Biology subjects

Ma, C.

Publications and source records attributed to Ma, C..

At least 73 records · Page 4Linked to original sources

bioRxiv2024

A Paradoxical Tumor Antigen Specific Response in the Liver

Functional tumor-specific CD8+ T cells are essential for an effective anti-tumor immune response and the efficacy of immune checkpoint inhibitor therapy. In comparison to other organ sites, we found higher numbers of tumor-specific CD8+ T cells in primary, metastatic liver tumors in murine tumor models. Despite their abundance, CD8+ T cells in the liver displayed an exhausted phenotype. Depletion of CD8+ T cells showed that liver tumor-reactive CD8+ T failed to control liver tumors but was effective against subcutaneous tumors. Similarly, analysis of single-cell RNA sequencing data from patients showed a higher frequency of exhausted tumor-reactive CD8+ T cells in liver metastasis compared to paired primary colon cancer. High-dimensional, multi-omic analysis combining proteomic CODEX and scRNA-seq data revealed enriched interaction of SPP1+ macrophages and CD8+ tumor-reactive T cells in profibrotic, alpha-SMA rich regions in the liver. Liver tumors grew less in Spp1-/- mice and the tumor-specific CD8+ T cells were less exhausted. Differential pseudotime trajectory inference analysis revealed extrahepatic signaling promoting an intermediate cell (IC) population in the liver, characterized by co-expression of VISG4, CSF1R, CD163, TGF-{beta}R, IL-6R, SPP1. scRNA-seq of a third data set of premetastatic adenocarcinoma showed that enrichment of this population may predict liver metastasis. Our data suggests a mechanism by which extrahepatic tumors facilitate the formation of liver metastasis by promoting an IC population inhibiting tumor-reactive CD8+ T cell function.

immunology↗

bioRxiv2024

Synaptonemal complex protects double-Holliday junctions during meiosis

Chromosomal linkages formed through crossover recombination are essential for accurate segregation of homologous chromosomes during meiosis1. The DNA events of recombination are linked to structural components of meiotic chromosomes2. Imperatively, the biased resolution of double-Holliday junction intermediates (dHJs) into crossovers3,4 occurs within the synaptonemal complex (SC), the meiosis-specific structure that mediates end-to-end synapsis of homologs during the pachytene stage5,6. However, the SCs roles in crossover-specific dHJ resolution remains unclear. Here, we show that key SC components function through dependent and interdependent relationships to protect dHJs from aberrant "dissolution" into noncrossover products. Conditional ablation experiments reveal that cohesin, the core of SC lateral elements, is required to maintain both synapsis and dHJ-associated crossover recombination complexes (CRCs) during pachytene. The SC central region transverse-filament protein is also required to maintain CRCs. Reciprocally, stability of the SC central region requires the continuous presence of CRCs, thereby coupling synapsis and desynapsis to dHJ formation and resolution. However, dHJ protection and maintenance of CRCs can occur without end-to-end homolog synapsis mediated by the central element of the SC central region. We conclude that local ensembles of SC components are sufficient to enable crossover-specific dHJ resolution and thereby ensure the linkage and segregation of homologous chromosomes.

cell biology↗

bioRxiv2024

PI(4)P recruits CIDE proteins to promote the formation of unilocular lipids droplets

Lipid droplets (LDs) are evolutionarily conserved organelles that play important roles in metabolism. Each LD is enclosed by a monolayer of phospholipids, distinct from bilayer membranes. The composition of LD surface phospholipids and their impact on LD growth and function remain to be clearly defined. Phosphoinositides mark cellular organelles and regulate cell signalling and organellar function. Here, we demonstrate that PI(4)P decorates a subset of LDs to recruit and activate the CIDE proteins. Enhanced expression of ORP2 and ORP5, LD-associated lipid transfer proteins that remove PI(4)P from LDs, abolished the localization and function of CIDE proteins. Blocking the synthesis of PI(4)P on LD surface via knocking down PI4K2A also impaired the localization and function of CIDE proteins. In adipocytes, depleting PI(4)P dramatically reduced the size of LDs, as well as adipose tissue mass. In severe steatotic liver, depleting PI(4)P reduced LD accumulation. Our results thus identify a key function of LD surface PI(4)P under physiological conditions and unveil how CIDE proteins are recruited to LDs.

