Previous Article | Next Article 
Volume 17, Number 13,
Issue of July 1, 1997
pp. 5101-5107
Copyright ©1997 Society for Neuroscience
Neuronal Localization of Presenilin-1 and Association with
Amyloid Plaques and Neurofibrillary Tangles in Alzheimer's Disease
Jorge Busciglio1,
Henrike Hartmann1,
Alfredo Lorenzo1,
Caine Wong1,
Karlheinz Baumann2,
Bernd Sommer2,
Matthias Staufenbiel2, and
Bruce A. Yankner1
1 Department of Neurology, Harvard Medical School and
Division of Neuroscience, The Children's Hospital, Boston,
Massachusetts 02115, and 2 Preclinical Research, Sandoz
Pharma Ltd., CH-4002 Basel, Switzerland
ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
FOOTNOTES
REFERENCES
ABSTRACT
Mutations in the presenilin-1 (PS1) gene is a cause of early- onset
familial Alzheimer's disease (AD). Endogenous PS1 is associated with
the endoplasmic reticulum in the cell body of undifferentiated SH-SY5Y
neuroblastoma cells. At early stages of neuronal differentiation in rat
hippocampal culture, PS1 appears in all neuritic processes and in
growth cones. In mature differentiated neurons, PS1 is concentrated in
the somatodendritic compartment but is also present at lower levels in
axons. A similar localization of PS1 is observed in vivo
in neurons of the adult human cerebral cortex. In sporadic AD, PS1
appears in the dystrophic neurites of mature amyloid plaques and
co-localizes with a subset of intraneuronal neurofibrillary tangles
(NFTs). About 30% of hippocampal NFTs are labeled with a highly
specific antibody to the PS1 C-terminal loop domain but not with an
antibody to the PS1 N terminus. This observation is consistent with a
potential association of the PS1 C-terminal fragment with NFTs, because
PS1 is constitutively cleaved to N- and C-terminal fragments in
neurons. These results suggest that PS1 is highly expressed and broadly
distributed during early stages of neuronal differentiation, consistent
with a role for PS1 in neuronal differentiation. Furthermore, the
co-localization of PS1 with NFTs and plaque dystrophic neurites
implicates a role for PS1 in the diverse pathological manifestations of
AD.
Key words:
Presenilin;
Alzheimer's disease;
differentiation;
degeneration;
dendritic;
cytoskeleton
INTRODUCTION
The identification of specific genes that give
rise to Alzheimer's disease (AD) has provided a powerful tool for the
elucidation of the disease mechanism (Yankner, 1996
). The majority of
familial early-onset AD is caused by mutations in a new gene family,
the presenilins (Sherrington et al., 1995
). Most familial early-onset AD is caused by mutations in the presenilin-1 (PS1) gene, which is
localized to chromosome 14. A much smaller number of cases are caused
by mutations in a highly homologous protein, presenilin-2 (PS2), which
is localized to chromosome 1 (Levy-Lahad et al., 1995
; Li et al., 1995
;
Rogaev et al., 1995
). AD-causing mutations occur in residues that are
highly conserved between PS1 and PS2, suggesting that they may alter
presenilin function. Presenilins are eight transmembrane domain
proteins that are expressed in the brain and other tissues (Doan et
al., 1996
; Li and Greenwald, 1996
). The presenilins are most homologous
to the protein sel-12 from Caenorhabditis elegans (Levitan
and Greenwald, 1995
). Sel-12 may act to facilitate signaling through
the Notch/lin-12 pathway that regulates cell fate decisions during
early development. The presenilins exhibit a lesser degree of homology
to the C. elegans protein spe-4, which may be involved in
protein segregation during spermatogenesis (L'Hernault and Arduengo,
1992
). However, the biological functions of the presenilins and the
mechanism by which they cause AD are unknown.
