title: Novel, selective EPO receptor ligands lacking erythropoietic activity reduce infarct size in acute myocardial infarction in rats.
abstract: Erythropoietin (EPO) has been shown to protect the heart against acute myocardial infarction in pre-clinical studies, however, EPO failed to reduce infarct size in clinical trials and showed significant safety problems. Here, we investigated cardioprotective effects of two selective non-erythropoietic EPO receptor ligand dimeric peptides (AF41676 and AF43136) lacking erythropoietic activity, EPO, and the prolonged half-life EPO analogue, darbepoetin in acute myocardial infarction (AMI) in rats. In a pilot study, EPO at 100U/mL significantly decreased cell death compared to vehicle (33.8±2.3% vs. 40.3±1.5%, p<0.05) in rat neonatal cardiomyocytes subjected to simulated ischemia/reperfusion. In further studies (studies 1-4), in vivo AMI was induced by 30min coronary occlusion and 120min reperfusion in male Wistar rats. Test compounds and positive controls for model validation (B-type natriuretic peptide, BNP or cyclosporine A, CsA) were administered iv. before the onset of reperfusion. Infarct size (IS) was measured by standard TTC staining. In study 1, 5000U/kg EPO reduced infarct size significantly compared to vehicle (45.3±4.8% vs. 59.8±4.5%, p<0.05). In study 2, darbepoetin showed a U-shaped dose-response curve with maximal infarct size-reducing effect at 5μg/kg compared to the vehicle (44.4±5.7% vs. 65.9±2.7%, p<0.01). In study 3, AF41676 showed a U-shaped dose-response curve, where 3mg/kg was the most effective dose compared to the vehicle (24.1±3.9% vs. 44.3±2.5%, p<0.001). The positive control BNP significantly decreased infarct size in studies 1-3 by approximately 35%. In study 4, AF43136 at 10mg/kg decreased infarct size, similarly to the positive control CsA compared to the appropriate vehicle (39.4±5.9% vs. 58.1±5.4% and 45.9±2.4% vs. 63.8±4.1%, p<0.05, respectively). This is the first demonstration that selective, non-erythropoietic EPO receptor ligand dimeric peptides AF41676 and AF43136 administered before reperfusion are able to reduce infarct size in a rat model of AMI. Therefore, non-erythropoietic EPO receptor peptide ligands may be promising cardioprotective agents.
authors: Cardiovascular Research Group, Department of Biochemistry, University of Szeged, Dom ter 9, Szeged H-6720, Hungary. Electronic address: kiss.krisztina.1@med.u-szeged.hu.
authors: Krisztina
authors: K
authors: Kiss
authors: Department of Biochemistry, University of Szeged, Dom ter 9, Szeged H-6720, Hungary. Electronic address: csonka.csaba@med.u-szeged.hu.
authors: Csaba
authors: C
authors: Csonka
authors: Cardiovascular Research Group, Department of Biochemistry, University of Szeged, Dom ter 9, Szeged H-6720, Hungary; Pharmahungary Group, Dom ter 9, Szeged H-6720, Hungary. Electronic address: janos.paloczi@pharmahungary.com.
authors: János
authors: J
authors: Pálóczi
authors: Cardiovascular Research Group, Department of Biochemistry, University of Szeged, Dom ter 9, Szeged H-6720, Hungary; Pharmahungary Group, Dom ter 9, Szeged H-6720, Hungary. Electronic address: judit.pipis@pharmahungary.com.
authors: Judit
authors: J
authors: Pipis
authors: Cardiovascular Research Group, Department of Biochemistry, University of Szeged, Dom ter 9, Szeged H-6720, Hungary; Pharmahungary Group, Dom ter 9, Szeged H-6720, Hungary. Electronic address: aniko.gorbe@pharmahungary.com.
authors: Anikó
authors: A
authors: Görbe
authors: Cardiovascular Research Group, Department of Biochemistry, University of Szeged, Dom ter 9, Szeged H-6720, Hungary; Pharmahungary Group, Dom ter 9, Szeged H-6720, Hungary. Electronic address: gokf1@leicester.ac.uk.
