Biology subjects

Fu, J.

Publications and source records attributed to Fu, J..

At least 127 records · Page 7Linked to original sources

bioRxiv2022

Unbiased identification of unknown cellular and environmental factors that mediate eQTLs using principal interaction component analysis

Expression quantitative trait loci (eQTL) can reveal the regulatory mechanisms of trait associated variants. eQTLs are highly cell-type and context-specific, but often these contexts are unknown or not measured. Here, we introduce PICALO (Principal Interaction Component Analysis through Likelihood Optimization), an unbiased method to identify known and hidden contexts that influence eQTLs. PICALO uses expectation maximization to identify latent components, referred to as Principal Interaction Components (PIC), that interact with genotypes to maximize explained eQTL effect-sizes. We applied PICALO to bulk RNA-seq eQTL datasets in blood (n=2,932) and brain (n=2,440). We identify 31 PICs in blood, interacting with 4,169 (32%) unique cis-eQTLs (BH-FDR[≤]0.05). In brain, we identified 21 PICs, interacting with 4,058 (39%) unique cis-eQTLs (BH-FDR[≤]0.05). These PICs are associated with RNA quality, cell type composition or environmental influences. Furthermore, PICs clearly disentangle distinct eQTL contexts, for example technical from non-technical factors. Combined, 3,065 unique genes showed a cis-eQTL effect that is dependent on a cell type or other non-technical context, emphasizing the value of methods like PICALO. PICALO is robust, works well with heterogeneous datasets, yields reproducible interaction components, and identifies eQTL interactions and contexts that would have been missed when using cell counts or expression based principal components. Since PICALO allows for the identification of many context-dependent eQTLs without any prior knowledge of such contexts, this method can help to reveal and quantify the influence of previously unknown environmental factors that play a role in common diseases.

genomics↗

bioRxiv2022

Predicting neoadjuvant chemotherapy benefit using deep learning from stromal histology in breast cancer

Neoadjuvant chemotherapy (NAC) is a standard treatment option for locally advanced breast cancer. However, not all patients benefit from NAC; some even get worse outcomes after therapy. Hence, predictors for treatment benefit are crucial for guiding clinical decision-making. Here, we investigated the predictive potentials of breast cancer stromal histology via a deep learning (DL)-based approach and proposed the tumor-associated stroma score (TS-score) for predicting pathological complete response (pCR) to NAC with a multi-center dataset. The TS-score is demonstrated to to be an independent predictor of pCR as it not only outperformed the baseline variables and stromal tumor-infiltrating lymphocytes (sTILs) but also significantly improved the prediction performance of the baseline variable-based model. Further, we discovered that unlike lymphocyte, collagen and fibroblasts in stroma were likely associated with poor response to NAC. The TS-score has potentials to be a candidate for better stratification of breast cancer patients in NAC settings.

pathology↗

bioRxiv2022

The faecal metabolome and its determinants in inflammatory bowel disease

ObjectiveInflammatory bowel disease (IBD) is a multifactorial immune-mediated inflammatory disease of the intestine, comprising Crohns disease and ulcerative colitis. By characterising metabolites in faeces, combined with faecal metagenomics, host genetics and clinical characteristics, we aimed to unravel metabolic alterations in IBD. DesignWe measured 1,684 different faecal metabolites and 8 short-chain and branched-chain fatty acids in stool samples of 424 IBD patients and 255 non-IBD controls. Regression analyses were used to compare concentrations of metabolites between cases and controls and determine the relationship between metabolites and each participants lifestyle, clinical characteristics and gut microbiota composition. Moreover, genome-wide association analysis was conducted on faecal metabolite levels. ResultsWe identified over 300 molecules that were differentially abundant in the faeces of patients with IBD. The ratio between a sphingolipid and L-urobilin could discriminate between IBD and non-IBD samples (AUC = 0.85). We found changes in the bile acid pool in patients with dysbiotic microbial communities and a strong association between faecal metabolome and gut microbiota. For example, the abundance of Ruminococcus gnavus was positively associated with tryptamine levels. In addition, we found 158 associations between metabolites and dietary patterns, and polymorphisms near NAT2 strongly associated with coffee metabolism. ConclusionIn this large-scale analysis, we identified alterations in the metabolome of patients with IBD that are independent of commonly overlooked confounders such as diet and surgical history. Considering the influence of the microbiome on faecal metabolites, our results pave the way for future interventions targeting intestinal inflammation.

