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Tang, S.

Publications and source records attributed to Tang, S..

At least 73 records · Page 4Linked to original sources

Benchmarking, detection, and genotyping of structural variants in a population of whole-genome assemblies using the SVGAP pipeline

Comparisons of complete genome assemblies offer a direct procedure for characterizing all genetic differences among them. However, existing tools are often limited to specific aligners or optimized for specific organisms, narrowing their applicability, particularly for large and repetitive plant genomes. Here, we introduce SVGAP, a pipeline for structural variant (SV) discovery, genotyping, and annotation from high-quality genome assemblies at the population level. Through extensive benchmarks using simulated SV datasets at individual, population, and phylogenetic contexts, we demonstrate that SVGAP performs favorably relative to existing tools in SV discovery. Additionally, SVGAP is one of the few tools to address the challenge of genotyping SVs within large assembled genome samples, and it generates fully genotyped VCF files. Applying SVGAP to 26 maize genomes revealed hidden genomic diversity in centromeres, driven by abundant insertions of centromere-specific LTR-retrotransposons. The output of SVGAP is well-suited for pan-genome construction and facilitates the interpretation of previously unexplored genomic regions.

bioinformatics↗

Aberrant Modular Dynamics of Functional Networks in Schizophrenia and Their Relationship with Neurotransmitter and Gene Expression Profiles

IntroductionNumerous studies have emphasized the time-varying modular architecture of functional brain networks and its relevance to cognitive functions in healthy participants. However, how brain modular dynamics change in schizophrenia and how these alterations relate to neurotransmitter and transcriptomic signatures have not been well elucidated. MethodsWe harmonized resting-state fMRI data from a multi-site sample including 223 patients and 279 healthy controls and applied the multilayer network method to estimate the regional module switching rate (flexibility) of functional brain connectomes. We examined aberrant flexibility in patients relative to controls and explored its relations to neurotransmitter systems and postmortem gene expression. ResultsCompared with controls, patients with schizophrenia had significantly higher flexibility in the somatomotor and right visual regions, and lower flexibility in the left parahippocampal gyrus, right supramarginal gyrus, right frontal-operculum-insula, bilateral precuneus posterior cingulate cortex, and bilateral inferior parietal gyrus. These alterations were associated with multiple neurotransmitter systems and weighted gene transcriptomic profiles. The most relevant genes were preferentially enriched for biological processes of transmembrane transport and brain development, specific cell types, and previously identified schizophrenia-related genes. ConclusionsThis study reveals aberrant modular dynamics in schizophrenia and its relations to neurotransmitter systems and schizophrenia-related transcriptomic profiles, providing insights into the understanding of the pathophysiology underlying schizophrenia.

neuroscience↗

Concurrent PIK3CA mutant drives cachexia through inflammatory signaling in EGFR mutant lung cancer

PIK3CA mutation is frequently concurrent with known oncogenic drivers such as EGFR mutation in lung cancer, raising an interesting question about its real function. Cachexia is a systemic disease involving complex interaction between primary tumors and distant organs, significantly contributing to cancer-related mortality. Through integrative study of genetically engineered mouse models (GEMMs) and clinical data, we find concurrent PIK3CA mutant preferentially drives cachexia in EGFR-mutant lung cancer, promoting malignant progression instead of cancer initiation. PIK3CA mutant-mediated cachexia could be overcome by osimertinib (Osi) treatment in Osi-sensitive GEMM. In contrast, chemotherapy, routinely used in clinic for those relapsed from Osi therapy, fails to ameliorate cachexia in Osi-resistant GEMM despite notable tumor suppression. PIK3CA mutant-driven cachexia is mediated through NF-{kappa}B activation and could be dampened by combined aspirin treatment. This work uncovers the biological function of PIK3CA mutant and mechanism behinds its clinical impacts, and proposes a potentially effective strategy for clinical management.

cancer biology↗

Computational constraints underlying theemergence of functional domains in thetopological map of Macaque V4

V4, an intermediate visual area in the ventral visual stream of primates, is known to contain neurons tuned to color, complex local patterns, shape, and texture. Neurons with similar visual attribute preferences are closely positioned on the cortical surface, forming a topological map. Recent studies based on multielectrode arrays and calcium imaging revealed the macaque V4 has neuronal columns tuned to specific natural image features, and these columns are clustered into various functional domains. There are domains tuned to attributes generally associated with object surface properties such as texture or color, as well as domains associated with the shape and form of object boundaries reminiscent of the blobs and inter-blobs in the primary visual cortex. Here, we explored the computational constraints underlying the development of the V4 topological map. We found that the map learned based on self-organizing principles constrained by neuronal columns tuning and retinotopy position can account for many characteristics of the observed V4 map, including the interwoven organization of texture and shape processing clusters. These anatomical clustering, with the implied local recurrent connectivity, might facilitate a modular parallel processing of surfaces and boundaries of objects along the ventral visual system.

