Postconditioning effect of granulocyte colony-stimulating factor is mediated through activation of risk pathway and opening of the mitochondrial KATP channels.
Granulocyte colony-stimulating factor (G-CSF) has been reported to improve cardiac function after myocardial infarction. However, whether postinfarct acute effect of G-CSF is mediated through the same signaling pathways as those of ischemic postconditioning is still unclear. We examined the postinfarct acute effect of G-CSF on myocardial infarct size and its precise molecular mechanism. Japanese white rabbits underwent 30 min of ischemia and 48 h of reperfusion. Rabbits were intravenously injected 10 μg/kg of G-CSF (G-CSF group) or saline (control group) immediately after reperfusion. The wortmannin + G-CSF, PD-98059 + G-CSF, N(ω)-nitro-L-arginine methyl ester (l-NAME) + G-CSF, and 5-hydroxydecanoic acid sodium salt (5-HD) + G-CSF groups were respectively injected with wortmannin (0.6 mg/kg), PD-98059 (0.3 mg/kg), L-NAME (10 mg/kg), and 5-HD (5 mg/kg) 5 min before G-CSF administration. Myocardial infarct size was calculated as a percentage of the risk area of the left ventricle. Western blot analysis was performed to examine the signals such as protein kinase B (Akt), extracellular signal-regulated protein kinase (ERK), eNOS, p70S6 kinase (p70S6K), and glycogen synthase kinase-3β (GSK3β) in the ischemic myocardium after 48 h of reperfusion. The infarct size was significantly smaller in the G-CSF group (26.7 ± 2.7%) than in the control group (42.3 ± 4.6%). The infarct size-reducing effect of G-CSF was completely blocked by wortmannin (44.7 ± 4.8%), PD-98059 (38.3 ± 3.9%), L-NAME (42.1 ± 4.2%), and 5-HD (42.5 ± 1.7%). Wortmannin, PD-98059, L-NAME, or 5-HD alone did not affect the infarct size. Western blotting showed higher myocardial expression of phospho-Akt, phospho-ERK, phosho-eNOS, phosho-p70S6K, and phosho-GSK3β at 10 min and 48 h after reperfusion in the G-CSF group than in the control group. In conclusion, postreperfusion G-CSF administration reduces myocardial infarct size via activation of phosphatidylinositol 3-kinase-Akt and ERK prosurvival signaling pathways and their downstream targets eNOS, p70S6 kinase, GSK3β, and mitochondrial ATP-dependent K(+) channel.
Sumi
Shohei
S
Department of Cardiology, Gifu University Graduate School of Medicine, Gifu, Japan.
Kobayashi
Hiroyuki
H
Yasuda
Shinji
S
Iwasa
Masamitsu
M
Yamaki
Takahiko
T
Yamada
Yoshihisa
Y
Ushikoshi
Hiroaki
H
Hattori
Arihiro
A
Aoyama
Takuma
T
Nishigaki
Kazuhiko
K
Takemura
Genzou
G
Minatoguchi
Shinya
S
D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D003652:Decanoic Acids / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D016179:Granulocyte Colony-Stimulating Factor / Q000627:therapeutic use*; D006321:Heart / Q000187:drug effects; D006880:Hydroxy Acids / Q000494:pharmacology; D054086:KATP Channels / Q000502:physiology*; D008297:Male; D008929:Mitochondria, Heart / Q000502:physiology*; D023421:Models, Animal; D009203:Myocardial Infarction / Q000503:physiopathology*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D058539:Phosphatidylinositol 3-Kinase / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D011817:Rabbits; D015427:Reperfusion Injury / Q000503:physiopathology* / Q000517:prevention & control*; D015398:Signal Transduction / Q000502:physiology*; D000077191:Wortmannin
D000730:Androstadienes; D003652:Decanoic Acids; D006880:Hydroxy Acids; D054086:KATP Channels; D016179:Granulocyte Colony-Stimulating Factor; C052853:5-hydroxydecanoic acid; D052250:Nitric Oxide Synthase Type III; D058539:Phosphatidylinositol 3-Kinase; D000071679:Glycogen Synthase Kinase 3 beta; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases; D038362:Glycogen Synthase Kinase 3; D019331:NG-Nitroarginine Methyl Ester; D000077191:Wortmannin