28 results on '"Bioinformatics"'
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2. Role of Distributed Computing in Biology Research Field and Its Challenges
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Azli, Bahiyah, Mat Isa, Nurulfiza, Ahmad, Kamarul Arifin, editor, Hamid, Nor Asilah Wati Abdul, editor, Jawaid, Mohammad, editor, Khan, Tabrej, editor, and Singh, Balbir, editor
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- 2024
- Full Text
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3. Genomic and Transcriptomic Examination of Functional Elements and Absent Sequences
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Chan, Candace S.Y
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Genetics ,Bioinformatics ,Biology ,Gene regulation ,Genomics ,Hypothalamus ,Nullomer ,Transcriptional regulatory elements - Abstract
Background: Genome-wide association studies have identified numerous disease-associated variants, but a vast majority are located in non-coding regions, making it challenging to understand their functional impact. This complexity necessitates new techniques to identify causal variants in non-coding regions and elucidate their specific cellular contexts and mechanisms of action. Here we present work i) examining mutations that create nullomers in the human genome to explore its potential utility in identifying pathogenic mutations and ii) a single-cell multi-omic study identifying the transcriptome and regulome of the human and mouse hypothalamus to identify regulatory regions of obesity-associated variants.Methods: (i) We generated all possible mutations of the human genome that can lead to emergence of a nullomer, and examine where in the genome they emerge. (ii) We apply single-cell RNA and ATAC sequencing to adult hypothalamus samples.Results and Conclusions: (i) Our findings highlight CpG hypermutability and methylated cytosines as key elements leading to resurfacing of nullomers in individuals. We also showcase that nullomers can have applications in disease annotation and pathogenic variant identification. (ii) We identified regulatory elements of hypothalamus cell types and mapped obesity-associated variants to cell-type specific peaks. We validated these regions to be enhancers using CRISPR editing and CRISPRi.
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- 2024
4. Mapping transcriptional regulation of cell types and states using systems genetics in mouse
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Rebboah, Elisabeth
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Biology ,Bioinformatics ,ENCODE ,IGVF ,Mouse development ,Single-cell RNA-seq ,Skeletal muscle ,Systems genetics - Abstract
Complex traits are intricately intertwined with an organism's genome, a relationship underscored by the dynamic landscape of its transcriptome. Selective gene expression regulates cell type specialization and fluctuation of cell states. The development of RNA sequencing has facilitated the capture of the whole transcriptome of a given sample. However, a bulk approach obscures cell type heterogeneity, impeding the precise dissection of cell-specific effects, including those modulated by genotype, developmental stage, and disease state. In contrast, single-cell and single-nucleus RNA-seq preserves cellular identity, enabling a comprehensive mapping of gene expression across various cell types and states.Here, I describe my work in single-cell transcriptomics to characterize cell types and cell states in mouse. First, I present our long-read single-cell RNA-seq method, benchmarked in the C2C12 mouse myogenic system, which revealed cell type-specific isoform switching in key genes during myogenesis. Next, I characterize 5 mouse tissues at single-nucleus resolution during postnatal development using the ENCODE4 mouse dataset, where I used topic modeling to reveal cell type- and state-specific cellular programs. Lastly, I investigate the impact of genetic variation on gene expression across 8 diverse tissues from 8 mouse genotypes, pinpointing genotype- driven variation in specific celltypes in both wild-derived and classical lab strains. Together, these projects lay the groundwork for cohesive cell type and cell state annotation and comparative analyses, contributing to future characterization of these tissues in other contexts such as human diseases and hybrid mouse genotypes.
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- 2024
5. Roles of DNA Methylation in Pancreatic Ductal Adenocarcinoma Progression
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Wang, Sarah
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Biology ,Bioinformatics ,Molecular biology ,DNA methylation ,Pancreatic cancer ,WGBS - Abstract
Cancer has historically been considered a genetic disease originating from activating mutations of oncogenes or inactivating mutations of tumor suppressors. More recently, appreciation for the contributions of epigenetic mechanisms to carcinogenesis has grown as they help to explain the aberrant gene expression and cellular identity associated with many cancers. For example, changes in DNA methylation at CpG dinucleotides can alter gene expression to promote malignant properties. In pancreatic ductal adenocarcinoma (PDA), the genetic underpinnings of tumorigenesis are known and primarily originate from mutations in KRAS and TP53. Furthermore, transcriptomic studies have identified transcriptional programs that are commonly enriched in subsets of patients, resulting in two main subtypes of PDA with clinical implications: squamous-PDA and progenitor-PDA. An understanding of the genome-wide DNA methylation aberrations in PDA and their contribution to tumor progression and subtype identity is less clear. In this dissertation, the genome-wide DNA methylation changes across PDA stages and subtypes as well as the impacts on metastatic characteristics and subtype differentiation are explored. Chapter 1 is a review of the literature highlighting our current understanding of the DNA methylation landscape in PDA which has primarily been learned from microarray studies that assay a very limited subset of CpGs. In Chapter 2, we characterize the genome-wide DNA methylation landscape of PDA organoids using whole genome bisulfite sequencing (WGBS), identifying and characterizing stage-specific and subtype-specific DNA methylation differences that may be beneficial as prognostic and predictive biomarkers. In Chapter 3, we identify subtype-specific DNA methylation differences in commercially available PDA cell lines and dissect GATA6-mediated epigenetic contributions to progenitor-PDA subtype differentiation. GATA6 is a known master regulator of progenitor-PDA and we found that its binding motifs are enriched in hypermethylated regions of squamous-PDA. While restoration of GATA6 expression in squamous-PDA did upregulate the progenitor-PDA gene signature, it did not reverse the observed hypermethylation suggesting that GATA6 does not directly mediate DNA methylation of its binding regions. Instead, GATA6 may epigenetically regulate transcription of its target genes through its interaction with the SWI/SNF family of chromatin remodelers. Thus, the SWI/SNF complex may be a therapeutically actionable target for treating patients with the progenitor-PDA subtype. In Chapter 4, we perform a combined transcriptomic and DNA methylome analysis of mouse PDA organoid models to identify genes whose methylation-mediated silencing likely contributes to PDA metastasis. We found that hypermethylation of the Pdzrn3 promoter represses Pdzrn3 transcription and promotes metastatic characteristics including increased cell migration and a pro-migratory cell morphology. Chapter 5 summarizes the main findings of this work, applications of the research, and future directions.
