Biology subjects

Ma, Q.

Publications and source records attributed to Ma, Q..

At least 109 records · Page 6Linked to original sources

bioRxiv2023

An explainable graph neural framework to identify cancer-associated intratumoral microbial communities

Microbes are extensively present among various cancer tissues and play a vital role in cancer prevention and treatment responses. However, the underlying relationships between intratumoral microbes and tumors are still not well understood. Here, we developed a MIcrobial Cancer-association Analysis using a Heterogeneous graph transformer (MICAH) to identify intratumoral cancer-associated microbial communities. MICAH integrates metabolic and phylogenetic relationships among microbes into a heterogeneous graph representation. It uses a graph attention transformer to holistically capture the relationships between intratumoral microbes and cancer tissues, which improves the explainability of the association between identified microbial communities and cancer. We applied MICAH to intratumoral microbiome data across five cancer types and demonstrated its good generalizability and reproducibility. We believe this graph neural network framework can provide novel insights into cancer pathogenesis associated with the intratumoral microbiome.

bioinformatics↗

bioRxiv2023

A Weighted Two-stage Sequence Alignment Framework to Identify DNA Motifs from ChIP-exo Data

Identifying precise transcription factor binding sites (TFBS) or regulatory DNA motifs plays a fundamental role in researching transcriptional regulatory mechanisms in cells and in helping construct regulatory networks. Current algorithms developed for motif searching focus on the analysis of ChIP-enriched peaks but are not able to integrate the ChIP signal in nucleotide resolution. We present a weighted two-stage alignment tool (TESA). Our framework implements an analysis workflow from experimental datasets to TFBS prediction results. It employs a binomial distribution model and graph searching model with ChIP-exonuclease (ChIP-exo) reads depth and sequence data. TESA can effectively measure the possibility for each position to be an actual TFBS in a given promoter sequence and predict statistically significant TFBS sequence segments. The algorithm substantially improves prediction accuracy and extends the scope of applicability of existing approaches. We apply the framework to a collection of 20 ChIP-exo datasets of E. coli from proChIPdb and evaluate the prediction performance through comparison with three existing programs. The performance evaluation against the compared programs indicates that TESA is more accurate for identifying regulatory motifs in prokaryotic genomes.

bioinformatics↗

bioRxiv2023

Dimension-agnostic and granularity-based spatially variable gene identification

Identifying spatially variable genes (SVGs) is critical in linking molecular cell functions with tissue phenotypes. Spatially resolved transcriptomics captures cellular-level gene expression with corresponding spatial coordinates in two or three dimensions and can be used to infer SVGs effectively. However, current computational methods may not achieve reliable results and often cannot handle three-dimensional spatial transcriptomic data. Here we introduce BSP (big-small patch), a spatial granularity-guided and non-parametric model to identify SVGs from two or three-dimensional spatial transcriptomics data in a fast and robust manner. This new method has been extensively tested in simulations, demonstrating superior accuracy, robustness, and high efficiency. BSP is further validated by substantiated biological discoveries in cancer, neural science, rheumatoid arthritis, and kidney studies with various types of spatial transcriptomics technologies.

bioinformatics↗

bioRxiv2023

Inhibition mechanism and antiviral activity of an α-ketoamide based SARS-CoV-2 main protease inhibitor

SARS-CoV-2 has demonstrated extraordinary ability to evade antibody immunity by antigenic drift. Small molecule drugs may provide effective therapy while being part of a solution to circumvent SARS-CoV-2 immune escape. In this study we report an -ketoamide based peptidomimetic inhibitor of SARS-CoV-2 main protease (Mpro), RAY1216. Enzyme inhibition kinetic analysis established that RAY1216 is a slow-tight inhibitor with a Ki of 8.6 nM; RAY1216 has a drug-target residence time of 104 min compared to 9 min of PF-07321332 (nirmatrelvir), the antiviral component in Paxlovid, suggesting that RAY1216 is approximately 12 times slower to dissociate from the protease-inhibitor complex compared to PF-07321332. Crystal structure of SARS-CoV-2 Mpro:RAY1216 complex demonstrates that RAY1216 is covalently attached to the catalytic Cys145 through the -ketoamide warhead; more extensive interactions are identified between bound RAY1216 and Mpro active site compared to PF-07321332, consistent with a more stable acyl-enzyme inhibition complex for RAY1216. In cell culture and human ACE2 transgenic mouse models, RAY1216 demonstrates comparable antiviral activities towards different SARS-CoV-2 virus variants compared to PF-07321332. Improvement in pharmacokinetics has been observed for RAY1216 over PF-07321332 in various animal models, which may allow RAY1216 to be used without ritonavir. RAY1216 is currently undergoing phase III clinical trials (https://clinicaltrials.gov/ct2/show/NCT05620160) to test real-world therapeutic efficacy against COVID-19.

