Biology subjects

Cao, W.

Publications and source records attributed to Cao, W..

At least 37 records · Page 2Linked to original sources

bioRxiv2025

A new typing scheme demonstrates high discriminatory power for Treponema pallidum subspecies

The global resurgence of treponematoses, particularly syphilis, poses a growing public health challenge. Despite recent advances in sequencing technologies, obtaining complete Treponema pallidum genome sequences for epidemiological studies remains time-consuming and challenging due to the difficulty related to procuring clinical samples with sufficient treponemal burden to fulfil the sequencing requirements. There is an urgent need for rapid, cost-effective and accessible typing methods suitable for laboratories with Sanger sequencing resources. Based on the analysis of 121 T. pallidum genomes from geographically diverse regions, we selected seven highly variable genes to form the basis of this new typing system. These seven genes show high discrimination capacity, identifying many allelic profiles among T. pallidum isolates. Importantly, the scheme employs a single-step PCR protocol for the amplification and sequencing of all seven targets enabling straightforward implementation in standard laboratory settings. The MLST was validated using a diverse set of T. pallidum clinical samples from across the globe. A significant proportion of the tested samples showed macrolide resistance, emphasizing the need for epidemiological surveillance. Utilizing this new tool, we have analyzed the genetic variation within and between populations of T. pallidum, considering the geographical origin of the samples. Population structure analysis revealed distinct genetic clusters, underlining complex transmission dynamics of T. pallidum, shaped by local epidemiological factors. The MLST scheme is publicly accessible through the PubMLST database, encouraging widespread adoption in standard laboratories due to this database being user-friendly, intuitive, and fast to implement. The novel MLST scheme offers a promising tool to advance the study of the molecular epidemiology of T. pallidum, facilitate tracking transmission, and establish a global surveillance network with the overall goal of strengthening public health interventions for syphilis control.

microbiology↗

bioRxiv2025

Specificity of Aberrant Exons in a Saturated Background of Differentially Expressed Exons

Determining the maximal specificity of aberrant exons from multifactorial disease tissues in a whole body background could provide insights into the exon origin as well as potential targets of diagnosis or therapy, but it remains a challenging task. For this purpose, we obtained a saturated list of differentially expressed exons (DEXs) from our independent reference human exome extracted from 56 normal tissues by DEXSeq. We found that the DEXs comprised the majority of the reference exome and that 99.4% of cancer-specific exons relative to paired normal tissues fell within the DEX list, consistent with the ectopic expression of the majority of aberrant exons. We then screened over seven thousand pathogenic single nucleotide variants (SNVs) in the TCGA and COSMIC databases by SpliceAI. The analysis identified over three hundreds of highly confident, mostly somatic SNV-specific splicing events and/or novel exonic fragments in five types of adenocarcinomas. Interestingly, these events are all associated with cis-acting mutations in tumor suppressor genes, particularly in TP53 with an antigenic novel peptide. This revelation of the DEX exome dominance and non-specificity of nearly all aberrant exons not only reshapes our understanding of the normal human exome by highlighting its mainly variable over constitutive exons, but also illuminates the path through cis-acting somatic and pathogenic SNVs to identify genuine cancer-specific exonic fragments that are absent in any normal tissues, beyond neo-exon junctions. This path holds promise for identifying novel peptide fragments for antigens in holistic cancer treatments including vaccination and immunotherapies.

cancer biology↗

bioRxiv2025

Convergence and conflict among telomere specialized transposons across 60 million years of Drosophilid evolution

The Drosophila telomere is one of the best-studied examples of active transposable elements (TEs) benefitting, rather than harming, a host genome. All Drosophila species lack telomerase and instead have telomeres composed of head-to-tail arrays of specialized retrotransposons. These TEs ostensibly act as mutualists by elongating chromosome ends, but evidence from species closely related to Drosophila melanogaster suggests that telomeric transposons may also antagonize their host genome. Importantly, the limited number of Drosophila species characterized thus far has precluded our ability to delineate idiosyncratic from universal evolutionary forces and genetic mechanisms that shape the history of these TEs. Here, we have surveyed long-read genome assemblies of over 100 species of Drosophila, identifying a total of 396 telomeric TE families. Our findings show that these telomere-specialized elements evolve rapidly and also undergo striking convergent evolution: the complete loss of telomeric TEs has occurred repeatedly across the genus while individual telomeric TE lineages have repeatedly lost one of their two protein-coding genes. These elements have also repeatedly undergone horizontal transfer between distantly related Drosophila lineages and have repeatedly captured host gene fragments that promote their selfish suppression of host TE-silencing systems. Furthermore, telomere specialization itself appears to have evolved convergently, as some non-telomeric families have gained the ability to target their insertions to telomeres. These results provide unprecedented resolution into the evolution of these unusual TEs and highlight several novel mechanisms by which they evolve in conflict both with each other and their host genome despite the essential telomere function they provide.

