title: Opposite effects of uracil and adenine nucleotides on the survival of murine cardiomyocytes.
abstract: We previously showed that the human heart expresses all known P2X and P2Y receptors activated by extra-cellular adenine or uracil nucleotides. Despite evidence that, both in humans and rodents, plasma levels of ATP and UTP markedly increase during myocardial infarction, the differential effects mediated by the various adenine- and uracil-preferring myocardial P2 receptors are still largely unknown. Here, we studied the effects of adenine and uracil nucleotides on murine HL-1 cardiomyocytes. RT-PCR analysis showed that HL-1 cardiomyocytes express all known P2X receptors (except for P2X(2)), as well as the P2Y(2,4,6,14) subtypes. Exposure of cardiomyocytes to adenine nucleotides (ATP, ADP or BzATP) induced apoptosis and necrosis, as determined by flow-cytometry. Cell death was exacerbated by tumour necrosis factor (TNF)-alpha, a cytokine implicated in chronic heart failure progression. Conversely, uracil nucleotides (UTP, UDP and UDPglucose) had no effect 'per se', but fully counteracted the deleterious effects induced by adenine nucleotides and TNF-alpha, even if added to cardiomyocytes after beginning exposure to these cell death-inducing agents. Thus, exposure of cardiomyocytes to elevated concentrations of ATP or ADP in the presence of TNF-alpha contributes to cell death, an effect which is counteracted by uracil-preferring P2 receptors. Cardiomyocytes do not need to be 'primed' by uracil nucleotides to become insensitive to adenine nucleotides-induced death, suggesting the existence of a possible 'therapeutic' window for uracil nucleotides-mediated protection. Thus, release of UTP during cardiac ischaemia and in chronic heart failure may protect against myocardial damage, setting the basis for developing novel cardioprotective agents that specifically target uracil-preferring P2Y receptors.
authors.affiliation: Laboratory of Molecular and Cellular Pharmacology of Purinergic Transmission, Department of Pharmacological Sciences, University of Milan, Milan, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Mazzola
authors.forename: Emanuela
authors.initials: E
authors.lastname: Amoruso
authors.forename: Elena
authors.initials: E
authors.lastname: Beltrami
authors.forename: Davide
authors.initials: D
authors.lastname: Lecca
authors.forename: Silvia
authors.initials: S
authors.lastname: Ferrario
authors.forename: Simona
authors.initials: S
authors.lastname: Cosentino
authors.forename: Elena
authors.initials: E
authors.lastname: Tremoli
authors.forename: Stefania
authors.initials: S
authors.lastname: Ceruti
authors.forename: Maria P
authors.initials: MP
authors.lastname: Abbracchio
mesh_terms: D000227:Adenine Nucleotides / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D006690:Bisbenzimidazole / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002467:Cell Nucleus / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005355:Fibrosis; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism; D058919:Purinergic P2 Receptor Antagonists; D051381:Rats; D018048:Receptors, Purinergic P2 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D014500:Uracil Nucleotides / Q000494:pharmacology*
chemical_list: D000227:Adenine Nucleotides; D058919:Purinergic P2 Receptor Antagonists; D018048:Receptors, Purinergic P2; D014409:Tumor Necrosis Factor-alpha; D014500:Uracil Nucleotides; D000255:Adenosine Triphosphate; D006690:Bisbenzimidazole