scholarly journals Role of peroxisome proliferator-activated receptor γ in amyloid precursor protein processing and amyloid β-mediated cell death

2005 ◽  
Vol 391 (3) ◽  
pp. 693-698 ◽  
Author(s):  
Cristina d'Abramo ◽  
Sara Massone ◽  
Jean-Marc Zingg ◽  
Antonio Pizzuti ◽  
Philippe Marambaud ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Amyloid Β ◽  
Precursor Protein ◽  
Amyloid Precursor Protein Processing ◽  
Transcriptional Level ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Aβ Amyloid ◽  
Pparγ Agonists ◽  
Amyloid Cascade

Recent data indicate that PPARγ (peroxisome proliferator-activated receptor γ) could be involved in the modulation of the amyloid cascade causing Alzheimer's disease. In the present study we show that PPARγ overexpression in cultured cells dramatically reduced Aβ (amyloid-β) secretion, affecting the expression of the APP (Aβ precursor protein) at a post-transcriptional level. APP down-regulation did not involve the pathway of the secretases and correlated with a significant induction of APP ubiquitination. Additionally, we demonstrate that PPARγ was able to protect the cells from H2O2-induced necrosis by decreasing Aβ secretion. Taken together, our results indicate a novel mechanism at the basis of the neuroprotection shown by PPARγ agonists and an additional pathogenic role for Aβ accumulation.

scholarly journals Activated PPARγ Abrogates Misprocessing of Amyloid Precursor Protein, Tau Missorting and Synaptotoxicity

2019 ◽  
Vol 13 ◽  
Author(s):  
Susanne Moosecker ◽  
Patrícia Gomes ◽  
Chrysoula Dioli ◽  
Shuang Yu ◽  
Ioannis Sotiropoulos ◽  
...  
Keyword(s):  
Amyloid Precursor Protein ◽  
Amyloid Β ◽  
Precursor Protein ◽  
Neuronal Cultures ◽  
Peroxisome Proliferator ◽  
Synaptic Loss ◽  
Peroxisome Proliferator Activated Receptor ◽  
Primary Mouse ◽  
Synaptic Pathology ◽  
Pparγ Agonists

Type 2 diabetes increases the risk for dementia, including Alzheimer’s disease (AD). Pioglitazone (Pio), a pharmacological agonist of the peroxisome proliferator-activated receptor γ (PPARγ), improves insulin sensitivity and has been suggested to have potential in the management of AD symptoms, albeit through mostly unknown mechanisms. We here investigated the potential of Pio to counter synaptic malfunction and loss, a characteristic of AD pathology and its accompanying cognitive deficits. Results from experiments on primary mouse neuronal cultures and a human neural cell line (SH-SY5Y) show that Pio treatment attenuates amyloid β (Aβ)-triggered the pathological (mis-) processing of amyloid precursor protein (APP) and inhibits Aβ-induced accumulation and hyperphosphorylation of Tau. These events are accompanied by increased glutamatergic receptor 2B subunit (GluN2B) levels that are causally linked with neuronal death. Further, Pio treatment blocks Aβ-triggered missorting of hyperphosphorylated Tau to synapses and the subsequent loss of PSD95-positive synapses. These latter effects of Pio are PPARγ-mediated since they are blocked in the presence of GW9662, a selective PPARγ inhibitor. Collectively, these data show that activated PPARγ buffer neurons against APP misprocessing, Tau hyperphosphorylation and its missorting to synapses and subsequently, synaptic loss. These first insights into the mechanisms through which PPARγ influences synaptic loss make a case for further exploration of the potential usefulness of PPARγ agonists in the prevention and treatment of synaptic pathology in AD.

scholarly journals Sp1 and Smad transcription factors co-operate to mediate TGF-β-dependent activation of amyloid-β precursor protein gene transcription

2004 ◽  
Vol 383 (2) ◽  
pp. 393-399 ◽  
Author(s):  
Fabian DOCAGNE ◽  
Cecilia GABRIEL ◽  
Nathalie LEBEURRIER ◽  
Sylvain LESNÉ ◽  
Yannick HOMMET ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activity ◽  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Amyloid Β ◽  
Transforming Growth Factor Β ◽  
Precursor Protein ◽  
Transcriptional Level ◽  
Amyloid Β Peptide ◽  
Aβ Amyloid

Abnormal deposition of Aβ (amyloid-β peptide) is one of the hallmarks of AD (Alzheimer's disease). This peptide results from the processing and cleavage of its precursor protein, APP (amyloid-β precursor protein). We have demonstrated previously that TGF-β (transforming growth factor-β), which is overexpressed in AD patients, is capable of enhancing the synthesis of APP by astrocytes by a transcriptional mechanism leading to the accumulation of Aβ. In the present study, we aimed at further characterization of the molecular mechanisms sustaining this TGF-β-dependent transcriptional activity. We report the following findings: first, TGF-β is capable of inducing the transcriptional activity of a reporter gene construct corresponding to the +54/+74 region of the APP promoter, named APPTRE (APP TGF-β-responsive element); secondly, although this effect is mediated by a transduction pathway involving Smad3 (signalling mother against decapentaplegic peptide 3) and Smad4, Smad2 or other Smads failed to induce the activity of APPTRE. We also observed that the APPTRE sequence not only responds to the Smad3 transcription factor, but also the Sp1 (signal protein 1) transcription factor co-operates with Smads to potentiate the TGF-β-dependent activation of APP. TGF-β signalling induces the formation of nuclear complexes composed of Sp1, Smad3 and Smad4. Overall, the present study gives new insights for a better understanding of the fine molecular mechanisms occurring at the transcriptional level and regulating TGF-β-dependent transcription. In the context of AD, our results provide additional evidence for a key role for TGF-β in the regulation of Aβ production.

