STAT-3 activation is necessary for ischemic preconditioning in hypertrophied myocardium

Karyn L. Butler, Lynn C. Huffman, Sheryl E. Koch, Harvey S. Hahn, Judith K. Gwathmey

Research output: Contribution to journalArticle

31 Scopus citations

Abstract

The JAK-STAT pathway is activated in the early and late phases of ischemic preconditioning (IPC) in normal myocardium. The role of this pathway and the efficacy of IPC in hypertrophied hearts remain largely unknown. We hypothesized that phosphorylated STAT-3 (pSTAT-3) is necessary for effective IPC in pressure-overload hypertrophy. Male Sprague-Dawley rats 8 wk after thoracic aortic constriction (TAC) or sham operation underwent echocardiography and Langendorff perfusion. Randomized hearts were subjected to 30 min of global ischemia and 120 min of reperfusion with or without IPC in the presence or absence of the JAK-2 inhibitor AG-490 (AG). Functional recovery and STAT activation were assessed. TAC rats had a 31% increase in left ventricular mass (1,347 ± 58 vs. 1,028 ± 43 mg, TAC vs. sham, P < 0.001), increased anterior and posterior wall thickness but no difference in ejection fraction compared with sham-operated rats. In TAC, IPC improved end-reperfusion maximum first derivative of developed pressure (+dP/dtmax; 4,648 ± 309 vs. 2,737 ± 343 mmHg/s, IPC vs. non-IPC, P < 0.05) and minimum -dP/dt (-dP/dtmin; -2,239 ± 205 vs. -1,215 ± 149 mmHg/s, IPC vs. non-IPC, P < 0.05). IPC increased nuclear pSTAT-1 and pSTAT-3 in sham-operated rats but only pSTAT-3 in TAC. AG in TAC significantly attenuated +dP/dtmax (4,648 ± 309 vs. 3,241 ± 420 mmHg/s, IPC vs. IPC + AG, P < 0.05) and -dP/dtmin (-2,239 ± 205 vs. -1,323 ± 85 mmHg/s, IPC vs. IPC + AG, P < 0.05) and decreased only nuclear pSTAT-3. In myocardial hypertrophy, JAK-STAT signaling is important in IPC and exhibits a pattern of STAT activation distinct from nonhypertrophied myocardium. Limiting STAT-3 activation attenuates the efficacy of IPC in hypertrophy.

Original languageEnglish (US)
Pages (from-to)H797-H803
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume291
Issue number2
DOIs
StatePublished - Aug 10 2006

Keywords

  • Cardiac preconditioning
  • Ischemia-reperfusion
  • Janus-activated kinase
  • Myocardial hypertrophy
  • Signal transducer and activator of transcription

ASJC Scopus subject areas

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

Fingerprint Dive into the research topics of 'STAT-3 activation is necessary for ischemic preconditioning in hypertrophied myocardium'. Together they form a unique fingerprint.

  • Cite this