Cytoprotective effects of ascorbic acid, deferoxamine and n-acetylysteine against simulated ischemia/reperfusion damage in cultivated cardiac fibroblasts
Acute myocardial infarction is one of the main causes of global death and, therefore, a disease that has been widely studied. In heart attack, one factor that contributes to cellular damage is post-ischemic reperfusion, caused essentially by oxidative stress. In this regard, the effects of ischemia/...
| Autor: | |
|---|---|
| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2019 |
| País: | Chile |
| OAI Identifier: | oai:repositorio.anid.cl:10533/246323 |
| Acceso en línea: | https://hdl.handle.net/10533/246323 |
| Access Level: | acceso abierto |
| Palabra clave: | Medicina y Ciencias de la Salud Medicina Básica Farmacología y Farmacia |
| Sumario: | Acute myocardial infarction is one of the main causes of global death and, therefore, a disease that has been widely studied. In heart attack, one factor that contributes to cellular damage is post-ischemic reperfusion, caused essentially by oxidative stress. In this regard, the effects of ischemia/reperfusion damage on cardiac fibroblasts, a very important cell type in the tissue repair process, are still unknown. Ascorbic acid, deferoxamine, and N-acetylcysteine (A/D/N) are well known to be antioxidants with cardioprotective effects. Therefore, the objective of this study was to assess whether the pharmacological association between these antioxidants, at concentrations that individually do not show protection, could confer protection to cardiac fibroblasts against ischemia/reperfusion damage. To assess this, neonatal rat cardiac fibroblasts were subjected to simulated ischemia/reperfusion in the presence or absence of treatment with added A/D/N at the start of simulated reperfusion. Cell viability was measured using trypan blue staining, the production of reactive oxygen species (ROS) was measured using the 2´, 7´-dichlorofluorescin diacetate probe. Cell death was measured by flow cytometry using propidium iodide. The mechanisms of cellular signaling, differentiation in myofibroblasts and synthesis of pro-collagen type I were determined by Western blotting, while migration was evaluated using the wound healing assay. Our results show that the A/D/N association, at concentrations where each of them by itself did not show cytoprotective activity, increased the viability of cardiac fibroblasts. The A/D/N association also decreased oxidative stress generated in simulated ischemia/reperfusion, induced phosphorylation of the ERK1/2 and Akt survival pathways, and decreased phosphorylation of pro-apoptotic proteins p38 and JNK. Treatment with A/D/N also reduced reperfusion-induced apoptosis evidenced by a decrease in the sub-G1 population, less fragmentation of pro-caspases 9 and 3, as well as an increase in the Bcl-xl/Bax ratio. Finally, the ischemia/reperfusion inhibited serum-induced migration, differentiation of cardiac fibroblasts to cardiac myofibroblasts mediated by TGF-β1, and pro-collagen synthesis induced by angiotensin II, but these effects were prevented by treatment with A/D/N. In conclusion, this Thesis presents the first antecedents not previously described for the pharmacological association A/D/N, protecting the viability and functionality of cardiac fibroblasts after simulated ischemia/reperfusion and, therefore, representing a novel alternative therapy for cardioprotection. |
|---|