Senescent dermal fibroblasts negatively influence fibroblast extracellular matrix-related gene expression partly via secretion of complement factor D

Biofactors. 2019 Jul;45(4):556-562. doi: 10.1002/biof.1512. Epub 2019 Apr 26.

Abstract

Aging is associated with a decrease of extracellular matrix and an increase of senescent cells in the dermal layer. Here, to examine whether and how senescent cells are involved in aging-related deterioration of the dermal layer, we cocultured dermal young fibroblasts (low-passage number) with senescent cells (high-passage number) in Transwells, in which the two cell types are separated by a semipermeable membrane. Young fibroblasts in coculture showed decreased collagen type I alpha 1 chain and elastin gene expression, and increased matrix metalloproteinase 1 (MMP1) gene expression. To identify causative factors, we compared gene expression of young and senescent cells and selected candidate secretory factors whose expression was increased by ≥2.5 in senescent fibroblasts. Then, we used siRNAs to knock down each of the 11 candidate genes in senescent fibroblasts in the coculture system. Knockdown of complement factor D (CFD) in senescent fibroblasts significantly reduced the increase of MMP1 in the cocultured young fibroblasts. In monocultures, treatment of young fibroblasts with CFD resulted in increased MMP1 gene expression, while knockdown of CFD in senescent fibroblasts decreased MMP1 gene expression. In addition, production of CFD was increased in culture medium of untreated senescent fibroblasts. Furthermore, CFD gene and protein expression were increased in the dermal layer of skin specimens from aged subjects (>70 years old), compared to young subjects (<20 years old). Overall, these results suggest that senescent cells negatively influence matrix production and promote degradation of nearby fibroblasts in the dermal layer, in part through secretion of CFD.

Keywords: CFD; MMP1; SASP; fibroblast; senescence.

MeSH terms

  • Cell Proliferation
  • Cellular Senescence / drug effects
  • Coculture Techniques
  • Collagen Type I / genetics
  • Collagen Type I / metabolism
  • Collagen Type I, alpha 1 Chain
  • Complement Factor D / antagonists & inhibitors
  • Complement Factor D / genetics
  • Complement Factor D / metabolism
  • Complement Factor D / pharmacology
  • Diffusion Chambers, Culture
  • Elastin / genetics
  • Elastin / metabolism
  • Extracellular Matrix / chemistry
  • Extracellular Matrix / drug effects
  • Extracellular Matrix / metabolism*
  • Fibroblasts / cytology
  • Fibroblasts / drug effects
  • Fibroblasts / metabolism*
  • Gene Expression Regulation
  • Humans
  • Matrix Metalloproteinase 1 / genetics*
  • Matrix Metalloproteinase 1 / metabolism
  • Primary Cell Culture
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • Signal Transduction

Substances

  • COL1A1 protein, human
  • Collagen Type I
  • Collagen Type I, alpha 1 Chain
  • RNA, Small Interfering
  • Elastin
  • CFD protein, human
  • Complement Factor D
  • MMP1 protein, human
  • Matrix Metalloproteinase 1