Smooth muscle-derived progenitor cell myofibroblast differentiation through KLF4 downregulation promotes arterial remodeling and fibrosis

JCI Insight. 2020 Dec 3;5(23):e139445. doi: 10.1172/jci.insight.139445.

Abstract

Resident vascular adventitial SCA1+ progenitor (AdvSca1) cells are essential in vascular development and injury. However, the heterogeneity of AdvSca1 cells presents a unique challenge in understanding signaling pathways orchestrating their behavior in homeostasis and injury responses. Using smooth muscle cell (SMC) lineage-tracing models, we identified a subpopulation of AdvSca1 cells (AdvSca1-SM) originating from mature SMCs that undergo reprogramming in situ and exhibit a multipotent phenotype. Here we employed lineage tracing and RNA-sequencing to define the signaling pathways regulating SMC-to-AdvSca1-SM cell reprogramming and AdvSca1-SM progenitor cell phenotype. Unbiased hierarchical clustering revealed that genes related to hedgehog/WNT/beta-catenin signaling were significantly enriched in AdvSca1-SM cells, emphasizing the importance of this signaling axis in the reprogramming event. Leveraging AdvSca1-SM-specific expression of GLI-Kruppel family member GLI1 (Gli1), we generated Gli1-CreERT2-ROSA26-YFP reporter mice to selectively track AdvSca1-SM cells. We demonstrated that physiologically relevant vascular injury or AdvSca1-SM cell-specific Kruppel-like factor 4 (Klf4) depletion facilitated the proliferation and differentiation of AdvSca1-SM cells to a profibrotic myofibroblast phenotype rather than macrophages. Surprisingly, AdvSca1-SM cells selectively contributed to adventitial remodeling and fibrosis but little to neointima formation. Together, these findings strongly support therapeutics aimed at preserving the AdvSca1-SM cell phenotype as a viable antifibrotic approach.

Keywords: Adult stem cells; Fibrosis; Stem cells; Vascular Biology.

Publication types

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

MeSH terms

  • Animals
  • Arteries / metabolism
  • Cell Differentiation / genetics
  • Female
  • Fibrosis / genetics
  • Fibrosis / metabolism
  • Humans
  • Kruppel-Like Factor 4
  • Kruppel-Like Transcription Factors / genetics
  • Kruppel-Like Transcription Factors / metabolism*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Muscle, Smooth, Vascular / cytology
  • Myocytes, Smooth Muscle / metabolism
  • Myofibroblasts / metabolism
  • Stem Cells / metabolism
  • Vascular Remodeling / genetics*
  • Vascular Remodeling / physiology
  • Wnt Signaling Pathway

Substances

  • KLF4 protein, human
  • Klf4 protein, mouse
  • Kruppel-Like Factor 4
  • Kruppel-Like Transcription Factors