Myeloid progenitor dysregulation fuels immunosuppressive macrophages in tumours.

Monocyte-derived macrophages (mo-macs) often drive immunosuppression in the tumour microenvironment (TME) and tumour-enhanced myelopoiesis in the bone marrow fuels these populations. Here we performed paired transcriptome and chromatin accessibility analysis over the continuum of myeloid progenitors, circulating monocytes and tumour-infiltrating mo-macs in mice and in patients with lung cancer to identify myeloid progenitor programs that fuel pro-tumorigenic mo-macs. We show that lung tumours prime accessibility for Nfe2l2 (NRF2) in bone marrow myeloid progenitors as a cytoprotective response to oxidative stress, enhancing myelopoiesis while dampening interferon response and promoting immunosuppression.

Adrenergic signaling coordinates distant and local responses to amputation in axolotl.

Many species regenerate lost body parts following amputation. Most limb regeneration research has focused on the immediate injury site. Meanwhile, body-wide injury responses remain largely unexplored but may be critical for regeneration.

The Somatic Mosaicism across Human Tissues Network.

From fertilization onwards, the cells of the human body acquire variations in their DNA sequence, known as somatic mutations. These postzygotic mutations arise from intrinsic errors in DNA replication and repair, as well as from exposure to mutagens. Somatic mutations have been implicated in some diseases, but a fundamental understanding of the frequency, type and patterns of mutations across healthy human tissues has been limited.

Expansion in situ genome sequencing links nuclear abnormalities to aberrant chromatin regulation.

Microscopy and genomics are used to characterize cell function, but approaches to connect the two types of information are lacking, particularly at subnuclear resolution. Here, we describe expansion in situ genome sequencing (ExIGS), a technology that enables sequencing of genomic DNA and super-resolution localization of nuclear proteins in single cells. Applying ExIGS to progeria-derived fibroblasts revealed that lamin abnormalities are linked to hotspots of aberrant chromatin regulation that may erode cell identity.

HBO1 functions as an epigenetic barrier to hepatocyte plasticity and reprogramming during liver injury.

Hepatocytes can reprogram into biliary epithelial cells (BECs) during liver injury, but the underlying epigenetic mechanisms remain poorly understood. Here, we define the chromatin dynamics of this process using single-cell ATAC-seq and identify YAP/TEAD activation as a key driver of chromatin remodeling. An in vivo CRISPR screen highlights the histone acetyltransferase HBO1 as a critical barrier to reprogramming.

Unified molecular approach for spatial epigenome, transcriptome, and cell lineages.

Spatial epigenomics and multiomics can provide fine-grained insights into cellular states but their widespread adoption is limited by the requirement for bespoke slides and capture chemistries for each data modality. Here, we present SPatial assay for Accessible chromatin, Cell lineages, and gene Expression with sequencing (SPACE-seq), a method that utilizes polyadenine-tailed epigenomic libraries to enable facile spatial multiomics using standard whole transcriptome reagents. Applying SPACE-seq to a human glioblastoma specimen, we reveal the state of the tumor microenvironment, extrachromosomal DNA copy numbers, and identify putative mitochondrial DNA variants.

Clonal memory of colitis accumulates and promotes tumor growth.

Chronic inflammation is a well-established risk factor for cancer, but the underlying molecular mechanisms remain unclear. Using a mouse model of colitis, we demonstrate that colonic stem cells retain an epigenetic memory of inflammation following disease resolution, characterized by a cumulative gain of activator protein 1 (AP-1) transcription factor activity. Further, we develop SHARE-TRACE, a method that enables simultaneous profiling of gene expression, chromatin accessibility and clonal history in single cells, enabling high resolution tracking of epigenomic memory.

Refining the cis-regulatory grammar learned by sequence-to-activity models by increasing model resolution.

Chromatin accessibility can be measured genome-wide with ATAC-seq, enabling the discovery of regulatory regions that control gene expression and determine cell type. Deep genomic sequence-to-function (S2F) models link underlying genomic sequences to the measured chromatin state and identify motifs that regulate chromatin accessibility. Previously, we developed AI-TAC, a S2F model that predicts chromatin accessibility across 81 immune cell types and identifies sequence patterns that control their differential ATAC-seq signals.

Multi-locus CRISPRi targeting with a single truncated guide RNA.

A critical goal in functional genomics is evaluating which non-coding elements contribute to gene expression, cellular function, and disease. Functional characterization remains a challenge due to the abundance and complexity of candidate elements. Here, we develop a CRISPRi-based approach for multi-locus screening of putative transcription factor binding sites with a single truncated guide.

