Biology subjects

Zhu, Y.

Publications and source records attributed to Zhu, Y..

At least 415 records · Page 23Linked to original sources

bioRxiv2023

Comprehensive Metabolomic Analysis of Human Heart Tissue Enabled by Parallel Metabolite Extraction and High-Resolution Mass Spectrometry

The heart contracts incessantly and requires a constant supply of energy, utilizing numerous metabolic substrates such as fatty acids, carbohydrates, lipids, and amino acids to supply its high energy demands. Therefore, a comprehensive analysis of various metabolites is urgently needed for understanding cardiac metabolism; however, complete metabolome analyses remain challenging due to the broad range of metabolite polarities which makes extraction and detection difficult. Herein, we implemented parallel metabolite extractions and high-resolution mass spectrometry (MS)-based methods to obtain a comprehensive analysis of the human heart metabolome. To capture the diverse range of metabolite polarities, we first performed six parallel liquid-liquid extractions (three monophasic, two biphasic, and one triphasic extractions) of healthy human donor heart tissue. Next, we utilized two complementary MS platforms for metabolite detection - direct-infusion ultrahigh-resolution Fourier-transform ion cyclotron resonance (DI-FTICR) and high-resolution liquid chromatography quadrupole time-of-flight tandem MS (LC-Q-TOF MS/MS). Using DI-FTICR MS, 9,521 metabolic features were detected where 7,699 were assigned a chemical formula and 1,756 were assigned an annotated by accurate mass assignment. Using LC-Q-TOF MS/MS, 21,428 metabolic features were detected where 626 metabolites were identified based on fragmentation matching against publicly available libraries. Collectively, 2276 heart metabolites were identified in this study which span a wide range of polarities including polar (benzenoids, alkaloids and derivatives and nucleosides) as well as non-polar (phosphatidylcholines, acylcarnitines, and fatty acids) compounds. The results of this study will provide critical knowledge regarding the selection of appropriate extraction and MS detection methods for the analysis of the diverse classes of human heart metabolites. Table of Contents Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=108 SRC="FIGDIR/small/558013v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@1db91c8org.highwire.dtl.DTLVardef@400d81org.highwire.dtl.DTLVardef@136b221org.highwire.dtl.DTLVardef@1e8d3b9_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2023

Rapid and synchronous chemical induction of replicative-like senescence via a small molecule inhibitor

Cellular senescence is now acknowledged as a key contributor to organismal ageing and late-life disease. Although popular, the study of senescence in vitro can be complicated by the prolonged and asynchronous timing of cells committing to it and its paracrine effects. To address these issues, we repurposed the small molecule inhibitor inflachromene (ICM) to induce senescence to human primary cells. Within six days of treatment with ICM, senescence hallmarks, including the nuclear eviction of HMGB1 and -B2, are uniformly induced across IMR90 cell populations. By generating and comparing various high throughput datasets from ICM-induced and replicative senescence, we uncovered significant similarity of the two states. Notably though, ICM suppresses the proinflammatory secretome associated with senescence, thus alleviating most paracrine effects. In summary, ICM induces a senescence-like phenotype rapidly and synchronously thereby allowing the study of its core regulatory program without any confounding heterogeneity.

genomics↗

bioRxiv2023

Structure of Native Chromatin Fibres Revealed by Cryo-ET in situ

The structure of chromatin plays pivotal roles in regulating gene transcription, DNA replication and repair, and chromosome segregation. This structure, however, remains elusive. Using cryo-FIB and cryo-ET, we delineated the 3D architecture of native chromatin fibres in intact interphase human T-lymphoblasts and determined the in-situ structures of nucleosomes in different conformations. These chromatin fibres are not structured as uniform 30 nm one-start or two-start filaments but are composed of relaxed, variable zigzag organizations of nucleosomes connected by straight linker DNA. Nucleosomes with little H1 and linker DNA density were distributed randomly without any spatial preference. This work sets a precedent for future high-resolution investigations on native chromatin structures in-situ at both a single-nucleosome level and a population level under many different cellular conditions in health and disease.

