Tompkins, J. | bioRxiv Science

bioRxiv2026

Epigenome Alterations and 3D Chromatin Architecture Remodeling in Inflammatory Macrophage Activation under Diabetic Conditions

Aberrant monocyte/macrophage activation in diabetes drives chronic inflammation and complications. While epigenetic mechanisms are implicated, the role of 3D-chromatin reorganization remains unclear. Using integrated multi-Omics, we profiled gene expression and 3D-chromatin architecture in human CD14+ monocyte-differentiated macrophages treated with high glucose + TNF- (HT) mimicking the diabetic milieu. HT induced inflammatory programs resembling those in diabetes, and dynamically altered chromatin accessibility, enhancer-promoter loops, transcriptionally active/inactive (A/B) compartments, and topologically associated domains. Inflammatory genes exhibited increased, whereas cell-cycle and metabolic genes showed reduced chromatin accessibility and enhancer-promoter interactions. These architectural changes facilitated the convergence of lineage-specific and signal-dependent transcription factors at enhancer-promoter loops, forming network hubs orchestrating pro-inflammatory responses. Similar enhancer-promoter interactions were observed in monocytes from individuals with diabetes. Perturbing chromatin interactions via CRISPR-interference targeting HT-induced enhancers suppressed inflammatory gene expression. Results from this first comprehensive enhancer connectome maps in macrophages under diabetic conditions reveal disease-associated rewiring of the 3D epigenome, highlighting epigenetic mechanisms as potential therapeutic targets. TeaserDiabetic conditions rewire 3D chromatin organization and enhancer-promoter interactions in human macrophages, promoting chronic inflammation.

genomics↗

bioRxiv2023

Tiered Sympathetic Control of Cardiac Function Revealed by Viral Tracing and Single Cell Transcriptome Profiling

The cell bodies of postganglionic sympathetic neurons innervating the heart primarily reside in the stellate ganglion (SG), alongside neurons innervating other organs and tissues. Whether cardiac-innervating stellate ganglionic neurons (SGNs) exhibit diversity and distinction from those innervating other tissues is not known. To identify and resolve the transcriptomic profiles of SGNs innervating the heart we leveraged retrograde tracing techniques using adeno-associated virus (AAV) expressing fluorescent proteins (GFP or Td-tomato) with single cell RNA sequencing. We investigated electrophysiologic, morphologic, and physiologic roles for subsets of cardiac-specific neurons and found that three of five adrenergic SGN subtypes innervate the heart. These three subtypes stratify into two subpopulations; high (NA1a) and low (NA1b and NA1c) Npy-expressing cells, exhibit distinct morphological, neurochemical, and electrophysiologic characteristics. In physiologic studies in transgenic mouse models modulating NPY signaling, we identified differential control of cardiac responses by these two subpopulations to high and low stress states. These findings provide novel insights into the unique properties of neurons responsible for cardiac sympathetic regulation, with implications for novel strategies to target specific neuronal subtypes for sympathetic blockade in cardiac disease.

neuroscience↗