Biology subjects

Shu, C.

Publications and source records attributed to Shu, C..

At least 19 recordsLinked to original sources

bioRxiv2026

ATAD2 BRD mediates liquid-liquid phase separation of ATAD2 to promote histone acetylation

ATAD2 possesses a C-terminal bromodomain (BRD) that plays a critical role in recognizing and binding to acetylated lysine residues. However, because the native intracellular structure of ATAD2 remains poorly defined, the mechanisms by which the ATAD2 BRD recruits acetylated histones and the regulatory pathways involved are not yet understood. In this study, we report that the ATAD2 BRD mediates the formation of liquid-liquid phase separation (LLPS) of ATAD2 in cells. This phase separation promotes the process of histone H4 acetylation, leading to the up-regulation of C-MYC, CCND3, and ATF2 gene expression and the facilitation of chromatin remodeling. Our findings elucidate a vital function of ATAD2, wherein BRD-mediated LLPS drives histone acetylation to promote cellular chromatin remodeling.

molecular biology↗

bioRxiv2024

Insights into Intestinal Barrier Disruption During Long-Term Gut Chlamydia Colonization in Mice: A Single-Cell Transcriptomic Approach

Chlamydia trachomatis, an intracellular pathogen, stands as the most prevalent sexually transmitted bacterial infection among women globally. Traditionally recognized as a genital pathogen, recent research indicates that the gastrointestinal tract may also act as a reservoir for its long-term colonization. However, the mechanisms underlying Chlamydias ability to persist in the gut remain poorly understood. This gap in knowledge limits our ability to develop effective treatments for persistent Chlamydia infections. In this study we utilized single-cell RNA sequencing to analyze the gene expression profiles and cellular heterogeneity of mouse colonic tissues during Chlamydia long-term infection. This approach provided detailed insights into the transcriptional changes and cellular interactions involved in the persistence of Chlamydia in the gut. Our results revealed significant alterations in the gene expression profiles of various intestinal cell populations, with distinct molecular pathways contributing to Chlamydia persistence. Notably, we observed a reduction in the expression of markers associated with epithelial tight junctions, indicating a potential breakdown of the intestinal epithelial barrier. This impairment may facilitate the penetration of Chlamydia into deeper tissues and contribute to the initiation of infection. We also found dysregulation of the transcriptional networks in goblet cells and an imbalance in communication between immune and epithelial cells. These disruptions were linked to the pathogens ability to establish persistent colonization and infection. IMPORTANCEFew studies have explored Chlamydia persistence in the gastrointestinal tract. In this study, we use single-cell RNA sequencing to identify the molecular and cellular mechanisms driving the pathogens long-term colonization. Our findings provide crucial insights into how Chlamydia overcomes the hosts immune defenses and epithelial barriers to establish chronic infection in the gut. Notably, we identify disruption of epithelial tight junctions and an imbalance in immune-cell interactions, offering new avenues for therapeutic interventions aimed at restoring mucosal integrity and preventing persistent infection.

microbiology↗

bioRxiv2024

Microglia States are Susceptible to Senescence and Cholesterol Dysregulation in Alzheimer's Disease

