PDGF-BB Promotes Type I IFN-Dependent Vascular Alterations and Monocyte Recruitment in a Model of Dermal Fibrosis

PLoS One. 2016 Sep 12;11(9):e0162758. doi: 10.1371/journal.pone.0162758. eCollection 2016.

Abstract

Systemic sclerosis (SSc) is a chronic autoimmune disorder that can result in extensive tissue damage in the skin and, in advanced cases, internal organs. Vasculopathy, aberrant immune activation, and tissue fibrosis are three hallmarks of the disease that have been identified, with vasculopathy and aberrant immunity being amongst the earliest events. However, a mechanistic link between these processes has not been established. Here, we have identified a novel role of platelet derived growth factor-BB (PDGF-BB)/PDGFRβ activation in combination with dermal injury induced by bleomycin as a driver of early, aberrant expression of interferon stimulatory genes (ISGs) and inflammatory monocyte infiltration. Activation of PDGFRβ in combination with bleomycin-induced dermal injury resulted in increased dermal thickness, vascular density, monocyte/macrophage infiltration, and exacerbation of tissue injury. Many of these features were dependent on IFNAR-signaling, and an increase in the number of interferon-beta (IFN-β) producing monocytes cells was found in the skin lesions. Taken together, these results identify a novel link between PDGFRβ activation, and Type I IFN-driven vascular maintenance and monocyte/macrophage cell recruitment, and provide a potential explanation linking key features of SSc that were previously thought to be unrelated.

MeSH terms

  • Animals
  • Becaplermin
  • Bleomycin / pharmacology
  • Blood Vessels / pathology*
  • Disease Models, Animal*
  • Fibrosis
  • Interferon Type I / physiology*
  • Mice
  • Mice, Inbred C57BL
  • Monocytes / pathology*
  • Proto-Oncogene Proteins c-sis / physiology*
  • Receptor, Platelet-Derived Growth Factor beta / metabolism
  • Scleroderma, Systemic / pathology*
  • Skin Diseases / pathology*

Substances

  • Interferon Type I
  • Proto-Oncogene Proteins c-sis
  • Bleomycin
  • Becaplermin
  • Receptor, Platelet-Derived Growth Factor beta

Grants and funding

This study was funded by Biogen. The funder provided support in the form of salaries for authors [JC, TF, TR, DS, SH, and LB], but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.