microbiology↗

bioRxiv2022

HIV-linked gut dysbiosis associates with cytokine production capacity in viral-suppressed people living with HIV

People living with HIV (PLHIV) are exposed to chronic immune dysregulation, even when virus replication is suppressed by antiretroviral therapy (ART). Given the emerging role of the gut microbiome in immunity, we hypothesized that the gut microbiome may be related to the cytokine production capacity of PLHIV. To test this hypothesis, we collected metagenomic data from 143 ART-treated PLHIV and assessed the ex vivo production capacity of eight different cytokines (IL-1{beta}, IL-6, IL-1Ra, IL-10, IL17, IL22, TNF and IFN-{gamma}) in response to different stimuli. We also characterized CD4+ T cell-counts, HIV reservoir and other clinical parameters. Compared to 190 age- and sex-matched controls and a second independent control cohort, PLHIV showed microbial dysbiosis that was correlated with viral reservoir levels, cytokine production capacity and sexual behavior. Notably, we identified two genetically different P. copri strains that were enriched in either PLHIV or healthy controls. The control-enriched strain was negatively associated with IL-10, IL-6 and TNF production, independent of age, sex and sexual behavior, and positively associated with CD4+ T cell-level, whereas the PLHIV-enriched strain showed no associations. Our findings suggest that modulating the gut microbiome may be a strategy to modulate immune response in PLHIV. Novel PointsO_LIWe identified compositional and functional changes in the gut microbiome of PLHIV that were strongly related to sexual behavior. C_LIO_LIHIV-associated bacterial changes are negatively associated with HIV reservoir. The relative abundance of Firmicutes bacterium CAG 95 and Prevotella sp CAG 5226 both show a negative association with CD4+ T cell-associated HIV-1 DNA. C_LIO_LIPrevotella copri and Bacteroides vulgatus show association with PBMC production capacity of IL-1{beta} and IL-10 that is independent of age, sex, BMI and sexual behavior. C_LIO_LIWe observed two genetically different P. copri strains that are enriched in PLHIV and healthy individuals, respectively. C_LIO_LIThe control-related P. copri strain specifically shows a negative association with IL-10, IL-6 and TNF production and a positive association with CD4+ T cell-level. This suggests it plays a potential protective role in chronic inflammation, which may be related to enrichment of a specific epitope peptide. C_LI

microbiology↗

bioRxiv2022

Digital twin reveals combinatorial code of non-linear computations in the mouse primary visual cortex

More than a dozen excitatory cell types have been identified in the mouse primary visual cortex (V1) based on transcriptomic, morphological and in vitro electrophysiological features. However, the functional landscape of excitatory neurons with respect to their responses to visual stimuli is currently unknown. Here, we combined large-scale two-photon imaging and deep learning neural predictive models to study the functional organization of mouse V1 using digital twins. Digital twins enable exhaustive in silico functional characterization providing a bar code summarizing the input-output function of each neuron. Clustering the bar codes revealed a continuum of function with around 30 modes. Each mode represented a group of neurons that exhibited a specific combination of stimulus selectivity and nonlinear response properties such as cross-orientation inhibition, size-contrast tuning and surround suppression. These non-linear properties were expressed independently spanning all possible combinations across the population. This combinatorial code provides the first large-scale, data-driven characterization of the functional organization of V1. This powerful approach based on digital twins is applicable to other brain areas and to complex non-linear systems beyond the brain.

neuroscience↗

bioRxiv2021

Strain dependent structural effects and in vivo efficacy of enterovirus-D68 inhibitors