biochemistry↗

bioRxiv2023

Mapping Neurophysiological Subtypes of Major Depressive Disorder Using Normative Models of the Functional Connectome

Major depressive disorder (MDD) is the most burdensome psychiatric disorder characterized by remarkably heterogeneous clinical phenotypes. It remains challenging to delineate the heterogeneity of neurobiological abnormalities underlying the clinical variance and, on this basis, to identify neurophysiological subtypes of MDD patients. Here, using a large multisite resting-state functional MRI data from 1,148 MDD patients and 1,079 healthy controls, we generated lifespan normative models of functional connectivity strengths, mapped the heterogeneity of patients individual deviations, and identified neurobiological MDD subtypes. MDD patients showed positive deviations mainly in the default mode and subcortical areas, and negative deviations widely distributed over the cortex. However, there was a great inter-subject heterogeneity as indicated by that no more than 3.14% of patients deviated from the normative range for any brain region. Two neurophysiological MDD subtypes were identified. Subtype 1 showed severe deviations with positive deviations in the default mode, limbic, and subcortical areas, and negative deviations in the sensorimotor, dorsal and ventral attention areas, while subtype 2 showed a moderate but conversed deviation pattern. The severe-deviation subtype had older age, higher medicated proportion, and higher Suicide item score, while the moderate-deviation subtype showed higher Work and Activities and Depressed Mood item scores. Moreover, the baseline deviations in the severe-deviation subtype were predictive of 6-month antidepressant treatment effects in a subsample. To our knowledge, the current study is the largest multisite analysis of neurophysiological MDD subtyping to date and the findings shed light on our understanding of the biological mechanisms underlying the intersubject heterogeneity of clinical phenotypes, which are informative for the development of personalized treatments for this disorder.

neuroscience↗

bioRxiv2023

Landscape of IGH germline genes of Chiroptera and the pattern of Rhinolophus affinisbat IGH CDR3 repertoire

The emergence and re-emergence of a number of viruses from bats that impact human and animal health has resulted in a resurgence of interest in bat immunology. Characterizing the immune receptor repertoire is critical to understanding how bats coexist with viruses in the absence of disease and developing new therapeutics to target viruses in humans and susceptible livestock. We annotated IGH germline genes of Rhinolophus ferrumequinum (RF), Phyllostomus discolor (RD) and Pipistrellus pipistrellus (PP), and investigated the evolutionary relationship between bat germline genes and that of human, mouse, cow, and dog. The IGH repertoire characteristics of Rhinolophus affinis bat (RA) were also analyzed. The V gene families of all three bat species can be classified into three Clan, although PD is special with the abnormal length of IGH locus and 22 reverse V genes. Moreover, the bats germline genes are quite differed from those of human, mouse, cow, and dog in evolution, but the three bat species have high homology. The CDR3 repertoire of RA are unique in many aspects including CDR3 subclass, V/J genes access and pairing, CDR3 clones and somatic high-frequency mutation compared with that of human and mouse, which may be the immunologic basis for the asymptomatic nature of viral infection in bats. This study provide immune genome information and extensive reference for the basic research of bat and virus infection mechanism.

immunology↗

bioRxiv2022

Neurological Disorder after Severe Pneumonia is Associated with Translocation of Bacteria from Lung to Brain

