Reduction of PGRN increased fibrosis during skin wound healing in mice

Histol Histopathol. 2019 Jul;34(7):765-774. doi: 10.14670/HH-18-076. Epub 2018 Dec 18.

Abstract

Progranulin (PGRN) is a multi-functional growth factor known to be involved in regulating of development, cell cycle progression, cell motility, tumorigenesis and angiogenesis. Research has revealed that PGRN is a crucial mediator of skin wound healing. Nonetheless, the role of PGRN in the fibrosis process of cutaneous wound healing has not been identified. In the present study, mice with excisional wounds were treated with si-m-PGRN or physiological saline. We observed the expression of PGRN in intact and post-injury skin by immunohistochemistry. Tissue sections of skin around the wound were performed by hematoxylin & eosin and masson's trichrome staining. After PGRN knockdown by siRNA, the expression of PGRN, collagen I (Col I), small mothers against decapentaplegic homolog 3 (Smad3), phosphorylated Smad3 (P-Smad3), transforming growth factor (TGF)-β1 and TGF-β receptor I (TβRI) were detected by real-time reverse transcription polymerase chain reaction (RT-qPCR) or Western blot. PGRN mRNA and protein expressions were increased after insult and remained above that of intact skin through day 20. Down-regulation of PGRN augmented fibrosis area, skin thickness and the expression of Col I. In addition, reduction of PGRN considerably increased the expression of TGF-β1, TβRI, Smad3 and P-Smad3. These results indicate that PGRN knockdown enhances the fibrosis degree, probably via the TGF-β/Smad signaling pathway.

MeSH terms

  • Animals
  • Collagen Type I / metabolism
  • Fibrosis
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Progranulins / genetics
  • Progranulins / metabolism*
  • Receptor, Transforming Growth Factor-beta Type I / metabolism
  • Signal Transduction
  • Skin / metabolism*
  • Skin / pathology
  • Skin / physiopathology
  • Smad3 Protein / metabolism
  • Time Factors
  • Transforming Growth Factor beta1 / metabolism
  • Wound Healing* / genetics

Substances

  • Collagen Type I
  • Progranulins
  • SMAD3 protein, human
  • Smad3 Protein
  • TGFB1 protein, human
  • Transforming Growth Factor beta1
  • Receptor, Transforming Growth Factor-beta Type I