Requirement of aggregation propensity of Alzheimer amyloid peptides for neuronal cell surface binding-5

<p><b>Copyright information:</b></p><p>Taken from "Requirement of aggregation propensity of Alzheimer amyloid peptides for neuronal cell surface binding"</p><p>http://www.biomedcentral.com/1471-2202/8/29</p><p>BMC Neuroscience 2007;8():29-29.</p><p>Published online 2 May 2007</p><p>PMCID:PMC1871596.</p><p></p>GF differentiated PC12 cells, while treatments that target cell surface lipids or carbohydrates had no effect. SBTI-inactivated trypsin had little effect on Aβ42 association. (B) Concentration dependence of trypsin treated NGF differentiated PC12 cells with 0, 5, 10 and 100 μg/mL trypsin as indicated, followed by 1 hour Aβ42 treatment. (C) 10 μg/mL trypsin treatment of NGF differentiated PC12 cells demonstrate that Aβ42 association with the cell surface recovers over time

Requirement of aggregation propensity of Alzheimer amyloid peptides for neuronal cell surface binding-4

<p><b>Copyright information:</b></p><p>Taken from "Requirement of aggregation propensity of Alzheimer amyloid peptides for neuronal cell surface binding"</p><p>http://www.biomedcentral.com/1471-2202/8/29</p><p>BMC Neuroscience 2007;8():29-29.</p><p>Published online 2 May 2007</p><p>PMCID:PMC1871596.</p><p></p> binding phase over the next 24 hours. Aβ40 (dashed line) did not display the initial rapid binding phase, but was otherwise similar to Aβ42. The mutant peptide (dotted line) did not interact with the live NGF differentiated PC12 cells. This finding suggests a correlation between aggregation propensity and cell association for Aβ

Requirement of aggregation propensity of Alzheimer amyloid peptides for neuronal cell surface binding-3

<p><b>Copyright information:</b></p><p>Taken from "Requirement of aggregation propensity of Alzheimer amyloid peptides for neuronal cell surface binding"</p><p>http://www.biomedcentral.com/1471-2202/8/29</p><p>BMC Neuroscience 2007;8():29-29.</p><p>Published online 2 May 2007</p><p>PMCID:PMC1871596.</p><p></p>iation, whereas mutant peptide did not appear to significantly associate with the live cells. It is interesting to note the bimodal distribution that develops over time

Requirement of aggregation propensity of Alzheimer amyloid peptides for neuronal cell surface binding-1

<p><b>Copyright information:</b></p><p>Taken from "Requirement of aggregation propensity of Alzheimer amyloid peptides for neuronal cell surface binding"</p><p>http://www.biomedcentral.com/1471-2202/8/29</p><p>BMC Neuroscience 2007;8():29-29.</p><p>Published online 2 May 2007</p><p>PMCID:PMC1871596.</p><p></p> present in the mutant peptide solution, two distributions of oligomers were present for Aβ40, and larger oligomers were present for Aβ42. (B) Aggregation marked by thioflavin-T fluorescence at pH 6 and pH 5 illustrated weak fluorescence for the mutant peptide (Mut), moderate aggregation for Aβ40, and the highest aggregation for Aβ42. The thioflavin-T alone sample represents the total emission peak area for a control sample not containing any Aβ. The data from these techniques indicates that the rank order of aggregation propensity is Aβ42 > Aβ40 > mutant

Requirement of aggregation propensity of Alzheimer amyloid peptides for neuronal cell surface binding-0

<p><b>Copyright information:</b></p><p>Taken from "Requirement of aggregation propensity of Alzheimer amyloid peptides for neuronal cell surface binding"</p><p>http://www.biomedcentral.com/1471-2202/8/29</p><p>BMC Neuroscience 2007;8():29-29.</p><p>Published online 2 May 2007</p><p>PMCID:PMC1871596.</p><p></p>rcles) was observed using circular dichroism. (B) Similar β-sheet conformation of TMR-labelled Aβ42 (closed squares) and unlabelled Aβ42 (open squares) was found using circular dichroism. Unstructured conformation of TMR-labelled mutant peptide (closed triangles) is also shown. (C) Thioflavin-T fluorescence indicated similar pH-dependent aggregation profiles for both TMR-labelled Aβ40 (solid line, closed circles) and unlabelled Aβ40 (dashed line, open circles). (D) Thioflavin-T fluorescence also indicated similar aggregation profiles for both TMR-labelled Aβ42 (solid line, closed squares) and unlabelled Aβ42 (dashed line, open squares) as well as very little aggregation produced by the TMR-labelled mutant peptide (dotted line, closed triangles). Electron microscopy images of TMR-labelled Aβ40 and TMR-labelled Aβ42 amyloid fibrils are shown in (E) and (F), respectively, with 100 nm scale bars. The high similarity between labelled and unlabelled peptides suggests that the addition of the fluorescent label has no observable effect on the aggregation profile of Aβ

Requirement of aggregation propensity of Alzheimer amyloid peptides for neuronal cell surface binding-2

<p><b>Copyright information:</b></p><p>Taken from "Requirement of aggregation propensity of Alzheimer amyloid peptides for neuronal cell surface binding"</p><p>http://www.biomedcentral.com/1471-2202/8/29</p><p>BMC Neuroscience 2007;8():29-29.</p><p>Published online 2 May 2007</p><p>PMCID:PMC1871596.</p><p></p>in red. Aβ42 displayed the greatest cell surface binding among the peptides to the differentiated neuronal cell lines (PC12, N2A and SH-SY5Y). The mutant peptide was not observed to associate with any of the cell lines tested. None of the peptides tested associated with the U937 cells

