scholarly journals β-Secretases, Alzheimer’s Disease, and Down Syndrome

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Robin L. Webb ◽  
M. Paul Murphy
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Down Syndrome ◽  
Amyloid Precursor Protein ◽  
Healthy Aging ◽  
Precursor Protein ◽  
Chromosome 21 ◽  
Rate Limiting Step ◽  
Age Related

Individuals with Down Syndrome (DS), or trisomy 21, develop Alzheimer’s disease (AD) pathology by approximately 40 years of age. Chromosome 21 harbors several genes implicated in AD, including the amyloid precursor protein and one homologue of theβ-site APP cleaving enzyme, BACE2. Processing of the amyloid precursor protein byβ-secretase (BACE) is the rate-limiting step in the production of the pathogenic Aβpeptide. Increased amounts of APP in the DS brain result in increased amounts of Aβand extracellular plaque formation beginning early in life. BACE dysregulation potentially represents an overlapping biological mechanism with sporadic AD and a common therapeutic target. As the lifespan for those with DS continues to increase, age-related concerns such as obesity, depression, and AD are of growing concern. The ability to prevent or delay the progression of neurodegenerative diseases will promote healthy aging and improve quality of life for those with DS.

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 Beta-Amyloid Precursor Protein (βAPP) Processing in Alzheimer’s Disease (AD) and Age-Related Macular Degeneration (AMD)

2014 ◽  
Vol 52 (1) ◽  
pp. 533-544 ◽  
Author(s):  
Yuhai Zhao ◽  
Surjyadipta Bhattacharjee ◽  
Brandon M. Jones ◽  
James M. Hill ◽  
Christian Clement ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Precursor Protein ◽  
Macular Degeneration ◽  
Beta Amyloid ◽  
Precursor Protein ◽  
Age Related Macular Degeneration ◽  
Age Related

scholarly journals Genetic dissection of down syndrome-associated alterations in APP/amyloid-β biology using mouse models

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Justin L. Tosh ◽  
◽  
Elena R. Rhymes ◽  
Paige Mumford ◽  
Heather T. Whittaker ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Down Syndrome ◽  
Amyloid Precursor Protein ◽  
Mouse Models ◽  
Early Onset ◽  
Amyloid Β ◽  
Chromosome 21 ◽  
Extra Copy ◽  
Early Onset Alzheimer’S Disease

AbstractIndividuals who have Down syndrome (caused by trisomy of chromosome 21), have a greatly elevated risk of early-onset Alzheimer’s disease, in which amyloid-β accumulates in the brain. Amyloid-β is a product of the chromosome 21 gene APP (amyloid precursor protein) and the extra copy or ‘dose’ of APP is thought to be the cause of this early-onset Alzheimer’s disease. However, other chromosome 21 genes likely modulate disease when in three-copies in people with Down syndrome. Here we show that an extra copy of chromosome 21 genes, other than APP, influences APP/Aβ biology. We crossed Down syndrome mouse models with partial trisomies, to an APP transgenic model and found that extra copies of subgroups of chromosome 21 gene(s) modulate amyloid-β aggregation and APP transgene-associated mortality, independently of changing amyloid precursor protein abundance. Thus, genes on chromosome 21, other than APP, likely modulate Alzheimer’s disease in people who have Down syndrome.

scholarly journals Down syndrome and Alzheimer's disease: common molecular traits beyond the amyloid precursor protein

Aging ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 1011-1033 ◽  
Author(s):  
Wileidy Gomez ◽  
Rodrigo Morales ◽  
Vinicius Maracaja-Coutinho ◽  
Valentina Parra ◽  
Melissa Nassif
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Down Syndrome ◽  
Amyloid Precursor Protein ◽  
Precursor Protein

The Search for Biomarkers of Alzheimer's Disease in Down Syndrome

2020 ◽  
Vol 125 (2) ◽  
pp. 97-99 ◽  
Author(s):  
Benjamin L. Handen
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Down Syndrome ◽  
Longitudinal Study ◽  
High Risk ◽  
Amyloid Precursor Protein ◽  
Current Knowledge ◽  
Amyloid Β ◽  
Chromosome 21 ◽  
Increased Risk

Abstract Adults with Down syndrome are at high risk for Alzheimer's disease (AD), with most individuals developing clinical dementia by their late 60s. This increased risk for AD has been attributed, at least in part, to triplication and overexpression of the gene for amyloid precursor protein (APP) on chromosome 21, leading to elevated levels of amyloid β peptides. This article offers a brief overview of our current knowledge of AD in the DS population. In addition, information on a NIA/NICHD-funded, multicenter longitudinal study of biomarkers of AD in adults with DS is provided.

HIPPOCAMPAL ASTROCYTES AND ALZHEIMER’S DISEASE

2014 ◽  
pp. 1-5
Author(s):  
J. Young
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Fatty Acid ◽  
Amyloid Precursor Protein ◽  
Precursor Protein ◽  
Fatty Acid Binding ◽  
Age Related ◽  
Mature Brain ◽  
Hippocampal Astrocytes

Considerable progress has been made in elucidating the molecules involved in the pathology of Alzheimer's disease (AD). However, it is still uncertain why the hippocampus is the focus of this pathology, since these molecules (amyloid precursor protein, beta secretase, apolipoprotein E) are not more abundant within the hippocampus than in other, undamaged brain areas. Several unique features of the hippocampus may make it more vulnerable to this age-related pathology. These include 1) a specialized metabolism that enhances damaging effects of oxidative stress, 2) a capacity for neurogenesis, and 3) specializations in mitochondrial and metal homeostasis. The thesis of this paper is that an unusual subset of hippocampal astrocytes makes a fundamental contribution to all three of these hippocampal features and allows different and seemingly conflicting risk factors for AD to be viewed in a unified manner. These astrocytes participate in neurogenesis, produce fatty acid binding protein 7, unlike most astrocytes in the mature brain, and undergo an age-related mitochondrial degeneration. Degeneration of astrocyte mitochondria appears due to oxidative stress arising from fatty acid metabolism. This mitochondrial degeneration produces intracellular deposits of iron and copper, metals that have been shown to harmfully interact with cleavage products of amyloid precursor protein. Pharmacological and dietary manipulations that protect these astrocytes from age-related oxidative stress may prove to be useful strategies in combatting the progression of AD.

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