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- 2024
6. Optimizing Third Generation Sequencing Technology to Address the Unknowns of the Adaptive Immune System
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Deng, Dori Zhiqian
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Biology ,Immunology ,Bioinformatics ,Adaptive immune system ,Genomics ,Third generation sequencing - Abstract
Since its inception in the 1970s with Frederick Sanger's pioneering work on Sanger sequencing, DNA sequencing technology has undergone a remarkable evolution. Automated Sanger sequencing in the 1980s and 1990s significantly increased throughput and accuracy, while the 21st century saw the emergence of next-generation sequencing (NGS) technologies like Illumina, revolutionizing genomics research by enabling high-throughput sequencing (van Dijk et al. 2014). However, short-read sequencing techniques, including Illumina, have limitations in accurately resolving repetitive regions and complex structural variations within the genome, hindering comprehensive understanding. In response, third-generation sequencing technologies such as Pacific Biosciences' (PacBio) and Oxford Nanopore Technologies (ONT) have arisen, offering long-read capabilities but facing challenges like DNA polymerase limitations (PacBio) and high error rates (ONT)(Rhoads and Au 2015). Despite these challenges, both PacBio and ONT sequencing technologies continue to advance rapidly, with potential to deepen our understanding of the genome's complexities (Wang et al. 2021). Leveraging the advantages of ONT sequencing, and developing molecular biology methods and bioinformatics tools that overcome the limitations of ONT sequencing to address the unknowns of the adaptive immune system (AIS), is the focus of my graduate work. The diversity of antibody repertoires poses significant challenges for sequencing and annotation. By developing assays that overcome these challenges, my research contributes to a deeper understanding of antibody diversity across vertebrate species, with implications for antibody-based therapy and research applications.
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- 2024
7. The Evolutionary Consequences of Introgression among Strongylocentrotid Sea Urchins
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Glasenapp, Matthew Robert
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Biology ,bioinformatics ,echinoderms ,gamete recognition proteins ,genomics ,Next Generation Sequencing ,phyloinformatics - Abstract
Understanding the genomic architecture of speciation remains a challenge in evolutionary biology. Among broadcast-spawning marine invertebrates, reproductive isolation is thought to be established and maintained by the divergence of gamete recognition proteins located on the surfaces of sperm and egg cells. However, it remains unclear whether gametic isolation has been an effective barrier to gene flow during and/or following speciation. In this dissertation, I characterized the history of introgression among the North Pacific sea urchin species of the family Strongylocentrotidae to deepen our understanding of their diversification and evaluate the importance of gametic isolation in speciation. Using whole-genome sequencing data from each strongylocentrotid species and cutting-edge phylogenomic approaches, I documented widespread introgression in both extant taxa and ancestral lineages, demonstrating that gametic isolation did not effectively limit introgression. I implemented a phylogenetic hidden Markov model to locate the specific regions of the genome affected by introgression, finding evidence of strong selection against introgression across much of the genome. Although introgressed variation has predominantly persisted in slowly evolving, low-divergence genomic regions, numerous protein-coding genes showed both introgression and historical positive selection, suggesting an adaptive role for introgression. Finally, I showed that the two gamete recognition proteins responsible for species-selectivity in sea urchin fertilization, sperm protein bindin and its egg receptor, EBR1, have experienced historical adaptive introgression, a pattern inconsistent with expectations for barrier loci. My findings contribute to the body of literature evaluating the biological consequences of introgression and question the importance of gamete recognition proteins in the evolution of reproductive isolation among incipient strongylocentrotid sea urchin species.
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- 2024
8. Investigating Functional Roles of Driver Mutations in the Context of Co-Occurring Mutations and Environmental Stress
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Liang, Cindy
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Molecular biology ,Bioinformatics ,Biology ,cancer ,KRAS ,lung adenocarcinoma ,splicing ,U2AF1 - Abstract
U2AF1S34F, a somatic splicing factor mutation, is frequently recurrent in human neoplasias such as lung adenocarcinoma (ADC). Although U2AF1S34F has been shown to occur early in tumor lineages, the mutation, alone, is insufficient for producing tumors. However, lung ADC patients with U2AF1S34F frequently have co-occurring KRAS mutations and smoking histories. We hypothesized that U2AF1S34F interacts with oncogenic KRAS and environmental stress to promote tumor-forming potential. To elucidate interaction of U2AF1S34F with a co-occurring mutation, we generated human bronchial epithelial cells (HBEC3kts) with U2AF1S34F or with co-occurring U2AF1S34F and KRASG12V. From analyzing short-read transcriptome sequences, we found synergistic effects of co-occurring mutations on gene expression in cell cycle and inflammatory pathways associated with increased tumors in mouse xenografts, anchorage-independent growth, proliferation, and altered cytokine production.nterestingly, HBEC3kts harboring only U2AF1S34F display increased splicing in stress granule protein genesand increased viability in cigarette smoke concentrate. Our results suggest that U2AF1S34F may prime cells for transformation by allowing precancerous cells to survive longer when environmental stress is present, permitting U2AF1S34F cells to accumulate transforming mutations, such as KRASG12V.Next, I sought to further investigate the impact of U2AF1S34F and environmental stress response by profiling the mRNA modification landscape of U2AF1S34F and U2AF1WT HBEC3kts exposed to cigarette smoke concentrate (CSC) using Nanopore direct RNA sequencing (dRNA-seq). Preliminary results show that RNA modificatios in autophagy gene VAMP8 were associated with altered protein expression levels. We also show that CSC and the presence of U2AF1S34F both increase the number of RNA modifications in the transcriptome, with the highest number of modifications occurring in CSC treated U2AF1S34F HBEC3kts. We hypothesize that U2AF1S34F and CSC modify the RNA modification landscape in a synergistic way to increase oncogenic potential.
