Biology subjects

Wei, Y.

Publications and source records attributed to Wei, Y..

At least 181 records · Page 10Linked to original sources

bioRxiv2022

Molecular insights into the gating mechanisms of voltage-gated calcium channel CaV2.3

High-voltage-activated R-type CaV2.3 channel plays pivotal roles in many physiological activities and is implicated in epilepsy, convulsions, and other neurodevelopmental impairments. Here, we determine the high-resolution cryo-electron microscopy (cryo-EM) structure of human CaV2.3 in complex with the 2{delta}1 and {beta}1 subunits. The VSDII is stabilized in the resting state. Electrophysiological experiments elucidate that the conformational change of VSDII in response to variation in membrane potential is not required for channel activation, whereas the other VSDs are essential for channel opening. The intracellular gate is blocked by the W-helix. A pre-W-helix adjacent to the W-helix can significantly regulate closed-state inactivation (CSI) by modulating the association and dissociation of the W-helix with the gate. Electrostatic interactions formed between the negatively charged domain on S6II, which is exclusively conserved in the CaV2 family, and nearby regions at the alpha-interacting domain (AID) and S4-S5II helix are identified. Further functional analyses indicate that these interactions are critical for the open-state inactivation (OSI) of CaV2 channels.

biophysics↗

bioRxiv2022

Human serum supplementation promotes Streptococcus mitis growth and induces specific transcriptomic responses

Streptococcus mitis is a normal member of the human oral microbiota and a leading opportunistic pathogen causing infective endocarditis (IE). Despite the complex interactions between S. mitis and human host, understanding of S. mitis physiology, as well as its mechanisms of adaptation to host-associated environments, is inadequate, especially when compared with other IE bacterial pathogens. This study reports growth-promoting effects of human serum on S. mitis and other pathogenic streptococci, including S. oralis, S. pneumoniae, and S. agalactiae. Using transcriptomic analyses we identified that, with the addition of human serum, S. mitis down-regulates uptake systems for metal ions and sugars, fatty acid biosynthetic genes, and genes involved in stress response and other processes related with growth and replication. S. mitis up-regulates uptake systems for amino acids and short peptides in response to human serum. Zinc availability and environmental signals sensed by the induced short peptide binding proteins were not sufficient to confer the seen growth-promoting effects. More investigation is required to establish the mechanism for growth promotion. Overall, our study contributes to the fundamental understanding of S. mitis physiology under host-associated conditions. SignificanceS. mitis is exposed to human serum components during commensalism in the human mouth and bloodstream pathogenesis. However, the physiological effects of serum components on this bacterium remain unclear. Using transcriptomic analyses, S. mitis biological processes that respond to the presence of human serum were revealed, providing the fundamental understanding of S. mitis adaptations towards human host conditions.

microbiology↗

bioRxiv2022

Robust identification of extrachromosomal DNA and genetic variants using multiple genetic abnormality sequencing (MGA-Seq)

Genomic abnormalities, including structural variation (SV), copy number variation (CNV), single-nucleotide polymorphism (SNP), homogenously staining regions (HSR) and extrachromosomal DNA (ecDNA), are strongly associated with cancer, rare diseases and infertility. A robust technology to simultaneously detect these genomic abnormalities is highly desired for clinical diagnosis and basic research. In this study, we developed a simple and cost-effective method - multiple genetic abnormality sequencing (MGA-Seq) - to simultaneously detect SNPs, CNVs, SVs, ecDNA and HSRs in a single tube. This method has been successfully applied in both cancer cell lines and clinical tumour samples and revealed that focal amplification in tumour tissue is substantially heterogeneous. Notably, we delineated the architecture of focal amplification and the ecDNA network by MGA-Seq, which facilitated the exploration of the regulation of gene expression in ecDNA. This method could be extensively applied for diagnosis and may greatly facilitate the investigation of the genomic mechanism for genetic diseases.

