Identification, biogenesis, and localization of precursors of Alzheimer's disease A4 amyloid protein

Weidemann, Andreas; König, Gerhard; Bunke, Dirk; Fischer, P.; Salbaum, J. Michael; Masters, Colin L.; Beyreuther, Konrad

doi:10.1016/0092-8674(89)90177-3

Cited by 1,176 publications

(790 citation statements)

References 41 publications

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“…APP‐transgenic animal models for AD have been available for 20 years and provided the basis for a better understanding of APP processing and the effects of different types of Aβ aggregates on synaptic dysfunction, learning and memory (Weidemann et al ., 1989). One of the first AD mouse models introduced solely overexpresses the neuronal isoform hAPP695, which additionally carries the Swedish mutation at the β‐cleavage site (Hsiao et al ., 1996).…”

Section: Discussionmentioning

confidence: 99%

Differential transgene expression patterns in Alzheimer mouse models revealed by novel human amyloid precursor protein‐specific antibodies

et al. 2016

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SummaryAlzheimer's disease (AD) is histopathologically characterized by neurodegeneration, the formation of intracellular neurofibrillary tangles and extracellular Aβ deposits that derive from proteolytic processing of the amyloid precursor protein (APP). As rodents do not normally develop Aβ pathology, various transgenic animal models of AD were designed to overexpress human APP with mutations favouring its amyloidogenic processing. However, these mouse models display tremendous differences in the spatial and temporal appearance of Aβ deposits, synaptic dysfunction, neurodegeneration and the manifestation of learning deficits which may be caused by age‐related and brain region‐specific differences in APP transgene levels. Consequentially, a comparative temporal and regional analysis of the pathological effects of Aβ in mouse brains is difficult complicating the validation of therapeutic AD treatment strategies in different mouse models. To date, no antibodies are available that properly discriminate endogenous rodent and transgenic human APP in brains of APP‐transgenic animals. Here, we developed and characterized rat monoclonal antibodies by immunohistochemistry and Western blot that detect human but not murine APP in brains of three APP‐transgenic mouse and one APP‐transgenic rat model. We observed remarkable differences in expression levels and brain region‐specific expression of human APP among the investigated transgenic mouse lines. This may explain the differences between APP‐transgenic models mentioned above. Furthermore, we provide compelling evidence that our new antibodies specifically detect endogenous human APP in immunocytochemistry, FACS and immunoprecipitation. Hence, we propose these antibodies as standard tool for monitoring expression of endogenous or transfected APP in human cells and APP expression in transgenic animals.

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Section: Discussionmentioning

confidence: 99%

Differential transgene expression patterns in Alzheimer mouse models revealed by novel human amyloid precursor protein‐specific antibodies

et al. 2016

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“…Keratanase (EC 3.2.1.103) was from Seikagaku (Kogyo, Japan). The primary antibody used in western immunoblotting, which recognizes an epitope near the aminoterminus of APP, was a mouse monoclonal antibody (22C11) raised against a recombinant APP695 bacterial fusion protein [8]. Affinity purified anti-rabbit immunoglobulin G conjugated to alkaline phosphatase was from Promega (Sydney, NSW, Australia).…”

Section: Methodsmentioning

confidence: 99%

“…HeLa cells were transiently transfected by calcium phosphate coprecipitation with a plasmid (pAD-695) encoding the 695-amino acid form of APP [8,12]. The following day, cells were subcultured into 6-well plastic culture dishes at a density of 2 x 105 cells/well in Dulbecco's 0014-5793195/$9.50 © 1995 Federation of European Biochemical Societies.…”

Section: Hela Cell Culture and Transfectionmentioning

confidence: 99%

Gelatinase A possesses a β‐secretase‐like activity in cleaving the amyloid protein precursor of Alzheimer's disease

et al. 1995

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“…AI~ can be produced by proteolysis of pAPP, a process that occurs constitutively in both normal and AD-affected tissues as well as in cultured cells [8][9][10][11][12], and its overproduction in AD is currently explained in terms of proteolytic processing of I~APP. pAPP proteolysis is effected by yet to be identified enzymes designated t~-, [~-and y-secretases ( Fig.…”

mentioning

confidence: 99%

A mechanism for β‐amyloid overproduction in Alzheimer's disease: precursor‐independent generation of β‐amyloid via antisense RNA‐primed mRNA synthesis

