| Autor: |
Martín, Rubén, Hernández, Marita, Ibeas, Elvira, Fuentes, Lucia, Salicio, Veronica, Arnés, Mercedes, Nieto, María Luisa |
| Předmět: |
|
| Zdroj: |
Journal of Neurochemistry; Nov2009, Vol. 111 Issue 4, p988-999, 12p, 3 Diagrams, 3 Graphs |
| Abstrakt: |
Human group IIA secreted phospholipase A2 (sPLA2-IIA) has been characterized in numerous inflammatory and neoplastic conditions. sPLA2-IIA can either promote or inhibit cell growth depending on the cellular type and the specific injury. We have previously demonstrated that exogenous sPLA2-IIA, by engagement to a membrane structure, induces proliferation and activation of mitogen-activated protein kinases cascade in human astrocytoma cells. In this study, we used human astrocytoma 1321N1 cells to investigate the key molecules mediating sPLA2-IIA-induced cell proliferation. We found that sPLA2-IIA promoted reactive oxygen species (ROS) accumulation, which was abrogated in the presence of allopurinol and DPI, but not by rotenone, discarding mitochondria as a ROS source. In addition, sPLA2-IIA triggered Ras and Raf-1 activation, with kinetics that paralleled ERK phosphorylation, and co-immunoprecipitation assays indicated an association between Ras, Raf-1 and ERK. Additionally, Akt, p70 ribosomal protein S6 kinase, and S6 ribosomal protein were also phosphorylated upon sPLA2-IIA treatment, effect that was abrogated by N-acetylcysteine or LY294002 treatment indicating that ROS and phosphatidylinositol 3 kinase are upstream signaling regulators. As the inhibitors N-acetylcysteine, PD98059, LY294002 or rapamycin blocked sPLA2-IIA-induced proliferation without activation of the apoptotic program, we suggest that inhibition of these intracellular signal transduction elements may represent a mechanism of growth arrest. Our results reveal new potential targets for therapeutic intervention in neuroinflammatory disorders and brain cancer in particular. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
Plný text