genomics↗

bioRxiv2022

Deep-learning based bioactive therapeutic peptides generation and screening

Many bioactive peptides demonstrated therapeutic effects over-complicated diseases, such as antiviral, antibacterial, anticancer, etc. Similar to the generating de novo chemical compounds, with the accumulated bioactive peptides as a training set, it is possible to generate abundant potential bioactive peptides with deep learning. Such techniques would be significant for drug development since peptides are much easier and cheaper to synthesize than compounds. However, there are very few deep learning-based peptide generating models. Here, we have created an LSTM model (named LSTM_Pep) to generate de novo peptides and finetune learning to generate de novo peptides with certain potential therapeutic effects. Remarkably, the Antimicrobial Peptide Database has fully utilized in this work to generate various kinds of potential active de novo peptide. We proposed a pipeline for screening those generated peptides for a given target, and use Main protease of SARS-COV-2 as concept-of-proof example. Moreover, we have developed a deep learning-based protein-peptide prediction model (named DeepPep) for fast screening the generated peptides for the given targets. Together with the generating model, we have demonstrated iteratively finetune training, generating and screening peptides for higher predicted binding affinity peptides can be achieved. Our work sheds light on to the development of deep learning-based methods and pipelines to effectively generating and getting bioactive peptides with a specific therapeutic effect, and showcases how artificial intelligence can help discover de novo bioactive peptides that can bind to a particular target.

bioinformatics↗

bioRxiv2022

Image-based quantification of histological features as a function of spatial location using the Tissue Positioning System

Tissues such as the liver lobule, kidney nephron, and intestinal gland exhibit intricate patterns of zonated gene expression corresponding to distinct cell types and functions. To quantitatively understand zonation, it would be important to measure cellular or genetic features as a function of position along a zonal axis. While it is possible to manually count, characterize, and locate features in relation to the zonal axis, it is very difficult to do this for more than a few hundred instances. We addressed this challenge by developing a deep-learning-based quantification method called the "Tissue Positioning System" (TPS), which can automatically analyze zonation in the liver lobule as a model system. By using algorithms that identified vessels, classified vessels, and segmented zones based on the relative position along the portal vein to central vein axis, TPS was able to spatially quantify gene expression in mice with zone specific reporters. TPS could discern expression differences between zonal reporter strains, ages, and disease states. TPS could also reveal the zonal distribution of cells previously thought to be randomly distributed. The design principles of TPS could be generalized to other tissues to explore the biology of zonation. The software is available at https://github.com/yunguan-wang/Tissue_positioning_system.

bioinformatics↗

bioRxiv2022

RabbitTClust: enabling fast clustering analysis of millions bacteria genomes with MinHash sketches

We present RabbitTClust, a fast and memory-efficient genome clustering tool based on sketch-based distance estimation. Our approach enables efficient processing of large-scale datasets by combining dimensionality reduction techniques with streaming and parallelization on modern multi-core platforms. 113,674 complete bacterial genome sequences (RefSeq: 455 GB in FASTA format) can be clustered within less than 6 minutes and 1,009,738 GenBank assembled bacterial genomes (4.0 TB in FASTA format) within only 34 minutes on a 128-core workstation. Our results further identify 1,269 repetitive genomes (identical nucleotide content) in RefSeq bacterial genomes.

bioinformatics↗

bioRxiv2022

IGFBP2 expressing midlobular hepatocytes preferentially contribute to liver homeostasis and regeneration