cell biology↗

bioRxiv2023

Local two-photon excitation reveals the mechanism of mitochondrial Ca2+ release

Mitochondrial Ca2+ (mitoCa2+) simultaneously implicates respiration, mitochondrial physiology, and cell signaling, which prevents the disentanglement of mitoCa2+ from those complex processes. Although mitochondria have long been recognized as temporary Ca2+ buffer, how mitoCa2+ is regulated and released remains unclear. In this study, we report a specific photochemical excitation to flavoproteins in single-mitochondrion tubulars by a tightly-focused femtosecond laser that triggers local mitoCa2+ transients, without any extra-mitochondrial Ca2+ involved. The two-photon excitation to complex I and II accelerates the entire electron transport chain (ETC) and promotes ATP synthesis. Free mitoCa2+ is thus released from the Ca2+-phosphate ion (Pi) complexes at complex V in mitochondrial matrix during ATP synthesis to form mitoCa2+ transients there. The abnormal mitoCa2+ signaling by knockdown of ATP synthase subunit affects cell proliferation, apoptosis, and mitophagy. Our results reveal mitoCa2+ is released and regulated by ETC and ATP synthesis rather than the reverse. Mitochondria are multi-functional units to simultaneously produce energy and coordinate molecular signaling for cells. The key process of metabolism, tricarboxylic acid (TCA) cycle, is continuously ongoing in mitochondrial matrix and generates reducing equivalents for subsequent electron transfer (Martinez-Reyes and Chandel, 2020; Martinez-Reyes et al., 2016). The respiration is accomplished by electron transport chain (ETC) in the inner mitochondrial membrane (IMM) (Marreiros et al., 2016). Mitochondria regulate a series of signaling cascades to mediate apoptosis, autophagy, and cell senescence (Galluzzi et al., 2014; Rasola and Bernardi, 2011; Ziegler et al., 2021). Biosynthesis of some amino acids and nucleotides also takes place in mitochondria (Ahn and Metallo, 2015; Li and Hoppe, 2023). Those processes are involved with each other through complex crosstalk and feedbacks. Mitochondria have long been recognized as Ca2+ buffer to temporarily deposit abnormal cytosolic Ca2+ for cellular Ca2+ homeostasis (Garbincius and Elrod, 2022; Kirichok et al., 2004; Lambert et al., 2019). However, the Ca2+ entry into mitochondria definitely influence those mitochondrial processes and functions (Garbincius and Elrod, 2022). The acute and direct consequences of Ca2+ entry into mitochondria are found as depolarization of mitochondrial membrane potential (MMP). If the cellular Ca2+ level is too high, mitochondria may become damaged and dysfunctional. Mitophagy/autophagy and even apoptosis are initiated (Galluzzi et al., 2014; Lou et al., 2020; Rasola and Bernardi, 2011). Moreover, Ca2+ in mitochondrial matrix (mitoCa2+) takes an essential role in quite a few physiological processes including mitochondrial fission and fusion, cell development, and proliferation (Doonan et al., 2014; Singh and Mabalirajan, 2021; Steffen and Koehler, 2018). The respiration is also believed to be related to mitoCa2+ (Glancy and Balaban, 2012; Wescott et al., 2019). Technically, perturbation to mitoCa2+ affects most mitochondrial processes and physiology, which makes it quite difficult to interrogate how Ca2+ is regulated and released in mitochondria. So far, the regulation of mitoCa2+ remains in mist. In this study, we report a single-mitochondrion photochemical process by tightly-focused femtosecond laser that specifically excites complex I and II by two-photon excitation and accelerate ETC. Free mitoCa2+ is released from Ca2+-phosphate ion (Pi) complexes by ATP synthesis at complex V in mitochondria. These results clarify the mechanism of mitoCa2+ regulation and provide further insights in the relationship between mitoCa2+ and respiration.

