This Article Abstract Full Text (PDF) All Versions of this Article: 34/4/875    most recent 01.STR.0000064320.73388.C6v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Aoki, K. Articles by Wakayama, Y. Search for Related Content PubMed PubMed Citation Articles by Aoki, K. Articles by Wakayama, Y. Related Collections Acute Cerebral Infarction Ischemic biology - basic studies Pathology of Stroke

(Stroke. 2003;34:875.)
© 2003 American Heart Association, Inc.

Original Contributions

Increased Expression of Neuronal Apolipoprotein E in Human Brain With Cerebral Infarction

Kazuko Aoki, MD, PhD; Toshiki Uchihara, MD, PhD; Nobuo Sanjo, MD, PhD; Ayako Nakamura; Kenji Ikeda, MD, PhD; Kuniaki Tsuchiya, MD, PhD Yoshihiro Wakayama, MD, PhD

From the Department of Neuropathology, Tokyo Metropolitan Institute for Neuroscience (K.A., T.U., N.S., A.N.), Tokyo; Department of Neurology, Fujigaoka Hospital of Showa University (K.A., Y.W.), Yokohama; Department of Neurology, Saitama Rehabilitation Center (N.S.), Saitama; Department of Neuropathology, Tokyo Institute of Psychiatry (K.I., K.T.), Tokyo; and Department of Laboratory Medicine and Pathology, Tokyo Metropolitan Matsuzawa Hospital (K.T.), Tokyo, Japan.

Correspondence to T. Uchihara, MD, PhD, Department of Neuropathology, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashi-dai, Fuchu, Tokyo, 183-8526 Japan. E-mail uchihara{at}tmin.ac.jp

	Abstract

Top Abstract Introduction Methods Results Discussion References

 
Background and Purpose— Cellular origin of apolipoprotein E (ApoE) in the human brain and its roles in physiological and pathological conditions remain to be clarified.

Methods— Immunolocalization of ApoE was investigated in a series of autopsied human brains with or without infarction. ApoE expression was also estimated on immunoblot on protein extracts from autopsied brains and a cultured neuroblastoma cell line of human origin (GOTO) subjected to an oxidative stress induced by exposure to hydrogen peroxide (0.2 mmol/L).

Results— In addition to astrocytes and microglia, neurons and degenerated axons in and around the ischemic foci contained ApoE-like immunoreactivity, which was more intense in recent ischemic foci. Immunoblot demonstrated an increase in expression of ApoE in brain extracts from ischemic lesion, and this increase was also pronounced in the cultured neuroblastoma cell line after the stress.

Conclusions— Accumulation of ApoE in neurons in and around ischemic foci of the human brain is related to an increase in ApoE synthesis in neurons, as seen in cultured neuronal cells after oxidative stress. Intrinsic regenerative activity of neuron in reaction to external insults may be related to this increase in ApoE of neuronal origin.

Key Words: apolipoproteins • cerebral infarction • neurons • oxidative stress

	Introduction

Top Abstract Introduction Methods Results Discussion References

 
Apolipoprotein E (ApoE) is synthesized in various organs, including liver, spleen, kidney, and brain, and is supposed to play multiple roles. There is accumulating evidence that ApoE in the central nervous system is involved not only in stable physiological conditions but also in more dynamic situations such as development, remodeling, degeneration, and regeneration.^1–6 Moreover, the cellular source of ApoE in the central nervous system, initially considered to be restricted to astrocytes,^7,8 is currently considered to be more variable according to conditions.^9–14

In this study we attempted to examine the manner in which ApoE is expressed in human brain with ischemic foci to clarify how an insult to the central nervous system modifies the expression of ApoE, which has been reported to play certain roles in repair of the central nervous system.^1,15–17 A parallel in vitro study on a cultured cell line corroborated these in vivo findings.^18,19

	Methods

Top Abstract Introduction Methods Results Discussion References

 
Autopsied brains from 9 patients with cerebral infarction, 6 patients with Alzheimer disease (AD), and 8 patients without neurological disorders were enrolled in this study. Clinical data of the patients are summarized in the Table. The time from the onset of the ischemic attack to death was between 8 days and 10 months, determined from the clinical records.