While midlobular hepatocytes in zone 2 are a recently identified cellular source for liver homeostasis and regeneration, these cells have not been exclusively fate mapped. We generated a Igfbp2-CreER knockin strain, which specifically labels midlobular hepatocytes. During homeostasis over 1 year, zone 2 hepatocytes increased in abundance from occupying 21% to 41% of the lobular area. After either pericentral injury with carbon tetrachloride or periportal injury with DDC, IGFBP2+ cells replenished lost hepatocytes in zones 3 and 1, respectively. IGFBP2+ cells also preferentially contributed to regeneration after 70% partial hepatectomy, as well as liver growth during pregnancy. Because IGFBP2 labeling increased substantially with fasting, we used single nuclear transcriptomics to explore zonation as a function of nutrition, revealing that the zonal division of labor shifts dramatically with fasting. These studies demonstrate the contribution of IGFBP2-labeled zone 2 hepatocytes to liver homeostasis and regeneration. HighlightsO_LILineage tracing showed that midlobular hepatocytes proliferate during homeostasis. C_LIO_LIZone 2 cells were protected from portal and centrilobular injuries and replaced lost hepatocytes. C_LIO_LIFasting induced significant changes in liver zonation. C_LI eTOC statementThe liver consists of different zones with spatial heterogeneity in their metabolic functions. Here, a new Igfbp2-CreER line enabled direct tracing of midlobular hepatocytes, which showed that IGFBP2+ cells serve as a source of new hepatocytes during normal homeostasis and regeneration.

developmental biology↗

bioRxiv2022

Activin A promotes bone fracture repair and acts through a novel myofibroblastic cell population in callus

Insufficient bone fracture repair represents a significant clinical burden, and identification of novel therapeutics enhancing repair would have substantial clinical and societal impact. Activin A is a TGF-{beta} protein superfamily member known to stimulate ectopic bone formation, but its roles in fracture repair and its therapeutic potentials remain unclear. Using two mouse tibia fracture repair models, here we mapped activin A expression at the tissue and single cell levels, tested its requirement for normal repair and evaluated its ability to enhance repair when provided exogenously. Activin A was minimally expressed in periosteum of intact bones but was markedly upregulated in developing callus soon after fracture. Single cell RNA-sequencing revealed that the activin A-encoding gene Inhba marked a unique, highly proliferative progenitor cell (PPC) population with a myofibroblast character which emerged over repair time and lay at the center of a developmental trajectory bifurcation producing cartilage and bone cells within callus. Systemic administration of a neutralizing activin A antibody impaired fracture repair and its endochondral and intramembranous phases, whereas local delivery of recombinant activin A enhanced repair. Activin A delivery also induced SMAD2 phosphorylation in vivo and increased the fraction of SMA+ myofibroblasts within fracture callus. Gain- and loss-of-function experiments in vitro showed that activin A directly stimulated myofibroblast differentiation, chondrogenesis and osteogenesis in periosteal progenitor cells. Together, these data identify a unique population of Inhba-expressing proliferative progenitor cells that give rise to chondrocytes and osteoblasts during fracture healing and establish activin A as a potential new therapeutic tool to enhance it. One Sentence SummaryDeficits in bone fracture repair remain a clinical challenge and the present study provides evidence for the therapeutic potentials of activin A

pathology↗

bioRxiv2022

Surface glia predominantly contribute to the development of ALS/FTD in Drosophila model

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disorder characterized by motor neuron degeneration in the primary motor neurons. C9orf72 repeat expansion mutation is the most prevalent genetic causes of ALS/FTD. Due to the complexity of ALS, there has been no successful therapy for the condition. The traditional neurocentric concept of ALS derives in part from the assumption that the degradation of motor neuron (MN) cells in ALS is driven by cell-autonomous mechanisms, however, recent research has focused on the non-cell-autonomous pathogenic mechanisms such as glial, immune cells and blood-brain barriers participate in the degeneration of MNs in ALS. Drosophila melanogaster is widely used as a genetic model for ALS, giving essential mechanistic data on disease onset and development. Using newly developed genetic tools to individually mark each subtype of the adult glial system in the fruit fly, we demonstrate that surface glia are the major glial subtypes for the pathogenesis of C9orf72-mediated ALS/FTD.

pathology↗

bioRxiv2022

Proteomics Characteristics Reveal the Risk of T1 Colorectal Cancer Metastasis to Lymph Nodes