cell biology↗

bioRxiv2023

The Diversity of NLRs in Brassica rapa Pan-genome

The species Brassica rapa is mainly cultivated as a vegetable crop with high economic value. But infectious diseases, such as soft rot disease and clubroot disease can cause severe yield losses. Introducing resistance genes through breeding is an efficient and sustainable way to reduce the susceptibility and improve the yield of crops. Nucleotide-Binding Leucine-Rich Repeat (NLR) genes are the main types of resistance genes. They can recognize pathogen effectors and initiate downstream immune response. However, the intraspecific diversity of NLR genes in Brassica rapa has remained unknown. Based on domain similarity search and machine learning pipeline, we identified 2188 NLRs in 17 accessions of Brassica rapa genomes, which constitute the species-wide pan-NLRome in Brassica rapa. The diversity of the four types of NLR genes are significantly different in the aspects of chromosome location, number stability, integrated domains (IDs), evolutionary trajectory, and positive selection sites. Phylogenetic analyses show TNL-type NLRs whose N terminus contain Toll/interleukin-1 receptor (TIR) domain experienced accession-specific expansion. Moreover, the expanded TNL-type NLRs carry more positively selected amino acid residues which are mainly located on the protein surface based on their 3D structures. These evidences might imply their important biological function in perceiving pathogen effectors. Taken together, our study provides better insights into the diversity and variation of NLR genes in Brassica rapa pangemone, which can facilitate the biofunction assigning, cloning, and subsequent application in breeding programs.

genomics↗

bioRxiv2023

Task success in trained spiking neuronal network models coincides with emergence of cross-stimulus-modulated inhibition

The neocortex is composed of spiking neuronal units interconnected in a sparse, recurrent network. Neuronal networks exhibit spiking activity that transforms sensory inputs into appropriate behavioral outputs. In this study, we train biologically realistic spiking neural network (SNN) models to identify the architectural changes which enable task-appropriate computations. Specifically, we employ a binary state change detection task, where each state is defined by motion entropy. This task mirrors behavioral paradigms that mice perform in the lab. SNNs are composed of excitatory and inhibitory units randomly interconnected with connection likelihoods and strengths matched to observations from mouse neocortex. Following training, we discover that SNNs selectively adjust firing rates depending on state, and that excitatory and inhibitory connectivity between input and recurrent layers change in accordance with this rate modulation. Input channels that exhibit bias to one specific motion entropy input develop stronger connections to recurrent excitatory units during training, while channels that exhibit bias to the other input develop stronger connections to inhibitory units. Furthermore, recurrent inhibitory units which positively modulated firing rates to one input strengthened their connections to recurrent units of the opposite modulation. This specific pattern of cross-modulation inhibition emerged as the optimal solution when imposing Dales law throughout training of the SNNs. Removing this constraint led to the absence of the emergence of this architectural solution. This work highlights the critical role of interneurons and the specific architectural patterns of inhibition in shaping dynamics and information processing within neocortical circuits.

neuroscience↗

bioRxiv2023

In situ structural insights into the excitation contraction coupling mechanism of skeletal muscle

Excitation-contraction coupling (ECC) is a fundamental mechanism in control of skeletal muscle contraction and occurs at triad junctions, where dihydropyridine receptors (DHPRs) on transverse tubules sense excitation signals and then cause calcium release from the sarcoplasmic reticulum via coupling to type 1 ryanodine receptors (RyR1s), inducing the subsequent contraction of muscle filaments. However, the molecular mechanism remains unclear due to the lack of structural details. Here, we explored the nanometre-resolution architecture of triad junction by cryo-electron tomography, solved the in situ structure of RyR1 in complex with FKBP12 and calmodulin, and discovered the intact RyR1-DHPR supercomplex. RyR1s arrange into two rows on the terminal cisternae membrane by forming right-hand corner-to-corner contacts, and tetrads of DHPRs bind to RyR1s in an alternating manner, forming another two rows on the transverse tubule membrane. Such unique arrangement is important for synergistic calcium release and provides direct evidence of physical coupling in ECC.

biophysics↗

bioRxiv2023

High-throughput Extracellular Matrix Proteomics of Human Lungs Enabled by Photocleavable Surfactant and diaPASEF

