title: Diverse cardioprotective signaling mechanisms of peroxisome proliferator-activated receptor-gamma ligands, 15-deoxy-Delta12,14-prostaglandin J2 and ciglitazone, in reperfusion injury: role of nuclear factor-kappaB, heat shock factor 1, and Akt.
abstract: Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a nuclear receptor that regulates diverse biological functions including inflammation. The PPARgamma ligands have been reported to exert cardioprotective effects and attenuate myocardial reperfusion injury. Here, we examined the molecular mechanisms of their anti-inflammatory effects. Male Wistar rats were subjected to myocardial ischemia and reperfusion and were treated with the PPAR-gamma ligands, 15-deoxy-Delta-prostaglandin J2 (15d-PGJ2) or ciglitazone, or with vehicle only, in the absence or presence of the selective PPAR-gamma antagonist GW-9662. In vehicle-treated rats, myocardial injury was associated with elevated tissue activity of myeloperoxidase, indicating infiltration of neutrophils, and elevated plasma levels of creatine kinase and tumor necrosis factor-alpha. These events were preceded by activation of the nuclear factor-kappaB pathway. The PPAR-gamma DNA binding was also increased in the heart after reperfusion. Treatment with ciglitazone or 15d-PGJ2 reduced myocardial damage and neutrophil infiltration and blunted creatine kinase levels and cytokine production. The beneficial effects of both ligands were associated with enhancement of PPAR-gamma DNA binding and reduction of nuclear factor-kappaB activation. Treatment with 15d-PGJ2, but not ciglitazone, enhanced DNA binding of heat shock factor 1 and upregulated the expression of the cardioprotective heat shock protein 70. Treatment with 15d-PGJ2, but not ciglitazone, also induced a significant increase in nuclear phosphorylation of the prosurvival kinase Akt. The cardioprotection afforded by ciglitazone was attenuated by the PPAR-gamma antagonist GW-9662. In contrast, GW-9662 did not affect the beneficial effects afforded by 15d-PGJ2. Thus, our data suggest that treatment with these chemically unrelated PPAR-gamma ligands results in diverse anti-inflammatory mechanisms.
authors.affiliation: Division of Critical Care Medicine, Cincinnati Children's Hospital Medical Center, The University of Cincinnati College of Medicine, Cincinnati, Ohio 45229, USA. basilia.zingarelli@cchmc.org
authors.forename: Basilia
authors.initials: B
authors.lastname: Zingarelli
authors.forename: Paul W
authors.initials: PW
authors.lastname: Hake
authors.forename: Prajakta
authors.initials: P
authors.lastname: Mangeshkar
authors.forename: Michael
authors.initials: M
authors.lastname: O'Connor
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Burroughs
authors.forename: Giovanna
authors.initials: G
authors.lastname: Piraino
authors.forename: Alvin
authors.initials: A
authors.lastname: Denenberg
authors.forename: Hector R
authors.initials: HR
authors.lastname: Wong
mesh_terms: D000813:Anilides / Q000494:pharmacology; D000818:Animals; D003402:Creatine Kinase / Q000097:blood; D004268:DNA-Binding Proteins / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis; D000076249:Heat Shock Transcription Factors; D007004:Hypoglycemic Agents / Q000493:pharmacokinetics*; D007155:Immunologic Factors / Q000494:pharmacology*; D007249:Inflammation / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D008024:Ligands; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D016328:NF-kappa B / Q000378:metabolism*; D020556:Neutrophil Infiltration / Q000187:drug effects; D047495:PPAR gamma / Q000819:agonists* / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D015230:Prostaglandin D2 / Q000031:analogs & derivatives* / Q000494:pharmacology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects*; D045162:Thiazolidinediones / Q000494:pharmacology*; D014157:Transcription Factors / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D015854:Up-Regulation / Q000187:drug effects
chemical_list: C097240:15-deoxy-delta(12,14)-prostaglandin J2; C457499:2-chloro-5-nitrobenzanilide; D000813:Anilides; D004268:DNA-Binding Proteins; D018840:HSP70 Heat-Shock Proteins; D000076249:Heat Shock Transcription Factors; D007004:Hypoglycemic Agents; D007155:Immunologic Factors; D008024:Ligands; D016328:NF-kappa B; D047495:PPAR gamma; D045162:Thiazolidinediones; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D009195:Peroxidase; D051057:Proto-Oncogene Proteins c-akt; D003402:Creatine Kinase; D015230:Prostaglandin D2; C039671:ciglitazone