Involvement of Bax protein in the prevention of glucocorticoid-induced thymocytes apoptosis by melatonin
The antiapoptotic effect of melatonin has been described in several systems. In this study, the antagonistic effect of the methoxyindole on dexamethasone-induced apoptosis in mouse thymocytes was examined. Melatonin decreased both DNA fragmentation, and the number of annexin V-positive cells incubat...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2004 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/186609 |
| Acceso en línea: | https://hdl.handle.net/2445/186609 |
| Access Level: | acceso abierto |
| Palabra clave: | Apoptosi Melatonina Glucocorticoides Proteïnes Apoptosis Melatonin Glucocorticoids Proteins |
| Sumario: | The antiapoptotic effect of melatonin has been described in several systems. In this study, the antagonistic effect of the methoxyindole on dexamethasone-induced apoptosis in mouse thymocytes was examined. Melatonin decreased both DNA fragmentation, and the number of annexin V-positive cells incubated in the presence of dexamethasone. Analysis of the expression of the members of the Bcl-2 family indicated that the synthetic glucocorticoid increased Bax protein levels without affecting the levels of Bcl-2, Bcl-XL, Bcl-XS, or Bak. This effect correlated with an increase in thymocytes bax mRNA levels. Dexamethasone also increased the release of cytochrome C from mitochondria. All of these effects were reduced in the presence of melatonin, which was ineffective per se on these parameters. In addition, the involvement of cAMP on glucocorticoid/melatonin antagonism was examined. Both melatonin and dexamethasone decreased the levels of this nucleotide in mouse thymocytes, indicating that the antagonistic action between both hormones involves a cAMP-independent pathway. In summary, the present results suggest that the antiapoptotic effect of melatonin on glucocorticoid-treated thymocytes would be a consequence of an inhibition of the mitochondrial pathway, presumably through the regulation of Bax protein levels. |
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