Cellular senescence is a major contributor to aging-related degenerative diseases, including Alzheimers disease (AD) but much less is known on the key cell types and pathways driving mechanisms of senescence in the brain. We hypothesized that dysregulated cholesterol metabolism is central to cellular senescence in AD. We analyzed whole transcriptomic data and utilized single-cell RNA seq integration techniques to unveil the convoluted cell-type-specific and sub-cell-type-state-specific senescence pathologies in AD using both ROSMAP and Sea-AD datasets. We identified that microglia are central components to AD associated senescence phenotypes in ROSMAP snRNA-seq data (982,384 nuclei from postmortem prefrontal cortex of 239 AD and 188 non-AD) among non-neuron cell types. We identified that homeostatic, inflammatory, phagocytic, lipid processing and neuronal surveillance microglia states were associated with AD associated senescence in ROSMAP (152,459 microglia nuclei from six regions of brain tissue of 138 early AD, 79 late AD and 226 control subject) and in Sea-AD (82,486 microglia nuclei of 42 dementia, 42 no dementia and 5 reference subjects) via integrative analysis, which preserves the meaningful biological information of microglia cell states across the datasets. We assessed top senescence associated bioprocesses including mitochondrial, apoptosis, oxidative stress, ER stress, endosomes, and lysosomes systems. Specifically, we found that senescent microglia have altered cholesterol related bioprocesses and dysregulated cholesterol. We discovered three gene co-expression modules, which represent the specific cholesterol related senescence transcriptomic signatures in postmortem brains. To validate these findings, the activation of specific cholesterol associated senescence transcriptomic signatures was assessed using integrative analysis of snRNA-seq data from iMGs (microglia induced from iPSCs) exposed to myelin, Abeta, and synaptosomes (56,454 microglia across two replicates of untreated and four treated groups). In vivo cholesterol associated senescence transcriptomic signatures were preserved and altered after treatment with AD pathological substrates in iMGs. This study provides the first evidence that dysregulation of cholesterol metabolism in microglia is a major driver of senescence pathologies in AD. Targeting cholesterol pathways in senescent microglia is an attractive strategy to slow down AD progression.

neuroscience↗

bioRxiv2024

Impact of oral Chlamydia Vaccination on Host Gut Microbiome and Metabolites Composition

Chlamydia trachomatis, an intracellular pathogen, is recognized as the most common sexually transmitted bacterial infection among women worldwide. Chlamydia infections can lead to undesirable clinical outcomes, including pelvic inflammatory disease and infertility. Recently, the gut has been identified as a niche for Chlamydia colonization; however, despite the biological impact on the host remaining under investigation, oral inoculation of Chlamydia as a whole-organism vaccine has been reported as a promising strategy for preventing genital Chlamydia infections. Few studies have evaluated the impact of oral Chlamydia vaccination on the gut microbiome and metabolite changes. In this study, we assessed time-series alterations in the gut microbiome and metabolites following oral Chlamydia inoculation, and we analyzed the composition and correlation between serum immune parameters and the sequencing profiles in the host. We identified 129 microbial changes and 186 significantly different metabolites in the gut across various vaccination approaches during the 30-day immunization process. Additionally, we discussed potential biomarkers of effective immunization based on correlation analysis. IMPORTANCEChlamydia infections primarily lead to morbidity rather than mortality. Consequently, in developing and implementing a Chlamydia vaccine, the utmost priority is ensuring safety. As a promising yet controversial approach, live oral vaccination for Chlamydia raises concerns regarding its impact on the hosts gut environment. Our study not only investigates changes in the gut microbiome and metabolites during vaccination but also identifies potential biomarkers during immunization. These findings are crucial for the development of whole-organism oral Chlamydia vaccines and provide valuable insights into the long-term colonization of Chlamydia in the gut.

microbiology↗

bioRxiv2024

YY1 Enhances the Stability of HIF-1α Protein by Interacting with NUSAP1 in Macrophages within the Prostate Cancer Microenvironment

Immune checkpoint therapy for prostate cancer (PCa) has failed in clinical trials; however, the precise underlying mechanisms involved remain elusive. PCa, a classic "immune-cold" tumor, is characterized by an immunosuppressive tumor microenvironment. Within this milieu, macrophages, the predominant immune cell population, have a propensity to infiltrate the hypoxic zones of tumors. In a previous study, we showed that Yin Yang 1 (YY1) is highly expressed in macrophages in PCa tissues. Here, through multiplexed imaging mass cytometry (IMC) of a PCa tissue microarray, we further demonstrate that YY1+ macrophages aggregate in hypoxic areas of tumors and that hypoxia promotes the phase separation of YY1 in the nucleus by increasing YY1 tyrosine phosphorylation in macrophages. Furthermore, YY1 binds to NUSAP1 and promotes the SUMOylation of HIF-1, which promotes phase separation and stabilization of the HIF-1 protein. We also demonstrated that either treatment with a small molecule inhibitor (tenapanor) to decrease the YY1-NUSAP1-HIF-1 interaction or myeloid-specific YY1 gene knockout impairs subcutaneous PCa tumor formation. Furthermore, we present a first-generation tetrahedral DNA nanostructure (TDN) based on the proteolysis targeting chimera (PROTAC) technique, named YY1-DcTAC, which targets and degrades YY1 in tumor-associated macrophages. In a PCa mouse model, YY1-DcTAC exhibited prolonged drug efficacy, robust macrophage-specific responsiveness, potent antitumor effects, and increased CD8+ T cell tumor infiltration. In summary, our findings underscore the pivotal role of YY1 within the hypoxia/HIF-1 pathway in tumor-associated macrophages and affirm the therapeutic potential of targeting YY1 for treating PCa.