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- 2024
9. A Bird’s Eye View of Speciation with Gene Flow: Insights from Genetic Clines Across the Yellow-Rumped Warbler Hybrid Zone
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Pierce, Daniel
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Biology ,Bioinformatics ,Evolution ,Gene flow ,Genomics ,Hybridization ,Speciation - Abstract
When divergent populations come into contact and interbreed, incompatible genotypes can result in decreased hybrid fitness and partial reproductive isolation. By studying patterns of gene flow between populations, we can identify the genetic, phenotypic, and ecological components of partial reproductive isolation. Using whole-genome sequence data generated from 1201 yellow-rumped warblers (Setophaga coronata coronata, S. c. auduboni, and their hybrids), we measure variation of a hybrid zone’s position in space and over time, identify genomic regions where gene flow is restricted, and compare the genetic basis of reproductive barriers to the genetic basis of plumage traits. We find that reproductive isolation is generated by the effects of many loci throughout the genome, with a large influence of the sex-chromosomes, that “barrier loci” cluster in some highly differentiated regions, and that gene flow and introgression are broadly asymmetric. Barrier loci show strong linkage disequilibrium, which augments the strength of the barrier to gene flow and may indicate the presence of genetic incompatibilities. Clines in plumage traits and their associated SNPs suggest strong selection against some hybrid phenotypes, although loci with the strongest associations with plumage color traits do not exhibit the strongest barrier to gene flow.
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- 2024
10. Exploration of GPCRs with Conserved Expression in Murine and Human TILs
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Lee, Justin
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Biology ,Bioinformatics ,Oncology ,Cancer immunotherapy ,GPCR ,scRNA-seq - Abstract
G protein coupled receptors (GPCRs) are the largest family of integral membrane receptor proteins, responsible for mediating numerous signaling pathways that are vital to a wide range of biological processes. As a result, over a third of FDA-approved drugs target GPCRs to treat a variety of conditions. Additionally, dysfunctional GPCR and G protein signaling contributes to several disease states, including cancer. Previous studies have shown that dysregulation of Gαs-coupled protein receptors have an important role in the immunosuppressive properties of the tumor microenvironment (TME). Despite this, the function of GPCRs in the context of cancer immunotherapy remains largely underexplored. Here, we used a bioinformatics analysis pipeline to identify and analyze the immune cells present in the TME of 42 different mouse tumor samples. With this information, we found several GPCRs with conserved upregulation in mouse and human tumor samples. Of these GPCRs, several are targets of FDA-approved drugs, providing several potential targets for future cancer immunotherapeutic drugs.
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- 2024
11. Methods for Optimizing Mechanistic and Predictive Models of Human Disease
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Mester, Rachel
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Bioinformatics ,Applied mathematics ,Biology - Abstract
A major goal of the biomathematics discipline is to optimize mathematical models for biological processes. This optimization can take on various forms; finding the appropriate model that fits available data, allows for accurate inference, and is computationally feasible is no easy task and requires an understanding of both the biological processes at hand and the mathematics behind each potential model or algorithm. In this dissertation, I seek to understand how mathematical modeling choices affect our ability to understand human disease. I study infectious, cancerous, and polygenic disease from a variety of computational perspectives. First, I apply methods for differential sensitivity analysis in biological models for both cancerous and infectious disease spread. I compare prediction accuracy for existing first-order methods and propose a second-order method with enhanced flexibility both in terms of the model for which it is applied and the programming environment available. Second, I compare statistical approaches for uncovering genetics of complex disease in admixed populations, using likelihood ratio tests to understand how to incorporate local ancestry in genome wide association studies to achieve the highest power. Third, I utilize machine learning methods to reduce diagnostic delay for patients across the University of California Health system. I adapt a logistic regression model to find patients likely to have common variable immune deficiencies from one health system to five health systems. I also adapt this algorithm from the immunology realm to the cardiology realm to predict cardiac amyloidosis. Along the way, I use this context to study automated feature selection, longitudinal feature engineering, and observational bias in electronic health record data.
