Targeting the Iron-Response Elements of the mRNAs for the Alzheimer’s Amyloid Precursor Protein and Ferritin to Treat Acute Lead and Manganese Neurotoxicity

The therapeutic value of inhibiting translation of the amyloid precursor protein (APP) offers the possibility to reduce neurotoxic amyloid formation, particularly in cases of familial Alzheimer’s disease (AD) caused by APP gene duplications (Dup–APP) and in aging Down syndrome individuals. APP mRNA translation inhibitors such as the anticholinesterase phenserine, and high throughput screened molecules, selectively inhibited the uniquely folded iron-response element (IRE) sequences in the 5’untranslated region (5’UTR) of APP mRNA and this class of drug continues to be tested in a clinical trial as an anti-amyloid treatment for AD. By contrast, in younger age groups, APP expression is not associated with amyloidosis, instead it acts solely as a neuroprotectant while facilitating cellular ferroportin-dependent iron efflux. We have reported that the environmental metallotoxins Lead (Pb) and manganese (Mn) cause neuronal death by interfering with IRE dependent translation of APP and ferritin. The loss of these iron homeostatic neuroprotectants thereby caused an embargo of iron (Fe) export from neurons as associated with excess unstored intracellular iron and the formation of toxic reactive oxidative species (ROS). We propose that APP 5’UTR directed translation activators can be employed therapeutically to protect neurons exposed to high acute Pb and/or Mn exposure. Certainly, high potency APP translation activators, exemplified by the Food and Drug Administration (FDA) pre-approved M1 muscarinic agonist AF102B and high throughput-screened APP 5’UTR translation activators, are available for drug development to treat acute toxicity caused by Pb/Mn exposure to neurons. We conclude that APP translation activators can be predicted to prevent acute metal toxicity to neurons by a mechanism related to the 5’UTR specific yohimbine which binds and targets the canonical IRE RNA stem loop as an H-ferritin translation activator.

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Iron and the translation of the amyloid precursor protein (APP) and ferritin mRNAs: riboregulation against neural oxidative damage in Alzheimer's disease

Biochemical Society Transactions ◽

10.1042/bst0361282 ◽

2008 ◽

Vol 36 (6) ◽

pp. 1282-1287 ◽

Cited By ~ 72

Author(s):

Jack T. Rogers ◽

Ashley I. Bush ◽

Hyan-Hee Cho ◽

Deborah H. Smith ◽

Andrew M. Thomson ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Amyloid Precursor Protein ◽

Brain Cortex ◽

Mrna Translation ◽

Precursor Protein ◽

Stem Loop ◽

Iron Storage ◽

Iron Regulatory Proteins ◽

Aβ Amyloid

The essential metals iron, zinc and copper deposit near the Aβ (amyloid β-peptide) plaques in the brain cortex of AD (Alzheimer's disease) patients. Plaque-associated iron and zinc are in neurotoxic excess at 1 mM concentrations. APP (amyloid precursor protein) is a single transmembrane metalloprotein cleaved to generate the 40–42-amino-acid Aβs, which exhibit metal-catalysed neurotoxicity. In health, ubiquitous APP is cleaved in a non-amyloidogenic pathway within its Aβ domain to release the neuroprotective APP ectodomain, APP(s). To adapt and counteract metal-catalysed oxidative stress, as during reperfusion from stroke, iron and cytokines induce the translation of both APP and ferritin (an iron storage protein) by similar mechanisms. We reported that APP was regulated at the translational level by active IL (interleukin)-1 (IL-1-responsive acute box) and IRE (iron-responsive element) RNA stem–loops in the 5′ untranslated region of APP mRNA. The APP IRE is homologous with the canonical IRE RNA stem–loop that binds the iron regulatory proteins (IRP1 and IRP2) to control intracellular iron homoeostasis by modulating ferritin mRNA translation and transferrin receptor mRNA stability. The APP IRE interacts with IRP1 (cytoplasmic cis-aconitase), whereas the canonical H-ferritin IRE RNA stem–loop binds to IRP2 in neural cell lines, and in human brain cortex tissue and in human blood lysates. The same constellation of RNA-binding proteins [IRP1/IRP2/poly(C) binding protein] control ferritin and APP translation with implications for the biology of metals in AD.

