Genetic Deletion of FXR1 Reduces Intimal Hyperplasia and Induces Senescence in Vascular Smooth Muscle Cells

Cali B. Corbett, Amanda St Paul, Tani Leigh, Sheri E. Kelemen, Amanda M. Peluzzo, Rachael N. Okune, Satoru Eguchi, Dale S. Haines, Michael V. Autieri

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Vascular smooth muscle cells (VSMC) play a critical role in the development and pathogenesis of intimal hyperplasia indicative of restenosis and other vascular diseases. Fragile-X related protein-1 (FXR1) is a muscle-enhanced RNA binding protein whose expression is increased in injured arteries. Previous studies suggest that FXR1 negatively regulates inflammation, but its causality in vascular disease is unknown. In the current study, RNA-sequencing of FXR1-depleted VSMC identified many transcripts with decreased abundance, most of which were associated with proliferation and cell division. mRNA abundance and stability of a number of these transcripts were decreased in FXR1-depleted hVSMC, as was proliferation (P < 0.05); however, increases in beta-galactosidase (P < 0.05) and γH2AX (P < 0.01), indicative of senescence, were noted. Further analysis showed increased abundance of senescence-associated genes with FXR1 depletion. A novel SMC-specific conditional knockout mouse (FXR1SMC/SMC) was developed for further analysis. In a carotid artery ligation model of intimal hyperplasia, FXR1SMC/SMC mice had significantly reduced neointima formation (P < 0.001) after ligation, as well as increases in senescence drivers p16, p21, and p53 compared with several controls. These results suggest that in addition to destabilization of inflammatory transcripts, FXR1 stabilized cell cycle–related genes in VSMC, and absence of FXR1 led to induction of a senescent phenotype, supporting the hypothesis that FXR1 may mediate vascular disease by regulating stability of proliferative mRNA in VSMC.

Original languageEnglish
Pages (from-to)638-653
Number of pages16
JournalAmerican Journal of Pathology
Volume193
Issue number5
DOIs
StatePublished - May 2023

Keywords

  • Animals
  • Carotid Arteries/metabolism
  • Cell Proliferation
  • Cells, Cultured
  • Disease Models, Animal
  • Hyperplasia/pathology
  • Mice
  • Muscle, Smooth, Vascular/metabolism
  • Myocytes, Smooth Muscle/metabolism
  • Neointima/metabolism
  • RNA, Messenger/metabolism
  • Vascular Diseases/pathology

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