Preconditioning attenuates apoptosis and necrosis: Role of protein kinase Cε and -δ isoforms

Huiping Liu, Bradley C. McPherson, Zhenhai Yao*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

72 Scopus citations

Abstract

Preconditioning reduces cardiomyocyte necrosis in vivo and in vitro, but it is unknown whether preconditioning blocks apoptosis. We wanted to compare the effects of preconditioning on necrosis and apoptosis in cardiomyocytes. Necrosis was detected with propidium iodide, and apoptosis was quantified by three complementary techniques: flow cytometry, TdT-mediated dUTP nick-end labeling assay, and DNA-laddering electrophoresis. Apoptosis increased with simulated ischemia time (6 h, 19 ± 1%; 12 h, 27 ± 2%; 18 h, 40 ± 4%; 24 h, 54 ± 4%; and 36 h, 83 ± 4%; n = 6 for each group). Simulated ischemia and reoxygenation contributed equally to apoptosis (12-h ischemia, 27 ± 2%, n = 6; 12-h ischemia and 12-h reoxygenation, 51 ± 4%, n = 6; and 24-h ischemia, 54 ± 5%, n = 8). Necrosis occurred primarily during reoxygenation; none was detected during simulated ischemia. Preconditioning with 10 min of simulated ischemia reduced necrosis (18 ± 6%, n = 8) but had no effect on apoptosis. However, three 1-min cycles of simulated ischemia separated by 5 min of reoxygenation reduced necrosis and apoptosis similarly. The protein kinase C (PKC) inhibitors Go6976 (0.1 μM) or chelerythrene (4 μM) abolished the effect of preconditioning. Preconditioning selectively activated PKCε but had no effect on PKCδ and on total PKC enzyme activity. Preconditioning protected against necrosis and apoptosis, but the preconditioning ischemia required for blocking apoptosis was less than that for reducing necrosis. Activation of PKCε isoform is important in mediating the protection.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume281
Issue number1 50-1
StatePublished - Oct 10 2001

Keywords

  • Cultured cardiomyocytes
  • Hypoxia

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

Fingerprint Dive into the research topics of 'Preconditioning attenuates apoptosis and necrosis: Role of protein kinase Cε and -δ isoforms'. Together they form a unique fingerprint.

Cite this