Multiscale footprints reveal the organization of cis-regulatory elements.

Cis-regulatory elements (CREs) control gene expression and are dynamic in their structure and function, reflecting changes in the composition of diverse effector proteins over time. However, methods for measuring the organization of effector proteins at CREs across the genome are limited, hampering efforts to connect CRE structure to their function in cell fate and disease. Here we developed PRINT, a computational method that identifies footprints of DNA-protein interactions from bulk and single-cell chromatin accessibility data across multiple scales of protein size.

scooby: Modeling multi-modal genomic profiles from DNA sequence at single-cell resolution.

Understanding how regulatory DNA elements shape gene expression across individual cells is a fundamental challenge in genomics. Joint RNA-seq and epigenomic profiling provides opportunities to build unifying models of gene regulation capturing sequence determinants across steps of gene expression. However, current models, developed primarily for bulk omics data, fail to capture the cellular heterogeneity and dynamic processes revealed by single-cell multi-modal technologies.

BACH2 regulates diversification of regulatory and proinflammatory chromatin states in T17 cells.

Interleukin-17 (IL-17)-producing helper T (T17) cells are heterogenous and consist of nonpathogenic T17 (npT17) cells that contribute to tissue homeostasis and pathogenic T17 (pT17) cells that mediate tissue inflammation. Here, we characterize regulatory pathways underlying T17 heterogeneity and discover substantial differences in the chromatin landscape of npT17 and pT17 cells both in vitro and in vivo. Compared to other CD4 T cell subsets, npT17 cells share accessible chromatin configurations with regulatory T cells, whereas pT17 cells exhibit features of both npT17 cells and type 1 helper T (T1) cells.

Cell of origin epigenetic priming determines susceptibility to Tet2 mutation.

Hematopoietic stem cell (HSC) mutations can result in clonal hematopoiesis (CH) with heterogeneous clinical outcomes. Here, we investigate how the cell state preceding Tet2 mutation impacts the pre-malignant phenotype. Using an inducible system for clonal analysis of myeloid progenitors, we find that the epigenetic features of clones at similar differentiation status are highly heterogeneous and functionally respond differently to Tet2 mutation.

Epigenetic memory of coronavirus infection in innate immune cells and their progenitors.

Inflammation can trigger lasting phenotypes in immune and non-immune cells. Whether and how human infections and associated inflammation can form innate immune memory in hematopoietic stem and progenitor cells (HSPC) has remained unclear. We found that circulating HSPC, enriched from peripheral blood, captured the diversity of bone marrow HSPC, enabling investigation of their epigenomic reprogramming following coronavirus disease 2019 (COVID-19).

Systematic benchmarking of single-cell ATAC-sequencing protocols.

Single-cell assay for transposase-accessible chromatin by sequencing (scATAC-seq) has emerged as a powerful tool for dissecting regulatory landscapes and cellular heterogeneity. However, an exploration of systemic biases among scATAC-seq technologies has remained absent. In this study, we benchmark the performance of eight scATAC-seq methods across 47 experiments using human peripheral blood mononuclear cells (PBMCs) as a reference sample and develop PUMATAC, a universal preprocessing pipeline, to handle the various sequencing data formats.

Positional influence on cellular transcriptional identity revealed through spatially segmented single-cell transcriptomics.

Single-cell RNA sequencing (scRNA-seq) is a powerful technique for describing cell states. Identifying the spatial arrangement of these states in tissues remains challenging, with the existing methods requiring niche methodologies and expertise. Here, we describe segmentation by exogenous perfusion (SEEP), a rapid and integrated method to link surface proximity and environment accessibility to transcriptional identity within three-dimensional (3D) disease models.

Photoselective sequencing: microscopically guided genomic measurements with subcellular resolution.

In biological systems, spatial organization and function are interconnected. Here we present photoselective sequencing, a new method for genomic and epigenomic profiling within morphologically distinct regions. Starting with an intact biological specimen, photoselective sequencing uses targeted illumination to selectively unblock a photocaged fragment library, restricting the sequencing-based readout to microscopically identified spatial regions.

Single-cell multi-scale footprinting reveals the modular organization of DNA regulatory elements.

-regulatory elements control gene expression and are dynamic in their structure, reflecting changes to the composition of diverse effector proteins over time. Here we sought to connect the structural changes at regulatory elements to alterations in cellular fate and function. To do this we developed PRINT, a computational method that uses deep learning to correct sequence bias in chromatin accessibility data and identifies multi-scale footprints of DNA-protein interactions.