cell biology↗

bioRxiv2024

A novel functional coordination in UNC-13 regulates neurotransmitter release

Munc13 plays a crucial role in short-term synaptic plasticity by regulating synaptic vesicle (SV) exocytosis and neurotransmitter release at the presynaptic terminals. However, the intricate mechanisms governing these processes have remained elusive due to the presence of multiple functional domains within Munc13, each playing distinct roles in neurotransmitter release. Here we report a coordinated mechanism in the C. elegans Munc13 homolog UNC-13 that controls the functional switch of UNC-13 during synaptic transmission. Mutations disrupting the interactions of C1 and C2B with diacylglycerol (DAG) and phosphatidylinositol 4,5-bisphosphate (PIP2) on the plasma membrane induced the gain-of-function state of UNC-13L, the long UNC-13 isoform, resulting in enhanced SV release. Concurrent mutations in both domains counteracted this enhancement, highlighting the functional interdependence of C1 and C2B. Intriguingly, the individual C1 and C2B domains exhibited significantly stronger facilitation of SV release compared to the presence of both domains, supporting a mutual inhibition of C1 and C2B under basal conditions. Moreover, the N-terminal C2A and X domains exhibited opposite regulation on the functional switch of UNC-13L. Furthermore, we identified the polybasic motif in the C2B domain that facilitates SV release. Finally, we found that disruption of C1 and C2B membrane interaction in UNC-13S, the short isoform, leads to functional switch between gain-of-function and loss-of-function. Collectively, our findings provide a novel mechanism for SV exocytosis wherein UNC-13 undergoes functional switches through the coordination of its major domains, thereby regulating synaptic transmission and short-term synaptic plasticity.

neuroscience↗

bioRxiv2024

Transcriptional and Metabolic Mechanism of Carbon Dots Enhancing Rice Growth and Resistance by Promoting Root

Increasing climate change and pollutant discharge induce constant challenges to crops, while crops are vulnerable to environmental and pollutant stresses. In this study, a carbon dots (CDs) was developed that significantly increased rice seedling growth, and successfully reduced the inhibition of heavy metal cadmium (Cd), salt (NaCl), and herbicide 2,4-D stresses on rice seedling growth by pre-spraying. The root of rice seedlings responded specifically to CDs exposure, with significant improvements in root biomass, architecture, cell wall thickness, mechanical strength, and metabolic vitality. Metabolomics and transcriptomics were combined to reveal the regulatory mechanism of CDs in rice seedlings. Transcriptome analysis indicated that CDs upregulated genes related to cytokinin, jasmonic acid, salicylic acid, MAPK signaling pathway, calcium homeostasis, and peroxidase, and downregulated those related to auxin, abscisic acid, and ethylene. Metabolomic analysis suggested CDs improved the metabolites related to antioxidant (betalain, ascorbate, aldarate, and glutathione), formation of cell wall, plasma membrane, xylem, and root cortex (phenylpropanoids biosynthesis, stilbenoid, diarylheptanoid and gingerol biosynthesis, and sphingolipid), and energy metabolism (nicotinate, nicotinamide, glyoxylate, dicarboxylate, and nitrate cycle) in rice seedlings. Therefore, pre-spraying CDs reprogrammed stress signaling pathways and enhanced adaptive responses in rice seedlings, ultimately increasing growth potential and stress resistance. This study presents a promising nano-bio-stimulant of CDs for crop resilience in the context of increasing climate change and contributes to sustainable agriculture.

physiology↗

bioRxiv2024

The m6A Reader ECT1 Mediates Seed Germination via the DAG2-ECT1-PHYB Regulatory Cascade in Arabidopsis

