The hydrogen-peroxide producing NADPH oxidase 4 does not limit neointima development after vascular injury in mice

Redox Biol. 2021 Sep;45:102050. doi: 10.1016/j.redox.2021.102050. Epub 2021 Jun 18.

Abstract

Objective: The NADPH oxidase Nox4 is an important source of H2O2. Nox4-derived H2O2 limits vascular inflammation and promotes smooth muscle differentiation. On this basis, the role of Nox4 for restenosis development was determined in the mouse carotid artery injury model.

Methods and results: Genetic deletion of Nox4 by a tamoxifen-activated Cre-Lox-system did not impact on neointima formation in the carotid artery wire injury model. To understand this unexpected finding, time-resolved single-cell RNA-sequencing (scRNAseq) from injured carotid arteries of control mice and massive-analysis-of-cDNA-ends (MACE)-RNAseq from the neointima harvested by laser capture microdissection of control and Nox4 knockout mice was performed. This revealed that resting smooth muscle cells (SMCs) and fibroblasts exhibit high Nox4 expression, but that the proliferating de-differentiated SMCs, which give rise to the neointima, have low Nox4 expression. In line with this, the first weeks after injury, gene expression was unchanged between the carotid artery neointimas of control and Nox4 knockout mice.

Conclusion: Upon vascular injury, Nox4 expression is transiently lost in the cells which comprise the neointima. NADPH oxidase 4 therefore does not interfere with restenosis development after wire-induced vascular injury.

Keywords: Carotid injury; Inflammation; NADPH oxidase; Nox4; Reactive oxygen species; Restenosis; Single-cell RNA sequencing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Hydrogen Peroxide
  • Mice
  • Mice, Knockout
  • Myocytes, Smooth Muscle
  • NADPH Oxidase 4* / genetics
  • Neointima*
  • Vascular System Injuries*

Substances

  • Hydrogen Peroxide
  • NADPH Oxidase 4
  • Nox4 protein, mouse