neuroscience↗

The Whole Proteome, Phosphoproteome, and Glycoproteome Landscape of Pan-Cancer Cell Lines Profiled by Mass Spectrometry and Reverse Phase Protein Array

Mammalian cancer cell lines are essential model systems in biomedical research. We conducted multi-level proteomics analyses on 54 widely used cancer cell lines derived from various tissue-of-origins using two prominent proteomics technologies: mass spectrometry (MS) and reverse-phase protein array (RPPA). Our analysis identified 10,088 proteins, 33,609 phosphorylation sites across 7,289 phosphoproteins, and 56,350 site-specific glycans on 16,296 glycosylation sites from 5,966 glycoproteins, along with 305 drug-relevant protein and phosphoprotein targets. Our results reveal both consistent and distinct patterns in protein expression and modification between MS and RPPA, underscoring their complementary strengths as discovery tools. Additionally, we identified protein features that distinguish tissue origins across different cell line lineages. This dataset supports model system selection for drug target-related studies in vitro and provides valuable insights into key signaling pathways. Overall, this comprehensive resource enables new opportunities for exploration in cancer biology and offers significant value to research communities focused on biomarker profiling, drug target discovery, and understanding mechanisms across diverse cancer types.

cancer biology↗

Principles of nutrition-dependent root-microbiome engineering for regulating crop yield via live microbial inoculants

As the second genome, host-associated microbiota can enhance the functions of host immune systems, improve host nutrient availability and acquisition capacity, and increase host resistance to abiotic stress. Constructing host-associated microbiomes by applying various bioinoculants has become an attractive tool for promoting human health and increasing food production. However, despite their promising properties, the efficacy of bioinoculants vary significantly in actual field and clinical practices. Understanding the global design principles that shape the outcomes of interactions between bioinoculants and target host-microbiome symbionts remains a considerable challenge. In this study, we used a wheat production system as a case study to quantitatively understand how soil nutrient status impacts the establishment of host-microbiome interaction networks and their subsequent interactions with external bioinoculants. We found that soil organic carbon, one of the most general soil properties for global crop productivity and resilience, could affect the outcome of bioinoculant applications in wheat production systems, which led to functional instability in bioinoculant application outcomes. The results of this study significantly improved our understanding of the global design principles of nutrition-dependent root-microbiome engineering for regulating crop yield via the application of live microbial inoculants and provide theoretical guidance for bioinoculant applications in agricultural practice.

microbiology↗

Imputing not available values in single-cell DNA methylation data using the median is straightforward and effective

Recent advances in single-cell DNA methylation have provided unprecedented opportunities to explore cellular epigenetic differences with maximal resolution. Due to the number of methylation sites exceeding the computational limits of current analytical methods, a common workflow for single-cell DNA methylation analysis is binning the genome into multiple regions and computing the average methylation level within each region. In this process, imputing not available (NA) values which are caused by the limited number of captured methylation sites is a necessary preprocessing step for downstream analyses. Existing studies have employed several simple imputation methods (such as zero imputation or mean imputation); however, there is a lack of theoretical studies or benchmark tests evaluating these approaches. Through both experiments and theoretical analysis, we found that using the median to impute missing data can effectively and simply reflect the methylation state of the NA values, providing an accurate foundation for downstream analyses.

bioinformatics↗

Growth and defence in a unicellular microalga: the coexistence of r and K strategies

r (high reproductivity but stress-sensitive offspring) and K (low reproductivity but high stress-resistant offspring) strategies are two classical life history theories. Contrary to the belief that one species only has a single strategy (i.e., either r or K), we present experimental evidence for the coexistence of both strategies in the isogenic microalga Haematococcus lacustris. Under standard conditions, swimming vegetative cells (SVC) normally grew and divided via binary fission (r strategy) and gradually shifted into non-swimming cysts (NSC) over time. Intriguingly, unlike the prevailing notion that NSC cannot propagate under stress, they were found to reproduce via multiple fission at a barely detectable growth rate, resulting in stress-resistant, non-mobile daughter cells and demonstrating a complete life history (K strategy). Collectively, our findings indicate that H. lacustris adopts both r and K strategies throughout its life history. This research enhances the understanding of the adaptation and survival of microbial populations in changing environments.

