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Biology subjects

Zhao, J.

Publications and source records attributed to Zhao, J..

At least 181 records · Page 10Linked to original sources

Imputation Disparities Driven by Recent Selectionand Their Impact on Disease Risk Estimation in East and Southeast Asian Populations

Using genotype data consisting of 8,316 individuals, we systematically evaluated imputation performance across six state-of-the-art reference panels for Chinese and Thai populations. A substantial proportion of variants identified through whole-genome sequencing, especially low-frequency variants, remained undetected by existing reference panels. In the Chinese population, the TOPMed panel required an R2 threshold of 0.60-0.70 to achieve comparable imputation accuracy of the ChinaMAP panel without R2 filtering, challenging the standard practice of applying a fixed R2 threshold for downstream analyses. Regional analysis highlighted the role of recent selection in imputation discrepancies and revealed an enrichment of immune-related genes in poorly imputed regions. In addition, we showed that the selection of reference panels and R2 thresholds could significantly influence estimation of polygenic risk score for disease prediction. These findings underscore the importance of developing ancestrally diverse reference panels and provide valuable guidelines for improving genotype imputation in East and Southeast Asian populations.

genomics↗

Extracellular Nanobody Screening using Conformationally Stable GPCR

G protein-coupled receptors (GPCRs) are prominent drug targets that have attracted intensive efforts in drug screening. Binding-based screening methods for GPCR ligands often require conformationally stable, purified receptors. However, obtaining large quantities of GPCRs in stable states, particularly with unoccupied extracellular ligand-binding pockets and especially in their active conformations, remains challenging due to the inherent dynamic nature of these receptors. To address this challenge, we propose a universal approach for stabilizing GPCRs in specific conformations. Using the M1 muscarinic acetylcholine receptor (M1R) as a model, we successfully stabilized M1R in its active conformation through de novo design of a fusion protein. We screened a synthetic yeast display library of nanobodies against both the stabilized active-state and previously reported inactive-state M1R, identifying several nanobodies that specifically recognize each conformation. This method not only facilitates the stabilization of GPCRs in desired states but also provides valuable tools for developing more selective therapeutic agents, enhancing drug discovery efficiency and specificity.

biochemistry↗

Respiratory Airway Secretory Cells act as Immune Sentinels in Human Distal Airways

Pulmonary immunity in the human distal respiratory airways is essential for lung function but remains poorly explored, mainly due to limited physiologically relevant models. Here, we develop distal lung organoids containing respiratory airway secretory (RAS) cells, a recently identified epithelial population unique to the distal airways of humans and large mammals, using human pluripotent stem cells (hPSCs). Lineage tracing identified RAS cells as descendants of SOX9brightNKX2-1bright progenitors. Single-cell transcriptomics elucidated that RAS cells exhibited a distinct immune-competent phenotype with enriched genes associated with viral host entry and pattern recognition receptor signaling. Functionally, RAS cells infected by respiratory syncytial virus (RSV) exhibited enhanced antiviral activity marked by upregulation of interferon-stimulated genes (ISGs) and complement component 3 (C3). In contrast, bacterial flagellin or Pseudomonas aeruginosa (PAO1) triggered a TLR5-driven immune response in RAS cells, inducing complement system activation, a response suppressed by selective TLR5 inhibition. Notably, in chronic obstructive pulmonary disease (COPD), RAS cells displayed dysregulated immune activation, characterized by elevated expression of adaptive immune mediators. Together, our findings identify RAS cells as previously unrecognized sensors and effectors of mucosal immunity in the human distal airways and reveal their roles in viral infection, bacterial stimulation, and chronic inflammatory lung disease, providing potential therapeutic targets for respiratory diseases.

cell biology↗

Root hair lifespan is antagonistically controlled by autophagy and programmed cell death