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- 2024
12. Integrative Precision Medicine Approach to Dissect Patient Heterogeneity in Systemic Lupus Erythematosus
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Cutts, Zachary
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Bioinformatics ,Biology ,Autoimmunity ,Retroviruses ,Systemic Lupus ,Transposable Elements - Abstract
Autoimmune disease arises from dysregulation of the immune system, leading to its attack on the body's own tissues and organs. The clinical heterogeneity of these diseases arises from several sources, such as genetic predisposition, environmental triggers, and aberrant immune responses. One emerging area of interest is the role of transposable elements (TEs) in autoimmune disease pathogenesis because these self-nucleic acids can be mistakenly detected as foreign, which can trigger a chronic immune reaction.There is growing appreciation for the role of TEs in systemic lupus erythematosus (SLE) and studies have found differentially expressed TEs in SLE patients, which suggests a link between TE activity and disease mechanisms. Our work investigated TE expression in four immune cell types from SLE patients, revealing cell-specific and SLE subphenotype-specific differentially expressed TEs, with additional cell-type-specific TE associations in different ancestry groups. TE expression was also associated with host gene expression involved in antiviral and immune responses, supporting the hypothesis that TEs could activate the innate immune system and contribute to chronic inflammation and autoimmunity.This study underscores the importance of TEs in SLE heterogeneity and highlights the need for further exploration of TE expression in normal immune cells and functional studies to understand their role in SLE pathogenesis. Future work to study whether antiretroviral drugs could reduce expression of TEs and mitigate SLE symptoms is warranted, given the potential involvement of TEs in autoimmune disease pathogenesis
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- 2024
13. Actionable Modeling: Elucidate Enzyme Interactions in Complex Biosynthesis Systems by Interpretable Models from Omics Data
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Liang, Chenguang
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Bioengineering ,Bioinformatics ,Biology ,Bioinformatics ,Cell Line Engineering ,Metabolic Engineering ,Omics ,Protein Engineering ,Systems Biology - Abstract
With advances in mass spectrometry, there is increasing demand for more effective and adaptive approaches to systematically extract biological insights from glycomic and lipidomic data. This thesis explores the application of Markov modeling in understanding two key cellular processes, N-glycosylation and lipid biosynthesis.In Chapter 2, we demonstrate that a Markov model of N-glycosylation network successfully captures intricate glycosyltransferase interactions by reproducing a set of glycoprofiles from glycoengineered CHO cells producing erythropoietin (EPO). We further validate the model parsimony and accuracy by predicting the glycoprofiles of other glycoengineered drugs from the trained models and their wildtype glycoprofiles. The results attest to the model’s ability to learn glycosyltranferase activities and substrate specificities. To increase the impact of this approach, we also develop GlycoMME to allow broader access to this modeling pipeline, presenting a promising direction for rational glycoengineering. Chapter 3 extends the modeling approach to lipid biosynthesis, introducing the Lipid Synthesis Investigative Markov Model (LipidSIM). As a low-parameter, biologically interpretable framework, LipidSIM proves powerful in leveraging the interdependency in lipidomic data and extracts and quantifies perturbations to lipid biosynthesis reactions, generating hypotheses directly testable by transcriptomic data. This method is showcased in 5 different scenarios with 3 different lipidomic datasets, and the results substantiate LipidSIM as a valuable tool for extracting insights from high-dimensional lipidomic data of different types. In Chapter 4, a Taguchi design is used to systematically characterize the impact of 15 media supplements on potential cellular phenotypes for CHO cells, especially N-glycosylation. The analytical pipeline allows disentangling the impact of individual supplements at different concentration levels with minimal numbers of experimental configurations. This approach answers the demand to find more flexible strategies for controlling N-glycosylation beyond genetic engineering. When applied in conjunction with the Taguchi design, our modeling framework has the potential to facilitate rapid customization of media for the growing market of glycoprotein drugs.This thesis encapsulates the innovative applications of probabilistic modeling in accounting for the biological dependency underlying omics data, offering insights into intricate cellular processes and motivating further exploration in actionable modeling of biological systems.
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- 2024
14. Expanding the applicability of gene set enrichment analysis with data-driven gene set refinement and adaptation for sparse data
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Wenzel, Alexander Thomas
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Bioinformatics ,Biology ,Medicine ,bioinformatics ,cancer genomics ,gene set enrichment analysis ,ovarian cancer - Abstract
The study of gene expression, the abundance of RNA transcripts in cells, has played a critical role in expanding knowledge of the molecular underpinnings of cancer and the ways in which treatments affect it. Because genes operate in interlinking pathways with nuanced and context-dependent behavior, deriving the phenotypic implication of changes in abundances of individual genes can be challenging. For this reason, Gene Set Enrichment Analysis (GSEA) was developed. GSEA is a statistical method that quantifies the activation of pathways or processes as represented by a priori annotated gene sets and plays a critical role in constructing pathway-level understandings of cell states in diseases such as cancer. In the use of GSEA and the expansion of its companion database of gene sets, the Molecular Signatures Database (MSigDB), two challenges have emerged. First, some gene sets lack the properties of context-specificity and coordinate regulation, that is, not all their members be collectively more expressed in samples that have a specific phenotype to which the gene set should correspond. Second, the new technologies for measuring gene expression at single cell resolution yield data with different properties than the “bulk” gene expression data for which GSEA was initially developed. I will address the first challenge in Chapter 1, in which I propose a data-driven method for gene set refinement and show that this method yields new gene sets that are both more coordinately regulated and context-specific. I address the second challenge in Chapter 2, in which I present a characterization of the performance of the single sample version of GSEA (ssGSEA) in multiple datasets and propose adaptations which I will show produce enrichment scores that are more stable and certain in the single cell context. Finally, Chapter 3 is an application of gene set based pathway characterization to the problem of understanding the development of chemoresistance in ovarian cancer. Using a cell cycle-aware approach incorporating single sample GSEA, we propose a new framework for modeling the development of resistance to carboplatin. These analyses together lay the groundwork for improving the robustness of GSEA results, adapting it to emerging technologies for gene expression measurement, and applying it to address key challenges in the treatment of cancer.
- Published
- 2024
15. Quantitative Development of Frequency Modulated Optogenetic Signaling
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Ho, Phuong T
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Bioengineering ,Bioinformatics ,Biology ,Cell Signaling ,Fluorescent Proteins ,Multiobjective Optimization ,Optogenetics ,Synthetic Biology ,Systems Biology - Abstract
Biomolecular signaling networks enable cells to decode signals from their environment into the appropriate responses needed for survival and maintaining biological function. Using principles derived from these systems, synthetic approaches such as optogenetics were developed to grant users with precise control over cellular activity. Nonetheless, it remains challenging to engineer synthetic signaling systems towards predefined dynamic behaviors. In this work, we present a quantitative framework that integrates multi-objective optimization, dynamic modeling, and biosensor imaging to streamline the design and implementation of synthetic signaling networks in cells. First, we formulated a general signaling model and applied an evolutionary algorithm to derive a network design capable of decoding two distinct frequency modulated stimuli into separate response channels. Based on this design, we implemented an optogenetic circuit to control protein interactions in cells according to the blue light input pattern. To aid this process, dimerization-dependent fluorescent proteins were used to characterize and select optogenetic components with the required dynamic characteristics. Lastly, we applied our frequency decoder system to regulate downstream biological outputs such as gene transcription, antigen presentation, and antigen triggered CAR-T killing in mice. This framework provides an integrative approach for developing synthetic signaling systems that reduces reliance on trial-and-error.
