bioRxiv Science⌕ Search

Biology subjects

Wen, B.

Publications and source records attributed to Wen, B..

35 records · Page 2Linked to original sources

G3BP1 Maintains Vascular Endothelial Barrier Integrity by Negatively Regulating the MYD88-ARNO-ARF6 Signaling Pathway

Endothelial permeability is essential for vascular function. This process is regulated by intercellular junctions, including adherens junctions (AJs) and tight junctions (TJs), which form the endothelial barrier and dynamically connect adjacent cells. However, the mechanisms that control endothelial permeability are not fully understood. We investigated the role of the RNA-binding protein G3BP1 in regulating endothelial permeability. We examined the effects of Loss of g3bp1 in conditional knockout mice and primary human HUVEC cells. We analyzed endothelial barrier integrity and permeability, focusing on AJ and TJ expression, under both normal and LPS-induced inflammatory conditions. Loss of g3bp1 in vascular endothelial cells decreased AJ and TJ expression, compromised barrier integrity, and increased permeability. These effects were exacerbated under LPS-induced inflammatory conditions. Loss of g3bp1 also increased the expression of MYD88, ARNO, and ARF6, and enhanced ARF6 activity. Mechanistically, G3BP1 bound to and stabilized MYD88 mRNA, negatively regulating the MYD88-ARNO-ARF6 signaling pathway. Inhibiting this pathway by reducing MYD88 or ARF6 expression, or inhibiting ARNO activity, restored AJ/TJ expression and barrier function in G3BP1-deficient models. Our findings identify G3BP1 as a novel regulator of vascular endothelial permeability. G3BP1 acts by negatively regulating the MYD88-ARNO-ARF6 signaling pathway. Targeting G3BP1 may be a potential therapeutic strategy for diseases associated with endothelial barrier dysfunction.

physiology↗

ANLN directly interacts with PCNA to regulate UV induced translesion synthesis

Anillin (ANLN) is a cytoskeletal binding protein involved in mitosis. ANLN is located in the nucleus during interphase and in the cytoplasmic contractile rings during mitosis. Our previous studies found that ANLN is abnormally overexpressed in esophageal squamous cell carcinoma (ESCC), promoting cell division by regulating contractile ring localization. However, the exact function of ANLN in the nucleus remains unclear. Here, we found that the expression of ANLN in the nucleus is associated with poor prognosis in ESCC patients, rather than in the cytoplasm. Protein mass spectrometry and bioinformatics analysis revealed that ANLN is related to DNA synthesis, and proliferating cell nuclear antigen (PCNA) is found to be a potential interacting protein of ANLN. PCNA directly interacts with the PIP box domain of ANLN and co-localizes in the nucleus. ANLN promotes DNA replication and S phase progression in a PCNA dependent manner and independent with the cytoskeletal function of ANLN. Importantly, ANLN is involved in transletion synthesis (TLS), a type of DNA synthesis under stress, by promoting PCNA monoubiquitination at K164 residue. Mechanistically, ANLN binds and recruits the E3 ligase RAD18 to promote PCNA monoubiquitination and DNA polymerase eta loading under UV radiation conditions. Consistently, depletion of ANLN leads to increased genomic instability and increased sensitivity to UV radiation. The findings of the study showed that ANLN in the nucleus as a protein scaffold is involved in UV induced DNA synthesis pathway, providing new insights into the function and mechanism of ANLN in cancer cells.

cancer biology↗

A transformer model for de novo sequencing of data-independent acquisition mass spectrometry data

A core computational challenge in the analysis of mass spectrometry data is the de novo sequencing problem, in which the generating amino acid sequence is inferred directly from an observed fragmentation spectrum without the use of a sequence database. Recently, deep learning models have made significant advances in de novo sequencing by learning from massive datasets of high-confidence labeled mass spectra. However, these methods are primarily designed for data-dependent acquisition (DDA) experiments. Over the past decade, the field of mass spectrometry has been moving toward using data-independent acquisition (DIA) protocols for the analysis of complex proteomic samples due to their superior specificity and reproducibility. Hence, we present a new de novo sequencing model called Cascadia, which uses a transformer architecture to handle the more complex data generated by DIA protocols. In comparisons with existing approaches for de novo sequencing of DIA data, Cascadia achieves state-of-the-art performance across a range of instruments and experimental protocols. Additionally, we demonstrate Cascadias ability to accurately discover de novo coding variants and peptides from the variable region of antibodies.