Root hairs are tubular tip-growing extensions of root epidermal cells that enhance root surface area for water and nutrient uptake. While mechanisms governing root hair fate, polarity, and tip growth are well understood, the regulation of root hair longevity remains largely unknown. Here, we show that root hair cells employ high levels of autophagy to promote their lifespan. Loss-of-function mutations in the autophagy regulators ATG2, ATG5, or ATG7 induce a premature, cell-autonomous cell death program. This cell death is activated via a gene regulatory network downstream of the NAC transcription factors ANAC046 and ANAC087. Our findings uncover an antagonistic relationship between autophagy and developmentally controlled cell death in root hair lifespan regulation, with potential implications for optimizing plant nutrient and water uptake in crop breeding. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=193 SRC="FIGDIR/small/643910v1_ufig1.gif" ALT="Figure 1"> View larger version (80K): org.highwire.dtl.DTLVardef@1bd570borg.highwire.dtl.DTLVardef@19db5eborg.highwire.dtl.DTLVardef@11279fborg.highwire.dtl.DTLVardef@661c7_HPS_FORMAT_FIGEXP M_FIG C_FIG

plant biology↗

A simplified hybrid capture approach retains high specificity and enables PCR-free workflow

Hybrid capture is a critical technology for selective enrichment of genomic regions of interest, enabling cost-effective focused sequencing in both clinical and research applications. We present a simplified hybrid capture approach that eliminates complexities typically associated with hybridization-based selection methods by directly loading the hybridization product onto the sequencing flow cell. The workflow removes bead-based steps, washes, and post-hybridization PCR, while retaining high capture specificity and library complexity. The approach is enabled by the development of a streptavidin flow cell surface, a method to circularize and amplify captured targets on the flow cell, and a fast hybridization protocol. We demonstrate application across targeted panel sizes and improvements to library complexity and variant calling. We also show how the approach can be used to create an entirely PCR-free targeted sequencing workflow that further improves variant calling and enables the detection of repeat expansions.

genomics↗

Cell-type specific autophagy in root hair forming cells is essential for salt stress tolerance in Arabidopsis thaliana

Autophagy is a vital cellular quality control pathway that enables plants to adapt to changing environments. By degrading damaged or unwanted components, autophagy maintains cellular homeostasis. While the organismal phenotypes of autophagy-deficient plants under stress are well-characterized, the contribution of cell-type-specific autophagy responses to whole-plant homeostasis remains poorly understood. Here, we show that root hair-forming cells (trichoblasts) of Arabidopsis thaliana exhibit higher autophagic flux than adjacent non-hair cells (atrichoblasts). This differential autophagy is genetically linked to cell fate determination during early development. Mutants disrupting trichoblast or atrichoblast identity lose the autophagy distinction between these cell types. Functional analyses reveal that elevated autophagy in trichoblasts is essential for sodium ion sequestration in vacuoles--a key mechanism for salt stress tolerance. Disrupting autophagy specifically in trichoblasts impairs sodium accumulation and reduces plant survival under salt stress. Conversely, cell-type-specific complementation restores both sodium sequestration and stress tolerance. Our findings uncover a cell-type-specific autophagy program in root hairs and demonstrate how developmental cues shape autophagy to enhance stress resilience. This work establishes a direct link between cell identity, autophagy, and environmental adaptation in plants.

plant biology↗

A rapid and efficient red-light-activated Cre recombinase system for genome engineering in mammalian cells and transgenic mice

The Cre-loxP recombination system enables precise genome engineering; however, existing photoactivatable Cre tools suffer from several limitations, including low DNA recombination efficiency, background activation, slow activation kinetics, and poor tissue penetration. Here, we present REDMAPCre, a red-light-controlled split-Cre system based on the {Delta}PhyA/FHY1 interaction. REDMAPCre enables rapid activation (1-second illumination) and achieves an 85-fold increase in recombination efficiency. We demonstrate its efficient regulation of DNA recombination in mammalian cells and mice, as well as its compatibility with other inducible recombinase systems for Boolean logic-gated DNA recombination. Using a single-vector adeno-associated virus (AAV) delivery system, we successfully induced REDMAPCre-mediated DNA recombination in mice. Furthermore, we generated a REDMAPCre transgenic mouse line and validated its efficient, light-dependent recombination across multiple organs. To explore its functional applications, REDMAPCre transgenic mice were crossed with the relative Cre-dependent reporter mice, enabling optogenetic induction of insulin resistance and hepatic lipid accumulation via Cre-dependent overexpression of ubiquitin-like with PHD and ring finger domains 1 (UHRF1), as well as targeted cell ablation through diphtheria toxin fragment A (DTA) expression. Collectively, REDMAPCre provides a powerful tool for achieving remote control of recombination and facilitating functional genetic studies in living systems.