genomics↗

bioRxiv2025

An Antibody Cocktail-Based Immunoaffinity-LC-MS Method Enabled Ultra-Sensitive and Robust Quantification of Circulating Proinsulin Proteoforms and C-peptide

Accurately measuring circulating proinsulin proteoforms is crucial for clinical investigation of diabetes, but was previously not feasible owing to limited assay specificity/sensitivity. Here we devised a highly sensitive LC-MS-based strategy to quantify intact proinsulin, des-31,32 and des-64,65 proinsulin, and C-peptide in circulation. The method involves: i)quantitative, robust affinity capture using an optimized antibody cocktail, eliminating the severe quantitative bias across multiple proteomes typically introduced when using a single antibody; ii)Lys-C digestion producing unique signature peptides for each proteoform, and iii)trapping-nano-LC coupled with FAIMS/dCV-MS for an ultra-sensitive analysis. The selective trapping/delivery ensured sensitive/selective analysis of the targets while achieving excellent analytical robustness that is critical for clinical assays, and the FAIMS/dCV substantially reduces baseline noise/interferences, further enhancing S/N. The assay achieved exceptional sensitivity, with serum LOQs of 1.7, 2.3, and 3.6 pg/mL respectively for intact-proinsulin, des-31,32 and des-64,65, representing the first assay capable of sensitively quantifying these major circulating proinsulin proteoforms. We applied this assay to 78 subjects, including autoantibody positive(n=20) and new-onset type-1-diabetes(T1D, n=19) with respective age/sex/BMI-matched controls, enabling the first accurate profiling of proinsulin proteoforms in clinical groups. The assay results demonstrated a clear separation of control and new-onset T1D groups that a parallel total-proinsulin ELISA assay fails to capture. Furthermore, distinct expression patterns in relative abundance ratios among proteoforms were observed across clinical groups. This assay may provide valuable insights into the {beta}-cell functions and the onset/progression of diabetes and other associated conditions. Moreover, the strategy is broadly applicable to targeted measurement of other biomarker proteoforms.

biochemistry↗

bioRxiv2025

De novo design of miniprotein agonists and antagonists targeting G protein-coupled receptors

G protein-coupled receptors (GPCRs) play key roles in physiology and are central targets for drug discovery and development, but the design of protein agonists and antagonists has been challenging as GPCRs are integral membrane proteins and conformationally dynamic. Here we describe computational de novo design methods and a high throughput "receptor diversion" microscopy-based screen for generating GPCR binding miniproteins with high affinity, potency and selectivity, and the use of these methods to generate agonists for MRGPRX1, NK1R and CCR5, as well as antagonists for CXCR4, CCR5, OXTR, GLP1R, GIPR, GCGR, PTH1R and CGRPR.. Cryo-electron microscopy data reveals atomic-level agreement between designed and experimentally determined structures for CGRPR- and CXCR4-bound antagonists and MRGPRX1-bound agonists. Our de novo design and screening approach opens new frontiers in GPCR drug discovery and development.

bioengineering↗

bioRxiv2025

Mediator-29 Limits Caenorhabditis elegans Fecundity

Mediator is an evolutionarily conserved multiprotein complex that acts as a critical coregulator of RNA polymerase II-mediated transcription. While core Mediator components are broadly required for transcription, others govern specific regulatory modules and signalling pathways. Here, we investigated the function of MDT-29/MED29 in the Caenorhabditis elegans germ line. We found that endogenously-tagged MDT-29 is ubiquitously expressed and concentrated in discrete foci within germ cell nuclei. Functionally, depleting MDT-29 in the germ line during larval development boosted fecundity. We determined that the increase in progeny production was likely caused by a combination of an expanded germline stem cell pool and decreased germ cell apoptosis. Thus, MDT-29 may act to optimize specific gene expression programs to control distinct germ cell behaviors, providing flexibility to progeny production in certain environments.