ecology↗

Genetic code expansion reveals site-specific lactylation in living cells reshapes protein function

Still in its infancy, the functions of lactylation remain elusive. To address this, we established a comprehensive workflow for lactylation studies that integrates the discovery of lactylation sites with proteomics, the expression of site-specifically lactylated proteins in living cells via genetic code expansion (GCE), and the evaluation of the resulting biological consequences. Specifically, we developed a wet-and-dry-lab combined proteomics strategy, and identified highly conserved lactylation at ALDOA-K147. Driven by its potential biological significance, we site-specifically expressed this lactylated ALDOA in mammalian cells and interrogated the biological changes. We discovered that it not only inhibited enzyme activity but also elicited gain-of-function effects----it dramatically reshaped the functionality of ALDOA by improving stability, enhancing nuclear translocation and affecting gene expression. Further, we demonstrated broad applicability of this workflow to study distinct histone lactylation sites. Together, we anticipate its wide uses in elucidating causative links between site-specific lactylation and target-centric or cell-wide changes.

molecular biology↗

eProbe: a capture probe design toolkit for genetic diversity reconstructions from ancient environmental DNA

Ancient environmental DNA (aeDNA) is now commonly used in paleoecology and evolutionary ecology, yet due to difficulties in gaining sufficient genome coverage on individual species from metagenome data, its genetic perspectives remain largely uninvestigated. Hybridization capture has proven as an effective approach for enriching the DNA of target species, thus increasing the genome coverage of sequencing data and enabling population and evolutionary genetics analysis. However, to date there is no tool available for designing capture probe sets tailored for aeDNA based population genetics. Here we present eProbe, an efficient, flexible and easy-to-use program toolkit that provides a complete workflow for capture probe design, assessment and validation. By benchmarking a probe set for foxtail millet, an annual grass, made by the eProbe workflow, we demonstrate a remarkable increase of capturing efficiency, with the target taxa recovery rate improved by 577-fold, and the genome coverage achieved by soil capture-sequencing data even higher than data directly shotgun sequenced from the plant tissues. Probes that underwent our filtering panels show notably higher efficiency. The capture sequencing data enabled accurate population and evolutionary genetic analysis, by effectively inferring the fine-scale genetic structures and patterns, as well as the genotypes on functional genes.

bioinformatics↗

Proteomics Landscape of Triple-Negative Apocrine Breast Carcinoma Reveals Molecular Mechanisms of Tumorigenesis and Characteristics of Chemo-insensitivity

Triple-negative apocrine carcinoma (TNAC) is an exceptionally rare, chemotherapy-insensitive subtype of triple-negative breast cancer (TNBC) characterized by androgen receptor (AR) positivity and low proliferative activity. Despite poor chemotherapy response, TNAC exhibits favorable long-term survival, suggesting distinct resistance mechanisms. Here, we integrate mass spectrometry-based proteomics and whole-exome sequencing (WES) to characterize TNACs molecular features. We identify progressive overexpression of PI3K/AKT and AR signaling proteins, along with ECM remodeling and upregulation of GTPase-related proteins, highlighting TNACs invasive potential. WES reveals somatic mutations in ECM-related genes (COL18A1) and immune-associated genes (C3, NRDC), implicating the tumor microenvironment. Unlike TNBC, post-chemotherapy TNAC proteomics shows mixed ribosomal regulation and heightened inflammation, rather than reliance on proliferation, suggesting a need for targeted metabolic and immune therapies. Our findings support PI3K/AKT inhibitors and AR antagonists, potentially alongside GTPase inhibitors, metabolic disruptors, and immune therapy, as alternative strategies to standard chemotherapy in TNAC.

