Lovastatin inhibits the extracellular-signal-regulated kinase pathway in immortalized rat brain neuroblasts.
We have shown previously that lovastatin, a 3-hydroxy-3-methyl- glutaryl coenzyme A reductase inhibitor, induces apoptosis in spontaneously immortalized rat brain neuroblasts. In the present study, we analysed the intracellular signal transduction pathways by which lovastatin induces neuroblast apoptosis. We showed that lovastatin efficiently inhibited Ras activation, which was associated with a significant decrease in ERK1/2 (extracellular-signal-regulated kinase 1/2) phosphorylation. Lovastatin also decreased CREB phosphorylation and CREB-mediated gene expression. The effects of lovastatin on the Ras/ERK1/2/CREB pathway were time- and concentration-dependent and fully prevented by mevalonate. In addition, we showed that two MEK [MAPK (mitogen-activated protein kinase)/ERK kinase] inhibitors, PD98059 and PD184352, were poor inducers of apoptosis in serum-treated neuroblasts. However, these inhibitors significantly increased apoptosis induced by lovastatin treatment. Furthermore, we showed that pharmacological inhibition of both MEK and phosphoinositide 3-kinase activities was able to induce neuroblast apoptosis with similar efficacy as lovastatin. Our results suggest that lovastatin triggers neuroblast apoptosis by regulating several signalling pathways, including the Ras/ERK1/2 pathway. These findings might also contribute to elucidate the intracellular mechanisms involved in the central nervous system side effects associated with statin therapy.
Cerezo-Guisado
Maria Isabel
MI
Departamento de Bioquímica, Biología Molecular y Genética Universidad de Extremadura, E-10071 Cáceres, Spain.
García-Román
Natalia
N
García-Marín
Luis Jesús
LJ
Alvarez-Barrientos
Alberto
A
Bragado
Maria Julia
MJ
Lorenzo
Maria Jesús
MJ
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002478:Cells, Cultured; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors*; D005333:Fetus; D017930:Genes, Reporter; D008148:Lovastatin / Q000494:pharmacology*; D008156:Luciferases / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D008148:Lovastatin; D008156:Luciferases; D048049:Extracellular Signal-Regulated MAP Kinases; D001616:beta-Galactosidase