The N6-methyladenosine (m6A) RNA modification, a significant epitranscriptomic mark, is integral to plant growth and development. m6A reader proteins are capable of recognizing m6A modifications to impact RNA metabolic and biological processes. Here, we discovered ECT1 as an m6A reader protein that directly binds to the m6A site and plays a role in positively regulating seed germination in the context of gibberellins (GAs). ECT1 undergoes m6A modification to ensure its own stability and engages in self-interaction to enhance its protein stability. Moreover, ECT1 establishes a regulatory circuit with DAG2, which has been reported to play a positive regulatory role in GA-mediated seed germination. We found that DAG2 directly binds to the ECT1 promoter to control its transcription. ECT1 modulates the mRNA stability of DAG2. Furthermore, we identified PHYB, which encodes a key photoreceptor controlling GA-regulated seed germination, as a common downstream target of DAG2 and ECT1. DAG2 and ECT1 regulate the expression of PHYB at the transcriptional and post-transcriptional levels, respectively. ECT1 binds directly to PHYB, thereby influencing its stability. While DAG2 binds to the PHYB promoter to regulate its transcription. Together, these results unveil that ECT1 participates in the m6A signaling pathway through complex and multifaceted molecular mechanisms, broadening the spectrum of m6A reader functions and deepening our insight into the m6A signaling network in Arabidopsis.

plant biology↗

bioRxiv2024

Probing tau citrullination in Alzheimer's disease brains and mouse models of tauopathy

Tauopathies, which include Alzheimers disease (AD) share a common defining factor, namely misfolded tau protein. However, the "upstream" etiology and downstream clinical manifestations of tauopathies are quite diverse. Tau deposition elicits different pathological phenotypes and outcomes depending on the tau strain and regional susceptibility. Posttranslational modifications (PTM) can alter tau structure, function, networks, and its pathological sequalae. We uncovered a novel PTM of tau, named citrullination, caused by peptidyl arginine deiminase (PAD) enzymes. PAD induced citrullination irreversibly converts arginine residues to citrulline, producing net loss of positive charge, elimination of pi-pi interactions, and increased hydrophobicity. We observed increased PAD2 and PAD4 in Alzheimers disease (AD) brain and that they both can citrullinate tau. Tau can become citrullinated by PADs at all 14 arginine residues throughout the N-terminal domain (N-term), proline-rich domain (PR), microtubule binding repeat domain (MBR), and C-terminal domain (C-term) on full length tau (2N4R). Citrullination of tau impacts fibrillization and oligomerization rates in aggregation assays. Utilizing a panel of novel citrullinated tau (citR tau) antibodies, we identified citrullination of tau in vitro, several animal models of tauopathies, and Alzheimers disease (AD). CitR tau increased with Braak stage and was enriched in AD brains with higher phospho-tau burden. This work provides a new area of tau biology that signifies further consideration in the emerging spectrum of tauopathies and its clinical understanding.

neuroscience↗

bioRxiv2024

Induction of Meiosis from Human Pluripotent Stem Cells

An in vitro model of human meiosis would accelerate research into this important reproductive process and development of therapies for infertility. We have developed a method to induce meiosis starting from male or female human pluripotent stem cells. We demonstrate that DNMT1 inhibition, retinoid signaling activation, and overexpression of regulatory factors (anti-apoptotic BCL2, and pro-meiotic HOXB5, BOLL, or MEIOC) rapidly activates meiosis, with leptonema beginning at 6 days, zygonema at 9 days, and pachynema at 12 days. Immunofluorescence microscopy shows key aspects of meiosis, including chromosome synapsis and sex body formation. The meiotic cells express genes similar to meiotic oogonia in vivo, including all synaptonemal complex components and machinery for meiotic recombination. These findings establish an accessible system for inducing human meiosis in vitro.

synthetic biology↗

bioRxiv2024

Epithelial NSD2 maintains FMOs-mediated taurine biosynthesis to prevent intestinal barrier disruption

