Cardiomyocyte Resistance to Doxorubicin Mediated by A3 Adenosine Receptor
| Autor: | Asher Shainberg, Liaman K. Mamedova, Vladimir Shneyvays, Avishag Korkus |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Agonist
medicine.drug_class Drug Resistance DNA Fragmentation Biology Mitochondrion Pharmacology chemistry.chemical_compound In Situ Nick-End Labeling Purinergic P1 Receptor Agonists medicine Diazoxide Animals Molecular Biology Cells Cultured Membrane potential Cardioprotection Antibiotics Antineoplastic Cell Death ATP synthase Myocardium Receptors Purinergic P1 Adenosine receptor Mitochondria Rats Microscopy Fluorescence chemistry Doxorubicin CCPA biology.protein Cardiology and Cardiovascular Medicine medicine.drug |
| Zdroj: | Journal of Molecular and Cellular Cardiology. 34:493-507 |
| ISSN: | 0022-2828 |
| DOI: | 10.1006/jmcc.2002.1532 |
| Popis: | Recently, we reported that the activation of A 3 adenosine receptor (A 3 R) in newborn cultured cardiomyocytes by highly selective agonist Cl-IB-MECA (2-chloro-N 6 -(3-iodobenzyl)adenosine-5′-N-methyluronamide) induces protection against the anthracycline antibiotic doxorubicin (DOX) cardiotoxicity. The present study was undertaken to further characterize the cardioprotective action of A 3 R activation by revealing the structural changes in cardiomyocytes elicited upon exposure to DOX. Morphological observations (ultrastructural and immunocytochemical) indicate that after DOX treatment, the cardiomyocytes undergo destructive alterations, and protective action of A 3 R is not connected with its anti-apoptotic activity. A 3 R activation appeared to prevent destructive alterations of cardiomyocyte mitochondria and dissipation of mitochondrial membrane potential. In DOX-treated cardiomyocytes, appearance of disorganized desmin and contractile filaments was related to detrimental alterations in the mitochondrial structure, in particular their position and transmembrane potential. In intact cardiomyocytes, diazoxide, a selective mitochondrial K ATP channel opener, induced an increase in ATP synthesis within 15 min of application. Similar effect was obtained by activation of adenosine A 1 R. However, A 3 R agonist Cl-IB-MECA did not affect ATP synthesis. Neither A 1 R agonist CCPA (2-chloro-N 6 -cyclopentyladenosine) nor diazoxide protected cardiomyocytes from the detrimental effects of DOX. Thus, the opening of mitochondrial K ATP channels does not seem to be effective during the slow development of anthracycline cytotoxicity. Our results indicate that DOX increases the activity of lysosomes, which may contribute to cell injury in an “oncotic” manner and also demonstrate the proinflammatory potency of the drug. Furthermore, the decreased acidification of cytoplasm upon activation of A 3 R may attenuate the ongoing inflammatory response. The present study identifies a novel role for A 3 R selective agonist Cl-IB-MECA and suggests its importance in regulating cardiac cellular function. |
| Databáze: | OpenAIRE |
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