Localization of Aβ
in lysosomes. A. Aβ42 in cellular fraction in NG2 cell line and culture supernatant was measured by immunoblots. The results were quantified and presented as mean ± SD; **p<0.01, denote significant difference from that at 0 hours. The experiment was replicated three times. B. NG2 cell line was incubated with HiLyte Fluor™ 488-labeled Aβ42 (400 nM) for 24 hours, then treated with lysotracker (40 nM) for 30 minutes. Cell nuclei were labeled with DAPI. Aβ42 was co-localized with the signal of lysotracker. Scale bars = 10 μm. C. The mRNA expression of LAMP1 and LAPM2 in NG2 cell line was measured by RT-PCR after treatment with Aβ42 at the indicated times. Data were presented as mean ± SD; **p<0.01, compared with cells treated with Aβ42 for 0 hours. The experiments were replicated three times. D and E. NG2 cell line was exposed to Aβ42 for 6 hours, then treated with leupeptin (20 μM) and pepstatin A (20 μM) for 18 hours. The levels of cellular Aβ42, and LC3, and beclin1 proteins were determined by immunoblotting and normalized to the expression of GAPDH. Data were presented as mean ± SD; *p<0.05, **p<0.01, denote significant difference from the group treated with Aβ42 alone (Ct). The experiments were replicated three times.