The neurological disorder is a common feature in patients who recovered from severe acute pneumonia. However, the underline mechanisms remain not very clear. Here we show that these neurological syndromes after severe acute pneumonia are partly attributed to the translocation of bacteria from the lung to the brain during pneumonia. We detected an emerging and increased bacteria in the brain tissue of mice with lipopolysaccharide-induced experimental severe pneumonia. Interestingly, using 16S rDNA amplification sequencing, similarities were found between the brains flora species and those of the lungs, indicating the bacteria in the brain may originate from the lung. We also observed the impairment of the lung-blood barrier and brain-blood barrier, simultaneously, allowing lung bacteria invade the brain during pneumonia. An elevated microglia and astrocytes activation signature through bacterial infection-related pathways is observed by single-cell RNA sequencing, indicating a bacteria-induced disruption of brain homeostasis. Rapamycin delivered by platelet-derived extracellular vesicles provides an effective strategy to rescue the dysfunction of microglia and astrocytes, and relief neurological disorders. Collectively, we identify lung bacteria that play a role in altering brain homeostasis, which provides new insight into the mechanism of neurological syndromes after severe pneumonia.

neuroscience↗

bioRxiv2022

Pre-mRNA splicing inhibits m6A deposition, allowing longer mRNA half-life and flexible protein coding

Both pre-mRNA splicing and N6-methyladenosine (m6A) mRNA modification occur during transcription, enabling the potential crosstalk regulation between these two fundamental processes. The regional m6A location bias of avoiding splice site region, calls for an open hypothesis whether pre-mRNA splicing could affect m6A deposition. By deep learning modeling, we find that pre-mRNA splicing represses a proportion (4% to 32%) of m6A deposition at nearby exons. Experimental validation confirms such an inhibition as the m6A signal increases in mRNA once the host gene does not undergo pre-mRNA splicing to produce the same mRNA. Pre-mRNA splicing inhibited m6A sites tend to have higher m6A enhancers and lower m6A silencers locally than the m6A sites that are not inhibited. Moreover, this m6A deposition inhibition by pre-mRNA splicing shows high heterogeneity at different exons of mRNAs at genome-widely, with only a small proportion (12% to 15%) of exons showing strong inhibition, enabling stable mRNAs and flexible protein coding for important biological functions.

genomics↗

bioRxiv2022

Enhancer-driven gene regulatory networks inference from single-cell RNA-seq and ATAC-seq data

Deciphering the intricate relationships between transcription factors (TFs), enhancers, and genes through the inference of enhancer-driven gene regulatory networks is crucial in understanding gene regulatory programs in a complex biological system. This study introduces STREAM, a novel method that leverages a Steiner Forest Problem model, a hybrid biclustering pipeline, and submodular optimization to infer enhancer-driven gene regulatory networks from jointly profiled single-cell transcriptome and chromatin accessibility data. Compared to existing methods, STREAM demonstrates enhanced performance in terms of TF recovery, TF-enhancer relation prediction, and enhancer-gene discovery. Application of STREAM to an Alzheimers disease dataset and a diffuse small lymphocytic lymphoma dataset reveals its ability to identify TF-enhancer-gene relationships associated with pseudotime, as well as key TF-enhancer-gene relationships and TF cooperation underlying tumor cells.

bioinformatics↗

bioRxiv2022

SpaGFT is a graph Fourier transform for tissue module identification from spatially resolved transcriptomics

Tissue module (TM) is a spatially organized tissue region and executes specialized biological functions, recurring and varying at different tissue sites. However, the computational identification of TMs poses challenges due to their convoluted biological functions, poorly-defined molecular features, and varying spatially organized patterns. Here, we present a hypothesis-free graph Fourier transform model, SpaGFT, to represent spatially organized features using the Fourier coefficients, leading to an accurate representation of spatially variable genes and proteins and the characterization of TM at a fast computational speed. We implemented sequencing-based and imaging-based spatial transcriptomics, spatial-CITE-seq, and spatial proteomics to identify spatially variable genes and proteins, define TM identities, and infer convoluted functions among TMs in mouse brains and human lymph nodes. We collected a human tonsil sample and performed CODEX to accurately demonstrate molecular and cellular variability within the secondary follicle structure. The superior accuracy, scalability, and interpretability of SpaGFT indicate that it is an effective representation of spatially-resolved omics data and an essential tool for bringing new insights into molecular tissue biology.

