title: High-density lipoproteins protect isolated rat hearts from ischemia-reperfusion injury by reducing cardiac tumor necrosis factor-alpha content and enhancing prostaglandin release.
abstract: The incidence and severity of primary cardiac events are inversely related to the plasma concentration of high-density lipoproteins (HDLs). We investigated whether HDLs may exert a direct cardioprotection in buffer-perfused isolated rat hearts, which underwent a 20-minute low-flow ischemia followed by a 30-minute reperfusion. The administration of HDLs at physiological concentrations (0.5 and 1.0 mg/mL) during the 10 minutes immediately before ischemia rapidly and remarkably improved postischemic functional recovery and decreased creatine kinase release in the coronary effluent. Reconstituted HDLs containing apolipoprotein A-I (apoA-I) and phosphatidylcholine, but not lipid-free apoA-I or phosphatidylcholine liposomes, were also effective in protecting the heart from ischemia-reperfusion injury. HDLs at reperfusion were less effective than when given before ischemia. HDLs caused a dose-dependent reduction of ischemia-induced cardiac tumor necrosis factor-alpha (TNF-alpha) expression and content, which correlated with the improved functional recovery. A parallel increase of TNF-alpha release in the coronary effluent was observed, due to a direct binding of cardiac TNF-alpha to HDLs. Taken together, these findings argue for a cause-effect relationship between the HDL-mediated removal of TNF-alpha from the ischemic myocardium and the HDL-induced cardioprotection. Indeed, etanercept, a recombinant TNF-alpha-blocking protein, caused a dose-dependent improvement of postischemic functional recovery. HDLs also enhanced ischemia-induced prostaglandin release, which may contribute to the cardioprotective effect. A low plasma HDL level may expose the heart to excessive ischemia-reperfusion damage, and HDL-targeted therapies may be helpful to induce immediate or delayed myocardial protection from ischemia-reperfusion injury.
authors.affiliation: Center E. Grossi Paoletti, Department of Pharmacological Sciences, University of Milano, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Calabresi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Rossoni
authors.forename: Monica
authors.initials: M
authors.lastname: Gomaraschi
authors.forename: Francesca
authors.initials: F
authors.lastname: Sisto
authors.forename: Ferruccio
authors.initials: F
authors.lastname: Berti
authors.forename: Guido
authors.initials: G
authors.lastname: Franceschini
mesh_terms: D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology; D003402:Creatine Kinase / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D000068800:Etanercept; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D007074:Immunoglobulin G / Q000494:pharmacology; D066298:In Vitro Techniques; D008075:Lipoproteins, HDL / Q000494:pharmacology*; D008297:Male; D017202:Myocardial Ischemia / Q000378:metabolism; D015425:Myocardial Reperfusion / Q000009:adverse effects; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D009206:Myocardium / Q000378:metabolism*; D011453:Prostaglandins / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018124:Receptors, Tumor Necrosis Factor; D020127:Recovery of Function / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D002316:Cardiotonic Agents; D007074:Immunoglobulin G; D008075:Lipoproteins, HDL; D011453:Prostaglandins; D012333:RNA, Messenger; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha; D003402:Creatine Kinase; D000068800:Etanercept