developmental biology↗

bioRxiv2025

Non-mutated human tau stimulates Alzheimer's disease-relevant neurodegeneration in a microglia-dependent manner

The accumulation of abnormal, non-mutated tau protein is a key pathological hallmark of Alzheimers disease (AD). Despite its strong association with disease progression, the mechanisms by which tau drives neurodegeneration in the brain remain poorly understood. Here, we selectively expressed non-mutated or mutated human microtubule-associated protein tau (hMAPT) in neurons across the brain and observed neurodegeneration in the hippocampus, especially associated with non-mutated human tau. Single-nuclei RNA sequencing confirmed a selective loss of hippocampal excitatory neurons by the wild-type tau and revealed the upregulation of neurodegeneration-related pathways in the affected populations. The accumulation of phosphorylated tau was accompanied by cellular stress in neurons and reactive gliosis in multiple brain regions. Notably, the lifelong absence of microglia significantly and differentially influenced the extent of neurodegeneration in the hippocampus and thalamus. Therefore, our study established an AD-relevant tauopathy mouse model, elucidated both neuron-intrinsic and neuron-extrinsic responses, and highlighted critical and complex roles of microglia in modulating tau-driven neurodegeneration.

neuroscience↗

bioRxiv2024

Human heart assembloids with autologous tissue-resident macrophages recreate physiological immuno-cardiac interactions

Interactions between the developing heart and the embryonic immune system are essential for proper cardiac development and maintaining homeostasis, with disruptions linked to various diseases. While human pluripotent stem cell (hPSC)-derived organoids are valuable models for studying human organ function, they often lack critical tissue-resident immune cells. Here, we introduce an advanced human heart assembloid model, termed hHMA (human heart-macrophage assembloid), which fully integrates autologous cardiac tissue- resident macrophages (MPs) with pre-existing human heart organoids (hHOs). Through multi-omic analyses, we confirmed that these MPs are phenotypically similar to embryonic cardiac tissue-resident MPs and remain viable in the assembloids over time. The inclusion of MPs significantly impacts hHMA development, influencing cardiac cellular composition, boosting cellular communication, remodeling the extracellular matrix, promoting ventricular morphogenesis, and enhancing sarcomeric maturation. Our findings indicate that MPs contribute to homeostasis via efferocytosis, integrate into the cardiomyocyte electrical system, and support catabolic metabolism. To demonstrate the versatility of this model, we developed a platform to study cardiac arrhythmias by chronic exposure to pro-inflammatory factors linked to arrhythmogenesis in clinical settings, successfully replicating key features of inflammasome-mediated atrial fibrillation. Overall, this work introduces a robust platform for examining the role of immune cells in cardiac development, disease mechanisms, and drug discovery, bridging the gap between in vitro models and human physiology. These findings offer insights into cardiogenesis and inflammation-driven heart disease, positioning the hHMA system as an invaluable tool for future cardiovascular research and therapeutic development.

bioengineering↗

bioRxiv2024

Establishment and Molecular Characterization of Patient-Derived Organoids for Primary Central Nervous System Lymphoma

Primary central nervous system lymphoma (PCNSL) exhibits substantial heterogeneity, both intra-tumoral and intertumoral, posing challenges in developing effective treatment methods. Existing in vitro models fail to simulate the inherent microenvironment and the cellular and mutational diversity of native tumors and require a prolonged generation time. To address this concern, we described an organoid culture method for patient-derived PCNSL organoids (CLOs) and evaluated them through extensive molecular characterization. These CLOs accurately mimicked the histological attributes, gene expression landscapes and mutational profiles of their original tumors through rigorous histopathological analysis, RNA sequencing and whole-exome sequencing. Notably, CLOs were generated within 2 weeks, demonstrating rapid development and reliability. Furthermore, therapeutic profiling was performed on three selected CLOs using four standard treatment drugs. High concordance was observed between the drug responses of patients and those observed in the CLOs, with specific sensitivity to ibrutinib and methotrexate and resistance to dexamethasone and rituximab. Taken together, these results emphasize that CLOs can effectively emulate the key characteristics of PCNSL, enhancing the understanding of the genetic landscape of this complex disease. CLOs provide a rapid and reliable platform for exploring individualized treatment strategies, potentially accelerating the transition of research findings to clinical practice.

