Figure 2.

Glucose oxidation in SH-SY5Y cells in not impaired following overexpression of secretase-dead BACE1 protein. (A) Representative immunoblots showing stable overexpression of wild type BACE1 and a secretase-dead BACE1 mutant (mBACE1) and resultant changes in cellular APP and sAPPβ shed into the culture media. (B–D) SH-SY5Y mBACE1 overexpression increased total BACE1 to levels equivalent to BACE1 overexpressed cells and ~3-4X greater than empty vector (EV) controls (B; n = 5), with no effect on APP levels (C; n = 3), but in contrast to BACE1 overexpression, mBACE1 reduced sAPPβ to levels below that of the EV controls (D; n = 6–10). (E–G) SH-SY5Y mBACE1 overexpression had no effect on ¹⁴C-glucose oxidation compared to EV controls, in contrast to the reduction in ¹⁴C-glucose oxidation observed in BACE1 overexpressing cells (E; n = 5), with mBACE1 having no effect on ¹⁴C-glucose incorporation (F; n = 5), resulting in the ratio of ¹⁴C-glucose oxidation to incorporation being unchanged in mBACE1 cells (G; n = 5). Values are means ± SEM. ^*p < 0.05; ^**p < 0.01; ^***p < 0.001.