cancer biology↗

bioRxiv2024

Deficiency of mitophagy mediator Parkin in aortic smooth muscle cells exacerbates abdominal aortic aneurysm

Abdominal aortic aneurysms (AAAs) are a degenerative aortic disease and associated with hallmarks of aging, such as mitophagy. Despite this, the exact associations among mitophagy, aging, and AAA progression remain unknown. In our study, gene expression analysis of human AAA tissue revealed downregulation of mitophagy pathways, mitochondrial structure, and function-related proteins. Human proteomic analyses identified decreased levels of mitophagy mediators PINK1 and Parkin. Aged mice and, separately, a murine AAA model showed reduced mitophagy in aortic vascular smooth muscle cells (VSMCs) and PINK1 and Parkin expression. Parkin knockdown in VSMCs aggravated AAA dilation in murine models, with elevated mitochondrial ROS and impaired mitochondrial function. Importantly, inhibiting USP30, an antagonist of the PINK1/Parkin pathway, increased mitophagy in VSMCs, improved mitochondrial function, and reduced AAA incidence and growth. Our study elucidates a critical mechanism that proposes AAAs as an age-associated disease with altered mitophagy, introducing new potential therapeutic approaches.

molecular biology↗

bioRxiv2024

Rejuvenation of aged oocyte through exposure to young follicular microenvironment

Reproductive aging is a major cause of fertility decline, attributed to decreased oocyte quantity and competence. Follicular somatic cells play crucial roles in the growth and development of the oocyte by providing nutrients and regulatory factors. Here we investigated how oocyte quality is affected by its somatic cell environment by creating chimeric follicles, whereby an oocyte from one follicle was transplanted into and cultured within another follicle whose native oocyte was removed. Somatic cells within the chimeric follicle re-establish connections with the oocyte and support oocyte growth and maturation in a three-dimensional (3D) culture system. We show that young oocytes transplanted into aged follicles exhibited reduced meiotic maturation and developmental potential, whereas the young follicular environment significantly improved the rates of maturation, blastocyst formation and live birth of aged oocytes. Aged oocytes cultured within young follicles exhibited enhanced interaction with somatic cells, more youth-like transcriptome, remodelled metabolome, improved mitochondrial function, and enhanced fidelity of meiotic chromosome segregation. These findings provide the basis for a future follicular somatic cell-based therapy to treat age-associated female infertility.

developmental biology↗

bioRxiv2024

Single-nucleus Multiomic Analyses Identifies Gene Regulatory Dynamics of Phenotypic Modulation in Human Aneurysmal Aortic Root

Aortic root aneurysm is a potentially life-threatening condition that may lead to aortic rupture and is often associated with genetic syndromes, such as Marfan syndrome (MFS). Although studies with MFS animal models have provided valuable insights into the pathogenesis of aortic root aneurysms, our understanding of the transcriptomic and epigenomic landscape in human aortic root tissue remains incomplete. This knowledge gap has impeded the development of effective targeted therapies. Here, this study performs the first integrative analysis of single-nucleus multiomic (gene expression and chromatin accessibility) and spatial transcriptomic sequencing data of human aortic root tissue under healthy and MFS conditions. Cell-type-specific transcriptomic and cis-regulatory profiles in the human aortic root are identified. Regulatory and spatial dynamics during phenotypic modulation of vascular smooth muscle cells (VSMCs), the cardinal cell type, are delineated. Moreover, candidate key regulators driving the phenotypic modulation of VSMC, such as FOXN3, TEAD1, BACH2, and BACH1, are identified. In vitro experiments demonstrate that FOXN3 functions as a novel key regulator for maintaining the contractile phenotype of human aortic VSMCs through targeting ACTA2. These findings provide novel insights into the regulatory and spatial dynamics during phenotypic modulation in the aneurysmal aortic root of humans.