authors: Gabriella F
authors: GF
authors: Kocsis
authors: Pharmahungary Group, Dom ter 9, Szeged H-6720, Hungary; Sports Science Program, Qatar University, Doha 00974, Qatar. Electronic address: zmurlasits@qu.edu.qa.
authors: Zsolt
authors: Z
authors: Murlasits
authors: Department of Biochemistry, University of Szeged, Dom ter 9, Szeged H-6720, Hungary. Electronic address: sarkozy.marta@med.u-szeged.hu.
authors: Márta
authors: M
authors: Sárközy
authors: Department of Biochemistry, University of Szeged, Dom ter 9, Szeged H-6720, Hungary. Electronic address: szucs.gergo@med.u-szeged.hu.
authors: Gergő
authors: G
authors: Szűcs
authors: Affymax, Inc., 4015 Miranda Ave Fl 1, Palo Alto, CA 94304, United States. Electronic address: chrisholmes64@gmail.com.
authors: Christopher P
authors: CP
authors: Holmes
authors: Affymax, Inc., 4015 Miranda Ave Fl 1, Palo Alto, CA 94304, United States. Electronic address: yijunpan@hotmail.com.
authors: Yijun
authors: Y
authors: Pan
authors: Affymax, Inc., 4015 Miranda Ave Fl 1, Palo Alto, CA 94304, United States. Electronic address: a.bhandari@protagonist-inc.com.
authors: Ashok
authors: A
authors: Bhandari
authors: Department of Biochemistry, University of Szeged, Dom ter 9, Szeged H-6720, Hungary. Electronic address: csont.tamas@med.u-szeged.hu.
authors: Tamás
authors: T
authors: Csont
authors: Stanford University School of Medicine, Department of Neurosurgery, 1050 Arastradero Road, Building A, Palo Alto, CA 94304, United States. Electronic address: mshamloo@stanford.edu.
authors: Mehrdad
authors: M
authors: Shamloo
authors: Affymax, Inc., 4015 Miranda Ave Fl 1, Palo Alto, CA 94304, United States; Avalanche Biotechnologies, 1035 O'Brien Drive, Menlo Park, CA 94025, United States. Electronic address: kathrynwoodburn@yahoo.com.
authors: Kathryn W
authors: KW
authors: Woodburn
authors: Cardiovascular Research Group, Department of Biochemistry, University of Szeged, Dom ter 9, Szeged H-6720, Hungary; Pharmahungary Group, Dom ter 9, Szeged H-6720, Hungary; Department of Pharmacology and Pharmacotherapy, Semmelweis University, Nagyvarad ter 4, Budapest H-1089, Hungary. Electronic address: peter.ferdinandy@pharmahungary.com.
authors: Péter
authors: P
authors: Ferdinandy
authors: Cardiovascular Research Group, Department of Biochemistry, University of Szeged, Dom ter 9, Szeged H-6720, Hungary; Pharmahungary Group, Dom ter 9, Szeged H-6720, Hungary. Electronic address: peter.bencsik@pharmahungary.com.
authors: Péter
authors: P
authors: Bencsik
mesh_terms: D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology*; D004921:Erythropoietin / Q000378:metabolism*; D008024:Ligands; D008297:Male; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000378:metabolism; D015428:Myocardial Reperfusion Injury / Q000188:drug therapy / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism; D020097:Natriuretic Peptide, Brain / Q000494:pharmacology; D010865:Pilot Projects; D051381:Rats; D017208:Rats, Wistar
chemical_list: D002316:Cardiotonic Agents; D008024:Ligands; C000599851:erythropoietin, rat; D004921:Erythropoietin; D020097:Natriuretic Peptide, Brain
keywords: 2,3,5-Triphenyltetrazolium chloride (PubChem CID:9283); Acute myocardial infarction; B-type natriuretic peptide; Cardioprotection; Cyclosporine A (PubChem CID:16404350); Darbepoetin; Erythropoietin; Erythropoietin, Darbepoetin, B-type natriuretic peptide (PubChem CID:16132422); Evans blue dye (PubChem CID:5359386); Na-pentobarbital (PubChem CID:4737); Non-erythropoietic EPO receptor ligand; Trypan blue (PubChem CID:6364561)