Analysis by in situ hybridization suggests that in the
brain, PS1 and PS2 mRNAs are expressed at the highest levels in neurons (Kovacs et al., 1996
). In this report, we show that endogenous PS1 is
highly expressed from the earliest stages of neuronal differentiation and is present in all neuritic processes and in growth cones. PS1
exhibits a predominantly somatodendritic localization in more mature
neurons in culture and in the adult brain but is still present at lower
levels in axons. In the brains of patients with AD, PS1 appears in
plaque dystrophic neurites and co-localizes with a subset of
intraneuronal neurofibrillary tangles. These findings suggest a role
for PS1 in neuronal differentiation and in the diverse pathological
manifestations of AD.
MATERIALS AND METHODS
Antibodies. The PS1 antibody 231 (Ab 231) is a rabbit
antiserum raised against a synthetic peptide corresponding to residues 2-20 of PS1 (Sherrington et al., 1995
) conjugated to keyhole limpet hemocyanin. Antibody R28 is a rabbit antiserum raised against a
bacterial glutathione S-transferase GST fusion protein
containing residues 263-407 of PS1, corresponding to the loop region
between the predicted sixth and seventh transmembrane domains. The GST fusion protein was expressed in Escherichia coli; inclusion
bodies were isolated and solubilized in 0.1% SDS and used for
immunization of rabbits as described (Harlow and Lane, 1988
). Antibody
preabsorptions were performed as described (Busciglio et al., 1993
)
using the PS1 peptide (residues 2-20) for Ab 231 and the PS1 fusion
protein (residues 263-407) for Ab R28. The mouse monoclonal antibody
to amyloid
protein (
1) has been described (Schrader-Fischer and Paganetti, 1996
). Other antibodies used include monoclonal anti-BiP (clone 10C3, 1:50; Stressgen), a polyclonal antibody to the Golgi marker JE4 (Gabuzda et al., 1994
), and monoclonal antibodies to phosphorylated tau (PHF-1, 1:500) (Greenberg and Davies, 1990
), nonphosphorylated tau (tau-1, 1:200; Boehringer Mannheim), MAP-2 (clone
AP20, 1:500; Sigma), and GFAP (clone GA5, 1:1000; Boehringer Mannheim).
Cell culture. Primary cultures of rat hippocampal neurons
were established from embryonic day 18 fetuses as described previously (Lorenzo and Yankner, 1994
). Primary human cortical cultures were established from 15- to 17-week-gestation fetal abortuses as described previously (Busciglio and Yankner, 1995
). Rat and human cortical cultures were plated on poly-L-lysine-coated dishes and
maintained in DMEM containing 10% supplemented calf serum (HyClone).
Forty-eight hours after plating the medium was changed to DMEM
containing N2 supplements (Gibco-BRL). Cells were harvested for Western
blotting at day 7 after plating. Primary human skin fibroblasts were
obtained from the Coriell Institute for Medical Research and were
maintained in DMEM containing 10% fetal bovine serum. Cells were
harvested for Western blotting in 4% SDS, 20% glycerol, and 0.1 M Tris-HCl, pH 6.8, supplemented with protease inhibitors
(Complete tablets, Boehringer Mannheim). COS-1 cells were grown in 35 mm dishes and transfected using LipofectAMINE (Gibco-BRL) by addition
of 0.8 µg of PS1 cDNA in the cytomegalovirus promoter-based pRK-7
vector (Gorman et al., 1990
). Controls were transfected with pRK-7
without the PS1 insert. Cells were harvested for Western blotting 36 hr after transfection. Detergent-extracted samples were sheared with a 22 gauge needle and centrifuged at 14,000 × g for 20 min,
and the protein concentration of the supernatant was determined
(Bio-Rad protein assay kit).
Western blotting. Fifteen micrograms of protein per lane
were separated by 4-20% PAGE without previous heating and
electrotransferred to a polyvinylidene difluoride membrane. Western
blotting was performed with antibodies 231 and R28 at dilutions of
1:3000 followed by incubation with peroxidase-conjugated anti-rabbit
IgG and detection by enhanced chemiluminescence (Amersham).