pathology↗

bioRxiv2022

Improving the secretion of designed protein assemblies through negative design of cryptic transmembrane domains

Computationally designed protein nanoparticles have recently emerged as a promising platform for the development of new vaccines and biologics. For many applications, secretion of designed nanoparticles from eukaryotic cells would be advantageous, but in practice they often secrete poorly. Here we show that designed hydrophobic interfaces that drive nanoparticle assembly are often predicted to form cryptic transmembrane domains, suggesting that interaction with the membrane insertion machinery could limit efficient secretion. We develop a general computational protocol, the Degreaser, to design away cryptic transmembrane domains without sacrificing protein stability. Retroactive application of the Degreaser to previously designed nanoparticle components and nanoparticles considerably improves secretion, and modular integration of the Degreaser into design pipelines results in new nanoparticles that secrete as robustly as naturally occurring protein assemblies. Both the Degreaser protocol and the novel nanoparticles we describe may be broadly useful in biotechnological applications.

biochemistry↗

bioRxiv2022

Multi-omics analysis of sarcospan overexpression in mdx skeletal muscle reveals compensatory remodeling of cytoskeleton-matrix interactions that promote mechanotransduction pathways

BackgroundThe dystrophin-glycoprotein complex (DGC) is a critical adhesion complex of the muscle cell membrane, providing a mechanical link between the extracellular matrix (ECM) and the cortical cytoskeleton that stabilizes the sarcolemma during repeated muscle contractions. One integral component of the DGC is the transmembrane protein, sarcospan (SSPN). Overexpression of SSPN in the skeletal muscle of mdx mice (murine model of DMD) restores muscle fiber attachment to the ECM in part through an associated increase in utrophin and integrin adhesion complexes at the cell membrane, protecting the muscle from contraction-induced injury. In this study, we utilized transcriptomic and ECM protein-optimized proteomics data sets from wild-type, mdx, and mdx transgenic (mdx TG) skeletal muscle tissues to identify pathways and proteins driving the compensatory action of SSPN overexpression. MethodsThe tibialis anterior and quadriceps muscles were isolated from wild-type, mdx, and mdx TG mice and subjected to bulk RNA-Seq and global proteomics analysis using methods to enhance capture of ECM proteins. Data sets were further analyzed through the Ingenuity Pathway Analysis (QIAGEN) and integrative gene set enrichment to identify candidate networks, signaling pathways, and upstream regulators. ResultsThrough our multi-omics approach, we identified 3 classes of differentially expressed genes and proteins in mdx TG muscle, included those that were: 1) unrestored (significantly different from wild-type, but not from mdx), 2) restored (significantly different from mdx, but not from wild-type), and 3) compensatory (significantly different from both wild-type and mdx). We identified signaling pathways that may contribute to the rescue phenotype, most notably cytoskeleton and ECM organization pathways. ECM optimized-proteomics revealed an increased abundance of collagens II, V, and XI, along with {beta}-spectrin in mdx TG samples. Using Ingenuity Pathway Analysis, we identified upstream regulators that are computationally predicted to drive compensatory changes, revealing a possible mechanism of SSPN rescue through a rewiring of cell-ECM bidirectional communication. We found that SSPN overexpression results in upregulation of key signaling molecules associated with regulation of cytoskeleton organization and mechanotransduction, including Rho, RAC, and Wnt. ConclusionsOur findings indicate that SSPN overexpression rescues dystrophin deficiency partially through mechanotransduction signaling cascades mediated through components of the ECM and the cortical cytoskeleton.

molecular biology↗

bioRxiv2021

Scrutiny of human lung infection by SARS-CoV-2 and associated human immune responses in humanized mice

