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Improved Rodent Model of Myocardial Ischemia and Reperfusion Injury
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Improved Rodent Model of Myocardial Ischemia and Reperfusion Injury

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Cardioprotective effects of transforming growth factor-beta1 during early reoxygenation or reperfusion are mediated

G F Baxter1, M M Mocanu, B K Brar

  • 1The Hatter Institute, University College, Grafton Way, London WC1E 6DB, U.K. hatter-institute@ucl.ac.uk

Journal of Cardiovascular Pharmacology
|November 15, 2001
PubMed

Insights

Transforming growth factor-beta1 (TGF-beta1) reduces heart cell death during reperfusion injury. This protection against apoptosis and infarct size is mediated by p42/p44 mitogen-activated protein kinase (MAPK) signaling.

Area of Science:

  • Cardiovascular Biology
  • Cellular Signaling
  • Molecular Medicine

Background:

  • Myocardial ischemia-reperfusion injury involves significant apoptosis, or programmed cell death.
  • Growth factors can promote cell survival and counteract apoptosis.
  • Transforming growth factor-beta1 (TGF-beta1) is a key growth factor implicated in cellular responses.

Purpose of the Study:

  • To investigate the protective effects of TGF-beta1 against reperfusion-induced apoptosis in cardiac myocytes.
  • To determine the role of p42/p44 mitogen-activated protein kinase (MAPK) signaling in TGF-beta1's protective mechanism.

Main Methods:

  • Rat ventricular myocytes were subjected to hypoxia and reoxygenation.
  • Apoptosis was quantified using TUNEL and annexin V assays.
  • Intact rat hearts underwent regional ischemia and reperfusion, with TGF-beta1 administration during reperfusion.
  • The p42/p44 MAPK pathway was inhibited using PD98059.

Main Results:

  • TGF-beta1 significantly attenuated cell membrane damage and reduced apoptosis in myocytes during reoxygenation.
  • The anti-apoptotic effect of TGF-beta1 was blocked by the p42/p44 MAPK inhibitor PD98059.
  • In intact hearts, TGF-beta1 administration during reperfusion markedly reduced infarct size.
  • The infarct-limiting effect of TGF-beta1 was abolished by PD98059, indicating MAPK pathway involvement.

Conclusions:

  • TGF-beta1 effectively mitigates cardiac myocyte apoptosis during early reperfusion.
  • TGF-beta1 limits infarct size in a model of myocardial ischemia-reperfusion injury.
  • The protective mechanisms of TGF-beta1 against cardiac reperfusion injury are dependent on the activation of the p42/p44 MAPK signaling pathway.

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