bioinformatics↗

Assessment of false discovery rate control in tandem mass spectrometry analysis using entrapment

A pressing statistical challenge in the field of mass spectrometry proteomics is how to assess whether a given software tool provides accurate error control. Each software tool for searching such data uses its own internally implemented methodology for reporting and controlling the error. Many of these software tools are closed source, with incompletely documented methodology, and the strategies for validating the error are inconsistent across tools. In this work, we identify three different methods for validating false discovery rate (FDR) control in use in the field, one of which is invalid, one of which can only provide a lower bound rather than an upper bound, and one of which is valid but under-powered. The result is that the field has a very poor understanding of how well we are doing with respect to FDR control, particularly for the analysis of data-independent acquisition (DIA) data. We therefore propose a theoretical formulation of entrapment experiments that allows us to rigorously characterize the behavior of the various entrapment methods. We also propose a more powerful method for evaluating FDR control, and we employ that method, along with other existing techniques, to characterize a variety of popular search tools. We empirically validate our entrapment analysis in the fairly well-understood DDA setup before applying it in the DIA setup. We find that none of the DIA search tools consistently controls the FDR at the peptide level, and the tools struggle particularly with analysis of single cell datasets.

bioinformatics↗

Dual Targeting of STING and PI3Kγ Eliminates Regulatory B Cells to Overcome STING Resistance for Pancreatic Cancer Immunotherapy

The immune suppression in tumors and lymph nodes of pancreatic ductal adenocarcinoma (PDAC), regulated by suppressive myeloid cells and regulatory B (Breg) cells, hinders the effectiveness of immunotherapy. Although STING agonists activate myeloid cells to overcome immune suppression, it expands Breg cells, conferring STING resistance in PDAC. We discovered that blocking PI3K{gamma} during STING activation abolished IRF3 phosphorylation to eliminate Breg cells, while PI3K{gamma} inhibition sustained STING-induced IRF3 phosphorylation to preserve STING function in myeloid cells. Therefore, we developed a dual functional compound SH-273 and its albumin nanoformulation Nano-273, which stimulates STING to activate myeloid cells and inhibits PI3K{gamma} to eliminates Breg cells overcoming STING resistance. Nano-273 achieved systemic antitumor immunity through intravenous administration, which decreases Breg cells and remodels microenvironment in tumors and lymph nodes. Nano-273, combined with anti-PD-1, extended median survival to 200 days in transgenic KPC PDAC mice (KrasG12D-P53R172H-Cre), offering potential for PDAC treatment.

pharmacology and toxicology↗

Modular vector assembly enables rapid assessment of emerging CRISPR technologies

The diversity of CRISPR systems, coupled with scientific ingenuity, has led to an explosion of applications; however, to test newly-described innovations in their model systems, researchers typically embark on cumbersome, one-off cloning projects to generate custom reagents that are optimized for their biological questions. Here, we leverage Golden Gate cloning to create the Fragmid toolkit, a modular set of CRISPR cassettes and delivery technologies, along with a web portal, resulting in a combinatorial platform that enables scalable vector assembly within days. We further demonstrate that multiple CRISPR technologies can be assessed in parallel in a pooled screening format using this resource, enabling the rapid optimization of both novel technologies and cellular models. These results establish Fragmid as a robust system for the rapid design of CRISPR vectors, and we anticipate that this assembly approach will be broadly useful for systematic development, comparison, and dissemination of CRISPR technologies.

genomics↗

CHAF1A promotes the translesion DNA synthesis pathway in response to DNA replication stress

