Primary cultures of neuronal and non-neuronal rat brain cells secrete similar proportions of amyloid β peptides ending at Aβ40 and Aβ42

Fukumoto, Hiroaki; Tomita, Taisuke; Matsunaga, Hirokazu; Ishibashi, Yoshihiro; Saido, Takaomi C.; Iwatsubo, Takeshi

doi:10.1097/00001756-199909290-00017

Cited by 61 publications

(45 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…CHO 7W cells were transfected either with BACE, sorLA, sorLA tail or a combination of BACE and sorLA constructs. For A␤ quantification in the media, media was exchanged after 24 h and collected after another 24 h. A␤40 levels were determined by sandwich ELISA using BNT77 (anti-A␤ 11-28) as the capture antibody and horseradish peroxidase-linked BA27 as detection antibodies (Takeda Chemical Company, Osaka, Japan) (Fukumoto et al, 1999;Irizarry et al, 2004). Purified A␤40 (Bachem, King of Prussia, PA) was used as standard.…”

Section: Methodsmentioning

confidence: 99%

Interaction of the Cytosolic Domains of sorLA/LR11 with the Amyloid Precursor Protein (APP) and β-Secretase β-Site APP-Cleaving Enzyme

Spoelgen¹,

Arnim²,

Thomas³

et al. 2006

J. Neurosci.

160

135

View full text Add to dashboard Cite

sorLA is a recently identified neuronal receptor for amyloid precursor protein (APP) that is known to interact with APP and affect its intracellular transport and processing. Decreased levels of sorLA in the brain of Alzheimer's disease (AD) patients and elevated levels of amyloid-␤ peptide (A␤) in sorLA-deficient mice point to the importance of the receptor in this neurodegenerative disorder. We analyzed APP cleavage in an APP-shedding assay and found that both sorLA and, surprisingly, a sorLA tail construct inhibited APP cleavage in a ␤-site APP-cleaving enzyme (BACE)-dependent manner. In line with this finding, sorLA and the sorLA tail significantly reduced secreted A␤ levels when BACE was overexpressed, suggesting that sorLA influences ␤-cleavage. To understand the effect of sorLA on APP cleavage by BACE, we analyzed whether sorLA interacts with APP and/or BACE. Because both full-length sorLA and sorLA C-terminal tail constructs were functionally relevant for APP processing, we analyzed sorLA-APP for a potential cytoplasmatic interaction domain. sorLA and C99 coimmunoprecipitated, pointing toward the existence of a new cytoplasmatic interaction site between sorLA and APP. Moreover, sorLA and BACE also coimmunoprecipitate. Thus, sorLA interacts both with BACE and APP and might therefore directly affect BACE-APP complex formation. To test whether sorLA impacts BACE-APP interactions, we used a fluorescence resonance energy transfer assay to evaluate BACE-APP interactions in cells. We discovered that sorLA significantly reduced BACE-APP interactions in Golgi. We postulate that sorLA acts as a trafficking receptor that prevents BACE-APP interactions and hence BACE cleavage of APP.

show abstract

Section: Methodsmentioning

confidence: 99%

Interaction of the Cytosolic Domains of sorLA/LR11 with the Amyloid Precursor Protein (APP) and β-Secretase β-Site APP-Cleaving Enzyme

Spoelgen¹,

Arnim²,

Thomas³

et al. 2006

J. Neurosci.

160

135

View full text Add to dashboard Cite

show abstract

“…A␤40 and A␤42 levels in the conditioned medium were determined by enzyme-linked immunosorbent assay, with BNT77 as a capture antibody and BA27-horseradish peroxidase for A␤40 or BC05-horseradish peroxidase for A␤42 as detection antibodies (28).…”

Section: Methodsmentioning

confidence: 99%

Induction of the Cholesterol Transporter ABCA1 in Central Nervous System Cells by Liver X Receptor Agonists Increases Secreted Aβ Levels

