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

• Published in: American journal of physiology. Heart and circulatory physiology Vol. 59; no. 2; p. H525
• Main Authors: Zheng, Jingang, Chin, Andrew, Duignan, Inga, Kyung-Heon Won
• Format: Journal Article
• Language: English
• Published: Bethesda American Physiological Society 01.02.2006
• Subjects: Aging; Comparative analysis; Drug therapy; Heart attacks; Medical treatment; Rodents; Signal transduction
• ISSN: 0363-6135; 1522-1539

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 ABSTRACT]