BackgroundThe presence of lymph node metastasis (LNM) affects treatment strategy decisions in T1NxM0 colorectal cancer (CRC), but the currently used clinicopathological-based risk stratification cannot predict LNM accurately. In this study, we established a classifier for predicting LNM in T1 CRC. MethodsWe detected proteins in formalin-fixed paraffin-embedded (FFPE) tumor samples from 143 LNM-negative and 78 LNM-positive patients with T1 CRC and revealed changes in molecular and biological pathways by label-free LC-MS/MS. An effective prediction model was built and validated in a training cohort (N=132) and two validation cohorts (VC1, N=42; VC2, N=47) by machine learning. We further built a simplified classifier with 9 proteins. The expression patterns of 13 proteins were confirmed by immunohistochemistry, and the IHC score of 5 proteins were used to build a IHC predict model. ResultPatients with or without LNM have different molecular signatures. The 55-proteins prediction model achieved an impressive AUC of 1.00 in the training cohort, 0.96 in VC1 and 0.93 in VC2. The 9-protein classifier achieved an AUC of 0.824, and the calibration plot was excellent. We found that 5 biomarkers could predict LNM by the IHC score, with an AUC of 0.825. RHOT2 silence significantly enhanced migration and invasion of colon cancer cells. ConclusionsOur study explored the mechanism of metastasis in T1 CRC and can be used to facilitate the individualized prediction of LNM in patients with T1 CRC, which may provide a guidance for clinical practice in T1 CRC.

cancer biology↗

bioRxiv2022

CDKL5 regulates p62-mediated selective autophagy and host antiviral defense

Virophagy, the selective autophagosomal engulfment and degradation of viral components, is crucial for antiviral immunity. However, the mechanisms leading to viral antigen recognition and autophagy induction remain poorly understood. Here, we identify a novel kinase, Cyclin-dependent kinase-like 5 (CDKL5), as an essential regulator of virophagy. Deletion of CDKL5 or abrogation of its kinase activity reduced virophagy of Sindbis virus (SINV), a neurotropic RNA virus, and increased intracellular accumulation of SINV capsid proteins and cellular cytotoxicity. Mechanistically, through direct phosphorylation of the selective autophagy receptor p62, CDKL5 promoted formation of p62 inclusion bodies that bound capsid. Loss of CDKL5 disrupted the capsid-p62 interaction, and a p62 phosphomimetic mutant rescued the interaction. CDKL5 knockout mice demonstrated increased neuronal cell death after SINV infection and enhanced lethality after infection with several human viruses. Overall, these findings identify a cell-autonomous innate immune mechanism for autophagy activation to clear toxic viral capsid aggregates during infection.

microbiology↗

bioRxiv2022

Abnormal intrinsic neural timescale in Parkinson's disease

BACKGROUND: Numerous studies indicate altered peak latency of event-related potential and altered time variability of brain function network in Parkinsons disease (PD), and the intrinsic neural timescale estimated how long neural information stored in a local brain area has been specialized. However, it was unclear whether PD patients exhibited abnormal intrinsic timescales and accompanied with abnormal grey matter and whether PD patients exhibited different temporal feature at different stages. STUDY TYPE: Prospective. POPULATION: 74 PD patients, including 44 patients in the early stage (PD-ES) and 30 patients in the late stage (PD-LS), and 73 healthy controls (HC). SEQUENCE: 3.0T MRI scanner; prototypic T1 magnetization prepared rapid acquisition gradient echo (MPRAGE); resting-state fMRI. ASSESSMENT: the intrinsic timescales were estimated by using the magnitude of the autocorrelation of intrinsic neural signals. Voxel-based morphometry (VBM) was performed to calculate the grey matter volume (GMV) in the whole brain. STATISTICAL TEST: Analysis of variance (ANOVA); two-sample t-tests; Spearman rank correlation analysis; Mann-Whitney U test; Kruskal-Wallis H test. RESULTS: We identified that the PD group had abnormal intrinsic timescales in bilateral lingual and calcarine gyri, bilateral postcentral and precentral gyri, and the right middle cingulum gyrus, which correlated with the symptom severity and the GMV. Moreover, longer timescale in the right middle frontal gyrus were also found in the PD group. Increasingly, the PD-ES group had longer timescales in the anterior cortical regions, whereas the PD-LS group had shorter timescales in the posterior cortical regions. DATA CONCLUSION: Our findings suggest that PD patients exhibit abnormal intrinsic timescales in visual, sensorimotor, and cognitive systems and distinct patterns of intrinsic timescales and GMV in cerebral cortex at different stages, which might provide new insights for the neural substrate of PD.

