Display Settings:

Items per page
We are sorry, but NCBI web applications do not support your browser and may not function properly. More information

Results: 7

1.
Figure 7

Figure 7. Synergism between Aβ/APP and tau is required to elevate αSyn protein levels in vivo. From: Soluble ?-synuclein is a novel modulator of Alzheimer's disease pathophysiology.

(A) Quantitative WB analysis of αSyn, synaptophysin (SYP) and actin using soluble brain extracts from 3- and 8-month-old non-transgenic (CTL), Tg2576 (Aβ), rTg4510 (Tau) and Tg2576xrTg4510 (AβxTau) mice. (B) Quantification of SYP mirrors neuronal toxicity previously reported in rTg4510. Values represent mean ± S.D (n = 3–4/age/genotype; ANOVA followed by Fisher PLSD test). (C) Quantification of soluble α protein levels revealed no apparent changes with aging in wild-type, Tg2576 and rTg4510 mice. In contrast, a ~1.6-fold increase of αSyn was observed in 8-month-old Tg2576xrTg4510 compared to 3-month-old animals. Empty and filled bars represent data at 3 and 8 months respectively. Values represent mean ± S.D (n = 3–4/age/genotype; ANOVA followed by Fisher PLSD test).

Megan E. Larson, et al. J Neurosci. ;32(30):10253-10266.
2.
Figure 3

Figure 3. SCNA and SCNB gene expression in the ROS cohort. From: Soluble ?-synuclein is a novel modulator of Alzheimer's disease pathophysiology.

(A–C) SCNA (A), SCNB (B) and GAPDH (C) mRNA levels were measured by reverse transcriptase-qPCR and normalized to the housekeeping gene β-actin. GAPDH was used as internal control. Quantification revealed a ~1.7-fold increase in SCNA gene expression in AD compared to age-matched controls, consistent with the ~2-fold elevation of soluble αSyn observed at the protein level. SCNB mRNA levels were lowered by ~1.8-fold. (D) Western blot (WB) analyses illustrating the biochemical segregation of of soluble βSyn in extracellular (EC)-, intracellular (IC)- or membrane (MB)-enriched fractions. (E) Quantification of βSyn in the inferior temporal cortex of subjects with NCI, MCI or AD. No statistical changes were observed. (F) In absence of LB pathology, βSyn levels were reduced by ~2-fold in AD compared to controls. Values represent mean ± S.D (ANOVA followed by Fisher PLSD test, *P < 0.05).

Megan E. Larson, et al. J Neurosci. ;32(30):10253-10266.
3.
Figure 2

Figure 2. Increase in soluble αSyn in AD brain in absence of Lewy bodies/neurites. From: Soluble ?-synuclein is a novel modulator of Alzheimer's disease pathophysiology.

(A) Western blot (WB) analyses of soluble αSyn species in extracellular (EC)-, intracellular (IC)- or membrane (MB)-enriched fractions using LB509. Similar results were obtained with 4D6 or Syn1 (not shown). Both transgenic and wild-type littermates from line G2.3-A53T (αSyn Tg) used in this panel were 10 months of age. (B) Gel filtration combined with SDS-PAGE confirmed the presence of SDS-resistant αSyn soluble assemblies. (C) Quantification of monomeric and oligomeric αSyn species in the inferior temporal cortex of subjects with NCI, MCI or AD. While monomeric and dimeric αSyn-EC remained unchanged across groups, monomeric αSyn-IC levels were significantly higher in AD than in MCI and NCI brain tissues. (D) In total absence of LB pathology, αSyn-IC monomers were increased by more than 2-fold in AD compared to controls.

Megan E. Larson, et al. J Neurosci. ;32(30):10253-10266.
4.
Figure 1

Figure 1. Characterization of the 4-step protein extraction protocol using human brain tissue. From: Soluble ?-synuclein is a novel modulator of Alzheimer's disease pathophysiology.

(A) Selected brain tissue (0.5 mm3 of inferior temporal gyrus of a control brain) was subjected to serial extractions allowing the segregation of proteins based on their cellular compartmentalization. Examples of obtained segregation for human proteins with known compartmentalization. (B) Extraction profile for selected disease-related proteins. Abbreviations: TIMP3, tissue inhibitor of metalloproteinase-3; ERK, Extracellular signal-regulated kinase; EB3, End-binding protein-3; βSyn, beta-synuclein; NeuN, Neuronal nuclei; GluN2, glutamate NMDA receptor subunit 2; PSD-95, Postsynaptic density protein-95; Fyn, Fyn kinase; SNAP-25, synaptosomal-associated protein 25; VAMP-2, vesicle-associated membrane protein 2; sAPP/APP, soluble/full length amyloid precursor protein; TDP-43, TAR DNA binding protein-43; PrPc, cellular prion protein; αSyn, alpha-synuclein; AD, Alzheimer’s disease; ALS, Amyotrophic lateral sclerosis; PD, Parkinson’s disease.

Megan E. Larson, et al. J Neurosci. ;32(30):10253-10266.
5.
Figure 6

Figure 6. Dissociation in the colocalization of αSyn and synapsins in AD brains with elevated levels of soluble αSyn. From: Soluble ?-synuclein is a novel modulator of Alzheimer's disease pathophysiology.