The translesion DNA synthesis (TLS) pathway mediated by proliferating cell nuclear antigen (PCNA) monoubiquitination is an essential mechanism by which cancer cells bypass DNA damage caused by DNA replication stress to maintain genomic stability and cell survival. Chromatin assembly factor 1 subunit A (CHAF1A) traditionally promotes histone assembly during DNA replication. Here, we revealed that CHAF1A is a novel regulator of the TLS pathway. High expression of CHAF1A is significantly associated with poor prognosis in cancer patients. CHAF1A promotes fork restart under DNA replication stress and maintains genome integrity. CHAF1A enhances the interaction between PCNA and E3 ubiquitin protein ligase RAD18 and promotes PCNA monoubiquitination, thereby promoting the recruitment of Y-family DNA polymerase Pol {eta} and enhancing cancer cell resistance to stimuli that trigger replication fork blockade. Mechanistically, CHAF1A-mediated PCNA monoubiquitination is independent of CHAF1A-PCNA interaction. CHAF1A interacts with both RAD18 and replication protein A2 (RPA2), mediating RAD18 binding on chromatin in response to DNA replication stress. Taken together, these findings improve our understanding of the mechanisms that regulate the TLS pathway and provide insights into the relationship between CHAF1A and the malignant progression of cancers.

cell biology↗

MATR3-antisense LINE1 RNA meshwork scaffolds higher-order chromatin organization

Long interspersed nuclear elements (LINEs) play essential role in shaping chromatin state, while the factors that cooperate with LINEs and their roles in higher-order chromatin organization remain poorly understood. Here we show that MATR3, a nuclear matrix protein, interplays with antisense LINE1 (AS L1) RNAs to form into a gel-like meshwork via phase-separation, providing a partially dynamic platform for chromatin spatial organization. Either depletion of MATR3 or AS L1 RNAs changes nuclear distribution of each other and leads to chromatin reorganization in the nucleus. After MATR3 depletion, topologically associating domains (TADs) that highly transcribed MATR3-associated AS L1 RNAs showed a decrease on local chromatin interactions. Furthermore, amyotrophic lateral sclerosis (ALS)-associated MATR3 mutants alter biophysical features of the MATR3-AS L1 RNA meshwork and cause chromatin reorganization. Collectively, we revealed an essential role of meshwork formed by nuclear matrix and retrotransposon-derived RNAs in gathering chromatin in the nucleus.

cell biology↗

Spike-specific CXCR3+ TFH cells play a dominant functional role in supporting antibody responses in SARS-CoV-2 infection and vaccination

CD4+ T follicular helper (TFH) cells are required for high-quality antibody generation and maintenance. However, the longevity and functional role of these cells are poorly defined in COVID-19 convalescents and vaccine recipients. Here, we longitudinally investigated the dynamics and functional roles of spike-specific circulating TFH cells and their subsets in convalescents at the 2nd, 5th, 8th, 12th and 24th months after COVID-19 symptom onset and in vaccinees after two and three doses of inactivated vaccine. SARS-CoV-2 infection elicited robust spike-specific TFH cell and antibody responses, of which spike-specific CXCR3+ TFH cells but not spike-specific CXCR3- TFH cells and neutralizing antibodies were persistent for at least two years in more than 80% of convalescents who experienced symptomatic COVID-19, which was well coordinated between spike-specific TFH cell and antibody responses at the 5th month after infection. Inactivated vaccine immunization also induced spike-specific TFH cell and antibody responses; however, these responses rapidly declined after six months with a two-dose standard administration, and a third dose significantly promoted antibody maturation and potency. Functionally, spike-specific CXCR3+ TFH cells exhibited better responsiveness than spike-specific CXCR3- TFH cells upon spike protein stimulation in vitro and showed superior capacity in supporting spike-specific antibody secreting cell (ASC) differentiation and antibody production than spike-specific CXCR3- TFH cells cocultured with autologous memory B cells. In conclusion, spike-specific CXCR3+ TFH cells played a dominant functional role in antibody elicitation and maintenance in SARS-CoV-2 infection and vaccination, suggesting that induction of CXCR3-biased spike-specific TFH cell differentiation will benefit SARS-CoV-2 vaccine development aiming to induce long-term protective immune memory. HighlightsO_LISARS-CoV-2 infection elicited robust spike-specific TFH cell and antibody responses, which persisted for at least two years in the majority of symptomatic COVID-19 convalescent patients. C_LIO_LIInactivated vaccine immunization also elicited spike-specific TFH cell and antibody responses, which rapidly declined over time, and a third dose significantly promoted antibody maturation and potency. C_LIO_LISpike-specific CXCR3+ TFH cells exhibited more durable responses than spike-specific CXCR3- TFH cells, correlated with antibody responses and showed superior capacity in supporting ASC differentiation and antibody production than spike-specific CXCR3- TFH cells. C_LI

immunology↗

LOXL2-dependent deacetylation of aldolase A induces metabolic reprogramming and tumor progression