View this table: [in this window] [in a new window]   Summary of Clinical Data

Immunohistochemistry
Formalin-fixed, paraffin-embedded blocks, including both the area of ischemic necrosis and the surrounding nonnecrotic area, were obtained at 10-µm thickness. Sections were deparaffinized and treated with a microwave oven in citrate buffer 3 times for 5 minutes, treated with 1% hydrogen peroxide for 30 minutes, then incubated for 3 days at 4°C with either ApoEC (1:2000; anti-human ApoE polyclonal antibody raised against a synthetic peptide EKVQAAVGTSAAPVPSDNH equivalent to the C-terminal amino acid sequence 299 to 317 of human apolipoprotein E; IBL) or ApoEAB947²⁰ (1:2000; anti-human recombinant ApoE; Chemicon) diluted with PBS containing 0.03% Triton-X 100 and the corresponding blocking serum. The sections were then incubated for 2 hours with a biotinylated secondary antibody (1:1000; Vector), followed by avidin-biotin-peroxidase complex (1:1000; ABC Elite, Vector). The peroxidase labeling was visualized with diaminobenzidine as chromogen, which yielded a brown reaction product after approximately 40 minutes, and then the stained sections were counterstained with hematoxylin.

Cellular localization of ApoE epitope was examined on double-labeled sections with the following combinations of probes: anti-carbindin²¹ (1:3000; anti-spot 35, rabbit polyclonal antibody; generous gift from Dr Yamakuni, Tohoku University) as a marker for neurons/ApoEAB947; anti–glial fibrillary acidic protein (1:1000; mouse monoclonal antibody; DAKO) as a marker for astrocytes/ApoEC; or biotinylated Ricinus communis agglutinin (1:1000; RCA-120; Seikagakukougyou) as a marker for microglia/ApoEC. After one of the probes (antibody or lectin) was visualized with diaminobenzidine and nickel ammonium sulfate as purple, the sections were subjected to second-cycle immunostaining with the other probe. They were then treated similarly except that diaminobenzidine was used without nickel ammonium sulfate to yield brown reaction products.

To localize ApoE-like immunoreactivity in relation to axons, double immunolabeling with ApoEC and anti-neurofilament (SMI31; Sternberger Monoclonal) was performed. Deparaffinized sections were incubated with SMI31 (1:1000), and the epitope was then immunofluorolabeled by FITC-conjugated anti-mouse IgG (1:200; Cappel). The FITC signal was observed under the fluorescence microscope combined with a laser confocal system (TCS-SP; Leica), and the images were captured and recorded on magneto-optical disks. The same section was subjected to second-cycle immunostaining with ApoEC (1:2000), visualized with the ABC method. The already photographed axons were identified with the use of various structures such as lipofuscin granules or blood vessels as landmarks. The relationship between ApoE-like immunoreactivity and neurofilaments was assessed on the same field.

Cell Culture, Cell Stimulation, and Protein Extraction
The human neuroblastoma cell line GOTO²² was cultured in RPMI 1640 medium supplemented with 20% fetal bovine serum. At 3 days in culture, the incubation medium was replaced with RPMI 1640 without fetal bovine serum. Hydrogen peroxide was added directly to the medium to produce a final concentration of 0.2 mmol/L and incubated for appropriate times. At fixed intervals (4, 24, and 48 hours) after the challenge with hydrogen peroxide, the incubation medium was rapidly aspirated, and the cells were washed twice with ice-cold PBS and fixed by 10% trichloroacetic acid for 30 minutes at 4°C. After the dishes were scraped with a rubber policeman, the lysate was centrifuged at 15 000g for 5 minutes, and the supernatant was discarded. Then each pellet of GOTO cell, at different intervals after the exposure to hydrogen peroxide, was resuspended by sonication in a sample buffer containing 9 mol/L urea, 2% Triton X, and 5% 2-mercaptoethanol. Then one fifth volume of 10% lithium dodecyl sulfate solution and approximately 2 µL of 1 mol/L Tris solution were added to the sample buffer, and the samples were sonicated again.

Each human brain homogenate from the autopsied brains (2 AD brains, 2 brains with infarction, and 4 control brains) was also fixed by 10% trichloroacetic acid, and extracted protein was treated in the same way as the GOTO cell.

Western Blot Analyses
Lysates containing equal amounts of protein (GOTO, 10 µg; autopsy brains, 10 µg) were subjected to 10% sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Proteins were then transferred to a polyvinylidene difluoride membrane. The blots were blocked with 10% (wt/vol) skim milk and 0.1% Tween 20 in Tris-buffered saline (TBS) at room temperature for 1 hour and washed in 1% (wt/vol) bovine serum albumin/TBS at room temperature for 10 minutes. Then the blots were probed with ApoEC (1:4000) or ApoEAB947 (1:4000) in 1% bovine serum albumin/TBS solution at 4°C for 3 days. After 3 washes with 1% (wt/vol) skim milk and 0.1% Tween 20 in TBS at room temperature for 30 minutes, the blots were incubated with horseradish peroxidase–coupled goat anti-rabbit IgG secondary antibody (Pierce) diluted to 1:2000 with 1% skim milk/TBS at room temperature for 2 hours. Then the blots were washed 3 times with 0.1% Tween 20/TBS and visualized with the use of an enhanced chemiluminescence system (Amersham). The same blots were reprobed with anti–ß-actin (1:40 000; Sigma) and visualized with horseradish peroxidase–coupled anti-mouse IgG secondary antibody (Kirkegaard and Perry Laboratory Inc). ApoE-immunoreactive bands were digitally captured, and their relative intensities were quantified with NIH Image (version 1.62). Because the number of the samples was not very large, quantified data were analyzed not only with ANOVA and the Fisher protected least significant difference test but also with the nonparametric rank method of Kruskal-Wallis.

	Results

Top Abstract Introduction Methods Results Discussion References

 
Immunolocalization of ApoE in Human Brains
Neurons exhibited an intense ApoE-like immunoreactivity at the periphery of ischemic focus (Figure 1A). This ApoE-like immunoreactivity was completely abolished throughout the adjacent section when ApoEC was coincubated with the antigen peptide (Figure 1B, the same area as Figure 1A), which confirmed the specificity of ApoE-like immunoreactivity with ApoEC. ApoEAB947 gave essentially the same results as ApoEC. This ApoE-like immunoreactivity in neurons was more pronounced in recent foci than in older foci. None of these neurons were atrophic or ischemic.

View larger version (162K): [in this window] [in a new window]   Figure 1. Immunostaining with ApoEC at the periphery of an ischemic focus counterstained with hematoxylin (bars=50 µm). A, Neurons exhibit ApoE-like immunoreactivity. B, ApoE-like immunoreactivity was completely abolished when ApoEC was coincubated with the antigen peptide. The same area as A in the adjacent section is shown, evidenced by the presence of the same blood vessel (arrow) and neurons (arrowhead).

Double-labeled sections of ischemic foci demonstrated that ApoE-like immunoreactivity was present variably in neurons, some ballooned neurons (Figure 2A), astrocytes (Figure 2B), and microglia (Figure 2C). Double-labeling immunohistochemistry with anti-neurofilament (SMI-31; Figure 3A) and ApoEC (Figure 3B) antibodies clarified colocalization of these 2 epitopes, which confirmed that accumulation of ApoE was also extended into axons. ApoE-positive glial cells were, however, rarely observed where ApoE accumulated in neurons or axons and vice versa: neurons and axons immunopositive for ApoE were rarely in close contact with glial cells containing ApoE-like immunoreactivity (Figures 1 to 3).

View larger version (104K): [in this window] [in a new window]   Figure 2. Cellular localization of ApoE around ischemic foci. A, Double immunolabeling of ApoEC (purple) and carbindin (brown) at the boundary of an ischemic focus. ApoE-like immunoreactivity is variable in each neuron, including a ballooned neuron (arrow; bar=50 µm). B, Double immunolabeling of GFAP (purple) and ApoEC (brown) at the boundary of an ischemic focus. In addition to double-stained astrocytes (arrows), intense ApoE-like immunoreactivity is present in neuronal cells (arrowheads; bar=50 µm). C, Double immunolabeling of RCA-120 (purple) and ApoEC (brown) at the boundary of ischemic foci. Some microglial cells (arrow) are ApoE immunopositive (bar=50 µm).

View larger version (63K): [in this window] [in a new window]   Figure 3. Accumulation of ApoE in degenerated axons (bar=50 µm). Colocalization of neurofilament epitope (A; labeling with SMI31 and visualized with FITC) and ApoE-like immunoreactivity (B; labeling with ApoEC and visualized with avidin-biotin-peroxidase method on the same section as A) confirmed axonal accumulation of ApoE.

Differences in immunolocalization of ApoE and in its immunoreactivity according to pathological conditions are shown in Figure 4. In control brains, ApoE-like immunoreactivity was at most faint in neurons (Figure 4A) or in subpial astroglia. In AD brains, ApoE-like immunoreactivity was accumulated in senile plaques and neurofibrillary tangles (Figure 4B), while other neuronal labeling was not comparable to that seen at the periphery of an ischemic focus (Figure 4C). Comparison of the ischemic area (Figure 4D, left) and its adjacent less affected area (Figure 4D, right) demonstrated that ApoE-like immunoreactivity in neurons was apparently more intense in areas involved in the ischemic process. Even in brains with ischemic focus, ApoE-like immunoreactivity in neurons was barely detectable in intact areas closely adjacent to the ischemic focus (Figure 4D).