cancer biology↗

bioRxiv2024

STAMBPL1 activates the GRHL3/HIF1A/VEGFA axis through interaction with FOXO1 to promote angiogenesis in triple-negative breast cancer

In the clinic, anti-tumor angiogenesis is commonly employed for treating recurrent, metastatic, drug-resistant triple-negative and advanced breast cancer. Our previous research revealed that the deubiquitinase STAMBPL1 enhances the stability of MKP-1, thereby promoting cisplatin resistance in breast cancer. In this study, we discovered that STAMBPL1 could upregulate the expression of the hypoxia-inducible factor HIF1 in breast cancer cells. Therefore, we investigated whether STAMBPL1 promotes tumor angiogenesis. We demonstrated that STAMBPL1 increased HIF1A transcription in a non-enzymatic manner, thereby activating the HIF1/VEGFA signaling pathway to facilitate TNBC angiogenesis. Through RNA-seq analysis, we identified the transcription factor GRHL3 as a downstream target of STAMBPL1 that is responsible for mediating HIF1A transcription. Furthermore, we discovered that STAMBPL1 regulates GRHL3 transcription by interacting with the transcription factor FOXO1. These findings shed light on the role and mechanism of STAMBPL1 in the pathogenesis of breast cancer, offering novel targets and avenues for the treatment of triple-negative and advanced breast cancer.

cancer biology↗

bioRxiv2024

Aging trajectories of memory CD8+ T cells differ by their antigen specificity

Memory T cells are a highly dynamic and heterogeneous population that is maintained by cytokine-driven homeostatic proliferation interspersed with episodes of antigen-mediated expansion and contraction which affect their functional state and their durability. This heterogeneity complicates studies on the impact of aging on global human memory cells, specifically, it is unclear how aging drives memory T cell dysfunction. Here, we used chronic infection with Epstein-Barr virus (EBV) to assess the influence of age on memory states at the level of antigen-specific CD8+ T cells. We find that in young adults (<40 years), EBV-specific CD8+ T cells assume preferred differentiation states depending on their peptide specificity. By age >65-years, different T cell specificities had undergone largely distinct aging trajectories, which had in common a loss in adaptive and a gain in innate immunity signatures. No evidence was seen for cellular senescence or exhaustion. While naive/stem-like EBV-specific T cells disappeared with age, T cell diversity of EBV-specific memory cells did not change or even increased. In summary, by controlling for antigen specificity we uncover age-associated shifts in gene expression and TCR diversity that have implications for optimizing vaccination strategies and adoptive T cell therapy.

immunology↗

bioRxiv2024

Functional Activity, Functional Connectivity and Complex Network Biomarkers of Progressive Hyposmia Parkinson's Disease with No Cognitive Impairment: Evidences from Resting-state fMRI Study