Immunocytochemistry. Cell cultures were fixed in 4%
paraformaldehyde/120 mM sucrose in PBS for 30 min. For
double labeling, coverslips were permeabilized with 0.02% Triton X-100
in PBS and blocked with 5% albumin in PBS for 1 hr. The coverslips
were then incubated with both primary antibodies for 12 hr at 4°C,
washed three times with PBS, and incubated for 1 hr at room temperature with Texas Red-conjugated anti-rabbit IgG (Jackson Labs) and
fluorescein-conjugated anti-mouse IgG (Vector Laboratories).
Fluorescence was visualized with a Nikon fluorescence microscope.
Formalin-fixed human brain tissue was embedded in paraffin, and 5-8
µm sections were obtained from the frontal and parietal cortices,
hippocampus, and parahippocampal gyrus. Sections were pretreated with
2% hydrogen peroxide followed by incubation in Target unmasking fluid
(Signet Laboratories) for 10 min at 90°C. After blocking in 5%
albumin in PBS for 30 min, sections were incubated in primary antibody
overnight at 4°C. The sections were then incubated with
biotin-conjugated secondary antibodies and developed with
streptavidin-alkaline phosphatase and Fast Red (Signet). For double
labeling, sections were incubated with the second primary antibody
followed by incubation with a peroxidase-conjugated secondary antibody.
The second antibody reaction was developed using a metal-enhanced DAB
reaction kit (Pierce). Some sections were lightly counterstained with
cresyl violet after immunostaining. For double label immunofluorescence of paraffin sections, the first antibody was visualized using an
enzyme-based fluorescence kit (ELF-AP kit, Molecular Probes). Sequential double labeling was performed using a secondary antibody conjugated to Cascade Blue (Molecular Probes). Both secondary antibodies were visualized by UV light with a Hoechst filter. Under
these conditions, the green ELF and blue Cascade signals are readily
distinguished from the tissue autofluorescence, which is pale
white.
RESULTS
Expression of PS1 in transfected cells and primary neurons
The PS1 protein was examined in neuronal and non-neuronal cells
using Ab 231 directed against residues 2-20 of the PS1 N terminus and
Ab R28 directed against residues 263-407 of the PS1 C-terminal loop
region. COS-1 cells were transiently transfected with the PS1 cDNA, and
cell lysates were analyzed by Western blotting. Ab 231 detected a
45-50 kDa species corresponding to the predicted Mr of full-length PS1. The 45-50 kDa species
was markedly increased by transfection and was abolished by
preabsorption of the antibody with the antigenic peptide (Fig.
1A). In addition, transfected cells
showed higher molecular weight PS1 aggregates and lower molecular
weight PS1 derivatives. In contrast, untransfected COS cells and
primary cultures of human fibroblasts, human cortical neurons, and rat
hippocampal neurons showed a major 28-30 kDa N-terminal derivative of
PS1 that was abolished by antibody preabsorption (Fig.
1A). Western blotting with Ab R28, which is directed
against the PS1 C-terminal loop, showed full-length PS1 in transfected COS cells and an additional 20-22 kDa species; both PS1 species were
abolished by antibody preabsorption (Fig. 1B). In
untransfected COS cells and primary neuronal cultures, the 20-22 kDa
band was the predominant species recognized by Ab R28. The full-length PS1 species was detectable at only low levels in primary neuronal and
fibroblast cultures using either antibody. These results suggest that
PS1 undergoes constitutive proteolytic cleavage to N- and C-terminal
fragments in human neurons and in other nontransfected cell types.
Antibodies 231 and R28 were not immunoreactive with PS2 in Western
blots of COS cells transfected with the PS2 cDNA (data not shown).
Fig. 1.
Expression of PS1 in transfected and primary cell
cultures. A, Western blot analysis of cell lysates with
Ab 231 directed against the PS1 N terminus. B, Western
blot analysis with Ab R28 directed against the PS1 C-terminal loop.
