title: Beneficial effects of poly (ADP-ribose) polymerase inhibition against the reperfusion injury in heart transplantation.
abstract: We investigated the effect of 3-aminobenzamide (3-AB), an inhibitor of the nuclear enzyme poly(ADP-ribose) polymerase (PARP), against early ischemia/reperfusion (IR) injury in heart transplantation. In our experimental model, rat heart subjected to heterotopic transplantation, low temperature global ischemia (2 h) was followed by an in vivo reperfusion (60 min). In these conditions, and in the absence of 3-AB treatment, clear signs of oxidative stress, such as lipid peroxidation, increase in protein carbonyls and DNA strand breaks, were evident; PARP was markedly activated in concomitance with a significant NAD+ and ATP depletion. The results of microscopic observations (nuclear clearings, plasma membrane discontinuity), and the observed rise in the serum levels of heart damage markers, suggested the development of necrotic processes while, conversely, no typical sign of apoptosis was evident. Compared to the effects observed in untreated IR heart, the administration of 3-AB (10 mg/kg to the donor and to the recipient animal), but not that of its inactive analogue 3-aminobenzoic acid, significantly modified the above parameters: the levels of oxidative stress markers were significantly reduced; PARP activation was markedly inhibited and this matched a significant rise in NAD+ and ATP levels. PARP inhibition also caused a reduced release of the cardiospecific damage markers and attenuated morphological cardiomyocyte alterations, save that, in this condition, we noted the appearance of typical apoptotic markers: activation of caspase-3, oligonucleosomal DNA fragmentation, ISEL positive nuclei. Possible mechanisms for these effects are discussed, in any case the present results indicate that PARP inhibition has an overall beneficial effect against myocardial reperfusion injury, mainly due to prevention of energy depletion. In this context, the signs of apoptosis observed under 3-AB treatment might be ascribed to the maintenance of sufficient intracellular energy levels. These latter allow irreversible damages triggered during the ischemic phase to proceed towards apoptosis instead of towards necrosis, as it appears to happen when the energetic pools are depleted by high PARP activity.
authors.affiliation: Dipartimento di Scienze Biochimiche, Università di Firenze, viale Morgagni 50, 50134, Fireze, Italia.
authors.forename: Claudia
authors.initials: C
authors.lastname: Fiorillo
authors.forename: Vanessa
authors.initials: V
authors.lastname: Ponziani
authors.forename: Lara
authors.initials: L
authors.lastname: Giannini
authors.forename: Cristina
authors.initials: C
authors.lastname: Cecchi
authors.forename: Alessandra
authors.initials: A
authors.lastname: Celli
authors.forename: Chiara
authors.initials: C
authors.lastname: Nediani
authors.forename: Avio Maria
authors.initials: AM
authors.lastname: Perna
authors.forename: Piero
authors.initials: P
authors.lastname: Liguori
authors.forename: Niccolò
authors.initials: N
authors.lastname: Nassi
authors.forename: Lucia
authors.initials: L
authors.lastname: Formigli
authors.forename: Alessia
authors.initials: A
authors.lastname: Tani
authors.forename: Paolo
authors.initials: P
authors.lastname: Nassi
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D017209:Apoptosis; D001549:Benzamides / Q000627:therapeutic use*; D015153:Blotting, Western; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D003402:Creatine Kinase / Q000378:metabolism; D004249:DNA Damage; D053938:DNA Fragmentation; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D004797:Enzyme-Linked Immunosorbent Assay; D016027:Heart Transplantation / Q000379:methods*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D015227:Lipid Peroxidation; D009206:Myocardium / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D051381:Rats; D015427:Reperfusion Injury / Q000517:prevention & control*; D013696:Temperature; D019210:Troponin I / Q000378:metabolism
chemical_list: D001549:Benzamides; D004791:Enzyme Inhibitors; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D019210:Troponin I; D009243:NAD; C025160:3-aminobenzamide; D000255:Adenosine Triphosphate; D007770:L-Lactate Dehydrogenase; D003402:Creatine Kinase; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases