title: Catestatin exerts direct protective effects on rat cardiomyocytes undergoing ischemia/reperfusion by stimulating PI3K-Akt-GSK3β pathway and preserving mitochondrial membrane potential.
abstract: Catestatin (Cst) is a 21-amino acid peptide deriving from Chromogranin A. Cst exerts an overall protective effect against an excessive sympathetic stimulation of cardiovascular system, being able to antagonize catecholamine secretion and to reduce their positive inotropic effect, by stimulating the release of nitric oxide (NO) from endothelial cells. Moreover, Cst reduces ischemia/reperfusion (I/R) injury, improving post-ischemic cardiac function and cardiomyocyte survival. To define the cardioprotective signaling pathways activated by Cst (5 nM) we used isolated adult rat cardiomyocytes undergoing simulated I/R. We evaluated cell viability rate with propidium iodide labeling and mitochondrial membrane potential (MMP) with the fluorescent probe JC-1. The involvement of Akt, GSK3β, eNOS and phospholamban (PLN) cascade was studied by immunofluorescence. The role of PI3K-Akt/NO/cGMP pathway was also investigated by using the pharmacological blockers wortmannin (Wm), L-NMMA and ODQ. Our experiments revealed that Cst increased cell viability rate by 65% and reduced cell contracture in I/R cardiomyocytes. Wm, L-NMMA and ODQ limited the protective effect of Cst. The protective outcome of Cst was related to its ability to maintain MMP and to increase AktSer473, GSK3βSer9, PLNThr17 and eNOSSer1179 phosphorylation, while treatment with Wm abolished these effects. Thus, the present results show that Cst is able to exert a direct action on cardiomyocytes and give new insights into the molecular mechanisms involved in its protective effect, highlighting the PI3K/NO/cGMP pathway as the trigger and the MMP preservation as the end point of its action.
authors.affiliation: Department of Life Sciences and Systems Biology, University of Torino, via Accademia Albertina 13, 10123, Torino, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Bassino
authors.affiliation: Department of Life Sciences and Systems Biology, University of Torino, via Accademia Albertina 13, 10123, Torino, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Fornero
authors.affiliation: Department of Life Sciences and Systems Biology, University of Torino, via Accademia Albertina 13, 10123, Torino, Italy.
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Gallo
authors.affiliation: Department of Life Sciences and Systems Biology, University of Torino, via Accademia Albertina 13, 10123, Torino, Italy.
authors.forename: Clara
authors.initials: C
authors.lastname: Gallina
authors.affiliation: Department of Clinical and Biological Sciences, University of Torino, Regione Gonzole 10, 10043, Orbassano (TO), Italy.
authors.forename: Saveria
authors.initials: S
authors.lastname: Femminò
authors.affiliation: Department of Life Sciences and Systems Biology, University of Torino, via Accademia Albertina 13, 10123, Torino, Italy.
authors.forename: Renzo
authors.initials: R
authors.lastname: Levi
authors.affiliation: Department of Cell Biology, University of Calabria, Arcavacata di Rende (CS), 87030, Cosenza, Italy; National Institute for Cardiovascular Research, via Irnerio 48, 40126, Bologna, Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Tota
authors.affiliation: Department of Life Sciences and Systems Biology, University of Torino, via Accademia Albertina 13, 10123, Torino, Italy; National Institute for Cardiovascular Research, via Irnerio 48, 40126, Bologna, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Alloatti
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D053379:Chromogranin A / Q000494:pharmacology* / Q000627:therapeutic use; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects*; D015428:Myocardial Reperfusion Injury / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D010446:Peptide Fragments / Q000494:pharmacology* / Q000627:therapeutic use; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D053379:Chromogranin A; D010446:Peptide Fragments; C109084:chromogranin A (344-364); D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D038362:Glycogen Synthase Kinase 3