Acute flaccid myelitis (AFM) leads to loss of limb control in young children and is likely due to Enterovirus-D68 (EV-D68), for which there is no current treatment. We have developed a lead isoxazole-3-carboxamide analog of pleconaril (11526092) which displayed potent inhibition of the pleconaril-resistant CVB3-Woodruff (IC50 6-20 nM), EV-D68 (IC50 58 nM), and other enteroviruses. A mouse respiratory model of EV-D68 infection, in which pleconaril is inactive, showed decreased viremia of 3 log units as well as statistically significant 1 log reduction in lung titer reduction at day 5 after treatment with 11526092. A cryo-electron microscopy (cryo-EM) structure of EV-D68 in complex with 11526092 suggests that the increased potency may be due to additional hydrophobic interactions. Cryo-EM structures of 11526092 and pleconaril demonstrate destabilization of EV-D68 (MO strain) compared to the previously described stabilization of EV-D68 (Fermon strain) with pleconaril, illustrating clear strain dependent mechanisms of this molecule. 11526092 represents a more potent inhibitor in vitro with in vivo efficacy providing a potential future treatment for EV-D68 and AFM, suggesting an improvement over pleconaril for further optimization. One-Sentence Summary11526092 demonstrates protein destabilization, improved in vitro potency and in vivo efficacy when compared with pleconaril against EV-D68.

pharmacology and toxicology↗

bioRxiv2021

Genetic, parental and lifestyle factors influence telomere length

The average length of telomere repeats (TL) declines with age and is considered to be a marker of biological ageing. Here, we measured TL in six blood cell types from 1,046 individuals using the clinically validated Flow-FISH method. We identified remarkable cell-type-specific variations in TL. Host genetics, environmental, parental and intrinsic factors such as sex, parental age, and smoking are associated to variations in TL. By analysing the genome-wide methylation patterns, we identified that the association of maternal, but not paternal, age to TL is mediated by epigenetics. Coupling these measurements to single-cell RNA-sequencing data for 62 participants revealed differential gene expression in T-cells. Genes negatively associated with TL were enriched for pathways related to translation and nonsense-mediated decay. Altogether, this study addresses cell-type-specific differences in telomere biology and its relation to cell-type-specific gene expression and highlights how perinatal factors play a role in determining TL, on top of genetics and lifestyle.

cell biology↗

bioRxiv2021

In-depth characterization of the serum antibody epitope repertoire in inflammatory bowel disease using phage-displayed immunoprecipitation sequencing

Inflammatory bowel diseases (IBD), e.g. Crohns disease (CD) and ulcerative colitis (UC), are chronic immune-mediated inflammatory diseases. A comprehensive overview of an IBD-specific antibody epitope repertoire is, however, lacking. We leveraged a high-throughput phage-displayed immunoprecipitation sequencing (PhIP-seq) workflow to identify antibodies against 344,000 antimicrobial, immune and food antigens in 497 IBD patients as compared to 1,326 controls. IBD was characterized by 373 differentially abundant antibodies (202 overrepresented and 171 underrepresented), with 17% shared by both IBDs, 55% unique to CD and 28% unique to UC. Antibodies against bacterial flagellins dominated in CD and were associated with ileal involvement, fibrostenotic disease and anti-Saccharomyces cerevisiae antibody positivity, but not with fecal microbiome composition. Antibody epitope repertoires accurately discriminated CD from controls (AUC=0.89), and similar discrimination was achieved when using only ten antibodies (AUC=0.87). IBD patients thus show a distinct antibody repertoire against selected peptides, allowing patient stratification and discovery of immunological targets.

immunology↗

bioRxiv2021

Genetic, environmental and intrinsic determinants of the human antibody epitope repertoire

Phage-displayed immunoprecipitation sequencing (PhIP-Seq) has successfully enabled high-throughput profiling of human antibody profiles. However, a comprehensive overview of environmental and genetic determinants shaping human adaptive immunity is currently lacking. In this study, we aimed to investigate the effects of genetic, environmental and intrinsic factors on the variation in human antibody repertoires. We characterized serological antibody repertoires against 344,000 peptides using PhIP-Seq libraries from a wide range of microbial and environmental antigens in 1,443 participants from a population cohort. We demonstrate individual-specificity, temporal consistency and co-housing similarities in antibody repertoire. Genetic analyses showed involvement of the HLA, IGHV and FUT2 regions. Furthermore, we uncovered associations between 48 phenotypic factors and 544 antibody-bound peptides, including age, cell counts, sex, smoking behavior and allergies, among others. Overall, our results indicate that human antibody epitope repertoires are shaped by both host genetics and environmental exposures and highlight unique signatures of distinct phenotypes and genotypes.