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- 2024
16. Genome-wide Association Study of serum Triglyceride to High-density Lipoprotein Ratio Reveals Novel Loci and Sex-dimorphic Genes for Insulin Resistance
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Zhu, Zhiyi
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Bioinformatics ,Biology ,GWAS ,High-density Lipoprotein ,insulin resistance ,Triglyceride - Abstract
Insulin resistance is implicated in multiple prevalent metabolic disorders, such as type 2 diabetes, cardiovascular disease, and fatty liver disease. While genome-wide association studies (GWAS) have been employed to identify genes associated with insulin resistance, the difficulty in measuring insulin resistance has led to limited sample sizes and reduced statistical power in previous GWAS studies. Conducting an expansive GWAS with a large sample size is essential to identify novel insulin resistance genes. The triglyceride to high-density lipoprotein ratio (TG/HDL) demonstrates a high correlation with insulin resistance phenotypes and is available in large cohorts, making it a potential surrogate marker for insulin resistance. Performing a GWAS of TG/HDL on 382,129 individuals in the UK Biobank, we identified 251 genomic risk loci, among which 62 displayed heightened significance compared to individual markers (TG or HDL), suggesting them as potential insulin resistance loci. We developed a systematic approach for the comprehensive analysis of these loci, prioritizing those that remain undiscovered and exhibit differential associations across different sexes. Through this analysis, we highlighted TNFAIP8, a gene involved in the regulation of apoptosis and immune responses, as a novel sex-dimorphic factor influencing insulin resistance. Our findings contribute to the genetic understanding of insulin resistance and identify potential sex-specific genes as therapeutic targets.
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- 2024
17. Genetic and Cellular Contributions to Liver Regeneration
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Yu Hsuan Lin, Hao Zhu, and Roger Liang
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Cirrhosis ,Liver tissue ,Regeneration (biology) ,Fatty liver ,medicine ,Context (language use) ,Disease ,Biology ,Liver cancer ,medicine.disease ,Bioinformatics ,General Biochemistry, Genetics and Molecular Biology ,Liver regeneration - Abstract
The regenerative capabilities of the liver represent a paradigm for understanding tissue repair in solid organs. Regeneration after partial hepatectomy in rodent models is well understood, while regeneration in the context of clinically relevant chronic injuries is less studied. Given the growing incidence of fatty liver disease, cirrhosis, and liver cancer, interest in liver regeneration is increasing. Here, we will review the principles, genetics, and cell biology underlying liver regeneration, as well as new approaches being used to study heterogeneity in liver tissue maintenance and repair.
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- 2024
18. Blockchain for Biomedical Research and Healthcare : Concept, Trends, and Future Implications
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Prasun Kumar, Aparna Kumari, Prasun Kumar, and Aparna Kumari
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- Biotechnology, Biology—Technique, Bioinformatics, Medicine—Research, Biology—Research, Biology
- Abstract
Blockchain is a new type of technology that combines and secures information exchange between different stakeholders such as medical practitioners, patients, healthcare providers, and other applicable parties. Among them, Blockchain Technology is one of the most important areas in the bioinformatics application of biomedical research and healthcare systems utilizing unique requirements and integration features. All the chapters are written by experts and researchers working in various areas of the biomedical and healthcare domain and they also dive into one of the most overlooked methodological, practical, and moral questions to secure and handle the enormous amount of data being generated from IoT-enabled biomedical and healthcare systems. In the beginning, this book presents an overview and then discusses open issues, challenges, and applicability aspect of Blockchain technology in healthcare. Then, this book presents a variety of perspectives on the most pressing questions in the field, for example: how IoT can connect billions of biomedical and healthcare information; how the blockchain-based secure access control mechanisms in biomedical and healthcare work; how to address the Quality-of-Service (QoS) and real-time accessibility requirements for healthcare applications; and how to ensure communication with efficiency. Also, it discusses Blockchain for IoT-enabled healthcare systems and presents a comparative analysis with respect to various performance evaluation metrics too.
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- 2024
19. Training Class: Bioinformatics and Biology Essentials for Librarians: Databases, Tools, and Clinical Applications, August 26-December 9, 2024.
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GENOMICS , *CONTINUING medical education , *BIOLOGY , *INTERNET , *BIOINFORMATICS , *PROFESSIONAL employee training , *PROTEOMICS , *LEARNING strategies , *MOLECULAR biology - Published
- 2024
20. Transcriptomic and Epigenetic Regulation of Fiber Cell Differentiation in Murine Ocular Lens
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Upreti, Anil
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- Bioinformatics, Biology, Cellular Biology, Molecular Biology, Lens, Explants, RNA-Seq, ATAC-seq, CUT&RUN, FGFRs, PDGFRs, PTEN, MicroRNA, miR26, FOXE3, Epigenetic
- Abstract
Lens epithelial explants serve as a valuable in vitro model for studying cellular processes related to lens development and differentiation. Despite significant research, key mechanisms underlying lens fiber cell differentiation and related signaling pathways remain unclear. This dissertation aims to address this gap by investigating the roles of key genes, transcription factors, and microRNAs in lens development and fiber cell differentiation through multiple studies involving RNA-sequencing, ATAC-sequencing, and other molecular biology techniques.Chapter 2 focuses on the influence of vitreous humor on lens epithelial explants, revealing that it increases chromatin accessibility and upregulates genes related to lens fiber cell differentiation while downregulating those associated with lens epithelial cells. The study's unbiased analysis indicated that RUNX, SOX, and TEAD transcription factors might drive these gene expression changes, providing a basis for further exploration.Chapter 3 investigates the role of Fgfrs and Pten in lens fiber cell differentiation and immune responses using RNA-sequencing on explants lacking Fgfrs, Pten, or both. The results show that the loss of Fgfr signaling impairs vitreous-induced fiber differentiation and immune responses, while the loss of Pten can partially rescue these effects. Gene set enrichment analysis suggested that PDGFR-signaling might mediate this rescue, which was confirmed with immunohistochemistry showing beta crystallin expression, indicating fiber cell differentiation.Chapter 4 explores the functional roles of specific microRNAs in lens development. A comprehensive analysis of miRNA transcripts revealed that the loss of miR-26 leads to postnatal cataracts and significant changes in gene expression, with abnormal increases in genes related to neural development, inflammation, and epithelial-to-mesenchymal transition. This demonstrates that miR-26 is crucial for normal lens development and cataract prevention.Chapter 5 examines mutations in FOXE3, a key transcription factor in the lens epithelium. Using CRISPR/Cas9 genome editing, the study generated three novel mutant alleles, uncovering varying degrees of lens-related abnormalities, including cataracts and anterior segment dysgenesis. RNA-seq analysis of homozygous mutants revealed a significant downregulation of genes associated with lens fiber cell differentiation and an upregulation of genes linked to neural and retinal differentiation.Together, these chapters highlight critical aspects of lens development and fiber cell differentiation, demonstrating the complex interplay between key signaling pathways, transcription factors, and microRNAs. The findings suggest future research directions, such as exploring the role of PDGFR in fiber cell differentiation and investigating chromatin architecture changes using ATAC-sequencing, to further understand the mechanisms driving lens development and differentiation.
