| First Author | Dumanis SB | Year | 2013 |
| Journal | J Neurochem | Volume | 124 |
| Issue | 1 | Pages | 4-14 |
| PubMed ID | 22862561 | Mgi Jnum | J:190575 |
| Mgi Id | MGI:5449138 | Doi | 10.1111/j.1471-4159.2012.07908.x |
| Citation | Dumanis SB, et al. (2013) APOE genotype affects the pre-synaptic compartment of glutamatergic nerve terminals. J Neurochem 124(1):4-14 |
| abstractText | Apolipoprotein E (APOE) genotype affects outcomes of Alzheimer's disease and other conditions of brain damage. Using APOE knock-in mice, we have previously shown that APOE-epsilon4 Targeted Replacement (TR) mice have fewer dendritic spines and reduced branching in cortical neurons. As dendritic spines are post-synaptic sites of excitatory neurotransmission, we used APOE TR mice to examine whether APOE genotype affected the various elements of the glutamate-glutamine cycle. We found that levels of glutamine synthetase and glutamate uptake transporters were unchanged among the APOE genotypes. However, compared with APOE-epsilon3 TR mice, APOE-epsilon4 TR mice had decreased glutaminase levels (18%, p < 0.05), suggesting decreased conversion of glutamine to glutamate. APOE-epsilon4 TR mice also had increased levels of the vesicular glutamate transporter 1 (20%, p < 0.05), suggesting that APOE genotype affects pre-synaptic terminal composition. To address whether these changes affected normal neurotransmission, we examined the production and metabolism of glutamate and glutamine at 4-5 months and 1 year. Using high-frequency (13)C/(1)H nuclear magnetic resonance spectroscopy, we found that APOE-epsilon4 TR mice have decreased production of glutamate and increased levels of glutamine. These factors may contribute to the increased risk of neurodegeneration associated with APOE-epsilon4, and also act as surrogate markers for Alzheimer's disease risk. |