(A) Triple labeling for MAP-2 (blue; a, b), αSyn (green; c, d) and synapsins (red; e, f) in 6 μm sections of the inferior temporal gyrus from AD brains with normal or high levels of αSyn (determined by biochemical measurements). Nuclei were stained using a DAPI (magenta)-containing mounting medium. Confocal images for AD brains with normal αSyn levels correspond to top panels, while images for AD brains with elevated αSyn levels are shown in bottom panels. Merged channels are shown in g,h, with selected magnified areas presented in i, j. (B) Colocalization analyses in the protein content of synaptic vesicles labeled for αSyn, synapsins (SYN) or synaptophysin (SYP) in AD brains of subjects with normal or high soluble αSyn levels. (C) Quantification of the co-localization between αSyn/SYN and αSyn/SYP in these selected AD cases was done using Bitplane’s Imaris7.0 co-localization tool. Z-stacks of images were transformed for volume rendering and voxel count analysis was performed. A representative image of the rendered images is displayed. Histogram values represent mean ± S.D (n = 6 cases, 3 fields per case).

Megan E. Larson, et al. J Neurosci. ;32(30):10253-10266.
6.
Figure 4

Figure 4. In absence of pathology, overexpression of wild-type human αSyn causes memory deficits in the Barnes circular maze. From: Soluble ?-synuclein is a novel modulator of Alzheimer's disease pathophysiology.

Seven-month-old non-transgenic C57BL6, J20 and Tg-I2.2 mice (n = 4 mice per genotype) were trained in the Barnes circular maze for 4 days. A probe trial (escape platform removed) was conducted 24 h after the last training session. (A, B) During acquisition of the task, latency (A) and distance travelled (B) were recorded. All three groups learned this task. Two-way repeated-measures ANOVA revealed a significant effect of training (F = 95.61, p = 0.0004), but no effect of transgene (F = 0.015, p = 0.9058) and no significant Day*transgene interaction (F = 1.10, p = 0.3827). (C–E) During the probe trial on day 5, wild-type mice, but not mice with hAPP or hαSyn, displayed a search bias for the target quadrant (C, D) and spent less time in non-target quadrants (D,E). Two-way ANOVA of these data revealed a significant effect of hAPP (C, F(1,6) = 4.32, p = 0.038; E, F(1,6) = 4.68, p = 0.015), of hαSyn (C, F(1,6) = 14.34, p = 0.009; E, F(1,6) = 13.45, p = 0.010), and significant day*transgene interactions for both transgenic lines (C, FJ20(4,24) = 3.916, p = 0.013 and FI2.2(4,24) = 4.64, p = 0.041; E, FJ20(4,24) = 5.08, p = 0.004 and FI2.2(4,24) = 2.88, p = 0.044). (F, G) Neither J20 nor TgI2.2 mice showed patterns of faster extinctions than non-transgenic animals during the 3 minutes of the probe trial as indicated by the averaged time spent in the target quadrant or non-target quadrants across 1-minute intervals. Data represent mean ± s.e.m. (n = 6 males/age/genotype; univariate RMANOVA test).

Megan E. Larson, et al. J Neurosci. ;32(30):10253-10266.
7.
Figure 5

Figure 5. A 2-fold increase in soluble αSyn is associated with a selective decrease in vesicular proteins in AD. From: Soluble ?-synuclein is a novel modulator of Alzheimer's disease pathophysiology.

(A) WB analysis of brain extracts from 17-month-old Tg2576 and 10-month-old TgG2.3-A53T (labeled as APP Tg and αSyn Tg respectively) brain tissue using infrared-conjugated secondary antibodies shows a selective reduction in synapsins in αSyn Tg. Rab3, synaptophysin and actin levels were unchanged in both lines. (B) Scatterplot of soluble αSyn levels in the ITG of subjects with AD. Measurements reflect the quantification of αSyn by WB following SDS-PAGE using the antibody LB509. Selected AD subjects were chosen to compose 2 groups (n = 3/group) whose soluble αSyn ratio equaled 2. They are referred as “AD-High” and “AD-Normal” and indicated by filled red circles. (C) Linear regression depicting the relationship between episodic memory and the levels of monomeric αSyn in the IC fraction measured by SDS-PAGE. Filled circles indicate specimen selected for analyses of vesicular presynaptic proteins (Figures 3–4). Please note that the AD subjects with a 2-fold elevated of αSyn are more impaired than AD subjects with lower αSyn expression. (D) Quantitative WB analysis of brain extracts from AD brain tissue with normal or high (2-fold increase) αSyn-IC levels, respectively labeled AD-Normal and AD-High, shows a reduction in synapsins and complexins but not Rab3 or synaptophysin. (E) Quantification confirms the observed changes in (B). Values represent mean ± S.D (n = 3). (F) Regression analyses between total synapsin protein expression and “monomeric” αSyn in all AD cases (n = 24) indicated a negative correlation (Spearman Rho).

Megan E. Larson, et al. J Neurosci. ;32(30):10253-10266.

Display Settings:

Items per page

Supplemental Content

Recent activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...
Write to the Help Desk