Lysyl-oxidase like-2 (LOXL2) regulates extracellular matrix remodeling and promotes tumor invasion and metastasis. Altered metabolism is a core hallmark of cancer, however, it remains unclear whether and how LOXL2 contributes to tumor metabolism. Here, we found that LOXL2 and its catalytically inactive L2{Delta}13 splice variant also function as novel deacetylases that trigger metabolic reprogramming during malignant transformation. Integrated transcriptomic and metabolomic analysis revealed that L2{Delta}13-overexpressing transgenic mice displayed perturbed glucose and lipid metabolism, which was associated with increased hepatic fibrosis and enhanced formation of precancerous lesions induced by chemical carcinogens, such as carbon tetrachloride and N-nitrosomethylbenzylamine. Furthermore, both LOXL2 and L2{Delta}13 boosted glucose metabolism of esophageal tumor cells, thereby facilitating tumor cell proliferation in vitro and in vivo. Mechanistically, LOXL2 and L2{Delta}13 interacted physically with several glycolic proteins including aldolase A to enhance their enzymatic activities and mobilization from the actin cytoskeleton. Using SILAC followed by proteomic analysis, we identified LOXL2 as a deacetylase targeting metabolic proteins in esophageal cancer. Importantly, both LOXL2 and L2{Delta}13 directly catalyzed the deacetylation of aldolase A at K13, resulting in enhanced glycolysis which subsequently reprogramed tumor metabolism and promoted tumor progression. High level expression of LOXL2/L2{Delta}13 combined with decreased acetylation of aldolase-K13 predicted poor clinical outcome in patients with esophageal cancer. In summary, we have characterized a novel molecular mechanism that mediates the pro-tumorigenic activity of LOXL2 independently of its classical amine oxidase activity. These findings may enable the future development of therapeutic agents targeting the metabolic machinery via LOXL2 or L2{Delta}13.

cell biology↗

In Vivo Generation of Bone Marrow from Embryonic Stem Cells in Interspecies Chimeras

Generation of bone marrow (BM) from embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) promises to accelerate the development of future cell therapies for life-threatening disorders. However, such approach is limited by technical challenges to produce a mixture of functional BM progenitor cells able to replace all hematopoietic cell lineages. Herein, we used blastocyst complementation to simultaneously produce all BM hematopoietic cell lineages from mouse ESCs in a rat. Based on FACS analysis and single-cell RNA sequencing, mouse ESCs differentiated into hematopoietic progenitor cells and multiple hematopoietic cell types that were indistinguishable from normal mouse BM cells based on gene expression signatures and cell surface markers. Transplantation of ESC-derived BM cells from mouse-rat chimeras rescued lethally-irradiated syngeneic mice and resulted in long-term contribution of donor cells to hematopoietic cell lineages. Altogether, a fully functional bone marrow was generated from mouse ESCs using rat embryos as "bioreactors". KEY POINTS- We used blastocyst complementation to simultaneously produce all bone marrow hematopoietic cell lineages from mouse ESCs in a rat. - ESC-derived cells from mouse-rat chimeras were fully functional and exhibited normal gene expression signatures and cell surface markers.