neuroscience↗

bioRxiv2022

Large scale production of human blastoids amenable to modeling blastocyst development and maternal-fetal crosstalk

Recent advances in human blastoids generated from naive pluripotent stem cells have opened a new avenue for modelling early human development and implantation. Despite the success, however, existing protocols have several limitations, e.g., the use of custom-built microwell arrays impedes wide adoption by the research community, and mass production of human blastoids is hampered by low-output or low-efficiency methods. To address these issues, here we developed an optimized protocol based on commercially available microwell plates, which enabled efficient generation of high-fidelity human blastoids at a large scale. Leveraging on the improved protocol, we identified MAPK. PI3K/AKT and mTOR signaling pathways were activated in both blastoids and blastocyst, and discovered endometrial stromal effects in promoting trophoblast cell survival, proliferation and syncytialization during extended co-culture with blastoids. Our optimized protocol will facilitate broader use of human blastoids as an accessible, perturbable, scalable, tractable, and ethical model for human blastocysts.

developmental biology↗

bioRxiv2022

Type 17 Follicular Helper T (Tfh17) Cells are Superior for Memory Maintenance

A defining feature of successful vaccination is the ability to induce long-lived antigen- specific memory cells. Follicular helper T (Tfh) cells specialize in providing help to B cells in mounting protective humoral immunity in infection and after vaccination. Memory Tfh cells that retain the CXCR5 expression can confer protection through enhancing humoral response upon antigen re-exposure but how they are maintained is poorly understood. CXCR5+ memory Tfh cells in human blood are divided into Tfh1, Tfh2 and Tfh17 cells by the expression of chemokine receptors CXCR3 and CCR6 associated with Th1 and Th17 respectively. Here, we developed a new method to induce Tfh1, Tfh2 and Tfh17-like (iTfh1, iTfh2 and iTfh17) cells in vitro. Although all three iTfh subsets efficiently support antibody responses in recipient mice with immediate immunization, iTfh17 cells are superior to iTfh1 and iTfh2 cells in supporting antibody response to a later immunization after extended resting in vivo to mimic memory maintenance. Notably, the counterpart human Tfh17 cells are selectively enriched in CCR7+ central memory Tfh (TfhCM) with survival and proliferative advantages. Furthermore, the analysis of multiple human cohorts that received different vaccines for HBV, influenza virus, tetanus toxin or measles revealed that vaccine-specific Tfh17 cells outcompete Tfh1 or Tfh2 cells for the persistence in memory phase. Therefore, the complementary mouse and human results showing the advantage of Tfh17 cells in maintenance and memory function supports the notion that Tfh17-induced immunization might be preferable in vaccine development to confer long-term protection.

immunology↗

bioRxiv2022

Epigenetic plasticity cooperates with emergent cell-cell interactions to drive neoplastic tissue remodeling in the pancreas

The response to tumor-initiating inflammatory and genetic insults can vary amongst morphologically indistinguishable cells, suggesting yet uncharacterized roles for epigenetic plasticity during early neoplasia. To investigate the origins and impact of such plasticity, we perform single-cell analyses on normal, inflamed, pre-malignant and malignant tissues in autochthonous models of pancreatic cancer. We reproducibly identify heterogeneous cell-states that are primed for diverse late-emerging neoplastic fates and link these to chromatin remodeling at cell-cell communication loci. Using a new inference approach, we reveal signaling gene modules and tissue-level crosstalk, including a neoplasia-driving feedback loop between discrete epithelial and immune cell populations that we validate by genetic perturbation in mice. Our results uncover a neoplasia-specific tissue remodeling program that may be exploited for pancreas cancer interception. One-Sentence SummarySingle-cell analysis reveals that enhanced epigenetic plasticity drives pro-neoplastic crosstalk in early pancreatic cancer.