synthetic biology↗

Bacteriophage protein Dap2 inhibits bacterial type III secretion system and synergizes with Dap1 to evade anti-phage immunity

The evolutionary arms race between bacterial immunity and phages has driven the emergence of sophisticated anti-defense systems (ADSs). However, certain ADSs exhibit incomplete suppression of their cognate defense systems, suggesting functional cooperation between multiple ADSs targeting the same bacterial safeguard. In this study, we characterize Dap2, a protein encoded by a Pseudomonas aeruginosa phage PaoP5, which directly binds to the Lon protease to prevent the degradation of the phage-encoded HNH endonuclease. Deletion of dap2 in PaoP5 exhibits significantly impaired genome packaging due to insufficient levels of HNH. Strikingly, Dap2 synergizes with its genomically adjacent partner Dap1, a previously identified HNH-binding protein providing partial Lon resistance, to achieve complete protection of HNH. Beyond anti-defense activity, Dap2 disrupts host virulence by sequestering the type III secretion system (T3SS) transcriptional activator ExsA, suppressing bacterial pathogenicity while redirecting metabolic resources toward phage progeny production. This study unveils a dual functional ADS that simultaneously modulates bacterial virulence and anti-phage immunity, both aimed at ensuring phage survival and maximizing progeny production. Furthermore, it elucidates a novel mechanism whereby phages employ synergistic ADS pairs (Dap1/Dap2) to achieve complete neutralization of a bacterial defense system, when individual components provide only partial protection. These findings significantly enhance our understanding of the intricate evolutionary arms race between phages and their bacterial hosts.

microbiology↗

Nitrogen deletion in the biosynthesis of HDAC-targeting anticancer drugs

Small molecules play indispensable roles in living systems as hormones, membrane bilayer constituents, enzyme cofactors, metal chelators, and defensive chemicals. The exceptional structural diversity of such molecules underpins their wide-ranging biological functions. Precise functional group insertion into various molecular scaffold classes is a hallmark of small molecule biosynthesis and is frequently important for biological activity. Functional group deletion is also important, but mechanisms are less well understood. Here, we report deletion of a cysteine-derived nitrogen atom during assembly of the conserved pharmacophore in the anticancer drug romidepsin, and related depsipeptide HDAC inhibitors. A shunt metabolite hydroxylated at the cysteine--carbon-derived position is a thousand-fold less active, indicating nitrogen deletion is important for potent HDAC inhibition. In vitro reconstitution and dissection of the complete nonribosomal peptide synthetase-polyketide synthase-mediated pathway for pharmacophore assembly reveal that cryptic S-octanoylation is catalysed by an atypical heterocyclisation domain, while multifunctional dehydratase and ketoreductase domains and trans-acting phosphotransferase and flavin-dependent oxidoreductase enzymes catalyse successive transformations in nitrogen deletion. Our findings significantly advance the understanding of heteroatom deletion mechanisms in small molecule biosynthesis and highlight the key role this can play in enhancing bioactivity. One-pot biocatalytic synthesis of the pharmacophore provides foundations for chemoenzymatic approaches to next-generation HDAC inhibitors.

biochemistry↗

Bimodality in pan-cancer proteomics reveals new opportunities for biomarker discovery

Bimodal protein expression, characterized by the distribution of protein expression with two modes, is linked to phenotypic variation across various biological systems. Whereas previous studies focused on RNA expression data, we developed a bimodality model tailored for proteomics to enhance the identification of cancer-associated biomarkers and targets, facilitating precision oncology. We analyzed proteomics data from various cancer types and identified 2401 tumor-associated bimodal proteins. These proteins were evaluated for pathway enrichment, revealing significant associations with critical cancer pathways, such as metabolism of non-essential amino acids, interaction between the extracellular matrix and its receptors on the cell surface, and central carbon metabolism in cancer. Utilizing an AI-enhanced knowledge graph, we further delineated common patterns among pan-cancer tumor-associated bimodal proteins. A case study on the bimodal expression of TROP2 in colon adenocarcinoma highlighted upregulation of MYC and WNT/{beta}-catenin signaling pathways and down-regulation of inflammatory and interferon-related pathways in the TROP2-high group. The biological difference between TROP2-high and TROP2-low groups underscored its significance in determining cancer heterogeneity and differences in cancer vulnerability, which can inform treatment decisions. Our findings show the value of proteomics in uncovering novel biomarkers and advancing precision medicine, setting a precedent for further multi-omics integration and clinical validation.