The extracellular matrix (ECM) is a complex assembly of proteins that provide interstitial scaffolding and elastic recoil to human lungs. The pulmonary extracellular matrix (ECM) is increasingly recognized as an independent bioactive entity by creating biochemical and mechanical signals that influence disease pathogenesis, making it an attractive therapeutic target. However, the pulmonary ECM proteome ("matrisome") remains challenging to analyze by mass spectrometry due to its inherent biophysical properties and relatively low abundance. Here, we introduce a strategy designed for rapid and efficient characterization of the human pulmonary ECM using the photocleavable surfactant Azo. We coupled this approach with trapped ion mobility MS with diaPASEF to maximize depth of matrisome coverage. Using this strategy, we identify nearly 400 unique matrisome proteins with excellent reproducibility that are known to be important in lung biology, including key insoluble ECM proteins.

systems biology↗

bioRxiv2023

Yeast TLDc domain-containing proteins control assembly and subcellular localization of the V-ATPase

Yeast vacuoles, equivalent to lysosomes in other eukaryotes, are important acidic degradative organelles as well as storage compartments and signaling hubs. To perform these functions, they rely on important protein complexes, including the V-ATPase, responsible for organelle acidification. In this study, we used cross-linking mass spectrometry to characterize the protein complexes of isolated vacuoles. We were able to detect many known protein-protein interactions, including known protein complexes, as well as undescribed ones. Among these, we identified the uncharacterized TLDc domain-containing protein Rtc5 as a novel interactor of the V-ATPase. We show that Rtc5 localizes to the vacuole membrane depending on N-myristoylation and on its interactions with the V-ATPase. We further analyzed the influence of this protein, and the second yeast TLDc domain-containing protein, Oxr1, on V-ATPase function. We find that both Rtc5 and Oxr1 promote the disassembly of the vacuolar V-ATPase in vivo, counteracting the role of the assembly chaperone, the RAVE complex. Finally, Oxr1 is necessary for the retention in the late Golgi complex of an organelle-specific subunit of the V-ATPase. Collectively, our results shed light on the in vivo roles of yeast TLDc domain-containing proteins in relation to the V-ATPase, highlighting the multifaceted regulation of this crucial protein complex.

cell biology↗

bioRxiv2023

Multi-omics map revealed PPARalpha activation protecting against myocardial ischemia-reperfusion injury by maintaining cardiac metabolic homeostasis

Timely percutaneous coronary intervention is the most effective initial therapy for the acute myocardial infarction (MI). However, the mechanism in energy metabolism underlying time-dependent coronary reperfusion remains largely unknown. Here, we generated an integrative map of cardiac cells using bulk and single-nucleus RNA-seq combined with metabolomics profiling of hearts with reperfusion at distinct time points post MI in rat. We found early time reperfusion (ETR), but not late time reperfusion (LTR) reduced myocardial injury by maintaining cardiac energy homeostasis. PPAR was identified as a key regulator for maintaining fatty acid metabolism after MI/R injury. Importantly, pretreatment with FDA-approved PPAR agonist, fenofibrate, improved the transcriptional signatures, and ameliorated the function of the MI/R injured hearts, particularly in the ETR. Together, our data not only deciphered the protective effect of ETR by maintaining cardiac energy homeostasis, but also provided insights into the translational potential of PPAR activation in alleviating MI/R injury.

cell biology↗

bioRxiv2023

Knockout studies using CD34+ hematopoietic cells suggest that CD44 is a physiological human neutrophil E-selectin ligand