immunology↗

bioRxiv2021

Selective YAP activation in Procr cells is essential for ovarian stem/progenitor expansion and epithelium repair

Ovarian surface epithelium (OSE) undergoes recurring ovulatory rupture and OSE stem cells rapidly generate new cells for the repair. How the stem cell senses the rupture and promptly turns on proliferation is unclear. Our previous study has identified that Protein C Receptor (Procr) marks OSE progenitors. In this study, we observed decreased adherent junction and selective activation of YAP signaling in Procr progenitors at OSE rupture site. OSE repair is impeded upon deletion of Yap in these progenitors. Interestingly, Procr+ progenitors show lower expression of Vgll4, an antagonist of YAP signaling. Overexpression of Vgll4 in Procr+ cells hampers OSE repair and progenitor proliferation, indicating that selective low Vgll4 expression in Procr+ progenitors is critical for OSE repair. In addition, YAP activation promotes transcription of the OSE stemness gene Procr. The combination of increased cell division and Procr expression leads to expansion of Procr+ progenitors surrounding the rupture site. These results illustrate a YAP- dependent mechanism by which the stem/progenitor cells recognize the ovulatory rupture, and rapidly multiply their numbers, highlighting a YAP- induced stem cell expansion strategy.

developmental biology↗

bioRxiv2021

Data-driven discovery of targets for bipotent anticancer drugs identifies Estrogen Related Receptor Alpha

Drugs that kill tumors through multiple mechanisms have potential for broad clinical benefits, with a reduced propensity to resistance. We developed BipotentR, a computational approach to find cancer-cell-specific regulators that simultaneously modulate tumor immunity and another oncogenic pathway. Using tumor metabolism as proof-of-principle, BipotentR identified 38 candidate immune-metabolic regulators by combining epigenomes with bulk and single-cell tumor transcriptomes from patients. Inhibition of top candidate ESRRA (Estrogen Related Receptor Alpha) killed tumors by direct effects on energy metabolism and two immune mechanisms: (i) cytokine induction, causing proinflammatory macrophage polarization (ii) antigen-presentation stimulation, recruiting CD8+T cells into tumors. ESRRA is activated in immune-suppressive and immunotherapy-resistant tumors of many types, suggesting broad clinical relevance. We also applied BipotentR to angiogenesis and growth-suppressor pathways, demonstrating a widely applicable approach to identify drug targets that act simultaneously through multiple mechanisms. BipotentR is publicly available at http://bipotentr.dfci.harvard.edu/. One-Sentence SummaryBipotentR identifies targets for bipotent anticancer drugs, as shown by the energy and immune effects of ESRRA inhibition.

cancer biology↗

bioRxiv2021

SCARECROW maintains the stem cell niche in Arabidopsis root by ensuring telomere integrity

Stem cells are the ultimate source of the cells in various tissues and organs, and thus are essential to postembryonic plant growth and development. SCARECROW (SCR) is a plant-specific transcription regulator well known for its role in stem-cell renewal in plant roots, but the mechanism by which SCR exerts this function is still unclear. To address this question, we carried out a genetic screen for mutants that no longer express SCR in the stem-cell niche in the Arabidopsis root, and one of the mutants is characterized herein. Using marker-assisted mapping, whole genome sequencing, and complementation tests, we pinpointed the causal mutation in this mutant at TEN1, which encodes telomere-end protecting factor. By sequence alignment of TEN1 homologs in a wide range of eukaryotes, we identified two novel motifs. The importance of these motifs was examined through site-directed mutagenesis of a conserved amino acid, and through complementation tests, which showed that G100 is required for TEN1 stability. Interestingly, we found that TEN1 expression was dramatically reduced in the scr mutant. Two components in the same protein complex as TEN1, STN1 and CTC1, were found to be also dramatically downregulated in scr, as well as telomerase. Further studies showed that loss of STN1, CTC1 and telomerase also caused defects in the root stem cells. In line with these findings, the scr mutant was hypersensitive to DNA damage reagents such as Zeocin. These results together suggest that SCR maintains root stem cells by promoting expression of genes that ensures genome integrity. One sentence summaryThis study reveals a role for the root development regulator SCARECROW in maintaining the expression of telomere-end protecting factors and a connection between genome integrity and stem-cell maintenance in Arabidopsis root.

