DNA glycosylase Neil3 regulates vascular smooth muscle cell biology during atherosclerosis development

Atherosclerosis. 2021 May;324:123-132. doi: 10.1016/j.atherosclerosis.2021.02.023. Epub 2021 Feb 23.

Abstract

Background and aims: Atherogenesis involves a complex interaction between immune cells and lipids, processes greatly influenced by the vascular smooth muscle cell (VSMC) phenotype. The DNA glycosylase NEIL3 has previously been shown to have a role in atherogenesis, though whether this is due to its ability to repair DNA damage or to other non-canonical functions is not yet clear. Hereby, we investigate the role of NEIL3 in atherogenesis, specifically in VSMC phenotypic modulation, which is critical in plaque formation and stability.

Methods: Chow diet-fed atherosclerosis-prone Apoe-/- mice deficient in Neil3, and NEIL3-abrogated human primary aortic VSMCs were characterized by qPCR, and immunohistochemical and enzymatic-based assays; moreover, single-cell RNA sequencing, mRNA sequencing, and proteomics were used to map the molecular effects of Neil3/NEIL3 deficiency in the aortic VSMC phenotype. Furthermore, BrdU-based proliferation assays and Western blot were performed to elucidate the involvement of the Akt signaling pathway in the transdifferentiation of aortic VSMCs lacking Neil3/NEIL3.

Results: We show that Neil3 deficiency increases atherosclerotic plaque development without affecting systemic lipids. This observation was associated with a shift in VSMC phenotype towards a proliferating, lipid-accumulating and secretory macrophage-like cell phenotype, without changes in DNA damage. VSMC transdifferentiation in Neil3-deficient mice encompassed increased activity of the Akt signaling pathway, supported by cell experiments showing Akt-dependent proliferation in NEIL3-abrogated human primary aortic VSMCs.

Conclusions: Our findings show that Neil3 deficiency promotes atherosclerosis development through non-canonical mechanisms affecting VSMC phenotype involving activation of the Akt signaling pathway.

Keywords: Akt signaling; Atherosclerosis; DNA damage repair; NEIL3; Phenotypic transdifferentiation; Vascular smooth muscle cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Atherosclerosis* / genetics
  • Cell Proliferation
  • Cells, Cultured
  • DNA Glycosylases* / genetics
  • Endodeoxyribonucleases
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout, ApoE
  • Muscle, Smooth, Vascular / cytology
  • Myocytes, Smooth Muscle / enzymology*
  • N-Glycosyl Hydrolases
  • Phenotype
  • Plaque, Atherosclerotic*

Substances

  • Endodeoxyribonucleases
  • NEIL3 protein, mouse
  • DNA Glycosylases
  • N-Glycosyl Hydrolases
  • NEIL3 protein, human