Proteoglycan 4 Modulates Osteogenic Smooth Muscle Cell Differentiation during Vascular Remodeling and Intimal Calcification

Asim Cengiz Akbulut, Moritz Lindquist Liljeqvist, Antti Siika, Hong Jin, Greg Winski, Rick H van Gorp, Eva Karlöf, Mariette Lengquist, Andrew J Buckler, Malin Kronqvist, Olivia J Waring, Jan H N Lindeman, Erik A L Biessen, Lars Maegdefessel, Anton Razuvaev, Leon J Schurgers, Ulf Hedin, Ljubica Matic

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Calcification is a prominent feature of late-stage atherosclerosis, but the mechanisms driving this process are unclear. Using a biobank of carotid endarterectomies, we recently showed that Proteoglycan 4 (PRG4) is a key molecular signature of calcified plaques, expressed in smooth muscle cell (SMC) rich regions. Here, we aimed to unravel the PRG4 role in vascular remodeling and intimal calcification. PRG4 expression in human carotid endarterectomies correlated with calcification assessed by preoperative computed tomographies. PRG4 localized to SMCs in early intimal thickening, while in advanced lesions it was found in the extracellular matrix, surrounding macro-calcifications. In experimental models, Prg4 was upregulated in SMCs from partially ligated ApoE-/- mice and rat carotid intimal hyperplasia, correlating with osteogenic markers and TGFb1. Furthermore, PRG4 was enriched in cells positive for chondrogenic marker SOX9 and around plaque calcifications in ApoE-/- mice on warfarin. In vitro, PRG4 was induced in SMCs by IFNg, TGFb1 and calcifying medium, while SMC markers were repressed under calcifying conditions. Silencing experiments showed that PRG4 expression was driven by transcription factors SMAD3 and SOX9. Functionally, the addition of recombinant human PRG4 increased ectopic SMC calcification, while arresting cell migration and proliferation. Mechanistically, it suppressed endogenous PRG4, SMAD3 and SOX9, and restored SMC markers' expression. PRG4 modulates SMC function and osteogenic phenotype during intimal remodeling and macro-calcification in response to TGFb1 signaling, SMAD3 and SOX9 activation. The effects of PRG4 on SMC phenotype and calcification suggest its role in atherosclerotic plaque stability, warranting further investigations.

Original languageEnglish
Article number1276
Number of pages26
JournalCells
Volume10
Issue number6
DOIs
Publication statusPublished - 21 May 2021

Keywords

  • ARTICULAR CHONDROCYTES
  • ATHEROSCLEROTIC LESIONS
  • BALLOON INJURY
  • CAROTID PLAQUE
  • COMPUTED-TOMOGRAPHY ANGIOGRAPHY
  • GENE-EXPRESSION
  • HISTOLOGICAL CLASSIFICATION
  • NATURAL-HISTORY
  • PHENOTYPIC MODULATION
  • Proteoglycan 4
  • ZONE PROTEIN SZP
  • atherosclerosis
  • calcification
  • extracellular matrix
  • smooth muscle cells
  • vascular remodeling

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