Inflammatory bowel disease (IBD) poses a significant challenge due to its intricate pathogenesis. NSD2, a histone methyltransferase responsible for dimethylating histone 3 at lysine 36, is associated with transcriptional activation. However, the precise role of NSD2 in IBD remains unexplored. In this study, we discovered a downregulation of NSD2 in both the intestinal epithelial cells (IECs) of patients and the IBD mouse model. Deficiency of NSD2 in mouse IECs aggravated epithelial barrier disruption and inflammatory response in IBD. Mechanically, NSD2 loss downregulated H3K36me2 and FMO (taurine-synthesis enzyme) mRNA in IECs, resulting in decreased taurine biosynthesis in IECs. Importantly, supplementation with taurine significantly attenuated the symptoms of NSD2 deficiency-induced IBD. These data demonstrate that NSD2 plays a pivotal role in maintaining FMOs-mediated taurine biosynthesis to prevent intestinal inflammation. Our findings also underscore the importance of NSD2-H3K36me2-mediated taurine biosynthesis in maintaining intestinal mucosal barrier homeostasis.

cell biology↗

bioRxiv2024

Super Enhancer-driven LncRNA UNC5B-AS1 Inhibits Inflammatory Phenotypic Transition in Smooth Muscle Cells via Lactylation Modification

BackgroundThe phenotypic transition of pulmonary artery smooth muscle cells (PASMCs) is a central pathological alteration in pulmonary artery remodeling that contributes to pulmonary hypertension (PH). The specific role of long noncoding RNAs (lncRNAs), especially super enhancer (SE)-driven lncRNAs, in the phenotypic transformation of PASMCs induced by hypoxia remains unclear. The objective of this study is to determine the mechanistic role of the super enhancer-driven LncRNA UNC5B-AS1 in phenotypic transformation of PASMCs and hypoxia-induced vascular remodeling. MethodsThe lncRNA UNC5B-AS1 regulated by super-enhancers was identified in hypoxic human PASMCs through RNA sequencing and H3K27ac ChIP sequencing. Overexpression of lncRNA UNC5B-AS1 in human PASMCs was performed to elucidate its role in the pathogenesis of PH. A conserved functional fragment of lncRNA UNC5B-AS1 was used for the treatment of mouse PH. ResultsIn PASMCs, we have identified a SE-driven lncRNA called UNC5B-AS1 that regulates phenotype transition. It is transcriptionally activated by the transcription factor FOXP3. We demonstrate that UNC5B-AS1, as a molecular scaffold in mitochondria, stabilizes the interaction between LRPPRC, which is rich in leucine, and oxidative respiratory chain complex IV. This complex regulates the lactylation modification level of upstream promoter regions of inflammatory genes IL-1{beta}, IL-6, and TNF- by influencing the glycolytic pathway in PASMCs under hypoxic conditions, ultimately affecting the inflammatory phenotype transition of PASMCs. ConclusionsOur findings identify the SE-driven lncRNA UNC5B-AS1 as a novel regulatory factor in hypoxia-induced phenotypic switch of PASMCs, and suggest that overexpression of UNC5B-AS1 may represent a promising therapeutic strategy for PH. HighlightsThe long non-coding RNA UNC5B-AS1, regulated by super-enhancers (SE), is downregulated in hypoxic PASMCs, and regulates PASMC phenotype transition through glycolysis. The super-enhancer region of lncRNA UNC5B-AS1 recruits the transcription factor FOXP3 to its promoter region, forming a chromatin loop to regulate its expression. The lncRNA UNC5B-AS1 acts as a molecular scaffold stabilizing the interaction between LRPPRC and mitochondrial complex IV. The lactate generated by glycolysis activation induces lactylation modification of histones at the IL-1{beta}, IL-6, and TNF- promoters, leading to the inflammatory phenotype transition of PASMCs. Overexpression of lncRNA UNC5B-AS1 conserved fragment reversed SuHx-induced PH in mice. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=121 SRC="FIGDIR/small/593065v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@864576org.highwire.dtl.DTLVardef@13a5fe4org.highwire.dtl.DTLVardef@16d7884org.highwire.dtl.DTLVardef@35d50_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2024

Knowledge Graph-based Thought: a knowledge graph enhanced LLMs framework for pan-cancer question answering