cancer biology↗

bioRxiv2022

Oxytocin receptor is not required for social attachment in prairie voles

Prairie voles are among a small group of mammals that display long-term social attachment between mating partners. Many pharmacological studies show that signaling via the oxytocin receptor (OxtR) is critical for the display of social monogamy in these animals. We used CRISPR-mutagenesis to independently generate three different OxtR null mutant prairie vole lines. OxtR mutants displayed social attachment such that males and females showed a behavioral preference for their mating partners over a stranger of the opposite sex when assayed using different paradigms. Mothers lacking OxtR delivered viable pups, and parents displayed care of their young and raised them to the weanling stage. Together, our studies unexpectedly reveal that OxtR-mediated signaling is genetically dispensable for social attachment, parturition, and parental behavior.

animal behavior and cognition↗

bioRxiv2022

Spatiotemporally selective ATP events from astrocytes encode injury information and guide sustained microglial response

Brain injuries, either directly result from external assaults or are accompanied with diseases, initiate a cascade of intrinsic responses for damage management, with resident microglia as one of the key responders in the early phase of reaction. Changes in microglia including their motility and activities can be tuned according to injury intensity and position, indicating such injury information is precisely encoded and actively presented. Also, microglia in a broad area can perform sustained migration towards a transient and local injury, suggesting a signal amplification process may exist that bridge differences between injury and microglial migration in time and space. Currently, the molecular identity and underlying mechanism for injury encoding, amplification and presentation have not been fully elucidated yet, although candidate molecules like ATP are linked with both injury and microglial response. Based upon our recent technique advancement in engineering novel genetically-encoded ATP sensors, we here identified and characterized that in the cortex of awake mice in vivo, a new type of spatiotemporally selective ATP events, referred to as Inflares, was selectively evoked after brain injuries, which were actively and repeatedly generated from astrocytes in a Ca2+-dependent manner through the opening of pannexin 1 channel. Functionally, Inflares amplified local injury over time and space with their persistence and widespread distribution, and provided continuous directionality that was necessary for guiding microglial migration. Excessive Inflares in pathological injuries drove microglial dysfunction and caused secondary damage, whereas blocking Inflares successfully reversed pathological changes and benefited the outcome of ischemic stroke. Together, we identified the internal mechanism that encoded and presented injury information, and provided rational target for treating injury-related diseases.

neuroscience↗

bioRxiv2022

Intratumoral mregDC and CXCL13 T helper niches enable local differentiation of CD8 T cells following PD-1 blockade

Here, we leveraged a large neoadjuvant PD-1 blockade trial in patients with hepatocellular carcinoma (HCC) to search for correlates of response to immune checkpoint blockade (ICB) within T cell-rich tumors. We show that ICB response correlated with the clonal expansion of intratumoral CXCL13+ CH25H+ IL-21+ PD-1+ CD4 T helper cells (CXCL13+ Th) and Granzyme K+ PD-1+ effector-like CD8 T cells, whereas terminally exhausted CD39hi TOXhi PD-1hi CD8 T cells dominated in non-responders. Strikingly, most T cell receptor (TCR) clones that expanded post-treatment were found in pre-treatment biopsies. Notably, PD-1+ TCF-1+ progenitor-like CD8 T cells were present in tumors of responders and non-responders and shared clones mainly with effector-like cells in responders or terminally differentiated cells in non-responders, suggesting that local CD8 T cell differentiation occurs upon ICB. We found that these progenitor CD8 T cells interact with CXCL13+ Th cells within cellular triads around dendritic cells enriched in maturation and regulatory molecules, or "mregDC". Receptor-ligand analysis revealed unique interactions within these triads that may promote the differentiation of progenitor CD8 T cells into effector-like cells upon ICB. These results suggest that discrete intratumoral niches that include mregDC and CXCL13+ Th cells control the differentiation of tumor-specific progenitor CD8 T cell clones in patients treated with ICB.

immunology↗