bioinformatics↗

Transcriptomic splicing analysis reveals a gene-independent form of TE reactivation in tumors representing unrecognized source of oncogenes and neoantigens

Transposable elements (TEs) are reactivated in tumors and serve as significant contributors to tumor transcriptomic complexity and heterogeneity. However, their repetitive nature and diverse transcriptional forms have hindered efforts to characterize TE-derived transcripts independent of host gene contexts. Here, using our self-developed splicing-junction analysis tool ASJA, we systematically interrogated TE transcription across 32 cancer types, identifying transcripts autonomously initiated from and exclusively spliced among TEs with high TE content, termed TEtrans. Our analysis revealed 5,361 TEtrans exhibiting pan-cancer prevalence, tumor-specific expression and features of mature transcripts, including canonical splicing, 5 caps and polyA tails. Mostly unannotated and enriched in intergenic regions, TEtrans are predominantly derived from primate-specific classes with conserved splice pattern. TEtrans burden demonstrates heterogeneous associations with prognosis and immune activity across cancers, while their expression can be epigenetically dual-regulated by stemness- and inflammation-associated transcription factors. Functional studies uncovered that TEtrans could act as oncogenes, exemplified by tsTE1, a HERVH-derived transcript that promotes colorectal cancer proliferation by enhancing TOP1-mediated DNA supercoil relaxation. Remarkably, [~]7.2% of TEtrans are identified to encode tumor neoantigens, including viral proteins and unannotated peptides, which are shared among patients and validated by proteogenomic analysis. These TEtrans-derived neoantigens are immunogenic both in vitro and in vivo, and exceed neoepitopes from genomic alterations in abundance per tumor, particularly in cancers with low mutational burden. Collectively, as a gene-independent form of TE-derived transcripts, TEtrans represents a unique source of oncogenes and tumor neoantigens, expanding the functional repertoire of TEs in cancer biology and offering new avenues for therapeutic targeting. HighlightsO_LITEtrans are tumor-specific transcripts with conserved splicing patterns, predominantly derived from primate TEs in intergenic regions. C_LIO_LITEtrans expression is epigenetically activated and dually regulated by stemness/inflammation transcription factors. C_LIO_LITEtrans function as oncogenes, exemplified by tsTE1 enhancing TOP1-mediated DNA relaxation. C_LIO_LITEtrans encode tumor neoantigens that elicit CD8+ T cell responses, providing targets for immunotherapy, especially in low-mutation tumors. C_LI Abstract figure O_FIG O_LINKSMALLFIG WIDTH=198 HEIGHT=200 SRC="FIGDIR/small/640928v1_ufig1.gif" ALT="Figure 1"> View larger version (78K): org.highwire.dtl.DTLVardef@1d2d4cforg.highwire.dtl.DTLVardef@918f14org.highwire.dtl.DTLVardef@489465org.highwire.dtl.DTLVardef@1069d17_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

Spatial transcriptomics elucidates the central role of cerebral vasculatures in the progression of Japanese encephalitis

The cellular and molecular mechanisms underlying the neuropathology of Japanese encephalitis virus (JEV) remain obscure. Herein, we designed Stereo-seq chips to simultaneously capture the in situ transcriptomes of both the host and JEV, constructing a comprehensive spatiotemporal pathological landscape for Japanese encephalitis (JE). This study reveals the central role of the vascular system in JE pathogenesis, particularly the meninges, which displayed the strongest signal of inflammation and cell death in the JEV-infected brain. The activation of the Ackr1+ endothelial cells, disruption of the blood-brain barrier, the migration of JEV-infected monocytes, secretion of immune factors by the infected cells, and the occurrence of pyroptosis and necroptosis form a positive feedback loop, resulting in an increasing influx of immune cells and tissue damage. JEV infection leads to neurological impairments, which may be attributed to the interaction between viral proteins and host cellular factors such as Stat1, Stat3, Nfkb1, and Sp1. As the vascular system serves as a central receiver and amplifier of inflammatory signals, regulating inflammation within the vascular system is essential in mitigating JE progression.