developmental biology↗

G9a/GLP-Sensitivity of H3K9me2 Demarcates Two Types of Genomic Compartments

In the nucleus, chromatin is folded into hierarchical architecture that is tightly linked to various nuclear functions. However, the underlying molecular mechanisms that confer these architectures remain incompletely understood. Here, we investigated the functional roles of H3 lysine 9 dimethylation (H3K9me2), one of the abundant histone modifications, in three-dimensional (3D) genome organization. Unlike mouse embryonic stem cells (mESCs), inhibition of methyltransferases G9a and GLP in differentiated cells eliminated H3K9me2 predominantly at A-type (active) genomic compartments, and the level of residual H3K9me2 modification was strongly associated with genomic compartments in differentiated cells. Furthermore, chemical inhibition of G9a/GLP in mouse hepatocytes led to the decreased chromatin-nuclear lamina interactions mainly at G9a/GLP sensitive regions (GSRs), the increased degree of genomic compartmentalization, and the up-regulation of hundreds of genes that were associated with alterations of the 3D chromatin. Collectively, our data demonstrated essential roles of H3K9me2 in 3D genome organization.

genomics↗

Microscaled Proteogenomic Methods for Precision Oncology

Cancer proteogenomics integrates genomics, transcriptomics and mass spectrometry (MS)-based proteomics to gain insights into cancer biology and treatment efficacy. A proteogenomics approach was therefore developed for frozen core biopsies using tissue-sparing specimen processing with a \"microscaled\" proteomics workflow. For technical proof-of-principle, biopsies from ERBB2 positive breast cancers before and 48-72 hours after the first dose of neoadjuvant trastuzumab-based chemotherapy were analyzed. ERBB2 protein and phosphosite levels, as well as mTOR target phosphosites, were significantly more suppressed upon treatment in cases associated with pathological complete response, suggesting MS-based pharmacodynamics is achievable. Furthermore, integrated analyses indicated potential causes of treatment resistance including the absence of ERBB2 amplification (false-ERBB2 positive) and insufficient ERBB2 activity for therapeutic sensitivity despite ERBB2 amplification (pseudo-ERBB2 positive). Candidate resistance features in true-ERBB2+ cases, including androgen receptor signaling, mucin expression and an inactive immune microenvironment were observed. Thus, proteogenomic analysis of needle core biopsies is feasible and clinical utility should be investigated.

cancer biology↗

Androgen-dmrt1 positive feedback programs the rice field eel (Monopterus albus) sex transdifferentiation

The rice field eel Monopterus albus is a hermaphroditic protogynous fish species that undergoes sex reversal from female to male. However, the potential mechanisms underlying the process of sex transformation are still unclear. We analyzed and compared the gene sequence of M. albus dmrt1 5' upstream region and its potential transcription factor binding sites with other known species and examined the in vitro effects of testosterone (T) on the expression levels of dmrt1a and foxl2 in the ovotestis. Moreover, we cloned and analyzed the expression of genes encoding enzymes, 11{beta}-hydroxylase (11{beta}-h) and 11{beta}-hydroxysteroid dehydrogenase (11{beta}-hsd), involved in the production of 11-ketotestosterone (11-KT). The results showed that, compared with other fish species, M. albus dmrt1 5' upstream region contained unique androgen response elements (AREs) with one on the sense strand and the other one on the antisense strand, indicating a crucial role for androgens in the transcriptional regulation of dmrt1. The expression of dmrt1a was induced but the expression of foxl2 was inhibited by T manipulation in vitro, suggesting that blood androgen could activate the transcription of dmrt1 in the ovotestis. Moreover, the expression levels of 11{beta}-h and 11{beta}-hsd2 were predominantly expressed in testis, much less in ovotestis, and barely in ovary, suggesting the production of 11-KT during sex reversal. Androgens are synthesized in large amounts during sex reversal, leading to the promotion of dmrt1 transcription, and thus, gonadal somatic cells transdifferetiation. Overall, androgen-dmrt1 positive feedback programs the M. albus sex reversal.

animal behavior and cognition↗

Integrated analysis of sex-biased mRNA and miRNA expression profiles in the gonad of the discus fish (Symphysodon aequifasciatus)