BackgroundOlfactory dysfunction stands as one of the most prevalent non-motor symptoms in the initial stage of Parkinsons disease (PD). Nevertheless, the intricate mechanisms underlying olfactory deficits in Parkinsons disease still remain elusive. MethodsThis study collected rs-fMRI data from 30 PD patients (15 with severe hyposmia (PD-SH) and 15 with no/mild hyposmia (PD-N/MH)) and 15 healthy controls (HC). To investigate functional segregation, the amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) were utilized. Functional connectivity (FC) analysis was performed to explore the functional integration across diverse brain regions. Additionally, the graph theory-based network analysis was employed to assess functional networks in PD patients. Furthermore, Pearson correlation analysis was conducted to delve deeper into the relationship between the severity of olfactory dysfunction and various functional metrics. ResultsFirstly, PD patients showed significantly higher ALFF values in the superior temporal gyrus compared to HC, especially in the PD-SH group versus PD-N/MH. Meanwhile, ALFF values in this region negatively correlated with olfactory testing scores. Secondly, PD patients had higher ReHo in middle temporal gyrus and superior frontal gyrus than HC, especially PD-SH. Meanwhile, olfactory scores negatively correlated with these ReHo values. Thirdly, we observed a negative correlation between superior cerebellar-insula connectivity and olfactory scores, suggesting a neural circuit link to olfactory dysfunction. Lastly, the PD patients brain networks consistently showed small-world attributes, with the PD-N/MH group having significantly higher nodal betweenness in the superior cerebellum than the PD-SH group. Theres also a positive link between superior cerebellums betweenness and olfactory scores. Additionally, there is a notable difference in the node degree of the superior temporal gyrus when comparing the PD-SH group to the PD-N/MH group. ConclusionUsing fMRI, our study analyzed brain function in PD-SH, PD-N/MH, and HC groups, revealing impaired segregation and integration in PD-SH and PD-N/MH. We hypothesize that changes in temporal, frontal, occipital, and cerebellar activities, along with aberrant cerebellum-insula connectivity and node degree and betweenness disparities, may be linked to olfactory dysfunction in PD patients.

neuroscience↗

bioRxiv2024

Fate-mapping and functional dissection reveal perilous influence of type I interferon signaling in mouse brain aging

Although aging significantly elevates the risk of developing neurodegenerative diseases, how age-related neuroinflammation preconditions the brain toward pathological progression is ill-understood. To comprehend the scope of type I interferon (IFN-I) activity in the aging brain, we surveyed IFN-I-responsive reporter mice and detected age-dependent signal escalation in multiple brain cell types from various regions. Selective ablation of Ifnar1 from microglia in aged mice significantly reduced overall brain IFN-I signature, dampened microglial reactivity, lessened neuronal loss, and diminished the accumulation of lipofuscin, a core hallmark of cellular aging in the brain. Overall, our study demonstrates pervasive IFN-I activity during normal mouse brain aging and reveals a pathogenic role played by microglial IFN-I signaling in perpetuating neuroinflammation, neuronal dysfunction, and molecular aggregation. These findings extend the understanding of a principal axis of age-related inflammation in the brain, and provide a rationale to modulate aberrant immune activation to mitigate neurodegenerative process at all stages.

neuroscience↗

bioRxiv2024

Development of a Two-Leaf Photosynthetic Model Sensitive to Chlorophyll and Its Coupling with a Wheat Growth Model

Crop growth models (CGMs) commonly simulates the response of photosynthetic rate to nitrogen (N) dynamic by calculating critical N concentration. However, critical N concentration makes it hard to describe the physiological effect of N dynamic on photosynthesis. Meanwhile, the effect of diffuse light on photosynthesis was limited in previous studies. In this study, we introduced a Two-leaf Photosynthetic Model Sensitive to Chlorophyll Content (TPMSCC) and coupled it with the crop growth model (WheatGrow) to enhance our understanding of how N dynamic and diffuse light affects photosynthesis. By coupling the Farquhar-von Caemmerer-Berry (FvCB) C3 photosynthesis model with a canopy radiative transfer model (PROSAIL), TPMSCC simulated the light interception of direct and diffuse light, and employed leaf chlorophyll content (LCC) to simulate the light absorption and electron transfer rate of leaves. Result showed that TPMSCC well simulated the light absorption of the wheat canopy and found the canopy photosynthetic rate benefited from the increase of diffuse radiation fraction (DRF) except for when the condition of a dense canopy at a high solar zenith angle was present. Research found the logarithmic and linear relationships of LCC to the initial light use efficiency ([a]) and the maximum photosynthetic rate (Amax), respectively, which followed the field measurements. Additionally, the optimized WheatGrow model outperforms its predecessor in describing the response of N application rate on photosynthesis.