BackgroundIn recent years, Large Language Models (LLMs) have shown promise in various domains, notably in biomedical sciences. However, their real-world application is often limited by issues like erroneous outputs and hallucinatory responses. ResultsWe developed the Knowledge Graph-based Thought (KGT) framework, an innovative solution that integrates LLMs with Knowledge Graphs (KGs) to improve their initial responses by utilizing verifiable information from KGs, thus significantly reducing factual errors in reasoning. The KGT framework demonstrates strong adaptability and performs well across various open-source LLMs. Notably, KGT can facilitate the discovery of new uses for existing drugs through potential drug-cancer associations, and can assist in predicting resistance by analyzing relevant biomarkers and genetic mechanisms. To evaluate the Knowledge Graph Question Answering (KGQA) task within biomedicine, we utilize a pan-cancer knowledge graph to develop a pan-cancer question answering benchmark, named the Pan-cancer Question Answering (PcQA). ConclusionsThe KGT framework substantially improves the accuracy and utility of LLMs in the biomedical field. This study serves as a proof-of-concept, demonstrating its exceptional performance in biomedical question answering. Key PointsO_LIWe introduce a framework combining LLMs with KGs to improve factual accuracy in LLM reasoning. C_LIO_LIOur system is a flexible architecture that seamlessly integrates various LLMs. C_LIO_LIUtilizing a pan-cancer knowledge graph, we have proposed the first KGQA benchmark in the field of biomedicine. C_LIO_LICase studies reveal our method enhanced LLMs in addressing biomedical challenges such as drug repositioning, resistance research, individualized treatment, and biomarker analysis. C_LIO_LIThe method performs favorably in comparison to existing methods. C_LI

bioinformatics↗

bioRxiv2024

Nutrient Sensing Receptor GPRC6A Regulates mTORC1 Signaling and Tau Biology

Tauopathies, including Alzheimers disease (AD), comprise microtubule-associated protein tau aggregates that cause neuronal cell death and clinical cognitive decline. Reducing overall tau abundance remains a central strategy for therapeutics; however, no disease-modifying treatment exists to date. One principal pathway for balancing cellular proteostasis includes the mechanistic target of rapamycin complex 1 (mTORC1) signaling. Recently, arginine emerged as one of the primary amino acids to activate mTORC1 through several intracellular arginine sensors and an extracellular arginine receptor, namely the G protein-coupled receptor (GPCR) family C, group 6, member A (GPRC6A). Human AD brains were previously reported with elevated mTORC1 signaling; however, it is unclear whether arginine sensing and signaling to mTORC1 plays a role in tauopathies. Herein, we examined arginine sensing associated with mTORC1 signaling in the human AD and animal models of tauopathy. We found that human AD brains maintained elevated levels of arginine sensors with potential uncoupling of arginine sensing pathways. Furthermore, we observed increased GPRC6A and arginine in the brain, accompanied by increased mTORC1 signaling and decreased autophagy in a mouse model of tauopathy (Tau PS19). We also discovered that both supplementing arginine and overexpressing GPRC6A in cell culture models could independently activate mTORC1 and promote tau accumulation. In addition, we found that suppressing GPRC6A signaling by either genetic reduction or pharmacological antagonism reduced tau accumulation, phosphorylation, and oligomerization. Overall, these findings uncover the crucial role of arginine sensing pathways in deregulating mTORC1 signaling in tauopathies and identify GPRC6A as a promising target for future therapeutics in tauopathies and other proteinopathies. Significance StatementTauopathies, including Alzheimers disease (AD), accumulate pathogenic tau protein inclusions that potentially contribute to the hyperactive mechanistic target of rapamycin complex 1 (mTORC1) signaling and eventually cause neuronal cell death. Here, we presented novel findings that AD and animal models of tauopathy maintained increased expression of arginine sensors and uncoupling of arginine sensing associated with mTORC1 signaling. We investigated the role of a putative extracellular arginine and basic L-amino acid sensing G protein-coupled receptor (GPCR) family C, group 6, member A (GPRC6A) in activating mTORC1 and accelerating pathogenic tau phenotypes in several cell models. Additionally, we showed that genetic repression or antagonism of GPRC6A signaling provides a novel therapeutic target for tauopathies and other proteinopathies.

neuroscience↗

bioRxiv2024

Evolutionary trajectory of TRPM2 channel activation by adenosine diphosphate ribose and calcium