Lanes:
, wild-type COS cells; PS1,
PS1-transfected COS cells; PS1/Preab, PS1-transfected COS cells blotted with preabsorbed antibody; Fib,
primary human fibroblasts; Fib/preab, fibroblasts
blotted with preabsorbed antibody; Neurons (Cort),
cultured human cortical neurons; Neurons (Cort)/Preab, cultured human cortical neurons blotted with preabsorbed antibody; Neurons (Hipp), cultured rat hippocampal neurons. Note
the predominant 28-30 kDa N-terminal and 20-22 kDa C-terminal PS1
fragments in nontransfected cells and primary neurons.
[View Larger Version of this Image (72K GIF file)]
Immunofluorescence microscopy of endogenous PS1 in the human
neuroblastoma cell line SH-SY5Y demonstrated a reticular and perinuclear distribution characteristic of the endoplasmic reticulum (ER) (Fig. 2A). The ER localization of
endogenous PS1 was confirmed by double labeling for PS1 and BiP, a
marker of the rough endoplasmic reticulum. Confocal microscopy
demonstrated co-localization of PS1 with the ER marker BiP (Fig.
2B,C). Endogenous PS1 did not co-localize with a
marker of the Golgi complex (data not shown). These results suggest
that endogenous PS1 is localized predominantly to the endoplasmic
reticulum in an undifferentiated neuronal cell line.
Fig. 2.
PS1 is a resident protein of the endoplasmic
reticulum in SH-SY5Y neuroblastoma cells. A, SH-SY5Y
neuroblastoma cells show a reticular pattern of PS1 immunoreactivity
(Ab R28) characteristic of the ER. B, C, Localization of
PS1 in the endoplasmic reticulum is confirmed by double label
immunofluorescence with the PS1 C-terminal loop antibody R28
(B) and anti-BiP (C).
Confocal microscopy demonstrates the overlap of both antigens in an
image section taken 5 µm above the substrate plane. PS1 does not
co-localize with the Golgi marker JE4 in SH-SY5Y cells (data not
shown). Scale bars, 10 µm.
[View Larger Version of this Image (55K GIF file)]
Broad distribution of PS1 during neuronal differentiation
To investigate the pattern of appearance of PS1 during neuronal
differentiation, the localization of PS1 was determined in primary E18
rat hippocampal cultures at different stages of neuronal differentiation. Immunofluorescence microscopy of rat hippocampal cultures using both the N- and C-terminal loop antibodies showed predominantly neuronal labeling; astrocytes were only very weakly labeled. After 1 d in culture, hippocampal pyramidal neurons
exhibited primary neuritic processes that labeled intensely for PS1
(Fig. 3A). PS1 was also detected in growth
cones in filopodia-like structures (Fig. 3B). After several
days in culture, hippocampal neuritic processes became polarized into
axons and dendrites that can be distinguished morphologically and by
immunoreactivity for tau and MAP-2, respectively. Double labeling for
PS1 and either MAP-2 or tau in 10-d-old cultures demonstrated that PS1
was concentrated in the MAP-2-positive somatodendritic compartment
(Fig. 4C,D). However, tau-positive axons were
also clearly immunoreactive for PS1, but at lower levels (Fig.
4A,B). The specificity of staining was confirmed by
preabsorption of the PS1 antibody with the antigenic PS1 peptide or
fusion protein, which abolished immunoreactivity (Fig. 3C).
A similar pattern of PS1 immunoreactivity was observed in
differentiated cultures of primary human cortical neurons (data not
shown). These results suggest that PS1 is broadly distributed in
neurons during early stages of differentiation and is concentrated in
the somatodendritic compartment in mature neurons.
Fig. 3.
Localization of PS1 during the initial stages of
neuronal differentiation. A, Rat hippocampal neurons
after 1 d in culture show PS1 immunoreactivity homogeneously
distributed in the cell body and primary neuritic processes.
Immunocytochemistry was performed with A
231 to the PS1 N terminus.
Scale bar, 10 µM. B, Examination at a
higher magnification shows that PS1 is present in neuritic growth
cones. Scale bar, 3 µM. C, Negative
immunostaining is obtained after preabsorption of the antibody with the
antigenic PS1 peptide.
[View Larger Version of this Image (52K GIF file)]
Fig. 4.