plant biology↗

bioRxiv2021

Dissecting tumor cell programs through group biology estimation in clinical single-cell transcriptomics

Given the growing number of clinically integrated cancer single-cell transcriptomic studies, robust differential enrichment methods for gene signatures to dissect tumor cellular states for discovery and translation are critical. Current analysis strategies neither adequately represent the hierarchical structure of clinical single-cell transcriptomic datasets nor account for the variability in the number of recovered cells per sample, leading to results potentially confounded by sample-driven biology with high false positives instead of accurately representing true differential enrichment of group-level biology (e.g., treatment responders vs. non-responders). This problem is especially prominent for single-cell analyses of the tumor compartment, because high intra-patient similarity (as opposed to inter-patient similarity) results in stricter hierarchical structured data that confounds enrichment analysis. Furthermore, to identify signatures which are truly representative of the entire group, there is a need to quantify the robustness of otherwise statistically significant signatures to sample exclusion. Here, we present a new nonparametric statistical method, BEANIE, to account for these issues, and demonstrate its utility in two cancer cohorts stratified by clinical groups to reduce biological hypotheses and guide translational investigations. Using BEANIE, we show how the consideration of sample-specific versus group biology greatly decreases the false positive rate and guides identification of robust signatures that can also be corroborated across different cell type compartments.

bioinformatics↗

bioRxiv2021

Legionella pneumophila modulates host energy metabolism by ADP-ribosylation of ADP/ATP translocases

The intracellular pathogen Legionella pneumophila delivers more than 330 effectors into host cells by its Dot/Icm secretion system. Those effectors direct the biogenesis of the Legionella-containing vacuole (LCV) that permits its intracellular survival and replication. It has long been documented that the LCV is associated with mitochondria and a number of Dot/Icm effectors have been shown to target to this organelle. Yet, the biochemical function and host cell target of most of these effectors remain unknown. Here, we found that the Dot/Icm substrate Ceg3 (Lpg0080) is a mono-ADP-ribosyltransferase that localizes to the mitochondria in host cells where it attacks ADP/ATP translocases by ADP-ribosylation, and blunts their ADP/ATP exchange activity. The modification occurs on the second arginine residue in the -RRRMMM- element, which is conserved among all known ADP/ATP carriers from different organisms. Our results reveal modulation of host energy metabolism as a virulence mechanism for L. pneumophila.

microbiology↗

bioRxiv2021

Analysis of combinatorial chemokine receptor expression dynamics using multi-receptor reporter mice

Inflammatory chemokines and their receptors are central to the development of inflammatory/immune pathologies. The apparent complexity of this system, coupled with lack of appropriate in vivo models, has limited our understanding of how chemokines orchestrate inflammatory responses and has hampered attempts at targeting this system in inflammatory disease. Novel approaches are therefore needed to provide crucial biological, and therapeutic, insights into the chemokine-chemokine receptor family. Here, we report the generation of transgenic multi-chemokine receptor reporter mice in which spectrally-distinct fluorescent reporters mark expression of CCRs 1, 2, 3 and 5, key receptors for myeloid cell recruitment in inflammation. Analysis of these animals has allowed us to define, for the first time, individual and combinatorial receptor expression patterns on myeloid cells in resting and inflamed conditions. Our results demonstrate that chemokine receptor expression is highly specific, and more selective than previously anticipated.