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S-Adenosylhomocysteine increases β-amyloid formation in BV-2 microglial cells by increased expressions of β-amyloid precursor protein and presenilin 1 and by hypomethylation of these gene promoters

NeuroToxicology ◽

10.1016/j.neuro.2009.03.011 ◽

2009 ◽

Vol 30 (4) ◽

pp. 622-627 ◽

Cited By ~ 33

Author(s):

Hung-Chi Lin ◽

Huei-Min Hsieh ◽

Yu-Hsuan Chen ◽

Miao-Lin Hu

Keyword(s):

Amyloid Precursor Protein ◽

Precursor Protein ◽

Microglial Cells ◽

Presenilin 1 ◽

Amyloid Formation ◽

Gene Promoters ◽

Β Amyloid

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AlphaLISA-based high-throughput screening assay to measure levels of soluble amyloid precursor protein α

Analytical Biochemistry ◽

10.1016/j.ab.2014.05.007 ◽

2014 ◽

Vol 459 ◽

pp. 24-30 ◽

Cited By ~ 5

Author(s):

Hongjie Wang ◽

Adel Nefzi ◽

Gregg B. Fields ◽

Madepalli K. Lakshmana ◽

Dmitriy Minond

Keyword(s):

Amyloid Precursor Protein ◽

High Throughput ◽

High Throughput Screening ◽

Precursor Protein ◽

Screening Assay ◽

High Throughput Screening Assay

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Development of a high-throughput screen targeting caspase-8-mediated cleavage of the amyloid precursor protein

Analytical Biochemistry ◽

10.1016/j.ab.2011.11.020 ◽

2012 ◽

Vol 421 (2) ◽

pp. 467-476 ◽

Cited By ~ 6

Author(s):

Matthew J. Hart ◽

Marcie Glicksman ◽

Min Liu ◽

Mohit K. Sharma ◽

Greg Cuny ◽

...

Keyword(s):

Amyloid Precursor Protein ◽

High Throughput ◽

Precursor Protein ◽

Caspase 8 ◽

High Throughput Screen

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Catabolism of amyloid precursor protein leads to beta-amyloid formation

Neurobiology of Aging ◽

10.1016/0197-4580(94)92661-1 ◽

1994 ◽

Vol 15 ◽

pp. S51

Keyword(s):

Amyloid Precursor Protein ◽

Beta Amyloid ◽

Precursor Protein ◽

Amyloid Formation

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Translation and processing of amyloid precursor protein (APP) by an M1 muscarinic agonist and an acetylcholinesterase inhibitor

Recent Progress in Alzheimer's and Parkinson's Diseases ◽

10.1201/b14441-36 ◽

2005 ◽

pp. 267-278

Author(s):

J Rogers ◽

N Greig ◽

D Lahiri ◽

A Fisher

Keyword(s):

Amyloid Precursor Protein ◽

Acetylcholinesterase Inhibitor ◽

Precursor Protein ◽

Muscarinic Agonist ◽

M1 Muscarinic

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A GG Nucleotide Sequence of the 3′ Untranslated Region of Amyloid Precursor Protein mRNA Plays a Key Role in the Regulation of Translation and the Binding of Proteins

Molecular and Cellular Biology ◽

10.1128/mcb.20.13.4572-4579.2000 ◽

2000 ◽

Vol 20 (13) ◽

pp. 4572-4579 ◽

Cited By ~ 24

Author(s):

E. G. Mbongolo Mbella ◽

S. Bertrand ◽

G. Huez ◽

J.-N. Octave

Keyword(s):