Polarized distribution of PS1 after neuronal
differentiation. Rat hippocampal neurons were cultured for 10 d
and then double labeled for PS1 using Ab R28 to the PS1 C-terminal loop
(A) and tau using Ab tau-1
(B). Arrows show co-localization
of PS1 and tau in axons. Double labeling for PS1
(C) and MAP-2 (D) using Ab
AP20 shows that PS1 is predominantly localized to the somatodendritic compartment (arrows) in differentiated neurons. Scale
bars, 10 µm.
[View Larger Version of this Image (87K GIF file)]
Association of PS1 with neurofibrillary tangles and dystrophic
neurites in Alzheimer's disease
The distribution of PS1 in the adult human brain was examined in
paraffin-embedded sections by immunocytochemistry with the antibodies
to the N terminus and the C-terminal loop. Using either antibody, PS1
immunoreactivity was detected predominantly in neurons of the cortex
and hippocampus (Fig. 5A,B). Astrocytes did
not exhibit significant levels of staining (Fig. 5D,E).
Immunofluorescence microscopy of hippocampal pyramidal neurons at high
magnification demonstrated a somatodendritic localization of PS1,
similar to that observed in differentiated neuronal cultures (Fig.
5C). However, neuropil staining for PS1 was also observed,
consistent with an axonal component at low levels, similar to that
detected in differentiated hippocampal cultures (Fig.
4A,B). Thus, the localization of PS1 in the adult
brain is similar to that observed in differentiated neuronal cultures
and suggests that PS1 is broadly distributed in neuritic processes.
Fig. 5.
Localization of PS1 in the human brain.
A, PS1 immunoreactivity in the perikarya of pyramidal
neurons in layer CA1 of the hippocampus. Shown is immunocytochemical
staining with the PS1 C-terminal loop antibody R28. B,
Preabsorption of Ab R28 with the PS1 fusion protein (PS1 residues
263-407) abolishes neuronal immunoreactivity. Cellular profiles are
still detected by the Nissl counterstain. C,
Immunofluorescence microscopy with Ab 231 at a higher magnification
shows PS1 immunoreactivity in the cytoplasm and primary dendrite of a
pyramidal neuron. Adjacent sections of hippocampus labeled with PS1 Ab
231 (D) and anti-GFAP (E)
demonstrate the absence of detectable PS1 in astrocytes. Sections were
derived from the hippocampus of a normal 60-year-old man. Scale bar, 10 µM.
[View Larger Version of this Image (151K GIF file)]
We then determined whether the localization of PS1 is perturbed in the
brain in AD. To determine the spatial relationship of PS1 to
neurofibrillary tangles (NFTs), immunocytochemical labeling was
performed on adjacent hippocampal sections from cases of sporadic AD
with the monoclonal antibody PHF-1 (Greenberg and Davies, 1990
), which
is specific for tau phosphorylated at Ser-396 and Ser-404, and
antibodies to the N terminus or C-terminal loop domain of PS1. The
antibody to the PS1 C-terminal loop specifically labeled a
subpopulation of intraneuronal NFTs (Fig.
6B,C). The specificity of PS1 staining
was confirmed by loss of staining after antibody preabsorption with the
antigenic fusion protein. Quantitative analysis of adjacent sections
stained with PHF-1 or the PS1 antibody R28 showed that 29 ± 2%
(mean ± SD) of intraneuronal NFTs were positive for PS1 in three
separate cases of sporadic late-onset AD. In contrast, the N-terminal
PS1 antibody (Ab 231) showed the normal PS1 somatodendritic staining
pattern in AD hippocampal sections but did not clearly label NFTs in
sections adjacent to those in which NFTs were labeled by the C-terminal
antibody (Fig. 6C,D). To confirm that the structures labeled
by the C-terminal PS1 antibody were NFTs, double label
immunofluorescence was performed with antibody PHF-1 to phosphorylated
tau and either the N- or C-terminal PS1 antibodies.