View larger version (81K): [in this window] [in a new window]   Figure 4. ApoE-like immunoreactivity (probed with ApoEC) in various pathological conditions (counterstained with hematoxylin). A, Control. Some neurons exhibit ApoE-like immunoreactivity, although it is at most very faint (bar=50 µm). B, AD. ApoE-like immunoreactivity is accumulated in senile plaques, while neuronal labeling is absent outside neurofibrillary tangles (bar=50 µm). C, At the periphery of an ischemic focus. ApoE-like immunoreactivity is intense in neurons (bar=50 µm). D, Low-power view of C. ApoE-immunoreactive neurons are abundant in the affected area (left), while they are absent in less affected area (right; bar=100 µm).

Western Blot Analyses
Probing human brain extracts with ApoEC on Western blot demonstrated a major band at approximately 36 kDa (Figure 5A), as was detected similarly when probed with ApoEAB947. Quantitative analysis of the relative intensity of ApoE-immunoreactive bands (Figure 5B) demonstrated that expression of ApoE protein was significantly increased (P=0.0498, nonparametric method of Kruskal-Wallis) in AD brains (214%, mean relative to mean of controls, indicated as 1; P=0.0320, ANOVA) and further increased in brains with infarction (247%, mean relative to mean of controls; P=0.0132, ANOVA).

View larger version (21K): [in this window] [in a new window]   Figure 5. Western blot of extracts from human brains probed with ApoEC (A) and its densitometric quantification (B). A, ApoEC-immunoreactive bands at approximately 36 kDa, derived from brains with infarction (Infarct) and from those with AD, are more intense than those from normal brains (Normal). Arrowhead: 36 kDa. ß-Actin–immunoreactive bands are shown as an internal control (bottom). B, Relative intensity of ApoEC-immunoreactive bands (mean±SD) was quantified and expressed with mean of normal brains (n=4) as a reference, indicated as 1. ApoE-immunoreactive bands are more intense in AD brains (n=2) and in brains with infarction (n=2) relative to normal brains. *P<0.05; broken line indicates not significant by ANOVA.

Probing extracts from human neuroblastoma cell line (GOTO) with ApoEC visualized bands similar to those seen in human brains (Figure 6A). Four independent sessions were followed up to 48 hours after exposure to hydrogen peroxide, and the density of ApoE-immunoreactive bands was quantified relative to the baseline (0 hours) of each session, indicated as 1 (Figure 6B). Quantitative analysis of the relative intensity of ApoE-immunoreactive bands demonstrated that expression of ApoE protein was dependent on intervals (P=0.0088, nonparametric method of Kruskal-Wallis) after exposure to hydrogen peroxide. It increased at 4 hours (133%, mean relative to mean before exposure; P=0.0213, ANOVA). At 24 hours, this increase was more significant (168%; P=0.0002, ANOVA), which was progressive up to 48 hours (187%; P=0.0002, ANOVA). A consistent amount of ß-actin immunoreactivity is seen at the bottom of Figure 5A and Figure 6A, suggesting that the amount of loaded protein was consistent.

View larger version (23K): [in this window] [in a new window]   Figure 6. A, Western blot of extracts from human neuroblastoma cell line, GOTO, probed with ApoEC, examined at different intervals after exposure to hydrogen peroxide (0.2 mmol/L). Arrowhead: 36 kDa. ß-Actin–immunoreactive bands are shown as an internal control (bottom). B, Quantification of ApoEC-immunoreactive bands expressed as mean of 4 sessions (n=4) at different intervals after challenge with hydrogen peroxide. Relative intensity of ApoEC-immunoreactive bands (mean±SD) was quantified and expressed with intensity at 0 hours (baseline) of each session as a reference, indicated as 1. The increase is statistically significant after 4 hours and thereafter (mean±SD). *P<0.05; **P<0.01; broken line indicates not significant by ANOVA.

