APP carboxyl-terminal fragment without or with A? domain equally induces cytotoxicity in differentiated PC12 cells and cortical neurons

Lee, Jean Pyo; Chang, Keun A.; Kim, Hye Sun; Kim, Sung Su; Jeong, Sung‐Jin; Suh, Yoo‐Hun

doi:10.1002/(sici)1097-4547(20000515)60:4<565::aid-jnr16>3.0.co;2-i

Cited by 33 publications

(15 citation statements)

References 39 publications

(49 reference statements)

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“…To examine the Rab5 + endosomes in axons, we expressed C99 and C83 following NGF treatment. Consistent with earlier studies (73)(74)(75), expression of C99 markedly suppressed NGF-induced activation of Erk1/2 at both 5 and 30 minutes (Supplemental Figure 2, B and C). While having no effect at 5 minutes, C83 induced a small decrease in pErk1/2 at 30 minutes.…”

Section: M596vsupporting

confidence: 91%

Amyloid precursor protein–mediated endocytic pathway disruption induces axonal dysfunction and neurodegeneration

Xu¹,

Weissmiller²,

White³

et al. 2016

Journal of Clinical Investigation

143

225

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R e s e a R c h a R t i c l e1 8 1 6jci.org Volume 126Number 5 May 2016 26, 54, 55). We assayed the level of GTP-Rab5 in brains of 12-monthold Ts65Dn and 2N mice following a published protocol (56). As previously reported (28), the level of full-length APP in Ts65Dn was approximately 1.5-fold than in 2N samples ( We next tested whether the increase in App gene dose in Ts65Dn BFCNs was responsible for enlargement of Rab5 + endosomes (Figure 1). By immunoblotting, the APP siRNA caused an approximately 30% reduction in the level of full-length APP, as compared with control siRNA ( Figure 2E). Rab5 + puncta in BFCNs treated with either the APP siRNA or control siRNA were analyzed (Figure 2, F and G) as in Figure 1. Large, sometimes lobulated Rab5 + puncta were seen in cultures treated with the control siRNA, whereas these structures were typically smaller and rounded in cultures treated with the APP siRNA ( Figure 2G). Treatment with the APP siRNA significantly reduced the size of Rab5 + puncta in Ts65Dn neurons to a value equivalent to that in 2N neurons ( Figure 2F). Thus, increased App gene dose is necessary for increased Rab5 activation and for early endosome enlargement in Ts65Dn neurons.Full-length APP and β-CTF caused enlargement of early endosomes in PC12 cells. To determine how increased APP expression caused an increase in Rab5 activation, we asked which APP product(s) were responsible (Supplemental Figure 1A). We transfected PC12M cells with full-length APP-GFP, C99-GFP (β-CTF), C83-GFP (α-CTF), or AICD-GFP and examined endosomes by live cell imaging (Supplemental Figure 1B). Bright foci of GFP + intracellular structures were present in PC12M cells that overexpressed APP-GFP or C99-GFP. In contrast, cells expressing C83-GFP or AICD-GFP showed diffuse, hazy signals for GFP, with occasional foci in C83-GFP cells. In APP-GFP and C99-GFP cells, the GFP + intracellular structures were, on average, approximately 2 μm 2 (Supplemental Figure 1E). GFP signals in C83-GFP or AICD-GFP cells contained speckled small puncta within the haze, as well as a small number of larger bright puncta, as seen in cells expressing C99-GFP and APP-GFP (Supplemental Figure 1B). However, the average puncta size in C83-GFP and AICD-GFP cells was approximately 1.2 and 1.3 μm 2 , respectively. Thus, overexpressing APP and β-CTF, but not α-CTF or AICD, routinely induced formation of enlarged, bright intracellular structures. We also tested two APP mutants: APP M596V and APP SWE . APP M596V , which abolishes β-secretase cleavage, prevents production of β-CTF (57); APP SWE enhances β-secretase cleavage to increase the level of β-CTF (57). Both induced the formation of enlarged intracellular structures (Supplemental Figure 1C).We examined colocalization of APP or C99 with Rab5 in cotransfection experiments; APP-mCherry with GFP-Rab5 WT ( Figure 3B); C99-GFP with mCherry-Rab5 WT ( Figure 3C); and Rab5 + endosomes (26, 28, 37) was correlated with reduced endosomal trafficking and signaling of nerve growth factor (NGF), leading to degeneration...