Amyloid β-peptide and Alzheimer's disease

2014 ◽  
Vol 56 ◽  
pp. 99-110 ◽  
Author(s):  
David Allsop ◽  
Jennifer Mayes
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Senile Plaques ◽  
Strong Support ◽  
Amyloid Β ◽  
Amyloid Β Peptide ◽  
Amyloid Cascade Hypothesis ◽  
Sequence Of Events ◽  
Aβ Amyloid ◽  
Amyloid Cascade

One of the hallmarks of AD (Alzheimer's disease) is the formation of senile plaques in the brain, which contain fibrils composed of Aβ (amyloid β-peptide). According to the ‘amyloid cascade’ hypothesis, the aggregation of Aβ initiates a sequence of events leading to the formation of neurofibrillary tangles, neurodegeneration, and on to the main symptom of dementia. However, emphasis has now shifted away from fibrillar forms of Aβ and towards smaller and more soluble ‘oligomers’ as the main culprit in AD. The present chapter commences with a brief introduction to the disease and its current treatment, and then focuses on the formation of Aβ from the APP (amyloid precursor protein), the genetics of early-onset AD, which has provided strong support for the amyloid cascade hypothesis, and then on the development of new drugs aimed at reducing the load of cerebral Aβ, which is still the main hope for providing a more effective treatment for AD in the future.

scholarly journals Zinc and Copper Differentially Modulate Amyloid Precursor Protein Processing by γ-Secretase and Amyloid-β Peptide Production

2017 ◽  
Vol 292 (9) ◽  
pp. 3751-3767 ◽  
Author(s):  
Hermeto Gerber ◽  
Fang Wu ◽  
Mitko Dimitrov ◽  
Guillermo M. Garcia Osuna ◽  
Patrick C. Fraering
Keyword(s):  
Amyloid Precursor Protein ◽  
Amyloid Β ◽  
Protein Processing ◽  
Precursor Protein ◽  
Amyloid Precursor Protein Processing ◽  
Amyloid Β Peptide

scholarly journals PPARγ-coactivator-1α gene transfer reduces neuronal loss and amyloid-β generation by reducing β-secretase in an Alzheimer’s disease model

2016 ◽  
Vol 113 (43) ◽  
pp. 12292-12297 ◽  
Author(s):  
Loukia Katsouri ◽  
Yau M. Lim ◽  
Katrin Blondrath ◽  
Ioanna Eleftheriadou ◽  
Laura Lombardero ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Pyramidal Neurons ◽  
Lentiviral Vector ◽  
Disease Model ◽  
Amyloid Β ◽  
Neuronal Loss ◽  
Peroxisome Proliferator ◽  
Neuroprotective Effects ◽  
Peroxisome Proliferator Activated Receptor

Current therapies for Alzheimer’s disease (AD) are symptomatic and do not target the underlying Aβ pathology and other important hallmarks including neuronal loss. PPARγ-coactivator-1α (PGC-1α) is a cofactor for transcription factors including the peroxisome proliferator-activated receptor-γ (PPARγ), and it is involved in the regulation of metabolic genes, oxidative phosphorylation, and mitochondrial biogenesis. We previously reported that PGC-1α also regulates the transcription of β-APP cleaving enzyme (BACE1), the main enzyme involved in Aβ generation, and its expression is decreased in AD patients. We aimed to explore the potential therapeutic effect of PGC-1α by generating a lentiviral vector to express human PGC-1α and target it by stereotaxic delivery to hippocampus and cortex of APP23 transgenic mice at the preclinical stage of the disease. Four months after injection, APP23 mice treated with hPGC-1α showed improved spatial and recognition memory concomitant with a significant reduction in Aβ deposition, associated with a decrease in BACE1 expression. hPGC-1α overexpression attenuated the levels of proinflammatory cytokines and microglial activation. This effect was accompanied by a marked preservation of pyramidal neurons in the CA3 area and increased expression of neurotrophic factors. The neuroprotective effects were secondary to a reduction in Aβ pathology and neuroinflammation, because wild-type mice receiving the same treatment were unaffected. These results suggest that the selective induction of PGC-1α gene in specific areas of the brain is effective in targeting AD-related neurodegeneration and holds potential as therapeutic intervention for this disease.

scholarly journals A cellular model of amyloid precursor protein processing and amyloid-β peptide production

2014 ◽  
Vol 223 ◽  
pp. 114-122 ◽  
Author(s):  
MiMi P. Macias ◽  
Amanda M. Gonzales ◽  
Ashley L. Siniard ◽  
Aaron W. Walker ◽  
Jason J. Corneveaux ◽  
...  
Keyword(s):  
Amyloid Precursor Protein ◽  
Amyloid Β ◽  
Protein Processing ◽  
Precursor Protein ◽  
Amyloid Precursor Protein Processing ◽  
Amyloid Β Peptide ◽  
Cellular Model
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