Growth factor-mediated reversal of senescent dysfunction of ischemia-induced cardioprotection

Am J Physiol Heart Circ Physiol. 2006 Feb;290(2):H525-30. doi: 10.1152/ajpheart.00470.2005. Epub 2005 Sep 23.

Abstract

Based on the role of tumor necrosis factor-alpha (TNF-alpha) in ischemic preconditioning (IPC) and the age-associated loss of both TNF-alpha-induced platelet-derived growth factor-AB (PDGF-AB)-mediated cardioprotection and IPC-mediated cardioprotection, we hypothesized that targeting of PDGF-AB-based pathways would restore cardioprotection by IPC in the aging heart. To study this, IPC was induced in 4- and 24-mo-old F344 rats. Sections of young hearts isolated 1 day post-IPC revealed increased TNF-alpha compared with controls. In old rats, TNF-alpha was higher at baseline than IPC young rats and was not significantly altered after IPC. Treatment of old rats with PDGF-AB with vascular endothelial growth factor and angiopoietin-2 (a combination termed PVA), but not PDGF-AB alone, at the time of IPC decreased TNF-alpha. In addition, when compared with young hearts, IPC induced greater apoptosis in the old hearts, which was decreased with PVA treatment but was markedly increased with PDGF-AB. To test the significance of these findings, additional rats underwent permanent coronary ligation 1 day post-IPC. IPC was cardioprotective in young rats [14 days postmyocardial infarction (MI), fractional shortening 29 +/- 6% vs. control MI 17 +/- 4%, P < 0.05; Masson's trichrome stain MI size: 13 +/- 2% vs. control MI 17 +/- 4% left ventricular area (LVA); P < 0.05]. In old rats, however, IPC reduced the post-MI 14-day survival (33% vs. controls 67%; P < 0.05). Treatment of IPC-aging rats with PVA, but not PDGF-AB-alone, reversed IPC-induced mortality (PVA-IPC-MI survival, 88%; PDGF-AB-IPC-MI, 14%) and reduced myocardial injury (fractional shortening: PVA-IPC, 31 +/- 1% vs. control MI, 21 +/- 6%, P < 0.05; MI size: PVA-IPC, 12 +/- 2% vs. control MI, 18 +/- 3% LVA, P < 0.05) and thus demonstrated that PDGF-AB-based pathways can reverse the senescent impairment in IPC-mediated cardioprotection.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging*
  • Angiopoietin-2 / pharmacology
  • Animals
  • Apoptosis Regulatory Proteins / metabolism
  • Cardiotonic Agents / pharmacology*
  • Drug Combinations
  • Echocardiography, Transesophageal
  • Heart / drug effects*
  • Heart / physiopathology*
  • Ischemic Preconditioning, Myocardial*
  • Myocardial Infarction / diagnostic imaging
  • Myocardial Infarction / pathology
  • Myocardial Infarction / physiopathology
  • Myocardium / metabolism
  • Platelet-Derived Growth Factor / pharmacology*
  • Rats
  • Rats, Inbred F344
  • Survival Analysis
  • Tumor Necrosis Factor-alpha / metabolism
  • Vascular Endothelial Growth Factor A / pharmacology

Substances

  • Angiopoietin-2
  • Apoptosis Regulatory Proteins
  • Cardiotonic Agents
  • Drug Combinations
  • Platelet-Derived Growth Factor
  • Tumor Necrosis Factor-alpha
  • Vascular Endothelial Growth Factor A
  • platelet-derived growth factor AB