biophysics↗

bioRxiv2024

Perinatal Brain Injury Triggers Niche-Specific Changes to Cellular Biogeography

Preterm infants are at risk for brain injury and neurodevelopmental impairment due, in part, to white matter injury following chronic hypoxia exposure. However, the precise molecular mechanisms by which perinatal hypoxia disrupts early neurodevelopment are poorly understood. Here, we constructed a brain-wide map of the regenerative response to newborn brain injury using high-resolution imaging-based spatial transcriptomics to analyze over 1.3 million cells in a mouse model of chronic neonatal hypoxia. Additionally, we developed a new method for inferring condition-associated differences in cell type spatial proximity, enabling the identification of niche-specific changes in cellular architecture. We observed hypoxia-associated changes in region-specific cell states, cell type composition, and spatial organization. Importantly, our analysis revealed mechanisms underlying reparative neurogenesis and gliogenesis, while also nominating pathways that may impede circuit rewiring following perinatal hypoxia. Altogether, our work provides a comprehensive description of the molecular response to newborn brain injury.

neuroscience↗

bioRxiv2023

Deciphering 3'UTR mediated gene regulation using interpretable deep representation learning

The 3untranslated regions (3UTRs) of messenger RNAs contain many important cis-regulatory elements that are under functional and evolutionary constraints. We hypothesize that these constraints are similar to grammars and syntaxes in human languages and can be modeled by advanced natural language models such as Transformers, which has been very effective in modeling protein sequence and structures. Here we describe 3UTRBERT, which implements an attention-based language model, i.e., Bidirectional Encoder Representations from Transformers (BERT). 3UTRBERT was pre-trained on aggregated 3UTR sequences of human mRNAs in a task-agnostic manner; the pre-trained model was then fine-tuned for specific downstream tasks such as predicting RBP binding sites, m6A RNA modification sites, and predicting RNA sub-cellular localizations. Benchmark results showed that 3UTRBERT generally outperformed other contemporary methods in each of these tasks. We also showed that the self-attention mechanism within 3UTRBERT allows direct visualization of the semantic relationship between sequence elements.

bioinformatics↗

bioRxiv2023

Distinct functional constraints driving conservation of the cofilin N-terminal regulatory tail

Cofilin family proteins have essential roles in remodeling the cytoskeleton through filamentous actin depolymerization and severing. The short unstructured N-terminal region of cofilin is critical for actin binding and harbors the major site of inhibitory phosphorylation. Atypically for a disordered sequence, the N-terminal region is highly conserved, but the aspects of cofilin functionality driving this conservation are not clear. Here, we screened a library of 16,000 human cofilin N-terminal sequence variants for their capacity to support growth in S. cerevisiae in the presence or absence of the upstream regulator LIM kinase. Results from the screen and subsequent biochemical analysis of individual variants revealed distinct sequence requirements for actin binding and regulation by LIM kinase. While the presence of a serine, rather than threonine, phosphoacceptor residue was essential for phosphorylation by LIM kinase, the native cofilin N-terminus was otherwise a suboptimal LIM kinase substrate. This circumstance was not due to sequence requirements for actin binding and severing, but rather appeared primarily to maintain the capacity for phosphorylation to inactivate cofilin. Overall, the individual sequence requirements for cofilin function and regulation were remarkably loose when examined separately, but collectively restricted the N-terminus to sequences found in natural cofilins. Our results illustrate how a regulatory phosphorylation site can balance potentially competing sequence requirements for function and regulation.

molecular biology↗

bioRxiv2023

A neuro-intestinal circuit controls mitochondrial dynamics and stress resistance

Neurons coordinate inter-tissue protein homeostasis to systemically manage cytotoxic stress. Specific neuropeptidergic signals coordinate the systemic mitochondrial stress response (UPRmt), but whether chemical neurotransmitters also influence this process is unclear. Here, we show that gamma-aminobutyric acid (GABA) inhibits, and acetylcholine (ACh) promotes the UPRmt in the Caenorhabditis elegans intestine. GABA controls the UPRmt by regulating extra-synaptic ACh release through metabotropic GABAB receptors GBB-1/2. We find that elevated ACh levels in animals that are GABA-deficient or lack ACh-degradative enzymes induce the UPRmt through ACR-11, an intestinal nicotinic 7 receptor. This neuro-intestinal circuit is critical for nonautonomously regulating mitochondrial dynamics and organismal survival of oxidative stress. These findings establish chemical neurotransmission as a crucial regulatory layer for nervous system control of systemic protein homeostasis and stress responses. One-Sentence SummaryRegulation of mitochondrial health with neurotransmission.

neuroscience↗