cancer biology↗

Inhibition of serine racemase prevents diabetic retinopathy

Retinal diabetic neuropathy (RDN) precedes retinal microvascular pathology in diabetic retinopathy (DR), but the therapy by antagonizing RDN to stall DR is rare. Emerging evidence including ours suggest that serine racemase (SRR) drives DR at least by promoting RDN. Thus, we explore the therapy by antagonizing SRR to stall and treat DR. We herein indicate that inhibition of SRR by oral gavage of l-aspartic acid {beta}-hydroxymate (L-ABH), a competitive inhibitor of SRR, mitigated photoreceptor dysfunction, loss of retinal ganglion cells (RGC) and retinal endothelial cell and pericyte in db/db mice, a type II diabetes model. To dissect the mechanism, intravitreal injection of L-ABH mitigates glutamate-induced neurotoxicity in the retina. In the whole body, gastrointestinal-based delivery of L-ABH maintained euglycemia and improved glucose tolerance either in db/db mice or in diet-induced obesity mice. In conclusion, inhibition of SRR prevented retinal neurovascular abnormalities in diabetic animals through executing neuroprotection in the retina and maintaining glucose homeostasis in the system. Our study reveals a novel strategy to prevent DR.

biochemistry↗

Urine Proteomics in Methamphetamine Addicted Patients

Drug addiction is a serious chronic relapsing brain disease, and methamphetamine dependence has a complex course and is difficult to treat, causing a serious public health burden. In this study, we compared and analyzed the urine proteome of methamphetamine-using patients, methamphetamine-withdrawing patients, healthy individuals. The urine proteome of methamphetamine-using patients and methamphetamine-withdrawing patients was significantly different from that of healthy individuals, and some differential proteins and their enriched biological functions showed that they were associated with addiction or neurotoxicity of methamphetamine. The fact, that the urine proteome of patients who withdrew methamphetamine for more than 3 months were significantly different from that of healthy patients, may reveal the reasons for the high rate of methamphetamine relapse and potential intervention targets. This study proved that urine proteome can reflect the effects of addiction on the body comprehensively, and has the potential to provide clues for addiction.

biochemistry↗

Coral hosts actively accumulate inorganic carbon for zooxanthellae to maintain symbiotic relationships

High primary productivity of coral reefs is widely attributed to the mutualistic symbiosis between coral hosts and their microalgal partners (Symbiodiniaceae). Although the mechanisms maintaining this symbiosis have been considerable investigated, how the symbiont microalgae within coral get sufficient CO2 for photosynthesis still remains inadquately explored. Here, we hypothesized that corals may actively accumulate dissolved inorganic carbon (DIC) for microalgae to maintain the symbiosis. Carbon (HCO3- and glucose) supply and consumption were evaluated in the scleractinian coral (Goniopora lobata) and its symbiont under light and dark conditions. Results suggest that Symbiodiniaceae were high DIC consumers, requiring about 2-3 fold more DIC than free-living species. The corals were high DIC producers, with internal concentrations up to 4.2 fold higher than in the surrounding seawater. In the absence of microalgae utilization, the excess DIC they produced appeared detrimental to their own growth. Moreover, transcriptomic analysis identified several DIC enrichment pathways are evolved in corals to attact the Symbiodiniaceae, including CO2 concentrating mechanisms, respiration, calcification and phosphoenolpyruvate carboxylase. Increased the CO2 dosage in seawater may induce coral symbiosis bleaching. Our findings can deeper reveal on the mechanisms sustaining coral symbiosis, and may help to predict how some corals respond to DIC imbalance under climate changes.

ecology↗

CRISPR Double Knockout Library Reveals Synthetic Lethal Gene Pairs in Triple-Negative Breast Cancer

Synthetic lethality, a genetic interaction involving two or more genes whose combined loss results in cell death, has emerged as a promising strategy for targeted cancer therapy. By exploiting synthetic lethal interactions, cancer cells can be selectively targeted and eradicated while preserving healthy cells, minimizing off-target effects, and reducing toxicity. The development of PARP inhibitors for ovarian and breast cancer patients with BRCA mutations exemplifies the potential of synthetic lethality-based therapy. Various experimental approaches, including CRISPR/Cas9 screens, have been employed to identify synthetic lethal gene pairs. Our lab has developed a CRISPR double knockout library, leveraging the XDeathDB database for candidate gene selection. This comprehensive platform offers insights into 12 cell death modes and 149 cell death hallmark genes. We aim to construct a cell-death double knock-out library using these genes and perform double knock-out screening on MDA-MB-231, a representative cell line for TNBC chemo poor responders. The identified synergistic lethal gene pairs may serve as potential drug targets for treating TNBC.

cancer biology↗

Identifying Novel Therapeutic Targets for Overcoming TNBC Chemo Resistance Through Comprehensive CRISPR-Cas9 Genome Screening