Volloch

1996

FEBS Letters

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The overproduction of ~amyloid (A~) appears to be a primary cause of Alzheimer's disease (AD). Ap can be generated by proteolytic cleavage of precursor protein (pAPP) at I~ and 7-secretasc sites in both disease and normal cells. There is, however, no evidence that proteolytic processing of ~APP in sporadic AD-affected tissues differs qualitatively or quantitatively from that occurring in normal cells, and additional pathways for the enhanced production of A~ in sporadic AD which constitutes the majority of all AD cases should be considered. The major factor limiting the production of A~ in normal cells is cleavage at the ~t-secretase site within the A~ sequence. But, whereas the intact ~APP is a substrate for cleavage at the ~secretase site, the immediate precursor of Ap, 12-kDa C-terminal ~APP fragment, is not susceptible to the ot-secretase cleavage but it can be cleaved by ~secretase thus generating A~. Moreover, the 7-secretase cleavage is not the ratelimiting step in the production of A~. Therefore, the increase in production of the 12-kDa C-terminal ~APP fragment may be an efficient way to overproduce A~. A mechanism for the generation of the 12-kDa fragment independently of pAPP is proposed. It postulates an additional step of amplification of mRNA, namely the antisense RNA-mediated generation of a truncated mRNA encoding 12-kDa C-terminal fragment. Initiation of translation at the first AUG in the truncated mRNA results in a polypeptide that is cleaved by ~'-secretase generating Ap. The proposed model makes several verifiable predictions and suggests new directions of experimentation that may lead to a better understanding of the mechanisms involved in AD.Key words: Alzheimer's disease; ~-Amyloid precursor protein (pAPP); [~-Amyloid (AI~); [~-Amyloid overproduction; Antisense RNA; mRNA replication cells from patients with a defect in the S182 gene, associated with the most common form of the early-onset AD, make abnormally high amounts of Ap [5]; Down syndrome, associated with trisomy 21 and, consequently, increased dosage of the 13APP gene which is located on chromosome 21, is characterized by increased levels of pAPP gene expression and by the early cerebral deposition of AI~ [6,7]. The most convincing evidence for the notion that overproduction of Ap is sufficient to trigger AD comes from experiments with transgenic mice overexpressing full-length human pAPP, which generate high levels of AI~ and develop AD-like neuropathology [8].AI~ can be produced by proteolysis of pAPP, a process that occurs constitutively in both normal and AD-affected tissues as well as in cultured cells [8][9][10][11][12], and its overproduction in AD is currently explained in terms of proteolytic processing of I~APP. pAPP proteolysis is effected by yet to be identified enzymes designated t~-, [~-and y-secretases ( Fig. 1) and occurs at Met596/Asp 597 (13-secretase; pAPP695 numbering), at Lys612/Leu 613 (ct-secretase) and between Va1635 and Thr 639 (y-secretase). Cleavage by 13-secretase generates an ectodomain fragmen...

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Identification, biogenesis, and localization of precursors of Alzheimer's disease A4 amyloid protein

Cited by 1,176 publications

References 41 publications

Differential transgene expression patterns in Alzheimer mouse models revealed by novel human amyloid precursor protein‐specific antibodies

Differential transgene expression patterns in Alzheimer mouse models revealed by novel human amyloid precursor protein‐specific antibodies

Gelatinase A possesses a β‐secretase‐like activity in cleaving the amyloid protein precursor of Alzheimer's disease

A mechanism for β‐amyloid overproduction in Alzheimer's disease: precursor‐independent generation of β‐amyloid via antisense RNA‐primed mRNA synthesis

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