Transduction of anti-cell death protein FNK protects isolated rat hearts from myocardial infarction induced by ischemia/reperfusion.

Abstract

Artificial anti-cell death protein FNK, a Bcl-x(L) derivative with three amino acid-substitutions (Y22F, Q26N, and R165K) has enhanced anti-apoptotic and anti-necrotic activity and facilitates cell survival in many species and cell types. The objectives of this study were (i) to investigate whether the protein conjugated with a protein transduction domain (PTD-FNK) reduces myocardial infarct size and improves post-ischemic cardiac function in ischemic/reperfused rat hearts, and (ii) to understand the mechanism(s) by which PTD-FNK exerts a protective effect. Isolated rat hearts were subjected to 35-min global ischemia, followed by 120-min reperfusion using the Langendorff methods. PTD-FNK (a total of 30 microl) was injected intramuscularly into the anterior wall of the left ventricle either at 1 min after induction of global ischemia (group A) or at 30 min after induction of global ischemia (at 5 min before reperfusion) (group B). In group A, infarct size was significantly reduced from 47.8+/-6.8% in the control to 30.4+/-5.2, 28.7+/-3.8, and 30.4+/-6.8% with PTD-FNK at 5, 50, and 500 nmol/l, respectively (p<0.05). Temporal recovery of left ventricular developed pressure at 60 min and 120 min after reperfusion was significantly better in PTD-FNK (50 and 500 nmol/l)-treated groups than in the control (p<0.05). In contrast, PTD-FNK treatment had no effect on group B. Western blot analysis showed that PTD-FNK markedly inhibited procaspase-3 cleavage (activation of caspase-3) and reduced the number of nuclei stained by a terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphoshate nick-end labeling (TUNEL) assay. These findings suggest that PTD-FNK reduces the volume of myocardial infarction with corresponding functional recovery, at least in part, through the suppression of myocardial apoptosis following ischemia/reperfusion.

• Authors: Masayuki Arakawa, Masahiro Yasutake, Masaaki Miyamoto, Teruo Takano, Sadamitsu Asoh, Shigeo Ohta
• Journal: Life sciences (Life Sci) Vol. 80 Issue 22 Pg. 2076-84 (May 08 2007) ISSN: 0024-3205 [Print] Netherlands
• PMID: 17467744 (Publication Type: Journal Article)

Chemical References

• Tumor Suppressor Proteins
• bcl-2-Associated X Protein
• PLK3 protein, human
• Protein Serine-Threonine Kinases

Topics

• Animals
• Cell Death (genetics)
• Disease Models, Animal
• Genes, bcl-2 (genetics)
• Immunohistochemistry
• In Situ Nick-End Labeling
• In Vitro Techniques
• Ischemia (metabolism)
• Male
• Mice
• Myocardial Infarction (metabolism, prevention & control)
• Myocardial Reperfusion Injury (metabolism, physiopathology, prevention & control)
• Myocardium (metabolism, pathology)
• Protein Serine-Threonine Kinases (metabolism)
• Rats
• Transduction, Genetic (methods)
• Tumor Suppressor Proteins
• bcl-2-Associated X Protein (metabolism)