Fig. 7.

AD-risk factors increase ANP32A via activating C/EBPβ. a Overexpressing htau in HEK293 cells increased protein level of ANP32A with elevation of total and the phosphorylated transcription factor C/EBPβ (pC/EBPβ) measured by Western blotting, the empty vector (Vec) was transfected as control. b, c Treatment of HEK293 cells with Aβ_1-42 (5 μM, 24 h) or H₂O₂ (50 μM, 40 min) increased protein level of ANP32A with elevation of total and the pC/EBPβ, and the scrambled Aβ_42-1 (b) or sterile water (veh, vehicle) (c) was used as control. d ANP32A with C/EBPβ and pC/EBPβ levels increased in the hippocampus of 12-month old htau mice compared with the age-matched wild-type (wt) littermates. e The quantitative analysis of ANP32A, C/EBPβ and pC/EBPβ level in a-d. The broken line indicates the control level received by the empty vector, Aβ_42-1, wt or the vehicle. ‘—‘ presents the relative level of control (Vec, Aβ_42-1, wt or the vehicle). f Overexpression of htau and treatment with Aβ_1-42 (5 μM, 24 h) or H₂O₂ (50 μM, 40 min) increased mRNA level of ANP32A in HEK293 cells, and ANP32A mRNA level also increased in the hippocampus of 12-m old htau mice, detected by RT-PCR. g–j Simultaneous downregulation of C/EBPβ by expressing siC/EBPβ for 48 h attenuated the htau–, Aβ_1-42–and H₂O₂–induced elevation of ANP32A protein in HEK293 cells, detected by Western blotting and quantitative analysis. k Overexpression of htau or H₂O₂ treatment increased luciferase activity of ANP32A in HEK293 cells, while simultaneous knockdown of C/EBPβ reduced the luciferase activity. Data were presented as mean ± SD. *, p<0.05, **, p<0.01 vs Vec, Aβ_42-1, wt or the vehicle (Unpaired Student's t-test (two-tailed))