Targeted inhibition of activin receptor-like kinase 5 signaling attenuates cardiac dysfunction following myocardial infarction

Am J Physiol Heart Circ Physiol. 2010 May;298(5):H1415-25. doi: 10.1152/ajpheart.01048.2009. Epub 2010 Feb 12.


Following myocardial infarction (MI), the heart undergoes a pathological process known as remodeling, which in many instances results in cardiac dysfunction and ultimately heart failure and death. Transforming growth factor-beta (TGF-beta) is a key mediator in the pathogenesis of cardiac remodeling following MI. We thus aimed to inhibit TGF-beta signaling using a novel orally active TGF-beta type I receptor [activin receptor-like kinase 5 (ALK5)] inhibitor (GW788388) to attenuate left ventricular remodeling and cardiac dysfunction in a rat model of MI. Sprague-Dawley rats underwent left anterior descending coronary artery ligation to induce experimental MI and then were randomized to receive GW788388 at a dosage of 50 or vehicle 1 wk after surgery. After 4 wk of treatment, echocardiography was performed before the rats were euthanized. Animals that received left anterior descending coronary artery ligation demonstrated systolic dysfunction, Smad2 activation, myofibroblasts accumulation, collagen deposition, and myocyte hypertrophy (all P < 0.05). Treatment with GW788388 significantly attenuated systolic dysfunction in the MI animals, together with the attenuation of the activated (phosphorylated) Smad2 (P < 0.01), alpha-smooth muscle actin (P < 0.001), and collagen I (P < 0.05) in the noninfarct zone of MI rats. Cardiomyocyte hypertrophy in MI hearts was also attenuated by ALK5 inhibition (P < 0.05). In brief, treatment with a novel TGF-beta type I receptor inhibitor, GW788388, significantly reduced TGF-beta activity, leading to the attenuation of systolic dysfunction and left ventricular remodeling in an experimental rat model of MI.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / biosynthesis
  • Animals
  • Antigens, CD / metabolism
  • Antigens, Differentiation, Myelomonocytic / metabolism
  • Benzamides / pharmacology*
  • Blotting, Western
  • Cell Size
  • Enzyme Inhibitors / pharmacology*
  • Extracellular Matrix / metabolism
  • Extracellular Matrix / ultrastructure
  • Heart / drug effects*
  • Heart / physiopathology*
  • Immunohistochemistry
  • Male
  • Myocardial Infarction / diagnostic imaging
  • Myocardial Infarction / drug therapy*
  • Myocardial Infarction / physiopathology*
  • Myocardium / metabolism
  • Myocardium / pathology
  • Myocytes, Cardiac / drug effects
  • Myocytes, Cardiac / ultrastructure
  • Protein-Serine-Threonine Kinases / antagonists & inhibitors*
  • Pyrazoles / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Receptor, Transforming Growth Factor-beta Type I
  • Receptors, Transforming Growth Factor beta / antagonists & inhibitors*
  • Smad2 Protein / biosynthesis
  • Transforming Growth Factor beta / metabolism
  • Ultrasonography


  • 4-(4-(3-(pyridin-2-yl)-1H-pyrazol-4-yl)pyridin-2-yl)-N-(tetrahydro-2H-pyran-4-yl)benzamide
  • Actins
  • Antigens, CD
  • Antigens, Differentiation, Myelomonocytic
  • Benzamides
  • CD68 antigen, human
  • Enzyme Inhibitors
  • Pyrazoles
  • Receptors, Transforming Growth Factor beta
  • Smad2 Protein
  • Smad2 protein, rat
  • Transforming Growth Factor beta
  • Protein-Serine-Threonine Kinases
  • Receptor, Transforming Growth Factor-beta Type I
  • TGFBR1 protein, human
  • Tgfbr1 protein, rat