There is an urgent need for animal models of COVID-19 to study immunopathogenesis and test therapeutic intervenes. In this study we showed that NSG mice engrafted with human lung (HL) tissue (NSG-L mice) could be infected efficiently by SARS-CoV-2, and that live virus capable of infecting Vero cells was found in the HL grafts and multiple organs from infected NSG-L mice. RNA-seq examination identified a series of differentially expressed genes, which are enriched in viral defense responses, chemotaxis, interferon stimulation, and pulmonary fibrosis between HL grafts from infected and control NSG-L mice. Furthermore, when infecting humanized mice with human immune system (HIS) and autologous HL grafts (HISL mice), the mice had bodyweight loss and hemorrhage and immune cell infiltration in HL grafts, which were not observed in immunodeficient NSG-L mice, indicating the development of anti-viral immune responses in these mice. In support of this possibility, the infected HISL mice showed bodyweight recovery and lack of detectable live virus at the later time. These results demonstrate that NSG-L and HISL mice are susceptible to SARS-CoV-2 infection, offering a useful in vivo model for studying SARS-CoV-2 infection and the associated immune response and immunopathology, and testing anti-SARS-CoV-2 therapies.

immunology↗

bioRxiv2021

Systematic discovery of mutation-directed neo-protein-protein interactions in cancer

Comprehensive sequencing of patient tumors reveals numerous genomic mutations across tumor types that enable tumorigenesis and progression. A subset of oncogenic driver mutations results in neomorphic activity where the mutant protein mediates functions not engaged by the parental molecule. Here, we identify prevalent variant-enabled neomorph-protein-protein interactions (neoPPI) with a quantitative High Throughput differential Screening (qHT-dS) platform. Coupling of highly sensitive BRET biosensors with miniaturized co-expression in an ultra-HTS format allows large-scale monitoring of interactions of wild-type and mutant variant counterparts with a library of cancer-associated proteins in live cells. Screening of 13,392 interactions with 1,474,560 data points revealed a landscape of gain-of-interactions encompassing both oncogenic and tumor suppressor mutations. For example, the recurrent BRAF V600E lesion mediates KEAP1 neoPPI, rewiring a BRAFV600E-KEAP1 signaling axis and creating collateral vulnerability to NQO1 substrates, offering a combination therapeutic strategy. Thus, cancer genomic alterations can create neo-interactions, informing variant-directed therapeutic approaches for precision medicine.

cancer biology↗

bioRxiv2021

Pre-clinical validation of an RNA-based precision oncology platform for patient-therapy alignment in a diverse set of human malignancies resistant to standard treatments

Predicting tumor sensitivity to antineoplastics remains an elusive challenge, with no methods demonstrating predictive power. Joint analysis of tumors--from patients with distinct malignancies who had progressed on multiple lines of therapy--and drug perturbation transcriptional profiles predicted sensitivity to 28 of 350 drugs, 26 of which (93%) were confirmed in low-passage, patient-derived xenograft (PDX) models. Drugs were prioritized based on their ability to either invert the activity of individual Master Regulator proteins, with available high-affinity inhibitors, or of the modules they comprise (Tumor-Checkpoints), based on de novo mechanism of action analysis. Of 138 PDX mice enrolled in 16 single and 18 multi-protein treatment arms, a disease control rate (DCR) of 68% and 91 %, and an objective response rate (ORR) of 12% and 17%, were achieved respectively, compared to 6% and 0% in the negative controls arm, with multi-protein drugs achieving significantly more durable responses. Thus, these approaches may effectively complement and expand current precision oncology approaches, as also illustrated by a case study.

systems biology↗

bioRxiv2021

Pharmacological rescue of tumor intrinsic STING expression and immune response in LKB1-mutant lung cancer via the IAP-JAK regulatory axis