Ion channel activation upon ligand gating triggers a myriad of biological events and, therefore, evolution of ligand gating mechanism is of fundamental importance. TRPM2, a typical ancient ion channel, is activated by adenosine diphosphate ribose (ADPR) and calcium and its activation has evolved from a simple mode in invertebrates to a more complex one in vertebrates, but the evolutionary process is still unknown. Molecular evolutionary analysis of TRPM2s from more than 280 different animal species has revealed that, the C-terminal NUDT9-H domain has evolved from an enzyme to a ligand binding site for activation, while the N-terminal MHR domain maintains a conserved ligand binding site. Calcium gating pattern has also evolved, from one Ca2+-binding site as in sea anemones to three sites as in human. Importantly, we identified a new group represented by olTRPM2, which has a novel gating mode and fills the missing link of the channel gating evolution. We conclude that the TRPM2 ligand binding or activation mode evolved through at least three identifiable stages in the past billion years from simple to complicated and coordinated. Such findings benefit the evolutionary investigations of other channels and proteins.

evolutionary biology↗

bioRxiv2024

MetagenomicKG: a knowledge graph for metagenomic applications

MotivationThe sheer volume and variety of genomic content within microbial communities makes metagenomics a field rich in biomedical knowledge. To traverse these complex communities and their vast unknowns, metagenomic studies often depend on distinct reference databases, such as the Genome Taxonomy Database (GTDB), the Kyoto Encyclopedia of Genes and Genomes (KEGG), and the Bacterial and Viral Bioinformatics Resource Center (BV-BRC), for various analytical purposes. These databases are crucial for genetic and functional annotation of microbial communities. Nevertheless, the inconsistent nomenclature or identifiers of these databases present challenges for effective integration, representation, and utilization. Knowledge graphs (KGs) offer an appropriate solution by organizing biological entities and their interrelations into a cohesive network. The graph structure not only facilitates the unveiling of hidden patterns but also enriches our biological understanding with deeper insights. Despite KGs having shown potential in various biomedical fields, their application in metagenomics remains underexplored. ResultsWe present MetagenomicKG, a novel knowledge graph specifically tailored for metagenomic analysis. MetagenomicKG integrates taxonomic, functional, and pathogenesis-related information from widely used databases, and further links these with established biomedical knowledge graphs to expand biological connections. Through several use cases, we demonstrate its utility in enabling hypothesis generation regarding the relationships between microbes and diseases, generating sample-specific graph embeddings, and providing robust pathogen prediction. Availability and ImplementationThe source code and technical details for constructing the MetagenomicKG and reproducing all analyses are available at Github: https://github.com/KoslickiLab/MetagenomicKG. We also host a Neo4j instance: http://mkg.cse.psu.edu:7474 for accessing and querying this graph. Contactdmk333@psu.edu Supplementary informationavailable at Bioinformatics online.

bioinformatics↗

bioRxiv2024

Inferring allele-specific copy number aberrations and tumor phylogeography from spatially resolved transcriptomics

A key challenge in cancer research is to reconstruct the somatic evolution within a tumor over time and across space. Spatially resolved transcriptomics (SRT) measures gene expression at thousands of spatial locations in a tumor, but does not directly reveal genetic aberrations. We introduce CalicoST, an algorithm to simultaneously infer allele-specific copy number aberrations (CNAs) and a spatial model of tumor evolution from SRT of tumor slices. By modeling CNA-induced perturbations in both total and allele-specific gene expression, CalicoST identifies important types of CNAs - including copy-neutral loss of heterozygosity (CNLOH) and mirrored subclonal CNAs- that are invisible to total copy number analysis. On SRT data from nine patients from the Human Tumor Atlas Network (HTAN) with matched whole exome sequencing (WES) data, CalicoST achieves an average accuracy of 86%, approximately 21% higher than existing methods. On two patients with SRT data from multiple adjacent slices, CalicoST reconstructs a tumor phylogeography that describes the spread of cancerous clones in three-dimensional space. CalicoST analysis of multiple SRT slices from a cancerous prostate organ reveals five spatially coherent clones, with mirrored subclonal CNAs distinguishing clones on the two sides of the prostate, forming a bifurcating phylogeography in both genetic and physical space.