	Discussion

Top Abstract Introduction Methods Results Discussion References

 
The major cellular source of ApoE in the brain has been considered to be astrocytes.^7,8 On the other hand, immunolocalization of ApoE to other cellular components, such as neurons in the hippocampus or frontal cortex, microglia, oligodendrocytes, and blood vessels, has also been reported.^9–14 It still remains to be clarified how ApoE is produced and handled in the brain. Moreover, little is known regarding how the metabolism of ApoE is altered in diseased brains. In the present study immunohistochemical investigation on human autopsied brains with ischemic lesions demonstrated that astrocytes and microglia contained ApoE-like immunoreactivity, as reported previously.^11,13 In addition to these glial components, neocortical neurons around the ischemic foci also contained abundant ApoE-like immunoreactivity. At least 2 possibilities have been proposed regarding the cellular source of ApoE in neurons. Because ApoE could be internalized through several receptors on plasma membrane,¹⁹ it is speculated that ApoE in neurons is derived from astrocytes and is internalized through these carrier molecules.^1,23 Another possibility is that ApoE is produced in neurons, as demonstrated previously by in situ hybridization.²⁴ Although these 2 pathways are not mutually exclusive, the present study demonstrated that neurons were one of the major sites of ApoE synthesis in ischemic foci, in addition to glial cells. The absence of ApoE-positive glial cells around ApoE-positive neurons in ischemic foci suggests that ApoE is synthesized in these neurons and is not derived exogenously. Moreover, accumulation of ApoE was not only restricted to neuronal soma but also extended into degenerated axons (Figure 3B), again not in contact with ApoE-positive glial cells, which suggests a neuronal origin of ApoE. Although it has been reported that some neurons without disease possibly exhibit ApoE-like immunoreactivity in human brain,^12,25 it was at most faint in the present study. Because the same antibody visualized a significant amount of ApoE on Western blot (Figure 5A), it is likely that sampling, routine fixation in formalin, and processing in paraffin, as used in the present study, might have attenuated immunohistochemical labeling of ApoE in normal neurons. Fixation with another fixative (such as paraformaldehyde) and use of free-floating sections might have visualized ApoE immunoreactivity even in normal neurons,²⁵ while brain tissue with ischemic focus is usually too fragile to be subjected to such a free-floating method. More importantly, ApoE-like immunoreactivity in neurons was more evident around ischemic foci. Immunoblots from brain extracts demonstrated that full-length form (34 to 37 kDa^2,5,20,26 ) of ApoE was present regardless of the disease conditions. Quantification of relative intensity of ApoE-immunoreactive bands demonstrated that the amount of ApoE is increased to 114% (>2-fold) in AD and more significantly increased to 146% in ischemic foci (Figure 5B). Because glial cells in ischemic foci also contain ApoE-like immunoreactivity, it is difficult to decide what kind of cell (neuronal or glial) is responsible for this increase seen on Western blot. Although synthesis of ApoE in other neuroblastoma cell lines has been reported,⁴ accumulation of ApoE protein in neuronal cells after exposure to hydrogen peroxide may have some pathological significance.²⁷ While synthesis of ApoE could be regulated through interaction between glia and neurons, possibly mediated, for example, by nuclear factor-B,^28,29 the present study on a neuroblastoma cell line demonstrated that neuronal accumulation of ApoE protein could occur independently of glial cells. Therefore, the increase in ApoE, as we observed in ischemic foci of human brains, is explained, at least in part, by upregulation of ApoE synthesis in neurons. Intense ApoE-like immunoreactivity in these neurons in ischemic focus also corroborated this interpretation.

Several epidemiological studies demonstrated that APOE genotype 4 was possibly linked to some neurological disorders (eg, Lewy body disease, amyotrophic lateral sclerosis, AIDS) other than AD.^30–32 Other studies demonstrated that recovery from cerebrovascular diseases was also influenced by APOE genotype.^33–35 These data suggest that ApoE in the brain plays certain essential roles during destruction and recovery of the nervous system,^33,35 as well as in physiological conditions.³⁴ It still remains to be proven how ApoE plays certain roles in ischemic foci. The present study suggested an upregulation of ApoE in neurons after cellular stress such as ischemia or oxidative stress. If this upregulation is linked to recovery of neurons after cellular stresses in general, regulation of ApoE expression will provide a clue to constructing a therapeutic strategy aimed at improving recovery from a wide variety of neurological diseases. It is therefore essential to know how the expression of ApoE is regulated in physiological and pathological conditions.

	Acknowledgments

 
This work is supported in part by grants from the Ministry of Culture Science and Education, Japan (128781246), Brain Science Foundation, and Sasagawa Foundation.

Received November 8, 2001; revision received November 11, 2002; accepted November 13, 2002.

	References

Top Abstract Introduction Methods Results Discussion References

 