Harnessing the power of the immune system to treat cancer has become a core clinical approach. However, rewiring of intrinsic circuitry enables tumor cells to escape immune attacks, leading to therapeutic failure. Pharmacological strategies to reverse tumor genotype-dictated therapeutic resistance are urgently needed to advance precision immunotherapy. Here, we identify antagonists of Inhibitor of Apoptosis Protein (IAP) as potent sensitizers that restore immune-dependent killing of LKB1-mutant lung cancer cells. Mechanistic studies reveal an LKB1-IAP-JAK trimolecular complex that bridges the LKB1-mutant genotype with IAP-dependency and a STING-deficiency-mediated immune resistance phenotype. Ultimately, inhibition of IAP re-establishes JAK-regulated STING expression and DNA sensing pathway as well as enhanced cytotoxic immune cell infiltration and selective immune-dependent anti-tumor activity in an LKB1-mutant immune-competent mouse model. Thus, IAP-JAK-modulatory strategies, like IAP inhibitors, offer promising immunotherapy adjuvants to re-establish the responsiveness of "immunologically-cold" LKB1-mutant tumors to immune checkpoint inhibitors or STING-directed therapies.

cancer biology↗

bioRxiv2021

Reconciling Inherent Interfacial Compatibility Conflict Enhances Adhesive Infiltration and Resolves Dentin Bonding Durability

Wet bonding is a basic technique used daily in clinics for tooth-restoration fixation. However, only 50% of the bonding lasts more than 5 years and thus patients must visit the dentists repeatedly. This is attributed to the limited infiltration of adhesives into the demineralized dentin (DD) matrix during wet-bonding. Herein, we show that reconciling interfacial compatibility conflict between the DD matrix and the critical hydrophobic adhesive molecules via hydrophobizing the DD matrix enables the adhesives to thoroughly infiltrate and uniformly distribute within the DD matrix. Thus, the bonding of the hydrophobic DD matrix using commercial dentin adhesives achieves the bonding strength 2-6 times higher than that of the non-treated DD matrix. When a hydrophobic adhesive is applied on the hydrophobic DD matrix, a flawless hybrid layer is produced as observed by nanoleakage investigation. A long-term bonding strength comes up to 7.3 fold that of the control group and very importantly, with no attenuation after 12 months. This study clarifies the basic cause of poor wet-bonding durability and demonstrates a paradigm in adhesive dentistry to overcome the long-existing bonding durability problem associated with inadequate adhesive infiltration into the DD matrix. This provides a new angle of view to resolve clinical dentin bonding durability problem and will significantly promote adhesive dentistry. HighlightsO_LIInherent interfacial compatibility conflict between demineralized dentin matrix and hydrophobic molecules of dentin adhesives is the basic cause for the dentin bonding durability problem. C_LIO_LIReconciling the interfacial compatibility conflict markedly facilitates adhesive infiltration in the demineralized dentin matrix and greatly enhances bonding effectiveness. C_LIO_LIHigh interfacial compatibility produces a flawless hybrid layer and ideal bonding effectiveness and durability. C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=180 SRC="FIGDIR/small/430396v1_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@9687e1org.highwire.dtl.DTLVardef@b2fc79org.highwire.dtl.DTLVardef@dd7379org.highwire.dtl.DTLVardef@c8117b_HPS_FORMAT_FIGEXP M_FIG For wet bonding, poor infiltration of adhesives within the DD matrix inevitably produces numerous defects throughout the hybrid layer, which always leads to the failure of restoration. Via hydrophobizing the DD matrix, reconciling interfacial compatibility conflict between the DD matrix and the hydrophobic adhesive monomers overcomes durability problems associated with the infiltration of adhesives into the DD matrix producing a flawless hybrid layer and providing ideal bonding effectiveness and durability. C_FIG

bioengineering↗

bioRxiv2020

Differential Expression of NPAS4 in the Dorsolateral Prefrontal Cortex Following Acute Opioid Intoxication

