Tumor necrosis factor triggers the expression and activation of matrix metalloproteinases through NADPH-dependent superoxide production

• Author / Creator

  Awad, Ahmed

• Tumor necrosis factor (TNF) is upregulated in a number of cardiomyopathies. This thesis investigates TNF in triggering the expression and activation of matrix metalloproteinases (MMPs) in pressure overload cardiac disease, and explores the role of superoxide.
  
  Cardiac pressure overload was generated in adult wild-type and TNF-/- mice by transverse aortic constriction. Isolated cardiomyocytes and cardiofibroblasts from neonatal mice ventricles were treated with recombinant TNF (rTNF), and MMP induction and activation were assessed, with and without apocynin (a NADPH-oxidase inhibitor).
  TNF-/- mice showed less superoxide production and MMP activation, compared to wild-type mice, following pressure overload. rTNF upregulated the production of NADPH-dependent superoxide in cardiomyocytes as early as 1 hour (24 hours in cardiofibroblasts). rTNF also increased the expression of MMP-9 and MMP-12 in cardiomyocytes more than in cardiofibroblasts, and MMP-8 and MMP-13 more in cardiofibroblasts. This induction in both cardiac cell types was concomitant with superoxide production.

• Subjects / Keywords

  • Matrix metalloproteinases
  • Reactive nitrogen species
  • Reactive oxygen species
  • Tumor necrosis factor
  • Neonatal cardiomyocytes and cardiofibroblasts isolation
  • Pressure overload cardiac disease

• Graduation date

  Spring 2010

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R31M1R

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.