bioinformatics↗

bioRxiv2022

Dalpiciclib Partially Abrogates ER Signaling Activation Induced by Pyrotinib In HER2+HR+ Breast Cancer

BackgroundRecent evidences from clinical trials (NCT04486911) revealed that the combination of pyrotinib, letrozole and dalpiciclib exerted optimistic therapeutic effect to treat HER2+HR+ breast cancer, however, the underlying molecular mechanism remained further investigation. MethodsThrough the drug sensitivity test, the drug combination efficacy of pyrotinib, tamoxifen and dalpiciclib to BT474 cells were tested. The underlying molecular mechanisms were investigated using immunofluorescence, western blot analysis, immunohistochemical staining and cell cycle analysis. Potential risk factor which may indicate the responsiveness to drug treatment in HER2+/HR+ breast cancer was selected out using RNA-sequence and tested using immunohistochemical staining and in vivo drug susceptibility test. ResultsWe found that pyrotinib combined with dalpiciclib exerted better cytotoxic efficacy than pyrotinib combined with tamoxifen in BT474 cells. Degradation of HER2 could enhance ER nuclear transportation, activating ER signaling pathway in BT474 cells whereas dalpiciclib could partially abrogate this process. This may be the underlying mechanism by which combination of pyrotinib, tamoxifen and dalpiciclib exerted best cytotoxic effect. Furthermore, CALML5 was revealed to be a risk factor in the treatment of HER2+/HR+ breast cancer and the usage of dalpiciclib might overcome this. ConclusionOur study provided evidence that the usage of dalpiciclib in the treatment of HER2+/HR+ breast cancer could partially abrogate the estrogen signaling pathway activation caused by anti-HER2 therapy and revealed that CALML5 could serve as a risk factor in the treatment of HER2+/HR+ breast cancer. FundingThis study was supported by the National Natural Science Foundation of China (#U20A20381, #81872159)

cancer biology↗

bioRxiv2022

Multi-omics analyses of single cell-derived colorectal cancer organoids reveal intratumor heterogeneity and immune response diversity

Colorectal cancer (CRC) organoids have similar genomic and functional characteristics to the original specimens. They have become a novel and promising tumor model. However, systematic research of heterogeneity and evolution based on tumor organoids and unbiased evaluation of CD4+ T cell-mediated tumor recognition is presently lacking. Here, we study the variability in genomic characterization and single-cell transcriptome between different tumor organoid clones derived from the same CRC patient. While clone-specific differences in driver gene mutations and cancer stem cell (CSC) subpopulations were observed, inter-clone heterogeneity was even more prevalent. Using single-cell RNA sequencing, we found that compared with bulk organoids, CRC organoid clones are mainly composed of cancer stem cells and transiently-amplifying cells (TACs), but no epithelial-mesenchymal transition (EMT)-like (S100A4+CDH1-) cells. In addition, we study the phenotypic characteristics and TCR properties of tumor-reactive CD4+ T cells by coupling the organoid-TILs co-culture model, single-cell profiling, and recognition testing of candidate TCRs. We found that the proliferating CD4+ T cells increased significantly from 7.1% to 35.4%, and the TCR clonotypes increased from 110 to 1043 after co-culture with organoids. Moreover, 4 of 10 (40%) candidate TCRs with a significant increase in clone abundance exhibited tumor recognition. These results provide evidence that the proliferating CD4+ T cells with clonal expansion after co-culture with tumor organoids are the potential tumor-reactive T cells. Collectively, we reconstructed intra-patient heterogeneity in single cell-derived organoid models and characterized the phenotypic characteristics and functional properties of tumor-reactive CD4+ T cells.

cancer biology↗

bioRxiv2022

Systematic characterization of brain cellular crosstalk signaling networks in Alzheimer's disease reveals a novel role for SEMA6D in TREM2-dependent microglial activation

