title: Association of Stat3 with HSF1 plays a critical role in G-CSF-induced cardio-protection against ischemia/reperfusion injury.
abstract: Granulocyte colony-stimulating factor (G-CSF) has been shown to be cardio-protective against ischemia through activating Jak2/Stat3 pathway, however, the mechanism is unclear. Heat shock transcription factor 1 (HSF1), a definite endogenous protective protein in cardiomyocytes, may interact with Stat family under stress conditions. We hypothesized that G-CSF could induce cardio-protection against ischemia/reperfusion (I/R) through association of HSF1 with Stat3. To test the hypothesis, we built cardiac I/R injury model with HSF1 knockout (KO) mice and wild type (WT) mice by occlusion of the left anterior descending (LAD) coronary artery for 30min and subsequent release of the occlusion for 24h. These mice were administered with G-CSF (100μg/kg/day) or vehicle subcutaneously for 3days before surgery. As expected, G-CSF induced significant cardio-protections against I/R injury, characterized by higher ejection fraction (EF%), lower left ventricular end diastolic pressure (LVEDP), increased dp/dt value and decreased infarct area as compared with the vehicle treatment in WT mice. In HSF1-KO mice, however, these cardio-protections induced by G-CSF were greatly attenuated. Inhibition of oxidative stress-induced cardiomyocyte apoptosis by G-CSF also disappeared due to the deficiency of HSF1 in vitro and in vivo. Furthermore, G-CSF increased the phosphorylation and the association of Stat3 with HSF1, which enhanced transcriptional activity of HSF1. Inhibition of either Stat3 or HSF1 by pharmacological agents suppressed G-CSF-induced association of the two proteins and anti-apoptotic effect on cardiomyocytes. Our data suggest that G-CSF stimulates phosphorylation and association of Stat3 with HSF1 and therefore enhances transcriptional activity of HSF1, leading to the cardio-protection against I/R injury.
authors.affiliation: Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, 180 Feng Lin Road, Shanghai, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Ma
authors.forename: Hui
authors.initials: H
authors.lastname: Gong
authors.forename: Zhidan
authors.initials: Z
authors.lastname: Chen
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Liang
authors.forename: Jie
authors.initials: J
authors.lastname: Yuan
authors.forename: Guoping
authors.initials: G
authors.lastname: Zhang
authors.forename: Jian
authors.initials: J
authors.lastname: Wu
authors.forename: Yong
authors.initials: Y
authors.lastname: Ye
authors.forename: Chunjie
authors.initials: C
authors.lastname: Yang
authors.forename: Akira
authors.initials: A
authors.lastname: Nakai
authors.forename: Issei
authors.initials: I
authors.lastname: Komuro
authors.forename: Junbo
authors.initials: J
authors.lastname: Ge
authors.forename: Yunzeng
authors.initials: Y
authors.lastname: Zou
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D016179:Granulocyte Colony-Stimulating Factor / Q000008:administration & dosage / Q000494:pharmacology*; D000076249:Heat Shock Transcription Factors; D051379:Mice; D018345:Mice, Knockout; D015428:Myocardial Reperfusion Injury / Q000378:metabolism* / Q000503:physiopathology / Q000517:prevention & control*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism; D018384:Oxidative Stress; D011485:Protein Binding; D051381:Rats; D017207:Rats, Sprague-Dawley; D050796:STAT3 Transcription Factor / Q000378:metabolism*; D014157:Transcription Factors / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D000076249:Heat Shock Transcription Factors; C490017:Hsf1 protein, mouse; D050796:STAT3 Transcription Factor; D014157:Transcription Factors; D016179:Granulocyte Colony-Stimulating Factor