The recruitment of peripheral blood neutrophils at sites of inflammation involves a multistep cascade, starting with E- and P-selectin expressed on the inflamed vascular endothelium binding sialofucosylated glycans on leukocytes. As the glycoconjugate biosynthesis pathways in different cells are distinct, the precise carbohydrate ligands of selectins varies both across species, and between different immune cell populations in a given species. To study this aspect in human neutrophils, we developed a protocol to perform CRISPR/Cas9 gene-editing on CD34+ hHSCs (human hematopoietic stem/progenitor cells) as they are differentiated towards neutrophil lineage. This protocol initially uses a cocktail of SCF (stem-cell factor), IL-3 (interleukin-3) and FLT-3L (FMS-like tyrosine kinase 3 ligand) to expand the stem/progenitor cells followed by directed differentiation to neutrophils using G-CSF (granulocyte colony-stimulating factor). Microfluidics based assays were performed on a confocal microscope platform to characterize the rolling phenotype of each edited cell type in mixed populations. These studies demonstrated that CD44, but not CD43, is a major E-selectin ligand on human neutrophils. The loss of function results were validated by developing sialofucosylated recombinant CD44. This glycosylated protein supported both robust E-selectin binding in a cell-free assay, and it competitively blocked neutrophil adhesion to E-selectin on inflamed endothelial cells. Together, the study establishes important methods to study human neutrophil biology and determines that sialoflucosylated-CD44 is a physiological human E-selectin ligand. KEY POINTSO_LIA CRISPR-Cas9 based protocol was optimized to knockout genes in primary human neutrophils derived from CD34+ hHSCs C_LIO_LIUnder physiological fluid shear conditions, a sialofucosylated form of CD44 expressed on human neutrophils is a major E-selectin ligand C_LI VISUAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=111 SRC="FIGDIR/small/553923v1_ufig1.gif" ALT="Figure 1"> View larger version (21K): org.highwire.dtl.DTLVardef@1891653org.highwire.dtl.DTLVardef@118e074org.highwire.dtl.DTLVardef@38052aorg.highwire.dtl.DTLVardef@1db0882_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2023

Global and local adaptation to aridity in a desert plant Gymnocarpos przewalskii

In order to thrive and survive plant species need to combine stability in the long term and rapid response to environmental challenges in the short term. The former would be reflected by global adaptation across species and the latter by pronounced local adaptation among populations of the same species. It remains unclear how much overlap is to be expected between the parts of the genome associated to these two contrasted adaptation processes. In the present study, we generated a high-quality genome and re-sequenced 177 individuals for Gymnocarpos przewalskii, an important desert plant species from North-West China, to detect local adaptation. To test for global adaptation to aridity at the molecular level we compared genomic data of 15 species that vary in their ability to withstand drought. A total of 118 genes were involved in global adaptation to aridity. Sixty-five G. przewalskii genes were shared across all xerophytic species, of which sixty-three were under stabilizing selection and two under directional selection. While 20% of G. przewalskii genome showed signatures of local adaptation to aridity during population divergence, only 13 of those genes were also under global adaptation. Hence, our results suggest that long-term stability is crucial for adaptation to extreme environmental stress but is only maintained in a small group of highly pleiotropic genes while a rapid response to recent changes elicits a genome-wide response, including gene family expansion. The overlap between the two evolutionary mechanisms appears limited.

evolutionary biology↗

bioRxiv2023

Early spiral arteriole remodeling in the uterine-placental interface: a rat model

The mammalian placentas interface with the parent is a richly vascularized tissue whose development relies upon communication between many different cell types within the uterine microenvironment. The uterine blood vessels of the interface are reshaped during pregnancy into wide-bore, flaccid vessels that convey parental blood to the exchange region of the placenta. Fetally-derived invasive trophoblast as well as parental uterine macrophages and Natural Killer cells are involved in the stepwise remodeling of these vessels and their respective contributions to this crucial process are still being delineated. However, the earliest steps in arteriole remodeling are understudied as they are difficult to study in humans, and other species lack the deep trophoblast invasion that is so prominent a feature of placentation in humans. Here, we establish the rat, with deep hemochorial placentation akin to humans, as a model system in which to tease apart the earliest, relatively understudied events in spiral arteriole remodeling. We show that the rat uterine placental interface increases in size and vascularity rapidly, before trophoblast invasion. The remodeling stages in the arterioles of the rat uterine-placental interface follow a sequence of anatomical changes similar to those in humans, and there are changes to the arterioles muscular tunica media prior to the marked influx of immune cells. The rat is a tractable model in which to better understand the cell/cell interactions occurring in vivo in an intact tissue microenvironment over time.

developmental biology↗

bioRxiv2023

An ancestral dual function of OmpM as outer membrane tether and nutrient uptake channel in diderm Firmicutes

