleave FQ probes, resulting in fluorescence signals for the quantification of DNA mutation. Future advancements in multiplex and high-throughput mutation detection using this assay will streamline self-diagnosis and treatment monitoring at home.

bioengineering↗

bioRxiv2024

Analysis of protein levels and solubility in distinct brain regions reveals several elements of the protein homeostasis network that are impacted by aging

The onset of protein conformation diseases is inextricably linked to aging. During aging, cellular protein quality control declines which results in diminished protein homeostasis (proteostasis). In model organisms, such as C. elegans and killifish, proteostatic decline with age has been linked to the onset of aggregation of proteins in wild-type animals, observed through detergent-insoluble fractionation. Analysis of studies applying detergent-insoluble fractionation in mice revealed that the composition of detergent-insoluble proteins changes with age. However, these individual fractionation studies have generally been limited to small numbers of mice. Herein, we expand on our previous analysis by extending the experiments to a larger cohort of mice and to two brain regions implicated in neurodegenerative diseases, the cortex and hippocampus. These experiments unveil insights into alterations in the abundance and solubility of proteins involved in protein quality control and in inflammation. For example, ribosomal proteins and many chaperone proteins are downregulated with age. Consistent enrichment of subunits of the extracellular C1q complex was also observed in both brain regions alongside an increase in immunoglobulin signal indicating that markers of increased inflammation may also become insoluble during aging. More generally, insoluble proteins share features observed in datasets of impaired protein degradation indicating that the loss of activity of cellular protein degradation machinery may contribute to the specific aggregation of these proteins.

cell biology↗

bioRxiv2024

Schlafen-11 and -9 are innate immune sensors for intracellular single-stranded DNA

Nucleic acids are major structures detected by the innate immune system. Although intracellular single-stranded DNA (ssDNA) is accumulated during pathogen infection or pathogenesis, it remains unclear whether and how intracellular ssDNA stimulates the immune system. We report that intracellular ssDNA triggers cytokine expression and cell death in a CGT motif-dependent manner. Through a genome-wide CRISPRLCas9 screen, we identified Schlafen-11 (SLFN11), which is essential for the response to endogenous and pathogen ssDNA. SLFN11 directly binds ssDNA containing CGT motifs and translocates to the cytoplasm upon ssDNA recognition. The mice deficient in SLFN9, the homologue of SLFN11, were resistant to CGT ssDNA-induced inflammation, acute hepatitis and septic shock. This study establishes CGT ssDNA and SLFN11/9 as a novel type of immunostimulatory nucleic acids and pattern recognition receptors, respectively. One-sentence summariessingle-stranded DNA inside cells can awaken Schlafens with a CGT motif to trigger cytokine expression and lytic cell death.

immunology↗

bioRxiv2024

Cluster decomposition-based anomaly detection for rare cell identification in single-cell expression data

Single-cell RNA sequencing (scRNA-seq) technologies have been widely used to characterize cellular landscapes in complex tissues. Large-scale single-cell transcriptomics holds great potential for identifying rare cell types critical to the pathogenesis of diseases and biological processes. Existing methods for identifying rare cell types often rely on one-time clustering using partial or global gene expression. However, these rare cell types may be overlooked in the initial clustering step, making them difficult to distinguish. In this paper, we propose a Cluster decomposition-based Anomaly Detection method (scCAD), which iteratively decomposes clusters based on the most differential signals in each cluster to effectively separate rare cell types and achieve accurate identification. We benchmark scCAD on 25 real-world scRNA-seq datasets, demonstrating its superior performance compared to 10 state-of-the-art methods. In-depth case studies across diverse datasets, including mouse airway, brain, intestine, human pancreas, immunology data, and clear cell renal cell carcinoma, showcase scCADs efficiency in identifying rare cell types in complex biological scenarios. Furthermore, scCAD can correct the annotation of rare cell types and identify immune cell subtypes associated with disease, providing new insights into disease progression.

bioinformatics↗