Statins promote the degradation of extracellular amyloid {beta}-peptide by microglia via stimulation of exosome-associated insulin-degrading enzyme (IDE) secretion - PubMed (original) (raw)

Increased IDE secretion by lovastatin and itraconazole promotes extracellular degradation of Aβ. A, conditioned media were collected from BV-2 cells after 24 h of incubation in the presence or absence of 5 μ

m

lovastatin (lova) or 2.5 μ

m

itraconazole (itra), and Aβ40 (1 μ

m

) was added to the cell-free conditioned media for 6 h. At the end of incubation, Aβ levels were analyzed by Western immunoblotting and ECL imaging. B, Aβ clearance was analyzed in the conditioned media obtained from lovastatin-treated BV-2 cells in the presence or absence of EDTA (10 μ

m

), bacitracin A (10 μ

m

, Baci. A), or recombinant insulin (10 μ

m

) by ECL imaging. Western immunoblotting showed equal amounts of IDE in all samples. C and D, BV-2 cells were treated with 5 μ

m

lovastatin (C) or 2.5 μ

m

itraconazole (D) for 24 h. IDE in the conditioned media was analyzed at the indicated time points by Western immunoblotting and by ECL imaging. E, BV-2 cells were treated with 5 μ

m

lovastatin (lova) or 2.5 μ

m

itraconazole (itra) for 24 h. Cellular and secreted IDE levels were analyzed by Western immunoblotting and ECL imaging. Cellular actin was detected as loading control. F, N9 cells were transfected with IDE targeting or nontargeting (NTR) control siRNA as indicated. 24 h after transfection, cells were treated with 5 μ

m

lovastatin or DMSO (control) for 24 h. Expression of cellular and secreted IDE was analyzed with Western immunoblotting. Cellular actin was detected as a loading control. G, control and IDE-suppressed (using siRNA) N9 cells were treated with 5 μ

m

lovastatin for 24 h. Conditioned media obtained from these cells were then incubated with 1 μ

m

Aβ40 for 6 h. Aβ levels in the beginning and at the end of incubation period were analyzed by Western immunoblotting and ECL imaging.