In Vitro Modulatory Evaluation of Mas Receptor/Angiotensin‐(1‐7) in Doxorubicin‐induced Cardiotoxicity

Abstract

BackgroundDoxorubicin (DOX) antineoplastic is considered the prototype of cardiotoxicity for inducing direct damage to the myocardium. Pharmacological blockage of Angiotensin (Ang) II action is one of the main strategies to manage DOX‐induced cardiomyopathy. The effects are also mediated by the activation of the Mas receptor (MasR)/Ang‐(1‐7) axis, which is the counter‐regulatory axis of Ang II. The modulation of MasR/Ang‐(1‐7) axis is Ang‐(1‐7) (agonist) and A779 (antagonist) and may be a potential strategy in the context of cardiotoxicity.ObjectiveEvaluate the influence of pharmacological modulation of MasR/Ang‐(1‐7) axis on DOX‐induced cardiotoxicity in cardiomyoblast cells.MethodsMurine cardiomyoblasts (H9c2) were treated with A779 (10μM) for 30′ followed by Ang‐(1‐7) (100nM) for 30′ previous to expose with 0.1μM and 0.35μM (IC50) of DOX for 24h. Cell viability (Neutral Red and Trypan Blue), cell death profile (Annexin/7AAD), DNA damage induction (Comet Assay) and mitochondrial membrane integrity (Rhodamine 123) were evaluated after treatment protocol. The experiments were performed in triplicate, and data were analyzed by ANOVA followed by Dunnet, considering p <0.05.ResultsMasR modulation did not prevent the reduction of viability of cardiomyoblasts by DOX, neither altered the pattern of cell death. Both concentrations of DOX induced DNA strand breaks (C: 27.5 ± 13.4; DOX 0.1μM: 53.5 ± 9.1; DOX IC50: 109.5 ± 17.6 U.A.). Pretreatment with peptides suggested a reduction of the frequency of nucleus damage (DOX 0.1μM + Ang‐(1‐7): 36.5 ± 6.3; DOX 0.1μM +A779: 36.5 ± 0.7 U.A.) only at 0.1 μM DOX concentration, while pretreatment with A779 or Ang‐(1‐7) preserved the mitochondrial membrane integrity.ConclusionModulation by agonism or antagonism of MasR in H9c2 cells reduces the DNA damage and the mitochondrial integrity. These results seem to be independent of MasR modulation, pointing to the involvement of other receptors and their crosstalk.Support or Funding InformationCAPES, CNPq and FAPICC/ICFUC