Effects of Neurotrophic Support and Amyloid-Targeted Combined Therapy on Adult Hippocampal Neurogenesis in a Transgenic Model of Alzheimer's Disease

<div><p>Although it is recognized that multi-drug therapies may be necessary to combat AD, there is a paucity of preclinical proof of concept studies. We present a combination treatment paradigm, which temporally affects different aspects of Alzheimer’s disease (AD)-like pathology, specifically Aβ-toxicity and neurogenesis. At early stages of AD-like pathology, in TgCRND8 mice, we found that combating Aβ pathology with <i>scyllo</i>-inositol ameliorated deficits in neurogenesis. Older TgCRND8 mice with established amyloid load had decreased progenitor cell proliferation and survival compared to non-transgenic mice, regardless of <i>scyllo</i>-inositol treatment. The prolonged exposure to Aβ-pathology leads to deficits in the neurogenic niche, thus targeting Aβ alone is insufficient to rescue neurogenesis. To support the neurogenic niche, we combined <i>scyllo</i>-inositol treatment with leteprinim potassium (neotrofin), the latter of which stimulates neurotrophin expression. We show that the combination treatment of <i>scyllo</i>-inositol and neotrofin enhances neuronal survival and differentiation. We propose this proof of concept combination therapy of targeting Aβ-pathology and neurotrophin deficits as a potential treatment for AD.</p></div

Hippocampal cell differentiation and survival in <i>scyllo</i>-inositol, neotrofin, and <i>scyllo</i>-inositol/neotrofin treated 200 day old Tg mice.

<p>(A) The number of DCX+ cells in Tg-SI (n = 6), Tg-NEO (n = 6) and Tg-SI/NEO (n = 7) mice were not significantly different between cohorts. (B) The percentage of DCX+ cells that were DCX+/CR+ immature neurons were assessed and showed no difference between treatment groups. (C) The percentage of DCX+/CR+ cells that were NeuN+ represents immature neurons approaching maturity. Tg-SI/NEO mice had a significantly greater percentage of DCX+/CR+/NeuN+ cells than Tg-SI and Tg-NEO mice. Tg-SI mice had a greater percentage than Tg-NEO mice. (D/E) Representative images of DCX (green) and CR (red) positive cells in the hippocampus, showing DCX+/CR- and DCX+/CR+ cells in Tg-SI mice and in Tg-SI/NEO mice. (E) Arrows indicate DCX+/CR+ cells. Scale bar indicates 20 μm. Data are mean ± SEM. One-way ANOVA with Fisher’s Post-hoc test, *** represents p<0.001.</p

Hippocampal cell proliferation in Tg mice with late AD-like pathology and age-matched NTg littermates.

<p>Cell proliferation was assessed at 200 days of age (A,B). (A) The number of proliferating BrdU+ cells in NTg (n = 6), NTg-SI (n = 6), Tg (n = 6) and Tg-SI (n = 5) mice was compared, demonstrating less proliferation in Tg and Tg-SI vs. NTg-SI. (B) The percentage of BrdU+/DCX+ cells in the dentate gyrus was not different between cohorts. (C) Dentate gyrus stained with BrdU (red) and DCX (green) demonstrating the distribution of proliferating cells, as well as neuroblasts and immature neurons, respectively. (D) Representative orthogonal projection of a BrdU+/DCX+ cell. Scale bar indicates 100 μm (C) or 25 μm (D). Data are mean ± SEM. One-way ANOVA with Fisher’s Post-hoc test, ** represents p< 0.01.</p

Hippocampal cell proliferation, differentiation and survival in Tg mice with early AD-like pathology and age-matched Tg littermates.

<p>(A) A representative image of the dentate gyrus stained for BrdU, demonstrates the distribution of proliferating BrdU+ cells. (B) A representative image of BrdU (green), DCX (red) and GFAP (white) positive cells in the dentate gyrus at 100 days of age. The arrow highlights a representative BrdU+/DCX+ cell. (C) A representative image of BrdU (green), NeuN (red) and GFAP (white) positive cells in the dentate gyrus. The arrow highlights a representative BrdU+/NeuN+ cell. Cell proliferation was examined at 100 days of age (D,E) while differentiation and survival was examined at 121 days of age (F,G) as a function of <i>scyllo</i>-inositol treatment. (D) The number of proliferating BrdU+ cells in the dentate gyrus of NTg (n = 7), NTg-SI (n = 6), Tg (n = 7) and Tg-SI (n = 5) mice were compared. This demonstrates more BrdU+ cells in Tg compared to NTg and to Tg-SI. (E) The percentage of BrdU+/DCX+ cells in the dentate gyrus showed less neuronal BrdU+ cells in Tg compared to the other three cohorts. (F) The number of BrdU+ cells surviving in NTg (n = 6), NTg-SI (n = 5), Tg (n = 6) and Tg-SI (n = 6) mice demonstrates more cell survival in Tg-SI mice. (G) The percentage of BrdU+/NeuN+ cells shows no difference between cohorts. Scale bars indicate 100 μm (A) or 25 μm (B,C). Data are mean ± SEM. One-way ANOVA with Fisher’s Post-hoc test, * represents p< 0.05 and ** represents p< 0.01.</p