Beta-amyloid induces neuronal apoptosis via a mechanism that involves the c-Jun N-terminal kinase pathway and the induction of Fas ligand.
Elevated levels of beta-Amyloid (Abeta) are present in the brains of individuals with either the sporadic or familial form of Alzheimer's disease (AD), and the deposition of Abeta within the senile plaques that are a hallmark of AD is thought to be a primary cause of the cognitive dysfunction that occurs in AD. Recent evidence suggests that Abeta induces neuronal apoptosis in the brain and in primary neuronal cultures, and that this Abeta-induced neuronal death may be responsible in part for the cognitive decline found in AD patients. In this study we have characterized one mechanism by which Abeta induces neuronal death. We found that in cortical neurons exposed to Abeta, activated c-Jun N-terminal kinase (JNK) is required for the phosphorylation and activation of the c-Jun transcription factor, which in turn stimulates the transcription of several key target genes, including the death inducer Fas ligand. The binding of Fas ligand to its receptor Fas then induces a cascade of events that lead to caspase activation and ultimately cell death. By analyzing the effects of mutations in each of the components of the JNK-c-Jun-Fas ligand-Fas pathway, we demonstrate that this pathway plays a critical role in mediating Abeta-induced death of cultured neurons. These findings raise the possibility that the JNK pathway may also contribute to Abeta-dependent death in AD patients.
Morishima
Y
Y
Division of Neuroscience, Children's Hospital, and Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Gotoh
Y
Y
Zieg
J
J
Barrett
T
T
Takano
H
H
Flavell
R
R
Davis
R J
RJ
Shirasaki
Y
Y
Greenberg
M E
ME
D000544:Alzheimer Disease / Q000209:etiology / Q000378:metabolism*; D016229:Amyloid beta-Peptides / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000235:genetics; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000187:drug effects; D053222:Fas Ligand Protein; D005786:Gene Expression Regulation; D048031:JNK Mitogen-Activated Protein Kinases; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D048057:Mitogen-Activated Protein Kinase 10; D020928:Mitogen-Activated Protein Kinases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D010766:Phosphorylation / Q000187:drug effects; D011505:Protein-Tyrosine Kinases / Q000172:deficiency / Q000235:genetics; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D015398:Signal Transduction / Q000187:drug effects; D014158:Transcription, Genetic / Q000187:drug effects; D019014:fas Receptor / Q000378:metabolism
D016229:Amyloid beta-Peptides; D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; C505662:Faslg protein, rat; D008562:Membrane Glycoproteins; D016755:Proto-Oncogene Proteins c-jun; D019014:fas Receptor; D048057:Mitogen-Activated Protein Kinase 10; D011505:Protein-Tyrosine Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases