Atmospheric oxygen accelerates the induction of a post-mitotic phenotype in human dermal fibroblasts: the key protective role of glutathione

Differentiation. 2000 Oct;66(2-3):147-55. doi: 10.1046/j.1432-0436.2000.660209.x.

Abstract

It has been proposed that ageing of human dermal fibroblasts occurs as a multi-stage process during which cells progress from a mitotic to a post-mitotic state. We describe the development of a simple and novel cell-cloning model for identifying and quantifying the different fibroblast morphotypes associated with the induction of post mitotic behaviour. We have found that under atmospheric (20%) oxygen tension a significant proportion of human dermal fibroblasts are rapidly induced to switch from a mitotic to a post-mitotic phenotype. In contrast, under more physiological (4%) oxygen conditions, the induction of a post-mitotic phenotype is largely prevented. Increasing oxidative stress by addition of hydrogen peroxide or depletion of glutathione also induced a switch from a mitotic to a post-mitotic phenotype in these cells, whereas addition of the anti-oxidant N-acetylcysteine under atmospheric (20%) oxygen tension potently inhibited this process. In addition, a statistically significant correlation was observed between the magnitude of intracellular glutathione depletion and the reduction in the population of mitotic cells in this model. We propose that the switch from a mitotic to a post-mitotic phenotype represents a process of cellular ageing and that standard atmospheric oxygen tension imposes a substantial oxidative stress on dermal fibroblasts which accelerates this process in culture. The data also suggest that intracellular glutathione levels strongly influence the induction of a post-mitotic phenotype and that, by implication, depletion of glutathione may play a significant role in the progression of cellular ageing in human skin.

MeSH terms

  • Acetylcysteine / pharmacology
  • Antioxidants / pharmacology
  • Buthionine Sulfoximine / pharmacology
  • Cell Differentiation
  • Cells, Cultured
  • Clone Cells
  • DNA / analysis
  • Fibroblasts / cytology
  • Fibroblasts / drug effects
  • Fibroblasts / physiology
  • Glutathione / metabolism*
  • Humans
  • Hydrogen Peroxide / pharmacology
  • Infant, Newborn
  • Male
  • Mitosis
  • Oxidative Stress / physiology*
  • Oxygen / pharmacology*
  • Phenotype
  • Skin / cytology*
  • Skin / drug effects
  • Skin Physiological Phenomena / drug effects*

Substances

  • Antioxidants
  • Buthionine Sulfoximine
  • DNA
  • Hydrogen Peroxide
  • Glutathione
  • Oxygen
  • Acetylcysteine