1. Mahley RW. Apolipoprotein E: cholesterol transport protein with expanding role in cell biology. Science. 1988; 240: 622–630.[Abstract/Free Full Text]
2. Ignatius MJ, Gebicke-Härter PJ, Skene JHP, Schilling JW, Weisgraber KH, Mahley RW, Shooter EM. Expression of apolipoprotein E during nerve degeneration and regeneration. Proc Natl Acad Sci U S A. 1986; 83: 1125–1129.[Abstract/Free Full Text]
3. Tomimoto H, Akiguchi I, Suenaga T, Wakita H, Nakamura S, Kimura J, Budka H. Immunohistochemical study of apolipoprotein E in human cerebrovascular white matter lesions. Acta Neuropathol (Berl). 1995; 90: 608–614.[Medline] [Order article via Infotrieve]
4. Dupont-Wallois L, Soulie C, Sergeant N, Wrieze NW, Chartier-Harlin M-C, Delacourte A, Caillet-Boudin M-L. ApoE synthesis in human neuroblastoma cells. Neurobiol Dis. 1997; 4: 356–364.[CrossRef][Medline] [Order article via Infotrieve]
5. Tesseur I, Dorpe JV, Bruynseels K, Bronfman F, Sciot R, Lommel AV, Leuven FV. Prominent axonopathy and disruption of axonal transport in transgenic mice expressing human apolipoprotein E4 in neurons of brain and spinal cord. Am J Pathol. 2000; 157: 1495–1510.[Abstract/Free Full Text]
6. White F, Nicoll JAR, Horsburgh K. Alterations in ApoE and ApoJ in relation to degeneration and regeneration in a mouse model of entorhinal cortex lesion. Exp Neurol. 2001; 169: 307–318.[CrossRef][Medline] [Order article via Infotrieve]
7. 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: 1501–1513.
8. Poirier J, Hess M, May PC, Finch CE. Astrocytic apolipoprotein E mRNA and GFAP mRNA in hippocampus after entorhinal cortex lesioning. Mol Brain Res. 1991; 11: 97–106.[Medline] [Order article via Infotrieve]
9. Namba Y, Tomonaga M, Kawasaki H, Otomo E, Ikeda K. Apolipoprotein E immunoreactivity in cerebral amyloid deposits and neurofibrillary tangles in Alzheimer’s disease and kuru plaque amyloid in Creutzfeldt-Jakob disease. Brain Res. 1991; 541: 163–166.[CrossRef][Medline] [Order article via Infotrieve]
10. Stoll G, Mueller HW, Trapp BD, Griffin JW. Oligodendrocytes but not astrocytes express apolipoprotein E after injury of rat optic nerve. Glia. 1989; 2: 170–176.[CrossRef][Medline] [Order article via Infotrieve]
11. Han S-H, Hulette C, Saunders AM, Einstein G, Pericak-Vance M, Strittmatter WJ, Roses AD, Schmechel DE. Apolipoprotein E is present in hippocampal neurons without neurofibrillary tangles in Alzheimer’s disease and in age-matched controls. Exp Neurol. 1994; 128: 13–26.[CrossRef][Medline] [Order article via Infotrieve]
12. Han S-H, Einstein G, Weisgraber KH, Strittmatter WJ, Saunders AM, Pericak-Vance M, Roses AD, Schmechel DE. Apolipoprotein E is localized to the cytoplasm of human cortical neurons: a light and electron microscopic study. J Neuropathol Exp Neurol. 1994; 53: 535–544.[Medline] [Order article via Infotrieve]
13. Uchihara T, Duyckaerts C, He Y, Kobayashi K, Seilhean D, Amouyel P, Hauw J-J. ApoE immunoreactivity and microglial cells in Alzheimer’s disease brain. Neurosci Lett. 1995; 195: 5–8.[CrossRef][Medline] [Order article via Infotrieve]
14. Metzger RE, LaDu MJ, Pan JB, Getz GS, Frail DE, Falduto MT. Neurons of the human frontal cortex display apolipoprotein E immunoreactivity: implications for Alzheimer’s disease. J Neuropathol Exp Neurol. 1996; 55: 372–380.[Medline] [Order article via Infotrieve]
15. Snipes GJ, McGuire CB, Norden JJ, Freeman JA. Nerve injury stimulates the secretion of apolipoprotein E by nonneuronal cells. Proc Natl Acad Sci U S A. 1986; 83: 1130–1134.[Abstract/Free Full Text]
16. Horsburgh K, Nicoll JAR. Selective alterations in the cellular distribution of apolipoprotein E immunoreactivity following transient cerebral ischaemia in the rat. Neuropathol Appl Neurobiol. 1996; 22: 342–349.[Medline] [Order article via Infotrieve]
17. Horsburgh K, Kelly S, McCulloch J, Higgins GA, Roses AD, Nicoll JAR. Increased neuronal damage in apolipoprotein E-deficient mice following global ischaemia. Clin Neurosci. 1999; 10: 837–841.
18. Dekroon RM, Armati PJ. Synthesis and processing of apolipoprotein E in human brain cultures. Glia. 2001; 33: 298–305.[CrossRef][Medline] [Order article via Infotrieve]