immunology↗

The hollow truth: ethylene-triggered ROS, PCD, senescence, and autophagy drive hollow stem formation

Hollow stems have independently evolved multiple times across the plant kingdom, and play crucial roles in plant development and various environmental adaptations. However, the mechanisms underlying stem hollowness remain poorly understood. Water spinach (Ipomoea aquatica) is one of the few hollow-stemmed plants in the Convolvulaceae family, and its hollow stems are essential for thriving in aquatic environments. Using histochemical staining and transcriptome analysis, we identified programmed cell death (PCD) is involved in cavity formation of water spinach shoot tips. Single-cell transcriptome analysis further revealed that ethylene and reactive oxygen species (ROS) drive and regulate this process by activating transcription factors IaNAC074, IaNAC087, IaNAC029, IaNTL9, and IaTGA9, which initiate PCD, senescence, and autophagy, collectively controlling cell death. These findings were validated through treatments with ethylene and ROS reagents in water spinach and transient expression in tobacco. Additionally, transcriptomic data suggest that these mechanisms may also play a role in hollow stem formation in bamboo, highlighting the conservation of PCD regulatory mechanisms in plant development. This work not only fills a major knowledge gap in the adaptive mechanisms of hollow stem formation but also opens new avenues for agricultural and ecological applications, offering strategies to enhance crop tolerance to flooding and accelerate crop growth.

plant biology↗

Distinct mechanisms are employed by T-cell-instructed myeloid cells for IL-1β production in humans and mice.

Interleukin-1 beta (IL-1{beta}) is known as an inflammasome-dependent pro-inflammatory cytokine that has been implicated in T-cell-driven autoimmune diseases. In mice, T-cells were reported to instruct myeloid cells to produce IL-1{beta} via an inflammasome-independent mechanism, that engages TNFR and Fas-caspase-8-dependent signalling pathways. In this study, we explored T-cell-driven myeloid IL-1{beta} production in humans. Co-culturing of autologous primary T-cells (memory CD4+ and CD8+) with myeloid cells (monocyte, macrophage and dendritic cells) revealed that both memory CD4+ and CD8+ T cells induce IL-1{beta} secretion. Also, caspase-1 rather than caspase-8 cleaves pro-IL-1{beta} in human myeloid cells. This process depends on TNF-, CD40L and IFN-{gamma} together rather than TNF- alone, leading to upregulated pro-IL-1{beta} expression in human myeloid cells. We additionally show that TNF-, CD40L and IFN-{gamma} independently enhance IL-1{beta} secretion. Together, our study highlights that, despite the shared biology in T-cell-instructed IL-1{beta} production between humans and mice, different underlying molecular pathways are implicated. SummaryLike murine cells, human T-cells stimulate IL-1{beta} secretion from myeloid cells. However, the underlying mechanisms differ, with IL-1{beta} production in humans being driven by TNF-, CD40L, IFN-{gamma}, and Caspase-1, whereas in mice, it is primarily regulated by TNF- and Caspase-8.

immunology↗

Amphetamine in Adolescence Induces a Sex-Specific Mesolimbic Dopamine Phenotype in the Adult Prefrontal Cortex

Drugs of abuse in adolescence impact brain maturation and increase psychiatric risk, with differences in sensitivity between males and females. Amphetamine in adolescent male, but not female mice, causes dopamine axons intended to innervate the nucleus accumbens and to grow ectopically to the prefrontal cortex (PFC). This is mediated by drug-induced downregulation of the Netrin-1 receptor DCC. How off-target dopamine axons function in the adult PFC remains to be determined. Here we report that males and females show place preference for amphetamine in adolescence. However, only in males, amphetamine increases PFC dopamine transporter expression in adulthood: leading to aberrant baseline dopamine transients, faster dopamine release, and exaggerated responses to acute methylphenidate. Upregulation of DCC in adolescence, using CRISPRa, prevents all these changes. Mesolimbic dopamine axons rerouted to the PFC in adolescence retain anatomical and functional phenotypes of their intended target, rendering males enduringly vulnerable to the harmful effects of drugs of abuse.

