Cell-type-specific transposon demethylation and TAD remodeling in aging mouse brain

Cell. 2026 Apr 2;189(7):2148-2166.e27. doi: 10.1016/j.cell.2026.02.015. Epub 2026 Mar 11.

Abstract

Aging is a major risk factor for neurodegenerative diseases, yet the underlying epigenetic mechanisms remain unclear. Here, we generated a comprehensive single-nucleus cell atlas of brain aging across multiple brain regions, comprising 132,551 single-cell methylomes and 72,666 joint chromatin conformation-methylome nuclei. Integration with companion transcriptomic and chromatin accessibility data yielded a cross-modality taxonomy of 36 major cell types. We observed that transposable element (TE) methylation alone distinguished age groups, showing cell-type-specific genome-wide demethylation. Chromatin conformation analysis demonstrated age-related increases in topologically associated domain (TAD) boundary strength with enhanced accessibility at CCCTC-binding factor (CTCF) binding sites. Spatial transcriptomics across 895,296 cells revealed regional heterogeneity during aging within identical cell types. Finally, we developed deep-learning models that reliably predict age-related gene expression changes using multi-modal epigenetic features, providing mechanistic insights into gene regulation. Age-related comparisons use a 2-month baseline reflecting the late-adolescent/early-young adult stage. This dataset advances our understanding of brain aging and offers potential translational applications.

Keywords: 3D genome; DNA methylation; brain aging; deep learning; multi-omic; neurons and glias; single-cell; spatial transcriptome; topologically associating domains; transposable elements.

MeSH terms

  • Aging* / genetics
  • Animals
  • Brain* / metabolism
  • Chromatin / metabolism
  • Chromatin Assembly and Disassembly*
  • DNA Methylation / genetics
  • DNA Transposable Elements* / genetics
  • Demethylation
  • Epigenesis, Genetic
  • Female
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Single-Cell Analysis
  • Transcriptome / genetics

Substances

  • DNA Transposable Elements
  • Chromatin