Lentivirus-Mediated Expression of Human Secreted Amyloid Precursor Protein-Alpha Promotes Long-Term Induction of Neuroprotective Genes and Pathways in a Mouse Model of Alzheimer’s Disease

2020 ◽  
pp. 1-16
Author(s):  
Margaret Ryan ◽  
Valerie T.Y. Tan ◽  
Nasya Thompson ◽  
Diane Guévremont ◽  
Bruce G. Mockett ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Model ◽  
Amyloid Precursor Protein ◽  
Precursor Protein ◽  
Integrated Analysis ◽  
Empty Vector ◽  
Mouse Transcriptome

Background: Secreted amyloid precursor protein-alpha (sAPPα) can enhance memory and is neurotrophic and neuroprotective across a range of disease-associated insults, including amyloid-β toxicity. In a significant step toward validating sAPPα as a therapeutic for Alzheimer’s disease (AD), we demonstrated that long-term overexpression of human sAPPα (for 8 months) in a mouse model of amyloidosis (APP/PS1) could prevent the behavioral and electrophysiological deficits that develop in these mice. Objective: To explore the underlying molecular mechanisms responsible for the significant physiological and behavioral improvements observed in sAPPα-treated APP/PS1 mice. Methods: We assessed the long-term effects on the hippocampal transcriptome following continuous lentiviral delivery of sAPPα or empty-vector to male APP/PS1 mice and wild-type controls using Affymetrix Mouse Transcriptome Assays. Data analysis was carried out within the Affymetrix Transcriptome Analysis Console and an integrated analysis of the resulting transcriptomic data was performed with Ingenuity Pathway analysis (IPA). Results: Mouse transcriptome assays revealed expected AD-associated gene expression changes in empty-vector APP/PS1 mice, providing validation of the assays used for the analysis. By contrast, there were specific sAPPα-associated gene expression profiles which included increases in key neuroprotective genes such as Decorin, betaine-GABA transporter, and protocadherin beta-5, subsequently validated by qRT-PCR. An integrated biological pathways analysis highlighted regulation of GABA receptor signaling, cell survival, and inflammatory responses. Furthermore, upstream gene regulatory analysis implicated sAPPα activation of Interleukin-4, which can counteract inflammatory changes in AD. Conclusion: This study identified key molecular processes that likely underpin the long-term neuroprotective and therapeutic effects of increasing sAPPα levels in vivo

scholarly journals SPON1 Can Reduce Amyloid Beta and Reverse Cognitive Impairment and Memory Dysfunction in Alzheimer’s Disease Mouse Model

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1275
Author(s):  
Soo Yong Park ◽  
Joo Yeong Kang ◽  
Taehee Lee ◽  
Donggyu Nam ◽  
Chang-Jin Jeon ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Model ◽  
Amyloid Precursor Protein ◽  
Amyloid Beta ◽  
Physiological Activity ◽  
Precursor Protein ◽  
Age Related

Alzheimer’s disease (AD) is a complex, age-related neurodegenerative disease that is the most common form of dementia. However, the cure for AD has not yet been founded. The accumulation of amyloid beta (Aβ) is considered to be a hallmark of AD. Beta-site amyloid precursor protein cleaving enzyme 1 (BACE1), also known as beta secretase is the initiating enzyme in the amyloidogenic pathway. Blocking BACE1 could reduce the amount of Aβ, but this would also prohibit the other functions of BACE1 in brain physiological activity. SPONDIN1 (SPON1) is known to bind to the BACE1 binding site of the amyloid precursor protein (APP) and blocks the initiating amyloidogenesis. Here, we show the effect of SPON1 in Aβ reduction in vitro in neural cells and in an in vivo AD mouse model. We engineered mouse induced neural stem cells (iNSCs) to express Spon1. iNSCs harboring mouse Spon1 secreted SPON1 protein and reduced the quantity of Aβ when co-cultured with Aβ-secreting Neuro 2a cells. The human SPON1 gene itself also reduced Aβ in HEK 293T cells expressing the human APP transgene with AD-linked mutations through lentiviral-mediated delivery. We also demonstrated that injecting SPON1 reduced the amount of Aβ and ameliorated cognitive dysfunction and memory impairment in 5xFAD mice expressing human APP and PSEN1 transgenes with five AD-linked mutations.

