Single-cell RNA sequencing reveals the induction of novel myeloid and myeloid-associated cell populations in visceral fat with long-term obesity

FASEB J. 2021 Mar;35(3):e21417. doi: 10.1096/fj.202001970R.


Macrophages and other immune cells are important contributors to obesity-associated inflammation; however, the cellular identities of these specific populations remain unknown. In this study, we identified individual populations of myeloid cells found in mouse epididymal/visceral adipose tissue by single-cell RNA sequencing, immunofluorescence, and flow cytometry. Multiple canonical correlation analysis identified 11 unique myeloid and myeloid-associate cell populations. In obese mice, we detected an increased percentage of monocyte-derived pro-inflammatory cells expressing Cd9 and Trem2, as well as significantly decreased percentages of multiple cell populations, including tissue-resident cells expressing Lyve1, Mafb, and Mrc1. We have identified and validated a novel myeloid/macrophage population defined by Ly6a expression, exhibiting both myeloid and mesenchymal characteristics, which increased with obesity and showed high pro-fibrotic characteristics in vitro. Our mouse adipose tissue myeloid cell atlas provides an important resource to investigate obesity-associated inflammation and fibrosis.

Keywords: adipokine; canonical correlation analysis; collagen; fibrotic; metabolic syndrome; scRNA-seq.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / metabolism
  • Animals
  • Inflammation / metabolism
  • Intra-Abdominal Fat / metabolism*
  • Macrophages / metabolism
  • Male
  • Membrane Glycoproteins
  • Mice
  • Mice, Inbred C57BL
  • Monocytes / metabolism
  • Myeloid Cells / metabolism*
  • Obesity / metabolism*
  • Receptors, Immunologic
  • Sequence Analysis, RNA*


  • Membrane Glycoproteins
  • Receptors, Immunologic
  • Trem2 protein, mouse