The outer membrane (OM) in diderm, or Gram-negative, bacteria must be tethered to peptidoglycan (PG) for mechanical stability and to maintain cell morphology. Most diderm phyla from the Terrabacteria group lack well-characterised OM attachment systems such as Brauns lipoprotein, Pal and OmpA, but instead have the OmpM protein. OmpM has a periplasmic region containing an S-layer homology domain and a {beta}-barrel region that is embedded in the OM. Here, we have determined the structure of the most abundant OmpM protein from the diderm firmicute Veillonella parvula by single particle cryogenic electron microscopy (cryo-EM). We reveal an OM portion similar to well-characterised trimeric general porins and a mobile periplasmic PG-binding region. Combining the cryo-EM data with crystal structures, structure predictions and molecular dynamics simulations, we show that the periplasmic region of OmpM likely adopts multiple conformations. Single-channel electrophysiology demonstrates ion conductance properties similar to E. coli OmpF. Finally, we demonstrate via functional assays that the four OmpM paralogues are likely to be the only general porins in V. parvula. Together, our results show that OM tethering and nutrient acquisition are genetically linked in V. parvula (and other diderm Firmicutes), suggesting that concurrent loss of two key OM-related functions, tethering and nutrient uptake, promoted the multiple OM loss events that have been inferred in the Terrabacteria.

biochemistry↗

bioRxiv2023

Interferon response and epigenetic modulation by SMARCA4 mutations drive ovarian tumor immunogenicity

Cell-intrinsic mechanisms of immunogenicity in ovarian cancer (OC) are not well understood. The presence of damaging mutations in the SWI/SNF chromatin remodeling complex, such as the SMARCA4 (BRG1) catalytic subunit, has been associated with improved response to ICB, however the mechanism by which this occurs is unclear. The aim of this current study was to examine the alterations in tumor cell-intrinsic and extrinsic immune signaling caused by SMARCA4 loss. Using OC models with loss-of-function mutations in SMARCA4, we found that SMARCA4 loss resulted in increased cancer cell-intrinsic immunogenicity, characterized by upregulation of long-terminal RNA repeats such as endogenous retroviruses, increased expression of interferon-stimulated genes, and upregulation of antigen presentation machinery. Notably, this response was dependent on IRF3 signaling, but was independent of the type I interferon receptor. Mice inoculated with cancer cells bearing SMARCA4 loss demonstrated increased activation of cytotoxic T cells and NK cells in the tumor microenvironment as well as increased infiltration with activated dendritic cells. These results were recapitulated when animals bearing SMARCA4-proficient tumors were treated with a BRG1 inhibitor, suggesting that modulation of chromatin remodeling through targeting SMARCA4 may serve as a strategy to reverse immune evasion in OC.

cancer biology↗

bioRxiv2023

Overcome Prostate Cancer Resistance to Immune Checkpoint Therapy with Ketogenic Diet-Induced Epigenetic Reprogramming

Advanced prostate cancer (PCa) is overwhelmingly resistant to immune checkpoint blockade (ICB) therapy, representing a formidable clinical challenge. In this study, we developed a syngeneic murine PCa model with acquired ICB resistance. Using this model, synergistic efficacy was achieved by combining anti-PD1 and anti-CTLA4 antibodies with histone deacetylase inhibitor (HDACi) vorinostat, a cyclic ketogenic diet (CKD), or supplementation of ketone body {beta}-hydroxybutyrate (BHB, endogenous HDACi) via 1,3-butanediol-admixed food. CKD and BHB supplementation delayed PCa tumors as monotherapy, and both BHB and adaptive immunity are required for the anti-tumor activity of CKD. Single-cell transcriptomic and proteomic profiling revealed that the HDACi and ketogenesis-enhanced ICB therapy involves cancer-cell-intrinsic (upregulated MHC class I molecules) and extrinsic mechanisms (CD8+ T cell chemoattraction, M1/M2 macrophage rebalancing, monocyte differentiation toward antigen presenting cells, and diminished neutrophils). Overall, these findings underscore the potential of using HDACi and optimized KD to enhance ICB therapy for PCa.

cancer biology↗

bioRxiv2023

CellGO: A novel deep learning-based framework and webserver for cell type-specific gene function interpretation

