title: 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.affiliation: Department of Biochemistry and Cell Biology, Institute of Development and Aging Sciences, Graduate School of Medicine, Nippon Medical School, 1-396 Kosugi-cho, Nakahara-ku, Kawasaki-shi, Kanagawa, 211-8533, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Arakawa
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yasutake
authors.forename: Masaaki
authors.initials: M
authors.lastname: Miyamoto
authors.forename: Teruo
authors.initials: T
authors.lastname: Takano
authors.forename: Sadamitsu
authors.initials: S
authors.lastname: Asoh
authors.forename: Shigeo
authors.initials: S
authors.lastname: Ohta
mesh_terms: D000818:Animals; D016923:Cell Death / Q000235:genetics*; D004195:Disease Models, Animal; D019254:Genes, bcl-2 / Q000235:genetics; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D066298:In Vitro Techniques; D007511:Ischemia / Q000378:metabolism; D008297:Male; D051379:Mice; D009203:Myocardial Infarction / Q000378:metabolism* / Q000517:prevention & control*; D015428:Myocardial Reperfusion Injury / Q000378:metabolism* / Q000503:physiopathology / Q000517:prevention & control*; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D051381:Rats; D014161:Transduction, Genetic / Q000379:methods; D025521:Tumor Suppressor Proteins; D051028:bcl-2-Associated X Protein / Q000378:metabolism; D000097868:Polo-like Kinases
chemical_list: D017346:Protein Serine-Threonine Kinases; D025521:Tumor Suppressor Proteins; D051028:bcl-2-Associated X Protein; C486256:PLK3 protein, human; D000097868:Polo-like Kinases