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- 2024
21. SEARCH FOR GENETIC FACTORS UNDERLYING PROTECTION AGAINST OR RISK FOR COGNITIVE IMPAIRMENT IN THE MIDWESTERN AMISH
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Main, Leighanne Regina
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- Aging, Bioinformatics, Biology, Biostatistics, Genetics, Neurobiology, Cognitive preservation, cognitive resistance, cognitive resilience, genetics, Alzheimer Disease, founder population
- Abstract
Alzheimer disease (AD) affects more than 6 million individuals in the US, and accountsfor 60-80% of dementia cases. AD demonstrates mixed pathologies of amyloid beta andtau tangle accumulation, leading to symptoms such as cognitive impairment andmemory loss. Taking advantage of a closed, isolated population, the Midwestern Amish,variants both in protection against AD as well as risk for AD were explored. Thecomparative reduction in incidence of AD within the Amish versus a general Europeanpopulation led to the examination cognitive preservation, rather than AD, as thediagnosis of interest. A genome-wide association study (GWAS) was performed on theAmish to identify protective loci for AD via the GENESIS R Package. PC-AiR and PC-Relatewere used for principal component analysis to assist in correcting for the highly relatedsample. Linkage analyses across the entire genome, once again for cognitivepreservation, were used to supplement and corroborate GWAS findings. These analyseswere initially completed in MERLIN, but certain regions demonstrating repeated16significance were run through MORGAN, an MCMC linkage analysis software. Theseanalyses highlighted one region on chromosome 2p11.2-13.1 that demonstrated aprotective effect against AD. This region was previously associated with risk for AD inthe Midwestern Amish, potentially indicating both protective and risk variants withinthis locus. Further evaluations of genetic loci implicated in AD took advantage of thisunique sample population to examine a potential risk factor. The MGMT locus waspreviously associated with increased risk for AD in the Hutterites, who are anotherclosed, isolated population of European decent. In the Midwestern Amish, one SNP inthe MGMT locus was significantly associated with AD diagnosis. However, this SNP wasa novel result, distinct from those detected in a previous study and not in linkagedisequilibrium with previously associated MGMT SNPs for AD. We argue that this is anew association for the MGMT region, not previously detected, possibly indicatingpopulation-specific variants impacting AD risk. Given these findings, this Amish population demonstrates a unique opportunity for identifying new variants for bothprotection against and risk for AD, and merits continued investigation.
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- 2024
22. Understanding Viral Infection and Lifecycle with Single Cell Transcriptomics
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Jung, Kyle Lawrence
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- Bioinformatics, Biology, Molecular Biology, Virology, virus, viral infection, Severe Fever with Thrombocytopenia Syndrome Virus, Kaposi’s Sarcoma-Associated Herpesvirus, single cell RNA sequencing, air-liquid interface, epithelial differentation, viral reactivation
- Abstract
Understanding the viral infection and lifecycle of Severe Fever with Thrombocytopenia Syndrome Virus (SFTSV) and Kaposi’s Sarcoma-Associated Herpesvirus (KSHV) is important in improving disease outcomes and reducing viral prevalence. In our SFTSV study, we discovered specific cytokine profiles associated with the severity of clinical symptoms. We used single cell RNA sequencing (scRNAseq) on patient blood samples to identify a unique expansion of the B cell population in SFTSV-induced fatal cases which indicated that plasma B cells are a primary reservoir of SFSTV replication. These findings present a potential method of reducing the severity of SFTSV infection, especially in aged patients who are more susceptible to adverse outcomes.In our KSHV study, we developed a novel oral 3D infection model and demonstrated that KSHV can only infect exposed basal epithelial cells in the oral epithelia. We used scRNAseq to show that keratinocyte differentiation and cell death pathways were affected by KSHV infection, suggesting that epithelial differentiation could contribute to KSHV reactivation through changes in epigenetic regulation. In addition, we found a unique population of infected cells with limited early lytic gene expression and a unique gene expression profile, which we termed latent-2 cells. These findings demonstrate that our in vitro 3D epithelial ALI culture model should be a valuable tool to further understand oral KSHV infection for the development of future anti-viral therapeutics to block KSHV transmission.
- Published
- 2024
23. Gene Family Evolution of Digestive Enzymes in the American Pika: A Comparative Genomics Analysis
- Author
-
Raba, Teresa J.