Triple-negative breast cancer (TNBC) represents 15-20% of cases but disproportionately contributes to 35% of breast cancer deaths. Chemotherapy resistance remains a significant challenge in TNBC treatment. In this study, we identified the MDA-MB-231 cell line as the most representative model for TNBC chemotherapy-poor responders by comparing genomic profiles from TNBC cell lines and patient samples. We performed a genome-wide CRISPR-Cas9 screen and RNAseq analysis in MDA-MB-231 cells to uncover potential synthetic lethal targets for cisplatin/doxorubicin treatment. Our analysis confirmed the involvement of known essential genes in DNA damage repair and regulation of DNA replication pathways, such as BCL2L1, ATM, CDC25B, and NBN, in sensitizing cells to cisplatin/doxorubicin. Additionally, We identified hundreds of previously unrecognized genes and pathways related to DNA repair, G2/M DNA damage checkpoint, AMPK signaling, and mTOR signaling. The observed differences between transcriptomic responses and essential pathways from the CRISPR screen suggest a complex regulatory system in cellular response to DNA damage drugs. By combining various data analysis methods and biological experimental approaches, we have pinpointed several promising genes, such as MCM9 and NEPPS, which could serve as potential drug targets to overcome chemoresistance. Overall, our approach efficiently identified essential genes with potential synthetic lethal interactions with cisplatin/doxorubicin, offering new possibilities for combination therapies in chemo resistant TNBC patients.

cancer biology↗

Highly accurate metagenome-assembled genomes from human gut microbiota using long-read assembly, binning, and consolidation methods

Long-read metagenomic sequencing is a powerful approach for cataloging the microbial diversity present in complex microbiomes, including the human gut microbiome. We performed a deep-sequencing experiment using PacBio HiFi reads to obtain metagenome-assembled genomes (MAGs) from a pooled human gut microbiome. We performed long-read metagenome assembly using two methods (hifiasm-meta, metMDBG), used improved bioinformatic and proximity ligation binning strategies to cluster contigs and identify MAGs, and developed a novel framework to compare and consolidate MAGs (pb-MAG-mirror). We found proximity ligation binning yielded more MAGs than bioinformatic binning, but our novel comparison framework resulted in higher MAG yields than either binning strategy individually. In total, from 255 Gbp of total HiFi data we produced 595 total MAGs (including 175 high-quality MAGs) using hifiasm-meta, and 547 total MAGs (including 277 high-quality MAGs) with metaMDBG. Hifiasm-meta assembled almost twice as many strain-level MAGs as metaMDBG (246 vs. 156), but both assembly methods produced up to five strains for a species. Approximately 85% of the MAGs were assigned to known species, but we recovered >35 high-quality MAGs that represent uncultured diversity. Based on strict similarity scores, we found 125 MAGs were unequivocally shared across the assembly methods at the strain level, representing [~]22% of the total MAGs recovered per method. Finally, we detected more total viral sequences in the metaMDBG assembly versus the hifiasm-meta assembly ([~]6,700 vs. [~]4,500). Overall, we find the use of HiFi sequencing, improved metagenome assembly methods, and complementary binning strategies is highly effective for rapidly cataloging microbial genomes in complex microbiomes.

microbiology↗

De novo gene synthesis by an antiviral reverse transcriptase

Bacteria defend themselves from viral infection using diverse immune systems, many of which sense and target foreign nucleic acids. Defense-associated reverse transcriptase (DRT) systems provide an intriguing counterpoint to this immune strategy by instead leveraging DNA synthesis, but the identities and functions of their DNA products remain largely unknown. Here we show that DRT2 systems execute an unprecedented immunity mechanism that involves de novo gene synthesis via rolling-circle reverse transcription of a non-coding RNA (ncRNA). Unbiased profiling of RT-associated RNA and DNA ligands in DRT2-expressing cells revealed that reverse transcription generates concatenated cDNA repeats through programmed template jumping on the ncRNA. The presence of phage then triggers second-strand cDNA synthesis, leading to the production of long double-stranded DNA. Remarkably, this DNA product is efficiently transcribed, generating messenger RNAs that encode a stop codon-less, never-ending ORF (neo) whose translation causes potent growth arrest. Phylogenetic analyses and screening of diverse DRT2 homologs further revealed broad conservation of rolling-circle reverse transcription and Neo protein function. Our work highlights an elegant expansion of genome coding potential through RNA-templated gene creation, and challenges conventional paradigms of genetic information encoded along the one-dimensional axis of genomic DNA. One-Sentence SummaryBacterial reverse transcriptases synthesize extrachromosomal genes via rolling-circle amplification to confer potent antiviral immunity.

molecular biology↗