Journal: Aging Cell
Article Title: Gamma frequency light flicker regulates amyloid precursor protein trafficking for reducing β‐amyloid load in Alzheimer's disease model
doi: 10.1111/acel.13573
Figure Lengend Snippet: Activated PKC by gamma frequency light flicker phosphorylates APP and KCC2 to maintain membrane levels of both, which contributes to the upregulation of surface‐GABA A R α1. (a) Representative immunoblots showing levels of p‐PKC in cortex of 6‐month‐old APP/PS1 mice after 7 days of 1 h/day dark, 40 Hz flicker, RO 31‐8220 (6 mg/kg/d, s.c), RO 31‐8220 (6 mg/kg/d, s.c) with 40 Hz flicker. Immunoprecipitates were analyzed to detect the serine phosphorylation levels of APP and KCC2 with anti‐KCC2, anti‐APP, and anti‐phosphoserine antibodies. (b) Quantification of phosphorylated KCC2 and APP normalized to total KCC2 and APP ( n = 4 mice per group). Data are presented as mean ± SEM. *p < 0.05 vs. APP/PS1 group; #p < 0.05 vs. indicated group; by two‐way ANOVA with Tukey's post hoc multiple comparisons test. (c) Soluble and insoluble Aβ 1‐40 and Aβ 1‐42 levels in cortex of APP/PS1 mice exposed to dark, 40 Hz flicker, RO 31‐8220 (6 mg/kg/d, s.c), RO 31‐8220 (6 mg/kg/d, s.c) with 40 Hz flicker were performed by ELISA (8 mice/group). Data are presented as mean ± SEM. **p < 0.01 vs. APP/PS1 group; ##p < 0.01 vs. indicated group, by two‐way ANOVA with Tukey's post hoc multiple comparisons test. (d) Representative immunoblots showing co‐immunoprecipitation with both KCC2 and APP antibodies in cortex of APP/PS1 mice exposed to dark, 40 Hz flicker, RO 31‐8220 (6 mg/kg/d, s.c), RO 31‐8220 (6 mg/kg/d, s.c) with 40 Hz flicker ( n = 6 mice/group). Data are presented as mean ± SEM. *p < 0.05 vs. APP/PS1 group; **p < 0.01 vs. APP/PS1 group; #p < 0.05 vs. indicated group; ##p < 0.01 vs. indicated group, by two‐way ANOVA with Tukey's post hoc multiple comparisons test. (e) Relative immunoreactivity of APP normalized to KCC2 (IP: KCC2). (f) Relative immunoreactivity of KCC2 normalized to APP (IP: APP). (g) Representative immunoblots of membrane proteins from 6‐month‐old APP/PS1 mice exposed to 7 days of dark, 40 Hz flicker, RO 31‐8220 (6 mg/kg/d, s.c), RO 31‐8220 (6 mg/kg/d, s.c) with 40 Hz flicker (3 mice per group). Data are presented as mean ± SEM. *p < 0.05 vs. APP/PS1 group; ##p < 0.01 vs. indicated group, by two‐way ANOVA with Tukey's post hoc multiple comparisons test. (h) Immunohistochemistry with anti‐APP (red) and anti‐KCC2 (green) in cortex of 6‐month‐old APP/PS1 treated with dark, 40 Hz light flicker, RO 31‐8220 (6 mg/kg/d, s.c), RO 31‐8220 (6 mg/kg/d, s.c) with 40 Hz flicker for 7 days ( n = 5 mice/group). Scale bar, 50 μm. (i) Gates P2 (green gate) and P3 (orange gate) for surface APP and GABA A R α1 were determined, respectively, in the unstained group, and the number of APP + cells (gate P2) was allowed to count 10,000 statistically in each experimental group, and the percentage number of GABA A R α1 + cells and mean fluorescence intensity (MFI) levels of surface GABA A R α1 in the gate P2 (APP + cells) were analyzed on a CytoFLEX flow cytometer, using CytExpert software ( n = 5 mice/group). Data are presented as mean ± SEM. *p < 0.05 vs. APP/PS1 group; **p < 0.01 vs. APP/PS1 group; #p < 0.05 vs. indicated group, by two‐way ANOVA with Tukey's post hoc multiple comparisons test. (j) Immunohistochemistry with anti‐Aβ (green) and anti‐EEA1 (red) antibodies in cortex of 6‐month‐old APP/PS1 treated with dark, 40 Hz light flicker, RO 31‐8220 (6 mg/kg/d, s.c), RO 31‐8220 (6 mg/kg/d, s.c) with 40 Hz flicker for 7 days ( n = 6 to 7 mice per group), scale bar, 50 μm. DAPI labeling was used for cell nuclei
Article Snippet: KCC2 siRNA , Santa Cruz Biotechnology , Cat# sc‐42607.
Techniques: Membrane, Western Blot, Phospho-proteomics, Enzyme-linked Immunosorbent Assay, Immunoprecipitation, Immunohistochemistry, Fluorescence, Flow Cytometry, Software, Labeling