Amyloid Precursor Protein ◽

Translational Control ◽

Cho Cells ◽

Untranslated Region ◽

Specific Binding ◽

Alternative Polyadenylation ◽

Mrna Translation ◽

Precursor Protein ◽

Mobility Shift ◽

Mobility Shift Assay

ABSTRACT The alternative polyadenylation of the mRNA encoding the amyloid precursor protein (APP) involved in Alzheimer's disease generates two molecules, with the first of these containing 258 additional nucleotides in the 3′ untranslated region (3′UTR). We have previously shown that these 258 nucleotides increase the translation of APP mRNA injected in Xenopus oocytes (5). Here, we demonstrate that this mechanism occurs in CHO cells as well. We also present evidence that the 3′UTR containing 8 nucleotides more than the short 3′UTR allows the recovery of an efficiency of translation similar to that of the long 3′UTR. Moreover, the two guanine residues located at the 3′ ends of these 8 nucleotides play a key role in the translational control. Using gel retardation mobility shift assay, we show that proteins from Xenopus oocytes, CHO cells, and human brain specifically bind to the short 3′UTR but not to the long one. The two guanine residues involved in the translational control inhibit this specific binding by 65%. These results indicate that there is a correlation between the binding of proteins to the 3′UTR of APP mRNA and the efficiency of mRNA translation, and that a GG motif controls both binding of proteins and translation.

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A High-Throughput Drug Screen Targeted to the 5'Untranslated Region of Alzheimer Amyloid Precursor Protein mRNA

CrossRef Listing of Deleted DOIs ◽

10.1177/1087057106287271 ◽

2006 ◽

Vol 11 (5) ◽

pp. 469-480 ◽

Cited By ~ 23

Author(s):

Sanghamitra Bandyopadhyay ◽

Jake Ni ◽

Amy Ruggiero ◽

Karen Walshe ◽

Mark S. Rogers ◽

...

Keyword(s):

Amyloid Precursor Protein ◽

High Throughput ◽

Translational Control ◽

Untranslated Region ◽

Fluorescent Protein ◽

Internal Ribosomal Entry Site ◽

Precursor Protein ◽

Luciferase Reporter ◽

Entry Site ◽

Novel Approach

The authors employed a novel approach to identify therapeutics effective in Alzheimer disease (AD). The 5'untranslated region (5'UTR) of the mRNA of AD amyloid precursor protein (APP) is a significant regulator of the levels of the APP holoprotein and amyloid beta (Aβ) peptide in the central nervous system. The authors generated stable neuroblastoma SH-SY5Y transfectants that express luciferase under the translational control of the 146-nucleotide APP mRNA 5'UTR and green fluorescent protein (GFP) driven by a viral internal ribosomal entry site. Using a high-throughput screen (HTS), they screened for the effect of 110,000 compounds obtained from the library of the Laboratory for Drug Discovery on Neurodegeneration (LDDN) on the APP mRNA 5'UTR-controlled translation of the luciferase reporter. This screening yielded several nontoxic specific inhibitors of APP mRNA 5'UTR-driven luciferase that had no effect on the GFP expression in the stable SH-SY5Y transfectants. Moreover, these compounds either did not inhibit or inhibited to a much lower extent the expression of the luciferase reporter regulated by a prion protein (PrP) mRNA 5'UTR, used as an alternative mRNA structure to counterscreen APP mRNA 5'UTR in stably transfected SH-SY5Y cell lines. The hits obtained from this robust, specific, and highly quantitative HTS will be characterized to identify agents that may be developed into useful future therapeutic agents to limit APP translation and Aβ production for AD.

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Memapsin 2, a drug target for Alzheimer's disease

Biochemical Society Symposium ◽

10.1042/bss0700213 ◽

2003 ◽

Vol 70 ◽

pp. 213-220 ◽

Cited By ~ 1

Author(s):

Gerald Koelsch ◽

Robert T. Turner ◽

Lin Hong ◽

Arun K. Ghosh ◽

Jordan Tang

Keyword(s):

Crystal Structure ◽

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Transition State ◽

Amyloid Precursor Protein ◽

Therapeutic Target ◽

Drug Target ◽

Aspartic Protease ◽

Precursor Protein ◽

Memapsin 2

Mempasin 2, a ϐ-secretase, is the membrane-anchored aspartic protease that initiates the cleavage of amyloid precursor protein leading to the production of ϐ-amyloid and the onset of Alzheimer's disease. Thus memapsin 2 is a major therapeutic target for the development of inhibitor drugs for the disease. Many biochemical tools, such as the specificity and crystal structure, have been established and have led to the design of potent and relatively small transition-state inhibitors. Although developing a clinically viable mempasin 2 inhibitor remains challenging, progress to date renders hope that memapsin 2 inhibitors may ultimately be useful for therapeutic reduction of ϐ-amyloid.

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