High-glucose environment enhanced oxidative stress and increased interleukin-8 secretion from keratinocytes: new insights into impaired diabetic wound healing

Diabetes. 2013 Jul;62(7):2530-8. doi: 10.2337/db12-1714. Epub 2013 Feb 19.

Abstract

Impaired wound healing frequently occurs in patients with diabetes. Interleukin (IL)-8 production by keratinocyte is responsible for recruiting neutrophils during healing. Intense inflammation is associated with diabetic wounds, while reduction of neutrophil infiltration is associated with enhanced healing. We hypothesized that increased neutrophil recruitment by keratinocytes may contribute to the delayed healing of diabetic wounds. Using cultured human keratinocytes and a diabetic rat model, the current study shows that a high-glucose environment enhanced IL-8 production via epidermal growth factor receptor (EGFR)-extracellular signal-regulated kinase (ERK) pathway in a reactive oxygen species (ROS)-dependent manner in keratinocytes. In addition, diabetic rat skin showed enhanced EGFR, ERK, and IL-8 expression compared with control rats. The dermal neutrophil infiltration of the wound, as represented by expression of myeloperoxidase level, was also significantly higher in diabetic rats. Treating diabetic rats with dapsone, an agent known to inhibit neutrophil function, was associated with improved healing. In conclusion, IL-8 production and neutrophil infiltration are increased in a high-glucose environment due to elevated ROS level and contributed to impaired wound healing in diabetic skin. Targeting these dysfunctions may present novel therapeutic approaches.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Diabetes Mellitus, Experimental / metabolism*
  • ErbB Receptors / metabolism
  • Glucose / pharmacology*
  • Humans
  • Interleukin-8 / metabolism*
  • Keratinocytes / drug effects
  • Keratinocytes / metabolism*
  • Oxidative Stress / drug effects
  • Oxidative Stress / physiology*
  • Rats
  • Reactive Oxygen Species / metabolism
  • Signal Transduction / drug effects
  • Signal Transduction / physiology
  • Skin / drug effects
  • Skin / metabolism*
  • Wound Healing / drug effects
  • Wound Healing / physiology*

Substances

  • Interleukin-8
  • Reactive Oxygen Species
  • ErbB Receptors
  • Glucose