19. Pitas RE, Boyles JK, Lee SH, Foss D, Mahley RW. Astrocytes synthesize apolipoprotein E and metabolize apolipoprotein E-containing lipoproteins. Biochim Biophys Acta. 1987; 917: 148–161.[Medline] [Order article via Infotrieve]
20. Schwab C, Steele JC, Akiyama H, McGeer PL. Distinct distribution of apolipoprotein E and ß-amyloid immunoreactivity in the hippocampus of Parkinson dementia complex of Guam. Acta Neuropathol (Berl). 1996; 92: 378–385.[CrossRef][Medline] [Order article via Infotrieve]
21. Yamakuni T, Usui H, Iwanaga T, Kondo H, Odani S, Takahashi Y. Isolation and immunohistochemical localization of a cerebellar protein. Neurosci Lett. 1984; 45: 235–240.[CrossRef][Medline] [Order article via Infotrieve]
22. Sekiguchi M, Oota T, Sakakibara K, Inui N, Fujii G. Establishment and characterization of a human neuroblastoma cell line in tissue culture. Jpn J Exp Med. 1979; 49: 67–83.[Medline] [Order article via Infotrieve]
23. Rebeck GW, Reiter JS, Strickland DK, Hyman BT. Apolipoprotein E in sporadic Alzheimer’s disease: allelic variation and receptor interactions. Neuron. 1993; 11: 575–580.[CrossRef][Medline] [Order article via Infotrieve]
24. Xu P-T, Gilbert JR, Qiu H-L, Ervin J, Rothrock-Christian TR, Hulette C, Schmechel DE. Specific regional transcription of apolipoprotein E in human brain neurons. Am J Pathol. 1999; 154: 601–611.[Abstract/Free Full Text]
25. Einstein G, Patel V, Bautista P, Kenna M, Melone L, Fader R, Karson K, Mann S, Saunders AM, Hulette C, et al. Intraneuronal ApoE in human visual cortical areas reflects the staging of Alzheimer disease pathology. J Neuropathol Exp Neurol. 1998; 57: 1190–1201.[Medline] [Order article via Infotrieve]
26. Huang Y, Liu XQ, Wyss-Coray T, Brecht WJ, Sanan DA, Mahley RW. Apolipoprotein E fragments present in Alzheimer’s disease brains induce neurofibrillary tangle-like intracellular inclusions in neurons. Proc Natl Acad Sci U S A. 2001; 98: 8838–8843.[Abstract/Free Full Text]
27. Desagher S, Glowinski J, Prémont J. Pyruvate protects neurons against hydrogen peroxide-induced toxicity. J Neurosci. 1997; 17: 9060–9067.[Abstract/Free Full Text]
28. Gabriel C, Justicia C, Camins A, Planas AM. Activation of nuclear factor-B in the rat brain after transient focal ischemia. Mol Brain Res. 1999; 65: 61–69.[Medline] [Order article via Infotrieve]
29. Petegnief V, Saura J, de Gregorio-Rocasolano N, Paul SM. Neuronal injury-induced expression and release of apolipoprotein E in mixed neuron/glia co-cultures: nuclear factor B inhibitors reduce basal and lesion-induced secretion of apolipoprotein E. Neuroscience. 2001; 104: 223–234.[CrossRef][Medline] [Order article via Infotrieve]
30. Saunders AM, Schmader K, Breitner JCS, Benson MD, Brown WT, Goldfarb L, Goldgaber D, Manwaring MG, Szymanski MH, McCown N, et al. Apolipoprotein E 4 allele distributions in late-onset Alzheimer’s disease and in other amyloid-forming diseases. Lancet. 1993; 342: 710–711.[CrossRef][Medline] [Order article via Infotrieve]
31. Moulard B, Sefiani A, Laamri A, Malafosse A, Camu W. Apolipoprotein E genotyping in sporadic amyotrophic lateral sclerosis: evidence for a major influence on the clinical presentation and prognosis. J Neurol Sci. 1996; 139 (suppl): 34–37.
32. Corder EH, Robertson K, Lannfelt L, Bogdanovic N, Eggertsen G, Wilkins J, Hall C. HIV-infected subjects with the E4 allele for APOE have excess dementia and peripheral neuropathy. Nat Med. 1998; 4: 1182–1184.[CrossRef][Medline] [Order article via Infotrieve]
33. Horsburgh K, Graham DI, Stewart J, Nicoll JAR. Influence of apolipoprotein E genotype on neuronal damage and apoE immunoreactivity in human hippocampus following global ischemia. J Neuropathol Exp Neurol. 1999; 58: 227–234.[Medline] [Order article via Infotrieve]
34. Pedersen WA, Chan SL, Mattson MP. A mechanism for the neuroprotective effect of apolipoprotein E: isoform-specific modification by the lipid peroxidation product 4-hydroxynonenal. J Neurochem. 2000; 74: 1426–1433.[CrossRef][Medline] [Order article via Infotrieve]
35. Horsburgh K, McCulloch J, Nilsen M, Roses AD, Nicoll JAR. Increased neuronal damage and apoE immunoreactivity in human apolipoprotein E, E4 isoform-specific, transgenic mice after global cerebral ischaemia. Eur J Neurosci. 2000; 12: 4309–4317.[CrossRef][Medline] [Order article via Infotrieve]