neuroscience↗

Mesoderm-specific transcript reduces ciliary sphingomyelin levels to promote tendon stem/progenitor cells osteochondrogenesis in traumatic heterotopic ossification

Traumatic heterotopic ossification (tHO) is a musculoskeletal disorder characterized by ectopic bone formation in soft tissues following trauma. However, the etiology and mechanisms of tHO remain unknown, and no treatments are highly effective for tHO. Here, by performing single-cell RNA sequencing (scRNA-seq) on two tHO mouse models, we found that ciliary Hedgehog (Hh) and PI3K-Akt signaling in tendon stem/progenitor cells (TSPCs) is upregulated during tHO development, leading to the activation of GLI family zinc finger 2 (GLI2) transcription factor, which promotes mesoderm-specific transcript (MEST) gene expression. Untargeted lipidomics using liquid chromatography-tandem mass spectrometry (LC-MS/MS) on detached cilia indicated that MEST could reduce ciliary sphingomyelin (SM) levels by inhibiting SM synthesis in TSPCs, creating a positive feedback loop that amplified ciliary Hh signaling, enhancing TSPCs osteochondrogenesis and driving tHO formation. Targeting ciliary genes intraflagellar transport 88 (IFT88) or ADP ribosylation factor like GTPase 3 (ARL3) restored normal TSPCs osteochondrogenesis in vitro and attenuated ectopic bone formation in vivo by suppressing Hh and PI3K-Akt signaling. AAV-mediated MEST inhibition or exogenous SM administration in vivo also alleviates tHO progression. These findings may provide novel insights into tHO pathogenesis and potential therapeutic strategies.

molecular biology↗

Accelerated genome shuffling associated with rapid evolution of sexual conflict in seed beetles

Structural variation (SV) has an extensive impact on the evolution of the genome. The diverse SV provide a material basis for genome evolution, which can affect gene expression, 3D genome structure, and even changes in complex chromosomal features through regional recombination, copy number variation, and chromosome rearrangement. Here, we assemble and compare the chromosome-level assemblies of three species (Acanthoscelides obtectus, Callosobruchus chinensis, and C. maculatus) in Bruchinae, a clade of Coleoptera that is often used as models to study sexual conflict, to investigate the influence of SV on the changes of various genomic characteristics during species evolution. Through comparative genomic analysis of Coleoptera species, we reveal extensive structural variants (SVs) within the Bruchinae family, which is linked to the ongoing activity of LINE transposons. We show that SV drive the rapid evolution of sex chromosomes and correlated with dynamic evolution of sex-biased gene expression in seed beetle species. Our analysis highlights the acquisition of novel genes on the Y chromosome through frequent gene translocations, gradually shaping them into genes exhibiting male-biased expression patterns. This underscores the Y chromosomes role in promoting sexual dimorphism evolution. Our findings reveal the significant contributions of SV to genome evolution, specifically through their influence on sex chromosome evolution and the evolutionary dynamics of sex-biased genes.

evolutionary biology↗

The first chromosomal-level genome assembly of an allotetraploid oyster

Tetraploid oysters are used to cross with diploids to produce triploid oysters that have become an important part of the oyster aquaculture industry worldwide. Although most tetraploid oysters are artificially induced autotetraploids, allotetraploids can be produced between closely related species, providing new opportunities for polyploid breeding and studying genome interactions. Using PacBio sequencing, Illumina sequencing, and high-throughput chromosome conformation capture scaffolding, we assembled the first high-quality genome assembly of an artificially induced allotetraploid between the Pacific oyster Crassostrea gigas and Portuguese oyster Crassostrea angulata. The assembled genome is 1.23 Gb, with a contig N50 of 2.56 Mb and a scaffold N50 of 57.22 Mb, and anchored to 20 chromosomes. The assembly contains 58,330 protein-coding genes, 98.34% of which are functionally annotated. The heterozygosity and the ratio of repetitive sequences is 5.50% and 46.43%, respectively. This chromosomal-level genome assembly of an allotetraploid oyster provides a valuable genetic resource for studying genome biology of molluscs and for advanced breeding of polyploids that are critical for the oyster aquaculture industry.

genomics↗