- Subjects
- Biology, Bioinformatics, copy number evolution, gene duplication, computational biology, OrthoFinder
- Abstract
The American pika (Ochotona princeps) is an herbivorous mammal that inhabits rocky, mountainous regions across the western United States. Although they share a common ancestor with rabbits and other species in the order Lagomorpha, American pikas have a specialized diet due to an inability to migrate from their narrow habitat range. Gene families are made up of genes similar in sequence and function among species that share a common ancestor. Increases in gene copy number due to random duplication results in gene family expansion, whereas gene deletion results in family contraction. Evolutionary divergence can result in functional and genetic differences in the way that pikas and other lagomorphs digest their food with the help of enzymes. We hypothesized that American pikas have undergone lineage-specific expansions or contractions in gene families encoding enzymes (particularly digestive enzymes), allowing the species to digest available food in their narrow and changing habitat. Using the computational tool, OrthoFinder, protein sequences of the American pika were compared to seven distantly related taxa to identify gene families. CAFE5 analysis identified copy number evolution compared to the most recent common ancestor of all eight species. Functional enrichment analysis with PANTHER showed gene families related to digestive enzymes are significantly expanded in the American pika compared to other species. This indicates that protease digestive enzymes are more highly expressed in the American pika, possibly contributing to their metabolism of plants that inhabit their habitat.
- Published
- 2024
24. A Framework for The Study of Compound Interactions in L1000
- Author
-
Lyons, Nicholas
- Subjects
- Connectivity Map, Gene expression, L1000, synergy, Biology, Bioinformatics
- Abstract
Treatment combinations are used broadly in clinical settings and are used to treat a variety of diseases and disorders. Despite the potential power of combination therapies to improve the lives of more patients, the complete potential of the space remains untapped. High-throughput screening methods allow for many experiments to be conducted in parallel, often testing hundreds of thousands or millions of single compounds. These approaches also enable researchers to test large volumes of compound combinations, but profiling many compound combinations is extremely resource demanding. This need has motivated many studies to computationally predict synergistic combinations using inputs such as compound targets, implicated pathways, or single-treatment transcriptional responses. Though some of these models have been successful, they are often generated with datasets intended for other applications, leaving ample room for improvement. To our knowledge there is currently no systemic dataset of transcriptional response intended to investigate the mechanisms of compound synergy. A dataset of this type would allow for an improvement of synergy prediction from phenotypic readouts in terms of model validation as well as the development of entirely novel models that may be retroactively applied to currently existing datasets. The Connectivity Map, and its underlying assay, the L1000 gene expression assay, is a powerful resource for high throughput small molecule screening and hypothesis generation (Subramanian et al., 2017). Though the assay has been used to profile single compounds extensively, there has yet been no large-scale effort to generate data using compound combinations. The L1000 platform relies strongly on comparisons to previously generated reference signatures (in L1000 and in other experimental contexts) and there is currently insufficient combinatorial reference data. We hope to enable future researchers to make use of those reference data generated to interrogate novel combinations.to predict synergies in novel disease areas. To address these shortcomings in both the synergistic research space as well as the L1000 platform reference dataset, we developed a framework to combine a cell-viability readout with an L1000-based gene expression readout on a diverse set of compound combinations. This allows us to better understand the molecular mechanisms of combinations shown previously to synergistically kill cancer cells. We have also developed a pilot workflow to carefully calibrate future experiments conducted with compound combinations, as well as identified several potential pitfalls to be avoided by future researchers generating combinatorial data on the L1000 platform. These data may subsequently be used to predict additional synergistic combinations and serve as a dataset to inform future experiments to be conducted on L1000 and other high-throughput screening platforms.
- Published
- 2024
25. Identification and characterization of novel eukaryotic chaperones
- Author
-
Nelliat, Anjali Rebecca
- Subjects
- chaperones, eEF1A, protein folding, proteostasis, translation elongation factors, Biology, Bioinformatics, Biochemistry
- Abstract
Protein folding and assembly is aided by molecular chaperones that prevent aggregation of unfolded or partially folded intermediates and guide them to their native folded state. Chaperones engage clients through cycles of binding and release from aggregation-prone, non-native regions. ATP-dependent chaperones utilize ATP hydrolysis to drive chaperone conformational changes between low and high affinity states, while ATP-independent chaperones are regulated by diverse mechanisms. Zinc-finger protein 1 (Zpr1) is an essential ATP-independent chaperone dedicated to the biogenesis of eukaryotic translation elongation factor 1A (eEF1A), a highly abundant GTP-binding protein. How Zpr1-mediated folding is regulated to ensure rapid Zpr1 recycling remains an unanswered question. We identified the highly conserved altered inheritance of mitochondria 29 (Aim29) as an eEF1A biogenesis factor. Structural modeling using AlphaFold-Multimer suggested that Aim29 senses the GTP-bound conformation of eEF1A folding intermediates bound to Zpr1. We validated this prediction using yeast genetics, cell biological and biochemical reconstitution approaches, and uncovered that Aim29 sensing of GTP-bound eEF1A coupled to a GTP hydrolysis event facilitates eEF1A exit from the folding cycle and allows for Zpr1 recycling. Our work reveals that a bespoke ATP-independent chaperone system has mechanistic similarity to ATPase chaperones, but unexpectedly relies on client GTP hydrolysis to regulate the chaperone-client interaction. Next, we attempted to use AlphaFold-Multimer to identify additional chaperones or biogenesis factors that haven’t yet been uncovered. We optimized an Alphafold-based pipeline for screening a protein of interest against the entire yeast proteome to identify high-confidence interactors. The success of this screening approach is highlighted by two examples. First, we identified the previously uncharacterized but conserved eukaryotic protein Ypl225w as an eEF1A chaperone candidate and subsequent work by another graduate student in the lab revealed that Ypl225w was a ribosome-associating chaperone that mediates GTP-driven vectorial folding of nascent eEF1A. We also applied this pipeline to an essential eukaryotic GTPase of unknown function, Drosophila melanogaster Misato-Like protein (Dml1). The top interactors for Dml1 were subunits of the chaperonin-containing T-complex (CCT), which we validated experimentally. Acute depletion of Dml1 lead to a decrease in levels of assembled CCT and accumulation of monomers. This observation, along with structural modeling and other preliminary results suggest that Dml1 could be an assembly chaperone for CCT.