Cellular crosstalk, mediated by membrane receptors and their ligands, is crucial for brain homeostasis and can contribute to neurodegenerative diseases such as Alzheimers disease (AD). To discover crosstalk dysregulations in AD, we reconstructed crosstalk networks from single-nucleus transcriptional profiles from 67 clinically and neuropathologically well-characterized controls and AD brain donors. We predicted a significant role for TREM2 and additional AD risk genes mediating neuron-microglia crosstalk in AD. The gene sub-network mediating SEMA6D-TREM2 crosstalk is activated near A{beta} plaques and SEMA6D-expressing cells and is disrupted in late AD stages. Using CRISPR-modified human induced pluripotent stem cell-derived microglia, we demonstrated that SEMA6D induces microglial activation in a TREM2-dependent manner. In summary, we demonstrate that characterizing cellular crosstalk networks can yield novel insights into AD biology. One Sentence SummaryWe investigate cell-to-cell communication in Alzheimers disease to characterize disease biology and suggest new avenues for therapeutic intervention.

neuroscience↗

bioRxiv2022

Identification of functional immune and neuronal tumor cells in glioma

Despite advances in molecular profiling, therapeutic development has been hindered by the inability to identify and target tumour-specific mechanisms without consequence to healthy tissue. Correspondingly, a computational framework capable of accurately distinguishing tumour from non-tumour cells has yet to be developed and cell annotation algorithms are unable to assign integrated genomic and transcriptional profiles to single cells on a cell-by-cell basis. To address these barriers, we developed the Single Cell Rule Association Mining (SCRAM) tool that integrates RNA-inferred genomic alterations with co-occurring cell type signatures for individual cells. Applying SCRAM to glioma, we identified tumour cell trajectories recapitulate temporally-restricted developmental paradigms and feature unique co-occurring identities. Specifically, we validated two previously unreported tumour cell populations with immune and neuronal signatures as hallmarks of human glioma subtypes. In vivo modeling revealed a rare immune-like tumour cell population resembling antigen presenting cells can direct CD8+ T cell responses. In parallel, Patch sequencing studies in human tumours confirmed that neuronal-like glioma cells fire action potentials and represent 40% of IDH1 mutant tumor cells. These studies identified new glioma cell types with functional properties similar to their non-tumour analogues and demonstrate the ability of SCRAM to identify these cell types in unprecedented detail.

cancer biology↗

bioRxiv2022

Oral Feeding of Nanoplastics reduces Brain function of Mice by Inducing Intestinal IL-1β-producing Macrophages

Background and AimsNanoplastics (NPs) as contaminants in food and water have drawn an increasing public attention. However, little is known about how NPs shape the gut immune landscape after entering the body. The objective of the study was to explore indirect effects caused by the interaction of NPs with the mammalian gut and whole immune system after entering the body. MethodsIn this study, we fabricated NPs ([~]500 nm) and microplastics (MPs) ([~]2 m) and aimed to evaluate their in vivo effects by feeding them in mice. The mechanism was then investigated by various technology including single-cell RNA sequencing of gut and brain tissue. ResultsThe results suggested that NPs showed a better ability to induce gut macrophage activation than did MPs. In addition, NPs triggered gut interleukin 1 beta (IL-1{beta})-producing macrophage reprogramming via inducing lysosomal damage after phagocytosis. More importantly, IL-1{beta} released from the intestine could affect brain immunity, leading to microglial activation and Th17 differentiation, all of which correlated with a decline in cognitive and short-term memory in NPs-fed mice ConclusionsThus, this study provides new insight into the mechanism of action of the gut-brain axis and delineates the way NPs reduce brain function, highlights the importance to fix the plastic pollution problem worldwide.

immunology↗

bioRxiv2022

Arabidopsis CPK6 regulates drought tolerance under high nitrogen by the phosphorylation of NRT1.1

Nitrogen is an essential macronutrient for plant growth and development, and its availability to some extent is regulated by drought stress. Calcium-dependent protein kinases (CPKs) are a unique family of Ca2+ sensors with diverse functions in nitrogen and drought signaling pathways. However, which and how CPKs involve in the crosstalk between drought stress and nitrogen transportation remains largely unknown. Here we identified the drought tolerant function of Arabidopsis CPK6 under high nitrogen condition. The CPK6 expression is induced by the treatments of ABA and drought. The mutant cpk6 is insensitive to the ABA treatment, but sensitive to drought only under high nitrogen condition. CPK6 interacts with and phosphorylates the Thr571 in NRT1.1 protein, and thus represses its NO3- transporting activity under drought stress. Taken together, we showed the evidences that CPK6 regulates Arabidopsis drought tolerance through the phosphorylation of NRT1.1, and that enriches the knowledge of nitrogen uptake in plants during drought stress.