bioinformatics↗

bioRxiv2024

Activation of locus coeruleus noradrenergic neuronsrapidly drives homeostatic sleep pressure

Homeostatic sleep regulation is essential for optimizing the amount and timing of sleep, but the underlying mechanism remains unclear. Optogenetic activation of locus coeruleus noradrenergic neurons immediately increased sleep propensity following transient wakefulness. Fiber photometry showed that repeated optogenetic or sensory stimulation caused rapid declines of locus coeruleus calcium activity and noradrenaline release. This suggests that functional fatigue of noradrenergic neurons, which reduces their wake-promoting capacity, contributes to sleep pressure.

neuroscience↗

bioRxiv2024

Engineering customized viral receptors for various coronaviruses

Coronaviruses display versatile receptor usage, yet in-depth characterization of coronaviruses lacking known receptor identities has been impeded by the absence of feasible infection models1,2. Here, we developed an innovative strategy to engineer functional customized viral receptors (CVRs). The modular design relies on building receptor frameworks comprising various function modules and generating specific epitope-targeting viral binding domains. We showed the key factors for CVRs to efficiently facilitate spike cleavage, membrane fusion, pseudovirus entry, and authentic virus propagation for various coronaviruses, resembling their native receptors. Applying this strategy, we delineated the accessible receptor binding epitopes for functional SARS-CoV-2 CVR design and elucidated the mechanism of entry supported by an amino-terminus domain (NTD) targeting S2L20-CVR. Furthermore, we created CVR-expressing cells for assessing antibodies and inhibitors against 12 representative coronaviruses from six subgenera, most of which lacking known receptors. Notably, a pan-sarbecovirus CVR supported entry of various sarbecoviruses, as well as propagation of a replicable HKU3 pseudovirus and the authentic strain RsHuB2019A3. Through combining an HKU5-specific CVR with reverse genetics, we successfully rescued and cultured wild-type and fluorescence protein-incorporated HKU5, a receptor-unidentified merbecovirus. Our study demonstrated the great potential of CVR strategy in establishing native receptor-independent infection models, paving the way for studying various viruses that are challenging to culture due to the lack of susceptible cells. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=162 SRC="FIGDIR/small/583237v1_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@7cb9ccorg.highwire.dtl.DTLVardef@8a2855org.highwire.dtl.DTLVardef@5e14f0org.highwire.dtl.DTLVardef@b0b993_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphic abstractC_FLOATNO C_FIG

microbiology↗

bioRxiv2024

Comparative study of enriched dopaminergic neurons from siblings with Gaucher disease discordant for parkinsonism

Inducible pluripotent stem cells (iPSCs) derived from patient samples have significantly enhanced our ability to model neurological diseases. Comparative studies of dopaminergic (DA) neurons differentiated from iPSCs derived from siblings with Gaucher disease discordant for parkinsonism provides a valuable avenue to explore genetic modifiers contributing to GBA1-associated parkinsonism in disease-relevant cells. However, such studies are often complicated by the inherent heterogeneity in differentiation efficiency among iPSC lines derived from different individuals. To address this technical challenge, we devised a selection strategy to enrich dopaminergic (DA) neurons expressing tyrosine hydroxylase (TH). A neomycin resistance gene (neo) was inserted at the C-terminus of the TH gene following a T2A self-cleavage peptide, placing its expression under the control of the TH promoter. This allows for TH+ DA neuron enrichment through geneticin selection. This method enabled us to generate comparable, high-purity DA neuron cultures from iPSC lines derived from three sisters that we followed for over a decade: one sibling is a healthy individual, and the other two have Gaucher disease (GD) with GBA1 genotype N370S/c.203delC+R257X (p.N409S/c.203delC+p.R296X). Notably, the younger sister with GD later developed Parkinson disease (PD). A comprehensive analysis of these high-purity DA neurons revealed that although GD DA neurons exhibited decreased levels of glucocerebrosidase (GCase), there was no substantial difference in GCase protein levels or lipid substrate accumulation between DA neurons from the GD and GD/PD sisters, suggesting that the PD discordance is related to of other genetic modifiers.

neuroscience↗