- Published
- 2024
26. Prediction of Long Non-Coding RNAs and Their Functions in Plant Immune Response
- Author
-
Li, Minghua
- Subjects
- Bioinformatics, Biology, lncRNA, machine learning, bioinformatics, XGBoost, OsRpp30, RNA-Seq, miRNA, mRNA, regulatory network, ceRNA network, plant immunity, rice
- Abstract
Long non-coding RNAs (lncRNAs) play critical roles in diverse biological processes. The extensive availability of public RNA-Seq data offers valuable resources for identifying novel lncRNAs. Here, we introduce LncDC (Long non-coding RNA detection), a machine learning-based tool designed to detect lncRNAs from RNA-Seq data. LncDC utilizes an XGBoost model incorporating features derived from primary sequences, secondary structures, and translated proteins to differentiate between lncRNAs and mRNAs. Notably, sequence and secondary structure k-mer score features, along with various open reading frame-related features, contribute to the classification of lncRNAs and mRNAs. Benchmarking experiments have shown that LncDC surpasses six state-of-the-art tools in several performance metrics. Applying LncDC to 180 RNA-Seq datasets from osteosarcoma patients led to the discovery of 97 novel osteosarcoma-specific lncRNAs. Additionally, the role of lncRNA in Oryza sativa RNase P protein 30 (OsRpp30)-mediated disease resistance in rice remains largely unexplored. OsRpp30 is known as a positive regulator of rice immunity against various pathogens. To further understand this mechanism, we conducted RNA-Seq and small RNA-Seq profiling of lncRNAs, miRNAs, and mRNAs in wild type, OsRpp30 overexpression, and OsRpp30 knockout rice plants. Our comprehensive transcriptome analysis identified 91 differentially expressed lncRNAs, 1671 differentially expressed mRNAs, and 41 differentially expressed miRNAs across these rice lines. We also explored interactions between differentially expressed lncRNAs and mRNAs, uncovering 10 trans- and 27 cis-targeting pairs specific to the OsRpp30 overexpression and knockout conditions. Furthermore, we constructed a competing endogenous RNA network comprising differentially expressed lncRNAs, miRNAs, and mRNAs to elucidate their interactions in rice immunity. Our findings reveal that lncRNAs participate in OsRpp30-mediated disease resistance in rice by regulating genes involved in pathogen recognition, hormone signaling pathways, transcription factor activation, and other critical biological processes related to plant immunity. Overall, the development of the LncDC bioinformatic tool, coupled with our comprehensive analysis of the interactions among lncRNAs, miRNAs, and mRNAs within the context of rice immunity, significantly advances our understanding of the complex roles and functional dynamics of lncRNAs.
- Published
- 2024
27. Engineering the Epigenetic Regulatory Networks of T Cell Exhaustion and Embryonic Stem Cell Differentiation with Transcription Factor Perturbations
- Author
-
Tay, Tristan
- Subjects
- ATAC-seq, Immuno-oncology, single-cell genomics, T cell exhaustion, Biology, Biochemistry, Bioinformatics
- Abstract
The complex interplay of epigenetic factors including chromatin remodeling, histone modifications, and transcription factor binding regulate gene expression and therefore give rise to the diversity of cells within the human body from a common genome. Transcription factors are master regulators of these gene programs and are an attractive lever to manipulate the 1000’s of regulatory elements at the end of a signal cascade with a single perturbation. Here, we screen transcription factor perturbations and characterize their ability to engineer epigenetic regulatory networks in the context of T cell exhaustion or embryonic stem cell differentiation. First, we develop a new in vitro model to study T cell exhaustion suitable for high-throughput screens. We use single-cell genomics to demonstrate our T cells recapitulate the exhaustion seen in human tumor infiltrating lymphocytes functionally, transcriptionally, and epigenetically. Second, we identify the transcription factor Ikaros as a regulator of T cell exhaustion with a CRISPR knockout screen. We determine that knockout of Ikaros is sufficient to prevent the establishment of exhaustion in our model and preserve effector function. We use the clinically approved Ikaros degrader iberdomide to phenocopy our knockout and characterize its genome-wide effects on the transcriptome and epigenome. Then, we determine its mechanism of action, demonstrating that Ikaros represses enhancers of key effector genes by recruiting nucleosomes and preventing the binding of the activation transcription factor families AP-1, NFAT, ETS, and NF-kB/REL. Third, we develop a new single-cell, multi-omic screening method termed Perturb SHARE-seq to enable high-throughput perturbations paired with rich readouts. We use this method both for CRISPR knockout screens in hematopoietic differentiation and transcription factor overexpression to guide differentiation of embryonic stem cells. Collectively, our results highlight the utility of transcription factor perturbations and necessity of single cell epigenomics for understanding and manipulating cell state. Our workflow can be generalized to map the epigenetic regulatory networks in a variety of biological contexts and perturb each network member to investigate its role in controlling gene regulation and cell state.
- Published
- 2024
28. Federal University Alagoas Researchers Report on Findings in Bioinformatics (Homeostatic status of thyroid hormones and brain water movement as determinant factors in biology of cerebral gliomas: a pilot study using a bioinformatics approach).
- Subjects
THYROID hormones ,HYDROCEPHALUS ,GLIOMAS ,RESEARCH personnel ,BIOLOGY ,BIOINFORMATICS - Abstract
Researchers from Federal University Alagoas in Brazil have conducted a pilot study using a bioinformatics approach to investigate the role of thyroid hormones and brain water movement in the biology of cerebral gliomas. The study found that aquaporins (AQPs), which are water channel transporters, are overexpressed in patients with glioma. The researchers also identified a correlation between the expression of genes involved in the tyrosine and thyroid hormone pathways and AQPs. These findings suggest that thyroid hormone pathways and AQPs 1 and 4 could be potential targets for new anti-tumor drugs and therapeutic biomarkers for malignant gliomas. [Extracted from the article]
- Published
- 2024
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