Abeta42 neurotoxicity in primary co-cultures: effect of apoE isoform and Abeta conformation - PubMed (original) (raw)

Abeta42 neurotoxicity in primary co-cultures: effect of apoE isoform and Abeta conformation

Arlene M Manelli et al. Neurobiol Aging. 2007 Aug.

Abstract

Autosomal dominant mutations that increase amyloid-beta(1-42) (Abeta42) cause familial Alzheimer's disease (AD), and the most common genetic risk factor for AD is the presence of the epsilon4 allele of apolipoprotein E (apoE). Previously, we characterized stable preparations of Abeta42 oligomers and fibrils and reported that oligomers induced a 10-fold greater increase in neurotoxicity than fibrils in Neuro-2A cells. To determine the effects of apoE genotype on Abeta42 oligomer- and fibril-induced neurotoxicity in vitro, we co-cultured wild type (WT) neurons with glia from WT, apoE-knockout (apoE-KO), and human apoE2-, E3-, and E4-targeted replacement (TR) mice. Dose-dependent neurotoxicity was induced by oligomeric Abeta42 with a ranking order of apoE4-TR>KO=apoE2-TR=apoE3-TR>WT. Neurotoxicity induced by staurosporine or glutamate were not affected by apoE genotype, indicating specificity for oligomeric Abeta42-induced neurotoxicity. These in vitro data demonstrate a gain of negative function for apoE4, synergistic with oligomeric Abeta42, in mediating neurotoxicity.

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Figures

Fig. 1

Fig. 1

Oligomeric Aβ42, but not fibrillar Aβ42, induced a dose- and time-dependent increase in neurotoxicity in the presence of WT glia (A) and KO glia (B). Cortical neurons from WT C57BL/6 mice were co-cultured with glial (~95% astrocytes) cells from WT or apoE-KO mice. Aβ42 oligomers or fibrils were added to cultures at 5 μM (■), 10 μM (formula image) and 20 μM (□) and incubated for 24, 48, and 72 h. Results are expressed as percent survival of Aβ42-treated cultures with vehicle-treated controls corresponding to 100% survival. Neurotoxicity was assessed using the ATP assay as described in Section 2. *Significant difference between oligomers and fibrils at equivalent dose and time (p < 0.05).

Fig. 2

Fig. 2

Oligomeric Aβ42, but not fibrillar Aβ42, induced a dose-dependent increase in neurotoxicity in the presence of apoE2-TR glia (A), apoE3-TR glia (B) and apoE4-TR glia (C). Cortical neurons from WT C57Bl/6 mice were co-cultured with glia from apoE2-, E3-, or E4-TR mice and exposed to 5 μM (■), 10 μM (formula image), and 20 μM (□) Aβ42 oligomers or fibrils for 48 h. Results are expressed as percent survival of Aβ42-treated cultures with vehicle-treated controls corresponding to 100% survival. Neurotoxicity was assessed using the ATP assay as described in Section 2. *Significant difference between oligomers and fibrils at equivalent dose (p < 0.05). #Significant difference between E4 and E2 or E3 at equivalent dose (p < 0.05).

Fig. 3

Fig. 3

Aβ42 oligomer-induced neurotoxicity is higher in the absence of glia. WT cortical neurons either alone (□) or in co-culture with WT glia (■) were treated with Aβ42 oligomers (5, 10, or 20 μM) for 48 h. *Significant difference between presence and absence of glia (p < 0.04).

Fig. 4

Fig. 4

Neurons co-cultured with apoE4-expressing glia showed the highest oligomeric Aβ42-induced neurotoxicity. Cortical neurons from WT C57BL/6 mice were co-cultured with glia (~95% astrocytes) from WT (■), apoE-KO (formula image), apoE2-TR (formula image), apoE3-TR (formula image), or apoE4-TR (□) mice. Oligomeric Aβ42 (10 μM) was added to cultures and incubated for 48 h. Results are expressed as percent survival of Aβ42-treated cultures with vehicle-treated controls corresponding to 100% survival. Neurotoxicity was assessed using the ATP assay as described in Section 2. *Significant difference between WT and apoE-KO (p < 0.04). **Significant difference between apoE-KO and apoE4 (p < 0.04). #Significant difference between E4 and E2 or E3 (p < 0.05).

Fig. 5

Fig. 5

ApoE genotype does not affect glutamate-induced (A) or staurosporine-induced (B) neurotoxicity. Neurotoxicity in WT mouse cortical neurons following 24-h treatment with increasing concentrations of (A) staurosporine, or (B) glutamate was assessed using the ATP assay as described in Section 2. Neurons in co-culture with glia from WT (■), apoE-KO (◆), apoE2-TR (▲), E3-TR (×), or E4-TR (○) mice.

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References

    1. Arriagada PV, Marzloff K, Hyman BT. Distribution of Alzheimer-type pathologic changes in nondemented elderly individuals matches the pattern in Alzheimer’s disease. Neurology. 1992;42(9):1681–8. - PubMed
    1. Banker G, Goslin K. Culturing nerve cells. xiii. Cambridge, MA: MIT Press; 1991. p. 453.
    1. Bowman BH, Jansen L, Yang F, Adrian GS, Zhao M, Atherton SS, et al. Discovery of a brain promoter from the human transferrin gene and its utilization for development of transgenic mice that express human apolipoprotein E alleles. Proc Natl Acad Sci USA. 1995;92:12115–9. - PMC - PubMed
    1. Boyles JK, Pitas RE, Wilson E, Mahley RW, Taylor JM. Apolipoprotein E associated with astrocytic glia of the central nervous system and with nonmyelinating glia of the peripheral nervous system. J Clin Invest. 1985;76:1501–13. - PMC - PubMed
    1. Butterfield DA. Amyloid beta-peptide (1–42)-induced oxidative stress and neurotoxicity, implications for neurodegeneration in Alzheimer’s disease brain. A review Free Radic Res. 2002;36(12):1307–13. - PubMed

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