immunology↗

bioRxiv2021

Rapid and Visible RPA-Cas12a fluorescence Assay for Accurate Detection of Zoonotic Dermatophytes

BackgroundDermatophytosis is an infectious disease of global significance caused by several fungal species, which affects the hair, nails, or superficial layers of the skin. The most common zoonotic dermatophytes are Microsporum canis, Nannizzia gypsea and Trichophyton mentagrophytes. Woods lamp examination, microscopic identification and fungal culture are the main conventional diagnostic methods used in clinics. Less common methods are dermatophyte PCR and biopsy/histopathology. However, these methods also have limitations for providing both accuracy and timely on-site detection. The recent development of CRISPR-based diagnostic platform provides the possibility of a rapid, accurate, and portable diagnostic tool, which has huge potential for clinical applications. ObjectivesThe purpose of this study is to establish a molecular method for rapid and accurate diagnosis of clinical dermatophytes, which can accelerate clinical diagnostic testing and help timely treatment. MethodsIn this paper, we design a Cas12a-based assay combined with recombinase polymerase amplification (RPA) to differentiate three main zoonotic dermatophytes. The limit of detection (LOD) is determined by using standard strains. A total of 25 clinical samples (hair and scurf) are identified to evaluate the sensitivity and specificity of this assay. ResultsThe RPA-Cas12a method showed high sensitivity and specificity (100% and 100%, respectively). The results could be observed directly by naked-eyes, and all tested samples were consistent with fungal culture and sequencing results. ConclusionsCompared with other methods, the RPA-Cas12a-fluorescence assay requires less time (30 minutes) and less complicated equipment, and visible changes can be clearly observed, which is suitable for on-site clinical diagnosis.

microbiology↗

bioRxiv2021

Discovery, diversity and functional associations of crAss-like phages in human gut metagenomes from four Dutch cohorts

The crAss-like phages are a diverse group of related viruses that includes one of the most abundant viruses of the human gut. To explore their diversity and functional role in human population and clinical cohorts, we analyzed gut metagenomic data collected from more than 2000 individuals from the Netherlands. We discovered 125 novel species-level and 32 novel genus-level clusters of crAss-like phages, all belonging to five previously recognized groups associated with the human gut. Analysis of their genomic features revealed that closely related crAss-like phages can possess strikingly divergent regions responsible for transcription, presumably acquired through recombination. Prediction of crAss-like phage hosts pointed primarily to bacteria of the phylum Bacteroidetes, consistent with previous reports. Finally, we explored the temporal stability of crAss-like phages over a 4-year period and identified associations between the abundance of crAss-like phages and several human phenotypes, including depletion of crAss-like phages in inflammatory bowel disease patients. HighlightsO_LI125 tentative new species of crAss-like phages were discovered C_LIO_LIClosely related crAss-like phages often possess highly divergent transcription gene modules possibly acquired via recombination C_LIO_LICrAss-like fraction of the human gut virome remains relatively stable over the period of 4 years C_LIO_LIPrevalence of crAss-like phages in the human gut is associated with several metabolic, dietary and health phenotypes C_LIO_LIGut crAss-like phages are depleted in inflammatory bowel disease patients C_LI

microbiology↗

bioRxiv2021

Reprogrammed iBlastoids contain amnion-like cells but not trophectoderm

Stem cell-based embryo models offer unprecedented experimental tools for studying early human development. The usefulness of embryo models hinges on their molecular, cellular and structural fidelities to their in vivo counterparts. To authenticate human embryo models, single-cell RNA-sequencing has been utilised for unbiased transcriptional profiling. However, a well-organised and integrated human single-cell RNA-sequencing dataset, serving as a universal reference for benchmarking human embryo models, remains unavailable. Herein, we developed such a reference, through integration of six published human datasets covering developmental stages from the zygote to the gastrula. Lineage annotations are contrasted and validated with available human and non-human primate datasets. Using stabilised UMAP we constructed a web tool, where query datasets can be projected on the reference and annotated with predicted cell identities. Using this reference tool, we examined several recent human embryo models, highlighting the risk of misannotation when relevant references are lacking.

developmental biology↗