genetics↗

bioRxiv2022

Single-cell transcriptomic profiling of kidney fibrosis identifies a novel specific fibroblast marker and putative disease target

BackgroundPersistent kidney fibroblast activation and tubular epithelial cell (TEC) injury are key contributors to CKD. However, transcriptional and cellular identities of advanced kidney disease, along with renal fibroblast specific markers and molecular targets contributing to persistent tubular injury, remain elusive. MethodsWe performed single-cell RNA sequencing with two clinically relevant murine kidney fibrosis models. Day 28 post-injury was chosen to ensure advanced fibrotic disease. Identified gene expression signatures were validated using multiple quantitative molecular analyses. ResultsWe revealed comprehensive single cell transcriptomic profiles of two independent kidney fibrosis models compared to normal control. Both models exhibited key CKD characteristics including renal blood flow decline, inflammatory expansion and proximal tubular loss. We identified novel populations including "secretory", "migratory" and "contractile" activated fibroblasts, specifically labelled by newly identified fibroblast-specific Gucy1a3 expression. Fibrotic kidneys elicited elevated embryonic and pro-fibrotic signaling, including separate "Embryonic" and "Pro-fibrotic" TEC clusters. Also, fibrosis caused enhanced cell-to-cell crosstalk, particularly between activated fibroblasts and pro-fibrotic TECs. Analysis of factors mediating mesenchymal phenotype in the injured epithelium identified persistent elevation of Ahnak, previously reported in AKI, in both CKD models. AHNAK knockdown in primary human renal proximal tubular epithelial cells induced a pro-fibrotic phenotype and exacerbated TGF{beta} response via p38, p42/44, pAKT, BMP and MMP signaling. ConclusionsOur study comprehensively examined kidney fibrosis in two independent models at the singe-cell resolution, providing a valuable resource for the field. Moreover, we newly identified Gucy1a3 as a kidney activated fibroblast specific marker and validated AHNAK as a putative disease target. Significance StatementMechanistic understanding of kidney fibrosis is principal for mechanistic understanding and developing targeted strategies against CKD. However, specific markers and molecular targets of key effector cells - activated kidney fibroblasts and injured tubular epithelial cells - remain elusive. Here, we created comprehensive single cell transcriptomic profiles of two clinically relevant kidney fibrosis models. We revealed "secretory", "contractile" and "migratory" fibroblasts and identified Gucy1a3 as a novel marker selectively labelling all three populations. We revealed that kidney fibrosis elicited remarkable epithelial-to-stromal crosstalk and pro-fibrotic signaling in the tubular cells. Moreover, we mechanistically validated AHNAK as a putative novel kidney injury target in a primary human in vitro model of epithelial-to-mesenchymal transition. Our findings advance understanding of and targeted intervention in fibrotic kidney disease.

molecular biology↗

bioRxiv2022

Spinal VGLUT3 lineage neurons drive visceral mechanical allodynia but not visceromotor reflexes

Visceral pain is among the most prevalent and bothersome forms of chronic pain, but their transmission in the spinal cord is still poorly understood. Here we used a focal colorectal distention (fCRD) method to drive visceromotor responses (VMRs) plus affective pain-indicative aversive learning. We first found that spinal CCK neurons were necessary for noxious fCRD to drive both VMRs and aversion. We next showed that spinal VGLUT3 neurons mediate affective visceral allodynia, whose ablation caused loss of aversion evoked by low-intensity fCRD in mice with gastrointestinal (GI) inflammation or spinal circuit disinhibition. Importantly, these neurons are dispensable for driving VMRs. Anatomically, VGLUT3 neurons send projection to the parabrachial nuclei, whose photoactivation sufficiently generated aversion in mice with GI inflammation. Our studies suggest the presence of different spinal substrates that transmit nociceptive versus affective dimensions of visceral sensory information.

neuroscience↗