Interpreting the function of genes and gene sets identified from omics experiments remains a challenge, as current pathway analysis tools often fail to account for complex interactions across genes and pathways under specific tissues and cell types. We introduce CellGO, a tool for cell type-specific gene functional analysis. CellGO employs a deep learning model to simulate signaling propagation within a cell, enabling the development of a heuristic pathway activity measuring system to identify cell type-specific active pathways given a single gene or a gene set. It is featured with additional functions to uncover pathway communities and the most active genes within pathways to facilitate mechanistic interpretation. This study demonstrated that CellGO can effectively capture cell type-specific pathways even when working with mixed cell-type markers. CellGOs performance was benchmarked using gene knockout datasets, and its implementation effectively infers the cell type-specific pathogenesis of risk genes associated with neurodevelopmental and neurodegenerative disorders, suggesting its potential in understanding complex polygenic diseases. CellGO is accessible through a python package and a four-mode web interface for interactive usage with pretrained models on 71 single-cell datasets from human and mouse fetal and postnatal brains.

bioinformatics↗

bioRxiv2023

Rapid and visual detection of Schistosoma japonicum circulating nucleic acids by CRISPR-Cas12a

BackgroundSchistosomiasis is the second most destructive parasitic disease globally. It poses a serious threat to human health if not diagnosed and treated promptly. However, the current detection methods have limitations due to their dependence on specialized equipments and personnel, and the long detection time, resulting in less-than-ideal detection outcomes. Therefore, more accurate and sensitive assays are required to aid in the control of schistosomiasis. This study aims to develop a rapid and practical method for detecting Schistosoma japonicum circulating nucleic acid by combining the Cas12a protein in the CRISPR (Clustered regularly interspaced short palindromic repeats) system with recombinase-mediated isothermal nucleic acid amplification technology. Methodology/Principal FindingsWe created a CRISPR-Cas12a detection method for Schistosomiasis. SjR2 and SjCHGCS19 genes with repetitive copies in the Schistosoma japonicum genome were targeted for detection. The CRISPR-Cas12a detection method can achieve a detection sensitivity of 1 cp/{micro}L, with no cross-reaction with the other three human-infecting trematode parasites. To vividly simulate clinical patients at different infection stages, we collected rabbits serums at 1 d, 3 d, 1 w, 3 w, 5 w, and 7 w post-infection. Circulating Schistosoma japonicum DNA in the serum can be detected as early as 3 days post-infection. The sample and positive rates of each stage were analyzed and the CRISPR-Cas12a detection method prevailed to Nested-PCR. Additionally, our assay offers flexible results readout options, including lateral test strips. Conclusions/SignificanceThis CRISPR-Cas12a detection method enables sensitive and specific detection of Schistosomiasis by detecting highly repetitive SjR2 and SjCHGCS19 genes. The method was fully validated with rabbits serums collected at different infection stages, which can be applied to monitoring the early infection of schistosomiasis in resource-limited regions. Author SummaryWith the development of schistosomiasis prevention and control efforts in recent years, the prevalence rate and infection intensity of schistosomiasis have decreased, making early and accurate diagnoses more challenging. Combining CRISPR-Cas12a protein with isothermal amplification technology, a detection method for the multi-copy sequences SjR2 and SjCHGCS19 in the genome of Schistosoma japonicum was developed in this study. The results demonstrated that the detection sensitivity of this method could reach 1 cp/{micro}L, with no cross reactivity with three other fluke-like human parasites. In this study, serum samples from 15 rabbits infected with Schistosoma japonicum were used to validate the method. The results demonstrated that rabbits could be identified as early as the third day after infection. CRISPR-Cas12a detection method has a higher positive rate than traditional Nested-PCR. In addition, lateral test strips enable direct observation of our assay results. The aforementioned research findings indicate that the CRISPR-Cas12a-based detection method can be utilized for the early diagnosis of schistosomiasis. In conjunction with the result reading method of the lateral test strips, it also provides a new method for the on-site diagnosis of schistosomiasis in environments with limited access to resources.

bioengineering↗