Gene therapy of endothelial nitric oxide synthase and manganese superoxide dismutase restores delayed wound healing in type 1 diabetic mice

Circulation. 2004 Oct 19;110(16):2484-93. doi: 10.1161/01.CIR.0000137969.87365.05. Epub 2004 Jul 19.

Abstract

Background: Nitric oxide (NO) deficiency contributes to diabetic wound healing impairment. The present study tested the hypothesis that increased cutaneous superoxide (O2-) levels in type 1 diabetic mice cause NO deficiency and delayed wound healing.

Methods and results: Wound healing was markedly delayed in streptozotocin-induced type 1 diabetic mice compared with the normal controls. There were significantly reduced levels of endothelial NO synthase (eNOS) protein and constitutive NOS activity in diabetic wounds, whereas O2- levels were markedly increased. A single regimen of cutaneous gene therapy of eNOS or manganese superoxide dismutase (MnSOD) restored such healing delay, with a concomitant suppression of wound O2- levels and augmentation of both eNOS protein and constitutive NOS activity. Gene therapy of MnSOD also increased cutaneous MnSOD activity. Cutaneous O2- levels were also increased in Ins2(Akita) diabetic mice. In vitro glucose treatment of cutaneous tissues from normal mice for 24 hours increased O2- levels in a concentration-dependent manner. The enhanced cutaneous O2- levels induced by high glucose in both normal and diabetic mice were abolished by the NADPH oxidase inhibitor apocynin and the protein kinase C inhibitor chelerythrine. Furthermore, ex vivo gene transfer of dominant-negative HA-tagged N17Rac1, which inhibits NADPH oxidase subunit Rac1, significantly inhibited cutaneous O2- formation induced by high glucose in both normal and Ins2(Akita) diabetic mice.

Conclusions: These results indicate that hyperglycemia augments cutaneous O2- levels, at least in part, via NADPH oxidase and protein kinase C pathways, resulting in impaired wound healing in type 1 diabetic mice. Gene therapy strategies aimed at restoring cutaneous NO bioavailability may provide an effective means to ameliorate delayed diabetic wound healing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetophenones / pharmacology
  • Adenoviridae / genetics
  • Alkaloids
  • Animals
  • Benzophenanthridines
  • Biological Availability
  • Diabetes Mellitus, Experimental / complications
  • Diabetes Mellitus, Experimental / physiopathology
  • Diabetes Mellitus, Experimental / therapy*
  • Enzyme Induction
  • Genetic Therapy*
  • Genetic Vectors / therapeutic use*
  • Glucose / pharmacology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • NADPH Oxidases / antagonists & inhibitors
  • NADPH Oxidases / physiology*
  • Nitric Oxide / deficiency
  • Nitric Oxide / physiology*
  • Nitric Oxide Synthase / biosynthesis
  • Nitric Oxide Synthase / genetics
  • Nitric Oxide Synthase / physiology*
  • Nitric Oxide Synthase Type II
  • Nitric Oxide Synthase Type III
  • Nitrites / analysis
  • Oxidative Stress
  • Phenanthridines / pharmacology
  • Protein Kinase C / antagonists & inhibitors
  • Protein Kinase C / physiology*
  • Recombinant Fusion Proteins / physiology
  • Signal Transduction
  • Skin / chemistry
  • Skin / injuries
  • Superoxide Dismutase / genetics
  • Superoxide Dismutase / physiology*
  • Superoxides / metabolism
  • Wound Healing / physiology*
  • rac1 GTP-Binding Protein / antagonists & inhibitors
  • rac1 GTP-Binding Protein / physiology

Substances

  • Acetophenones
  • Alkaloids
  • Benzophenanthridines
  • Nitrites
  • Phenanthridines
  • Recombinant Fusion Proteins
  • Superoxides
  • Nitric Oxide
  • acetovanillone
  • chelerythrine
  • Nitric Oxide Synthase
  • Nitric Oxide Synthase Type II
  • Nitric Oxide Synthase Type III
  • Nos3 protein, mouse
  • Superoxide Dismutase
  • NADPH Oxidases
  • Protein Kinase C
  • Rac1 protein, rat
  • rac1 GTP-Binding Protein
  • Glucose