Fukumoto¹,

Deng²,

Irizarry³

et al. 2002

Journal of Biological Chemistry

Self Cite

148

133

View full text Add to dashboard Cite

The expression, function, and regulation of the cholesterol efflux molecule, ABCA1, has been extensively examined in peripheral tissues but only poorly studied in the brain. Brain cholesterol metabolism is of interest because several lines of evidence suggest that elevated cholesterol increases the risk of Alzheimer's disease. We found a largely neuronal expression of ABCA1 in normal rat brain by in situ hybridization. ABCA1 message was dramatically up-regulated in neurons and glia in areas of damage by hippocampal AMPA lesion after 3-7 days. Immunoblot analysis demonstrated ABCA1 protein in cultured neuronal and glial cells, and expression was induced by ligands of the nuclear hormone receptors of the retinoid X receptor and liver X receptor family. ABCA1 was induced by treatment with retinoic acid and several oxysterols, including 22(R)-hydroxycholesterol and 24-hydroxycholesterol. Expression of an ABCA1-green fluorescent protein construct in neuroblastoma cells demonstrated fluorescence in perinuclear compartments and on the plasma membrane. Because the A␤ peptide is important in Alzheimer's disease pathogenesis, we examined whether ABCA1 induction altered A␤ levels. Treatment of neuroblastoma cells with retinoic acid and 22(R)-hydroxycholesterol caused significant increases in secreted A␤40 (29%) and A␤42 (65%). Treatment with a nonsteroidal liver X receptor ligand, TO-901317, similarly increased levels of secreted A␤40 (25%) and A␤42 (126%). The increase in secreted A␤ levels was reduced by RNAi blocking of ABCA1 expression. These data suggest that the cholesterol efflux molecule ABCA1 may also be involved in the secretion of the membrane-associated molecule, A␤.ABCA1 encodes an ATP-binding cassette protein that promotes efflux of cholesterol and phospholipids from intracellular compartments to high density lipoprotein, lipid-deficient apoAI, 1 and other apolipoproteins (1). Disruption of ABCA1 byTangier disease mutations in humans or by engineered knockout in mice is associated with a loss of cellular cholesterol efflux, an ablation of circulating high density lipoprotein, and, interestingly, peripheral neuropathies (2-5). Like many genes involved in cholesterol homeostasis, ABCA1 is regulated by the liver X receptors (LXR) (6 -8), nuclear receptors activated by oxysterols. ABCA1 is also regulated by peroxisome proliferatoractivated receptor ␦, which can be activated by fatty acid metabolites (9). Both of these classes of receptors form heterodimers with retinoid X receptors (RXR), which bind retinoic acid; as heterodimers, they alter gene transcription. These systems for ABCA1 induction help decrease cellular cholesterol after cholesterol loading (10). The importance of cerebral cholesterol metabolism in Alzheimer's disease (AD) risk and pathogenesis is supported by genetic, cell culture, mouse model, and epidemiologic data. ApoE in the central nervous system is implicated in supplying appropriate membrane lipid for development, nerve growth, and responses to injury and repair in the central nervous syste...

show abstract

“…To measure sAPP␣ in brain lysates, the homogenate buffer free of detergents was used to preclude contamination of membrane-associated APP. A␤ 40 or A␤ 42 was quantitated by two-site sandwich ELISA using a capture antibody BNT77, which recognizes the midportion of A␤ without detecting A␤ 17-40/42 (i.e., the cleaved products by ␣-and ␥-secretases) (Fukumoto et al, 1999), and the detector antibodies of BA27-HRP or BC05-HRP that specifically detect the C termini of A␤ 40 or A␤ 42 , respectively, as described previously (Asami-Odaka et al, 1995). TMB substrate (Pierce) was used as a chromogenic substrate.…”

Section: Quantitation Of Sapp␣ and A␤ By Elisamentioning

confidence: 99%

A Noncompetitive BACE1 Inhibitor TAK-070 Ameliorates Aβ Pathology and Behavioral Deficits in a Mouse Model of Alzheimer's Disease

Fukumoto

Takahashi²,

Tarui³

et al. 2010

J. Neurosci.

121

View full text Add to dashboard Cite

We discovered a nonpeptidic compound, TAK-070, that inhibited BACE1, a rate-limiting protease for the generation of A␤ peptides that are considered causative for Alzheimer's disease (AD), in a noncompetitive manner. TAK-070 bound to full-length BACE1, but not to truncated BACE1 lacking the transmembrane domain. Short-term oral administration of TAK-070 decreased the brain levels of soluble A␤, increased that of neurotrophic sAPP␣ by ϳ20%, and normalized the behavioral impairments in cognitive tests in Tg2576 mice, an APP transgenic mouse model of AD. Six-month chronic treatment decreased cerebral A␤ deposition by ϳ60%, preserving the pharmacological efficacy on soluble A␤ and sAPP␣ levels. These results support the feasibility of BACE1 inhibition with a noncompetitive inhibitor as disease-modifying as well as symptomatic therapy for AD.

show abstract

Primary cultures of neuronal and non-neuronal rat brain cells secrete similar proportions of amyloid β peptides ending at Aβ40 and Aβ42

Cited by 61 publications

References 5 publications

Interaction of the Cytosolic Domains of sorLA/LR11 with the Amyloid Precursor Protein (APP) and β-Secretase β-Site APP-Cleaving Enzyme

Interaction of the Cytosolic Domains of sorLA/LR11 with the Amyloid Precursor Protein (APP) and β-Secretase β-Site APP-Cleaving Enzyme

Induction of the Cholesterol Transporter ABCA1 in Central Nervous System Cells by Liver X Receptor Agonists Increases Secreted Aβ Levels

A Noncompetitive BACE1 Inhibitor TAK-070 Ameliorates Aβ Pathology and Behavioral Deficits in a Mouse Model of Alzheimer's Disease

Contact Info

Product

Resources

About