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Eres, I.

Publications and source records attributed to Eres, I..

4 recordsLinked to original sources

Basic-Leucine-Zipper Transcription Factors Regulate Selective Molecular Phenotypes in Regulatory T Cells During IL-2-Induced Activation

Regulatory T (Treg) cells have long been recognized as modulators of immunological tolerance and homeostasis. Previously, we used scRNA-seq to reveal significant Treg heterogeneity in response to IL-2-induced activation. Herein, we leveraged enrichment analyses, as well as bulk and single-nucleus multi-omics in splenic and lung Tregs, to uncover and confirm the importance of transcription factors (TFs) and chromatin remodeling in Treg activation. Multiple bZIP TF motifs showed increased chromatin accessibility post IL-2 treatment, with correlated transcriptional changes resembling Th1 and Th2 molecular phenotypes, further confirmed by spatial ATAC-seq. By combining gene perturbation and CUT&RUN assays before and after Treg stimulation, we show that bZIP TFs, such as BATF and BACH1, are critical to IL-2-induced Treg activation, coordinating epigenetic and transcriptional changes that selectively drive T-helper phenotypes and metabolic pathways.

genomics↗

Dissecting Regulatory Non-Coding Heart Disease GWAS Loci with High-Resolution 3D Chromatin Interactions Reveals Causal Genes with Pathophysiological Relevance to Heart Failure

Heart failure is caused in part by cardiac remodeling processes that include the death of cardiac myocytes and their replacement by cardiac fibroblasts. We hypothesized that these two cell types may harbor epigenetic contexts in which heart disease-associated non-coding SNPs perturb gene expression relevant to disease. Accordingly, we generated high-resolution Hi-C data layered with chromatin accessibility and transcriptomic information to annotate and link putative distal regulatory elements in heart disease-associated loci to gene promoters. Our analysis identified several target genes with established roles in cardiac fibrosis and/or heart disease (GJA1, TBC1D32, CXCL12, IL6R, and FURIN). Perturb-seq in cardiac fibroblasts to knock out putative regulatory elements confirmed regulatory relationships involving GJA1, CXCL12, and FURIN, as gene editing led to changes in transcriptomic signatures associated with fibroblasts in heart failure. Our results demonstrate how integrative multi-omic approaches can delineate pathophysiologically relevant regulatory circuits that connect protein-coding genes to non-coding genetic variants associated with disease.

genomics↗

The Role of the 3-Dimensional Genome in New Gene Evolution

Previous evolutionary models of duplicate gene evolution have overlooked the pivotal role of genome architecture. Here, we show that proximity-based regulatory recruitment of distally duplicated genes (enhancer capture) is an efficient mechanism for modulating tissue-specific production of pre-existing proteins. By leveraging genomic asymmetries in synteny and function that distinguish new genes evolving under enhancer capture-divergence (ECD) from those evolving under previous models, we performed a co-expression analysis on Drosophila melanogaster tissue data to show the generality of ECD as a significant evolutionary driver of asymmetric, distally duplicated genes. We use the recently evolved gene HP6/Umbrea, which duplicated <15 million years ago (mya), as an example of the ECD process. By assaying genome-wide chromosomal conformations in multiple Drosophila species, we show that HP6/Umbrea was inserted into a pre-existing, evolutionarily stable 3D genomic structure spanning over 125kb. We then utilize this data to identify a newly discovered enhancer (FLEE1), buried within the coding region of the highly conserved, essential gene MFS18, that likely neo-functionalized HP6/Umbrea, thereby driving the new duplicate gene copy to fixation. Finally, we demonstrate ancestral transcriptional co-regulation of HP6/Umbreas future insertion site using single-cell transcriptomics, illustrating how enhancer capture provides a highly evolvable, one-step solution to Ohnos Dilemma. The intuitive molecular mechanism underpinning the ECD model unveils a novel and robust framework to understand the fixation and neofunctionalization of distally duplicated genes.

evolutionary biology↗

A comparison of gene expression and DNA methylation patterns across tissues and species

Previously published comparative functional genomic data sets from primates using frozen tissue samples, including many data sets from our own group, were collected and analyzed using non-optimal study designs and analysis approaches. In addition, when samples from multiple tissues were studied in a comparative framework, individual and tissue were confounded. We designed a multi-tissue comparative study of gene expression and DNA methylation in primates that minimizes confounding effects by using a balanced design with respect to species, tissues, and individuals. We also developed a comparative analysis pipeline that minimizes biases due to sequence divergence. We thus present the most comprehensive catalog of similarities and differences in gene expression and methylation levels between livers, kidneys, hearts, and lungs, in humans, chimpanzees, and rhesus macaques. We estimate that overall, only between 7 to 11% (depending on the tissue) of inter-species differences in gene expression levels can be accounted for by corresponding differences in promoter DNA methylation. However, gene expression divergence in conserved tissue-specific genes can be explained by corresponding inter-species methylation changes more often. We end the paper by providing recommendations for effective study design and best practices for meta-data recording for comparative functional genomic studies in primates.

genomics↗