The discus fish (Symphysodon aequifasciatus) is an ornamental fish that is well-known around the world. Phenotype investigation indicated that there are no significant differences in appearance between males and females of the discus fish. To better understand the sexual development mechanisms and obtain a high efficiency sex identification method in the artificial reproduction process of the discus fish, we constructed six cDNA libraries from three adult testes and three adult ovaries, and perform RNA-sequencing for identifying sex-biased candidate genes, microRNA (miRNA), and metabolic pathway using the Illumina Hiseq 4000. A total of 50,082 non-redundant genes (unigenes) were identified, of which 18,570 unigenes were significantly overexpressed in testes, and 11,182 unigenes were significantly overexpressed in ovaries, and 8 differentially expressed unigenes were validated by quantitative Real-Time PCR (qPCR). A total of 551 miRNAs were identified, of which 47 miRNAs were differentially expressed between testes and ovaries, and 7 differentially expressed miRNAs and one non-differential miRNA were validated by qPCR. Twenty-four of these differentially expressed miRNAs and their 15 predicted target genes constituted 41 important miRNA-mRNA interaction pairs, which may be important candidates for sex-related miRNAs and sex-related genes in the discus fish. Some of vital sex-related metabolic pathways were also identified that may play key roles in regulating gonad development of the discus fish. These results can provide important insights to better understand molecular mechanisms for sexual dimorphism in gonads development.

genetics↗

Recovered and dead outcome patients caused by influenza A (H7N9) virus infection show different pro-inflammatory cytokine dynamics during disease progress and its application in real-time prognosis

The persistent circulation of influenza A(H7N9) virus within poultry markets and human society leads to sporadic epidemics of influenza infections. Severe pneumonia and acute respiratory distress syndrome (ARDS) caused by the virus lead to high morbidity and mortality rates in patients. Hyper induction of pro-inflammatory cytokines, which is known as \"cytokine storm\", is closely related to the process of viral infection. However, systemic analyses of H7N9 induced cytokine storm and its relationship with disease progress need further illuminated. In our study we collected 75 samples from 24 clinically confirmed H7N9-infected patients at different time points after hospitalization. Those samples were divided into three groups, which were mild, severe and fatal groups, according to disease severity and final outcome. Human cytokine antibody array was performed to demonstrate the dynamic profile of 80 cytokines and chemokines. By comparison among different prognosis groups and time series, we provide a more comprehensive insight into the hypercytokinemia caused by H7N9 influenza virus infection. Different dynamic changes of cytokines/chemokines were observed in H7N9 infected patients with different severity. Further, 33 cytokines or chemokines were found to be correlated with disease development and 11 of them were identified as potential therapeutic targets. Immuno-modulate the cytokine levels of IL-8, IL-10, BLC, MIP-3a, MCP-1, HGF, OPG, OPN, ENA-78, MDC and TGF-{beta} 3 are supposed to be beneficial in curing H7N9 infected patients. Apart from the identification of 35 independent predictors for H7N9 prognosis, we further established a real-time prediction model with multi-cytokine factors for the first time based on maximal relevance minimal redundancy method, and this model was proved to be powerful in predicting whether the H7N9 infection was severe or fatal. It exhibited promising application in prognosing the outcome of a H7N9 infected patients and thus help doctors take effective treatment strategies accordingly.

immunology↗

Improvements to the rice genome annotation through large-scale analysis of RNA-Seq and proteomics datasets

Rice (Oryza sativa) is one of the most important worldwide crops. The genome has been available for over 10 years and has undergone several rounds of annotation. We created a comprehensive database of transcripts from 29 public RNA sequencing datasets, officially predicted genes from Ensembl plants, and common contaminants in which to search for protein-level evidence. We re-analysed nine publicly accessible rice proteomics datasets. In total, we identified 420K peptide spectrum matches from 47K peptides and 8,187 protein groups. 4168 peptides were initially classed as putative novel peptides (not matching official genes). Following a strict filtration scheme to rule out other possible explanations, we discovered 1,584 high confidence novel peptides. The novel peptides were clustered into 692 genomic loci where our results suggest annotation improvements. 80% of the novel peptides had an ortholog match in the curated protein sequence set from at least one other plant species. For the peptides clustering in intergenic regions (and thus potentially new genes), 101 loci were identified, for which 43 had a high-confidence hit for a protein domain. Our results can be displayed as tracks on the Ensembl genome or other browsers supporting Track Hubs, to support re-annotation of the rice genome.

plant biology↗