Search bioRxiv⌕ Search

Biology subjects

Ergun, A.

Publications and source records attributed to Ergun, A..

5 recordsLinked to original sources

Mapping the Transcriptional Landscape of Drug Responses in Primary Human Cells Using High-Throughput DRUG-seq

To advance our understanding of drug action in physiologically-relevant systems, we developed a high-throughput transcriptomic atlas of compound responses in primary human cell types. Leveraging the scalable and cost-effective Digital RNA with the pertUrbation of Genes (DRUG-seq) assay, we profiled gene expression responses to 89 pharmacologically-active compounds across six concentrations in four distinct primary cell types: aortic smooth muscle cells (AoSMCs), skeletal muscle myoblasts (SkMMs), dermal fibroblasts, and melanocytes. Through rigorous quality control and normalization, we generated reproducible and cell type-resolved transcriptomic signatures, enabling the discovery of both shared and divergent regulatory programs. This dataset revealed core cellular responses, such as brefeldin A-mediated ER stress across all cell types, as well as lineage-specific effects, including dexamethasone-induced hypoxia signaling in AoSMCs, complex inflammatory responses linked to epithelial-to-mesenchymal transition pathways in SkMMs, TGF-{beta}-modulated states in fibroblasts, and dabrafenib-driven transcriptional shifts towards quiescence in melanocytes. By integrating systematic perturbations with primary models, this dataset serves as a resource for building systems-level models of drug response and mechanism. Ultimately, we aim to accelerate predictive pharmacology by enabling high-throughput data generation grounded in human biology and readily usable by artificial intelligence models.

systems biology↗

Fbxl10/Kdm2b is required for Kmt2b/Mll2 binding across thegenome and regulates H3K4 methylation on bivalent promoters

The presence of histone modifications associated with both transcriptional repression (H3K27me3) and activation (H3K4me3) on key developmental promoters in embryonic stem cells results from the co-localization of repressive Polycomb group (PcG) and activating Trithorax group (TrxG) protein complexes. Functional interactions between PcG and TrxG on these promoters are not fully understood. Here we focus on the relationships between Fbxl10/Kdm2b, a component of a PcG complex PRC1, and Kmt2b/Mll2, an essential component of TrxG at bivalent promoters. Computational analysis of previously published data revealed genome-wide correlation between chromatin occupancies of these two proteins, suggesting potential crosstalk between Kdm2b and Mll2 at both active and repressed promoters. We tested this hypothesis experimentally and found that loss of Kdm2b resulted in depletion of Mll2 at promoters genome-wide, suggesting that Kdm2b is required for Mll2 occupancy at both bivalent and active promoters. Loss of Kdm2b or the core PRC1 component Ring1b also resulted in the reduction of H3K4me3 specifically at bivalent promoters. These findings provide a direct pathway for cooperation between PcG and TrxG at bivalent promoters, suggesting an unexpected modification to the current model of bivalency. In addition, these findings reveal genome-wide role of Kdm2b independent of the full PRC1 complex.

molecular biology↗

Pipeline to detect the relationship between transposable elements and adjacent genes in host genome

AO_SCPLOWBSTRACTC_SCPLOWUnderstanding the relationship between transposable elements (TEs) and their closest positional genes in the host genome is a key point to explore their potential role in genome evolution. Transposable elements can regulate and affect gene expression not only because of their mobility within the genome but also because of their transcriptional activity. A comprehensive knowledge of structural organization between transposable elements and neighboring genes is important to study TE functional role in gene regulation. We implemented a pipeline to display the relationship between the distribution of TEs and adjacent genes in host genomes. Our tool is freely available here: https://github.com/marieBvr/TEs_genes_relationship_pipeline.

bioinformatics↗

Deconvolving the contributions of cell-type heterogeneity on cortical gene expression

Complexity of cell-type composition has created much skepticism surrounding the interpretation of brain bulk-tissue transcriptomic studies. We generated paired tissue genome-wide gene expression data and immunohistochemistry data, enabling us to assess statistical methods for modeling and estimating cellular heterogeneity in the brain. We demonstrate that several algorithms that rely on single-cell and cell-sorted data to define cell marker gene sets yield accurate relative and absolute estimates of constituent cell-type proportions.

neuroscience↗

Meta-analysis of the human brain transcriptome identifies heterogeneity across human AD coexpression modules robust to sample collection and methodological approach

Alzheimers disease (AD) is a complex and heterogenous brain disease that affects multiple inter-related biological processes. This complexity contributes, in part, to existing difficulties in the identification of successful disease-modifying therapeutic strategies. To address this, systems approaches are being used to characterize AD-related disruption in molecular state. To evaluate the consistency across these molecular models, a consensus atlas of the human brain transcriptome was developed through coexpression meta-analysis across the AMP-AD consortium. Consensus analysis was performed across five coexpression methods used to analyze RNA-seq data collected from 2114 samples across 7 brain regions and 3 research studies. From this analysis, five consensus clusters were identified that described the major sources of AD-related alterations in transcriptional state that were consistent across studies, methods, and samples. AD genetic associations, previously studied AD-related biological processes, and AD targets under active investigation were enriched in only three of these five clusters. The remaining two clusters demonstrated strong heterogeneity between males and females in AD-related expression that was consistently observed across studies. AD transcriptional modules identified by systems analysis of individual AMP-AD teams were all represented in one of these five consensus clusters except ROS/MAP-identified Module 109, which was specific for genes that showed the strongest association with changes in AD-related gene expression across consensus clusters. The other two AMP-AD transcriptional analyses reported modules that were enriched in one of the two sex-specific Consensus Clusters. The fifth cluster has not been previously identified and was enriched for genes related to proteostasis. This study provides an atlas to map across biological inquiries of AD with the goal of supporting an expansion in AD target discovery efforts.

systems biology↗