scholarly journals The Amyloid Precursor Protein (APP) Family Members are Key Players in S-adenosylmethionine Formation by MAT2A and Modify BACE1 and PSEN1 Gene Expression-Relevance for Alzheimer's Disease

2012 ◽  
Vol 11 (11) ◽  
pp. 1274-1288 ◽  
Author(s):  
Andreas Schrötter ◽  
Kathy Pfeiffer ◽  
Fouzi El Magraoui ◽  
Harald W. Platta ◽  
Ralf Erdmann ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Precursor Protein ◽  
Senile Plaques ◽  
Mrna Level ◽  
Family Members ◽  
Precursor Protein ◽  
A Cell ◽  
Psen1 Gene

Central hallmark of Alzheimer's disease are senile plaques mainly composed of β-amyloid, which is a cleavage product of the amyloid precursor protein (APP). The physiological function of APP and its family members APLP1 and APLP2 is poorly understood. In order to fill this gap, we established a cell-culture based model with simultaneous knockdown of all members of the family. A comprehensive proteome study of the APP/APLP1/APLP2 knockdown cell lysates versus controls revealed significant protein abundance changes of more than 30 proteins. Targeted validation of selected candidates by immunoblotting supported the significant down-regulation of the methionine adenosyltransferase II, alpha (MAT2A) as well as of peroxiredoxin 4 in the knockdown cells. Moreover, MAT2A was significantly down-regulated at the mRNA level as well. MAT2A catalyzes the production of S-adenosylmethionine from methionine and ATP, which plays a pivotal role in the methylation of neurotransmitters, DNA, proteins, and lipids. MAT2A-dependent significant up-regulation of S-adenosylmethionine was also detectable in the knockdown cells compared with controls. Our results point to a role of the APP family proteins in cellular methylation mechanisms and fit to findings of disturbed S-adenosylmethionine levels in tissue and CSF of Alzheimer disease patients versus controls. Importantly, methylation plays a central role for neurotransmitter generation like acetylcholine pointing to a crucial relevance of our findings for Alzheimer's disease. In addition, we identified differential gene expression of BACE1 and PSEN1 in the knockdown cells, which is possibly a consequence of MAT2A deregulation and may indicate a self regulatory mechanism.

Effect of Soluble Amyloid Precursor Protein-alpha on Adult Hippocampal Neurogenesis in a Mouse Model of Alzheimer’s Disease

2021 ◽  
Author(s):  
Shane M. Ohline ◽  
Connie Chan ◽  
Lucia Schoderboeck ◽  
Hollie E. Wicky ◽  
Warren P. Tate ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Model ◽  
Amyloid Precursor Protein ◽  
Hippocampal Neurogenesis ◽  
Precursor Protein ◽  
Adult Hippocampal Neurogenesis ◽  
Wild Type ◽  
Viral Expression ◽  
Model Of Alzheimer’S Disease

Abstract Soluble amyloid precursor protein-alpha (sAPPα) is a regulator of neuronal and memory mechanisms, while also having neurogenic and neuroprotective effects in the brain. As adult hippocampal neurogenesis is impaired in Alzheimer’s disease, we tested the hypothesis that sAPPα delivery would rescue adult hippocampal neurogenesis in an APP/PS1 mouse model of Alzheimer’s disease. An adeno-associated virus-9 (AAV9) encoding murine sAPPα was injected into the hippocampus of 8 month-old wild-type and APP/PS1 mice, and later two different thymidine analogues (XdU) were systemically injected to label adult-born cells at different time points after viral transduction. The proliferation of adult-born cells, cell survival after eight weeks, and cell differentiation into either neurons or astrocytes was studied. Proliferation was impaired in APP/PS1 mice but was restored to wild-type levels by viral expression of sAPPα. In contrast, sAPPα overexpression failed to rescue the survival of XdU+-labelled cells that was impaired in APP/PS1 mice, although it did cause a significant increase in the area density of astrocytes in the granule cell layer across both genotypes. Finally, viral expression of sAPPα reduced amyloid-beta plaque load in APP/PS1 mice in the dentate gyrus and somatosensory cortex. These data add further evidence that increased levels of sAPPα could be therapeutic for the cognitive decline in AD, in part through restoration of the proliferation of neural progenitor cells in adults.

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