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Section: M596vsupporting

confidence: 91%

Amyloid precursor protein–mediated endocytic pathway disruption induces axonal dysfunction and neurodegeneration

Xu¹,

Weissmiller²,

White³

et al. 2016

Journal of Clinical Investigation

143

225

View full text Add to dashboard Cite

show abstract

“…Generally, APP is a marker for cell differentiation, however, previous studies also demonstrated that the overexpression of APP could inhibite neurite outgrowth in N2a cell [16]. Its membrane location and its structural similarities with cysteine-rich growth factors suggest that APP might be functioning as a cell surface receptor or growth factor [17], and such proteins, such as G0 protein [18], Fe65 [19], and low density lipoprotein receptor-related protein [20], have been reported as its ligands.…”

Section: Discussionmentioning

confidence: 98%

Effect of amyloid peptides on serum withdrawal-induced cell differentiation and cell viability

Wang

Zhang

et al. 2004

Cell Res

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Abnormal deposition of amyloid-β(Aβ) peptides and formation of neuritic plaques are recognized as pathological processes in Alzheimer's disease (AD) brain. By using amyloid precursor protein (APP) transfected cells, this study aims to investigate the effect of overproduction of Aβ on cell differentiation and cell viability. It was shown that after serum withdrawal, untransfected cell (N2a/Wt) and vector transfected cells (N2a/vector) extended long and branched cell processes, whereas no neurites was induced in wild type APP (N2a/APP695) and Swedish mutant APP (N2a/ APPswe) transfected N2a cells. After differentiation by serum withdrawal, the localization of APP/Aβ and neurofilament was extended to neurites, whereas those of APP-transfected cells were still restricted within the cell body. Levels of both APP and Aβ were significantly higher in N2a/APP695 and N2a/APPswe than in N2a/Wt, as determined by Western blot and Sandwich ELISA, respectively. To further investigate the effect of Aβ on the inhibition of cell differentiation, we added exogenously the similar level or about 10-times of the Aβ level produced by N2a/APP695 and N2a/APPswe to the culture medium and co-cultured with N2a/Wt for 12 h, and we found that the inhibition of serum withdrawalinduced differentiation observed in N2a/APP695 and N2a/APPswe could not be reproduced by exogenous administration of Aβ into N2a/Wt. We also observed that neither endogenous production nor exogenous addition of Aβ 1-40 or Aβ 1-42 , even to hundreds fold of the physiological concentration, affected obviously the cell viability. These results suggest that the overproduction of Aβ could not arrest cell differentiation induced by serum deprivation and that, at least to a certain degree and in a limited time period, is not toxic to cell viability.

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“…AICD harbors several internalization and trafficking motifs and might possess transcriptional activity that resembles the Notch1-IC of Notch1 (Baek et al, 2002;Cao and Sudhof, 2001;Gao and Pimplikar, 2001). AICD regulates phosphoinositide-mediated calcium signaling in vitro (Leissring et al, 2002) and also induces apoptosis and cytotoxicity in neurons (Lee et al, 2000). Previous reports have suggested the possibility of crosstalk between the Notch and APP signaling pathways, which would manifest as -secretase substrate competition (Berezovska et al, 2001;Lleo et al, 2003).…”

Section: Discussionmentioning

confidence: 99%

Regulation of Notch1 signaling by the APP intracellular domain facilitates degradation of the Notch1 intracellular domain and RBP-Jk

Kim

Ann

et al. 2011

Journal of Cell Science

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The Notch1 receptor is a crucial controller of cell fate decisions, and is also a key regulator of cell growth and differentiation in a variety of contexts. In this study, we have demonstrated that the APP intracellular domain (AICD) attenuates Notch1 signaling by accelerated degradation of the Notch1 intracellular domain (Notch1-IC) and RBP-Jk, through different degradation pathways. AICD suppresses Notch1 transcriptional activity by the dissociation of the Notch1-IC–RBP-Jk complex after processing by γ-secretase. Notch1-IC is capable of forming a trimeric complex with Fbw7 and AICD, and AICD enhances the protein degradation of Notch1-IC through an Fbw7-dependent proteasomal pathway. AICD downregulates the levels of RBP-Jk protein through the lysosomal pathway. AICD-mediated degradation is involved in the preferential degradation of non-phosphorylated RBP-Jk. Collectively, our results demonstrate that AICD functions as a negative regulator in Notch1 signaling through the promotion of Notch1-IC and RBP-Jk protein degradation.

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APP carboxyl-terminal fragment without or with A? domain equally induces cytotoxicity in differentiated PC12 cells and cortical neurons

Cited by 33 publications

References 39 publications

Amyloid precursor protein–mediated endocytic pathway disruption induces axonal dysfunction and neurodegeneration

Amyloid precursor protein–mediated endocytic pathway disruption induces axonal dysfunction and neurodegeneration

Effect of amyloid peptides on serum withdrawal-induced cell differentiation and cell viability

Regulation of Notch1 signaling by the APP intracellular domain facilitates degradation of the Notch1 intracellular domain and RBP-Jk

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