Fig. 3: Reduced ALDH2 activity induced 4-hydroxy-2-nonenal (4-HNE) accumulation, and only the chiral (R)−4-HNE led to Aβ40/42 ratio increase.
From: The aldehyde dehydrogenase 2 rs671 variant enhances amyloid β pathology
a Proteomic profiling was carried out using N2a-APPswe cells pretreated with PBS or 60 μM daidzin for 48 h. KEGG pathways analysis of the differentially expressed proteins (DEPs). b Representative images of 4-HNE immunohistochemical staining of paraffin sections of the human hippocampus with pathological AD. n = 3 per group. rs671 GG (86.33 ± 7.02 yr), GA/AA (82.33 ± 1.15 yr). Scale bar, 50 μm. c Representative images of 4-HNE immunostaining of frozen brain sections of 3-month-old male Aldh2−/− mice (n = 5) and wild-type mice (n = 4). Scale bar, 50 μm. d Representative images of immunocytochemical staining with 4-HNE antibody (green) in SH-SY5Y cells after ALDH2 silencing. Three independent biological replicates were performed. Scale bar, 25 μm. e Separation of (R)−4-HNE and (S)−4-HNE from (±)−4-HNE by high-performance liquid chromatography (Shimadzu) with a chiral column (4.6 × 150 mm, CHIRALPAK AS-H). f and g SH-SY5Y cells were pretreated with PBS, or (±)−4-HNE, (R)−4-HNE, or (S)−4-HNE at 2 μM for 72 h or 10 μM for 4 h. f Autophagy was assessed by WB for LC3A-I/LC3A-II, the typical marker of autophagy. g Apoptosis was assessed by flow cytometry. The flow-cytometry gating strategies were shown in Supplementary Fig. 7e. h and i Levels of intracellular Aβ40 and Aβ42 were determined by quantitative ELISA. h SH-SY5Y cells were treated with 0, 5, or 10 μM (±)−4-HNE, (R)−4-HNE, or (S)−4-HNE for 4 h. i SH-SY5Y cells were treated with 2 μM (±)−4-HNE, (R)−4-HNE, or (S)−4-HNE for 24 h. n = 3 biologically independent samples. Data are presented as mean values ± SD. All box plots include the median line, the box indicates the interquartile range, whiskers indicate minima and maxima. Statistical analysis was performed using two-tailed Student’s t-test for two groups (b and c) and one-way ANOVA with LSD post-hoc test for multiple groups (h and i). Source data are provided as a Source Data file.
