Figure 8.
Aβ1-42 at sublethal concentrations does not interfere with the activation of TrkB and PLCγ. A, BDNF-induced phosphorylation of PLCγ at tyrosine residues. Cortical neurons were stimulated with 50 ng/ml BDNF for 10 min. Cell lysates were immunoprecipitated by agarose-linked anti-phosphotyrosine antibodies, and proteins of the washed immunoprecipitates were resolved by SDS-PAGE and subjected to Western blot analysis with a specific anti-PLCγ antibody (P-PLCγ). BDNF-induced PLCγ phosphorylation was not influenced significantly by Aβ1-42 pretreatment; in terms of phosphorylated PLCγ levels obtained in the BDNF-exposed cultures, the estimate in the Aβ1-42-treated cultures was 92 ± 7.1% (5 μm) and 97 ± 7.2% (10 μm) (n = 3). B, Phosphorylation of TrkB was examined via Western blotting with an antibody against TrkB phosphorylated at Tyr490 (P-TrkB). Pretreatment with 10 μm Aβ1-42 had no significant influence on the BDNF-induced P-TrkB content; in terms of P-TrkB levels obtained in the BDNF-exposed culture, the estimate in the Aβ1-42-pretreated cells was 94 ± 4.1% (n = 3).