Background and AimsThe physical, emotional, and social impacts of opioid abuse are well known; although preclinical models reveal the neurobiological pathways altered through opioid abuse, comprehensive assessments of gene expression in human brain samples are lacking. The goals of the present study were to compare gene expression in the prefrontal cortex between brain samples of individuals who died of acute opioid intoxication and group-matched controls, and to test if differential gene expression was enriched in gene sets related to opioid use. DesignCross-sectional study using human brains donated to the Lieber Institute for Brain Development. Study groups included 72 brain samples from individuals who died of acute opioid intoxication, 53 group-matched psychiatric control samples, and 28 group-matched normal control samples. SettingMaryland, USA. ParticipantsPostmortem tissue samples of the dorsolateral prefrontal cortex from 153 deceased individuals (Mage = 35.42, SD = 9.43 years; 62% male; 77% White). MeasurementsWhole transcriptome RNA sequencing was used to generate exon counts, and differential expression was tested using limma-voom. Analyses controlled for relevant sociodemographic characteristics, technical covariates, and cryptic relatedness and batch effects using quality surrogate variable analysis. Gene set enrichment analyses (GSEA) also were conducted. FindingsSixteen genes were differentially expressed (i.e., FDR-corrected p < .10) in opioid samples compared to control samples. The top differentially expressed gene, NPAS4 (FDR adjusted p = .005), was downregulated in opioid samples and has previously been implicated in cocaine use. Enrichment analyses did not provide evidence for enrichment in pathways obviously related to opioid use. ConclusionsNPAS4 is differentially expressed in the prefrontal cortex of subjects that died of an opioid overdose, providing evidence for another gene with functional relevance to opioid use and overdose.

genomics↗

bioRxiv2020

Epigenome-wide study of brain DNA methylation among opioid users and controls

Opioid abuse poses significant risk to individuals in the United States and epigenetic changes are a leading potential biomarker of abuse. Current evidence, however, is mostly limited to candidate gene analysis in whole blood. To clarify the association between opioid abuse and DNA methylation, we conducted an epigenome-wide analysis (EWAS) of DNA methylation in brains of individuals who died from opioid intoxication and controls. Tissue samples were extracted from the dorsolateral prefrontal cortex of 160 deceased individuals (Mage = 35.15, SD = 9.42 years; 62% male; 78% White). The samples included 73 individuals who died of opioid intoxication, 59 group-matched psychiatric controls, and 28 group-matched normal controls. EWAS was implemented using the Illumina Infinium MethylationEPIC BeadChip; analyses adjusted for sociodemographic characteristics, negative control and ancestry principal components, cellular composition, and surrogate variables. Epigenetic age was calculated using the Horvath and Levine clocks, and gene ontology (GO) analyses were performed. No CpG sites were epigenome-wide significant after multiple testing correction, but 13 sites reached nominal significance (p < 1.0 x 10-5). There was a significant association between opioid use and Levine phenotypic age (b = 2.24, se = 1.11, p = .045). Opioid users were approximately two years phenotypically older compared to controls. GO analyses revealed enriched pathways related to cell function and neuron differentiation, but no terms survived multiple testing correction. Results inform our understanding of the neurobiology of opioid use, and future research with larger samples across stages of opioid use will elucidate the complex genomics of opioid abuse.

genomics↗

bioRxiv2019

Predicting cellular position in the Drosophila embryo from Single-Cell Transcriptomics data

Single-cell RNA-seq technologies are rapidly evolving but while very informative, in standard scRNAseq experiments the spatial organization of the cells in the tissue of origin is lost. Conversely, spatial RNA-seq technologies designed to keep the localization of the cells have limited throughput and gene coverage. Mapping scRNAseq to genes with spatial information increases coverage while providing spatial location. However, methods to perform such mapping have not yet been benchmarked. To bridge the gap, we organized the DREAM Single-Cell Transcriptomics challenge focused on the spatial reconstruction of cells from the Drosophila embryo from scRNAseq data, leveraging as gold standard genes with in situ hybridization data from the Berkeley Drosophila Transcription Network Project reference atlas. The 34 participating teams used diverse algorithms for gene selection and location prediction, while being able to correctly localize rare subpopulations of cells. Selection of predictor genes was essential for this task and such genes showed a relatively high expression entropy, high spatial clustering and the presence of prominent developmental genes such as gap and pair-ruled genes and tissue defining markers.

systems biology↗