This article has been cited by other articles:

				Y. Nagayasu, J.-i. Ito, T. Nishida, and S. Yokoyama Reactivity of Astrocytes to Fibroblast Growth Factor-1 for Biogenesis of Apolipoprotein E-High Density Lipoprotein is Down-regulated by Long-time Secondary Culture J. Biochem., May 1, 2008; 143(5): 611 - 616. [Abstract] [Full Text] [PDF]

				J.-i. Ito, Y. Nagayasu, K. Okumura-Noji, R. Lu, T. Nishida, Y. Miura, K. Asai, A. Kheirollah, S. Nakaya, and S. Yokoyama Mechanism for FGF-1 to regulate biogenesis of apoE-HDL in astrocytes J. Lipid Res., September 1, 2007; 48(9): 2020 - 2027. [Abstract] [Full Text] [PDF]

				Q. Xu, A. Bernardo, D. Walker, T. Kanegawa, R. W. Mahley, and Y. Huang Profile and Regulation of Apolipoprotein E (ApoE) Expression in the CNS in Mice with Targeting of Green Fluorescent Protein Gene to the ApoE Locus. J. Neurosci., May 10, 2006; 26(19): 4985 - 4994. [Abstract] [Full Text] [PDF]

				R. W. Mahley, K. H. Weisgraber, and Y. Huang Inaugural Article: Apolipoprotein E4: A causative factor and therapeutic target in neuropathology, including Alzheimer's disease PNAS, April 11, 2006; 103(15): 5644 - 5651. [Abstract] [Full Text] [PDF]

				Y. Huang Apolipoprotein E and Alzheimer disease Neurology, January 24, 2006; 66(1_suppl_1): S79 - S85. [Abstract] [Full Text] [PDF]

				S. Chang, T. r. Ma, R. D. Miranda, M. E. Balestra, R. W. Mahley, and Y. Huang Lipid- and receptor-binding regions of apolipoprotein E4 fragments act in concert to cause mitochondrial dysfunction and neurotoxicity PNAS, December 20, 2005; 102(51): 18694 - 18699. [Abstract] [Full Text] [PDF]

				J.-i. Ito, Y. Nagayasu, R. Lu, A. Kheirollah, M. Hayashi, and S. Yokoyama Astrocytes produce and secrete FGF-1, which promotes the production of apoE-HDL in a manner of autocrine action J. Lipid Res., April 1, 2005; 46(4): 679 - 686. [Abstract] [Full Text] [PDF]

				Q. Xu, W. J. Brecht, K. H. Weisgraber, R. W. Mahley, and Y. Huang Apolipoprotein E4 Domain Interaction Occurs in Living Neuronal Cells as Determined by Fluorescence Resonance Energy Transfer J. Biol. Chem., June 11, 2004; 279(24): 25511 - 25516. [Abstract] [Full Text] [PDF]

				W. J. Brecht, F. M. Harris, S. Chang, I. Tesseur, G.-Q. Yu, Q. Xu, J. Dee Fish, T. Wyss-Coray, M. Buttini, L. Mucke, et al. Neuron-Specific Apolipoprotein E4 Proteolysis Is Associated with Increased Tau Phosphorylation in Brains of Transgenic Mice J. Neurosci., March 10, 2004; 24(10): 2527 - 2534. [Abstract] [Full Text] [PDF]

				F. M. Harris, I. Tesseur, W. J. Brecht, Q. Xu, K. Mullendorff, S. Chang, T. Wyss-Coray, R. W. Mahley, and Y. Huang Astroglial Regulation of Apolipoprotein E Expression in Neuronal Cells: IMPLICATIONS FOR ALZHEIMER'S DISEASE J. Biol. Chem., January 30, 2004; 279(5): 3862 - 3868. [Abstract] [Full Text] [PDF]

				F. M. Harris, W. J. Brecht, Q. Xu, I. Tesseur, L. Kekonius, T. Wyss-Coray, J. D. Fish, E. Masliah, P. C. Hopkins, K. Scearce-Levie, et al. Carboxyl-terminal-truncated apolipoprotein E4 causes Alzheimer's disease-like neurodegeneration and behavioral deficits in transgenic mice PNAS, September 16, 2003; 100(19): 10966 - 10971. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) All Versions of this Article: 34/4/875    most recent 01.STR.0000064320.73388.C6v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Aoki, K. Articles by Wakayama, Y. Search for Related Content PubMed PubMed Citation Articles by Aoki, K. Articles by Wakayama, Y. Related Collections Acute Cerebral Infarction Ischemic biology - basic studies Pathology of Stroke