PHF-1-immunoreactive NFTs were not labeled by Ab 231 against the PS1 N
terminus, although N-terminal PS1 immunoreactivity was present in
perikarya of tangle-bearing neurons (Fig. 7C,
arrows). However, when double labeling was performed with PHF-1
and the PS1 C-terminal loop antibody, double-labeled NFTs that stained
light blue were clearly apparent (Fig. 7D, arrow). Because
PS1 is constitutively processed to 28-30 kDa N-terminal and 20 kDa
C-terminal fragments in human neurons (Fig. 1), these results raise the
possibility that the PS1 C-terminal fragment may selectively associate
with NFTs.
Fig. 6.
Differential labeling of NFTs by antibodies to the
N- and C-terminal loop domains of PS1. Paraffin sections of hippocampus from a case of sporadic late-onset AD were immunocytochemically labeled
with antibodies to phosphorylated tau and PS1. A,
Labeling of an NFT with antibody PHF-1 to phosphorylated tau.
B, Same region of an adjacent section immunostained with
Ab R28 to the PS1 C-terminal loop labels an NFT with similar
morphology. C, Section showing several NFTs
(arrows) labeled by PS1 Ab R28. D,
Section adjacent to the one shown in C immunostained
with Ab 231 to the PS1 N terminus shows somatodendritic staining
(arrow). NFTs are not labeled.
[View Larger Version of this Image (122K GIF file)]
Fig. 7.
Association of PS1 with amyloid plaques and NFTs
in AD. Shown are sections of hippocampus from an individual with
sporadic AD. A, Double labeling with Ab 231 to PS1
(brown) and the monoclonal antibody
1 to A
(red) shows that PS1-positive neurons
(arrow) surround amyloid plaques
(arrowhead). B, Analysis of a single mature plaque by double label immunofluorescence for PS1
(green) and A
(dark blue). Note
that PS1 appears in dystrophic neurites, which are labeled
green for PS1 or light blue from the
overlap of PS1 and A
. A low level of PS1 immunoreactivity appears in the amyloid core (arrowhead), which is stained
dark blue for A
. C, Double labeling
for phosphorylated tau (dark blue, Ab PHF-1) and the
N-terminal epitope of PS1 (green, Ab 231). Two
neurons with NFTs (arrows) are labeled for both
phosphorylated tau and PS1, but the N-terminal PS1 Ab does not double
label NFTs, which are labeled with Ab PHF-1. D, Double
labeling for phosphorylated tau (dark blue, Ab PHF-1)
and the C-terminal loop region of PS1 (green, Ab
R28). Shown is an NFT that is double-labeled (arrow, light
blue). An example of a neuron showing predominantly PHF-1 labeling (dark blue) is seen in the bottom right
corner.
[View Larger Version of this Image (98K GIF file)]
To determine the relationship of PS1 to amyloid deposits in AD, double
labeling of cortical sections was performed with antibodies to amyloid
protein (A
) and PS1. PS1-positive neurons were detected adjacent
to and surrounding amyloid plaques, but significant PS1 immunoreactivity was not detected in most plaque cores (Fig.
7A). The spatial relationship of PS1 to plaques was further
analyzed by high-resolution double label immunofluorescence for PS1
and A
. PS1 was detected in plaque dystrophic neurites and in
surrounding cell bodies (Fig. 7B). Very low levels of PS1
immunoreactivity were detected in the region of the amyloid core, which
showed strong immunoreactivity for A
(Fig. 7B,
arrowhead). Thus, PS1 is selectively associated with dystrophic
neurites in plaques, where it could potentially play a role in amyloid
deposition or in the degenerative process.
DISCUSSION
These experiments suggest that during the early stages of neuronal
differentiation PS1 is localized in the cell body and in all neuritic
processes. After differentiation, PS1 is concentrated in the
somatodendritic region but is still detected at lower levels in axons.
These findings provide information on the localization of endogenous
PS1 in neurons in culture and in vivo and therefore provide
information that is different than that obtained in transfected cells
or in transgenic mice, in which PS1 is overexpressed, possibly altering
its localization. A previous study suggested that PS1 is restricted to
the cell body and dendrites in the NT2N neuronal cell line after
infection with a recombinant PS1 Semliki virus (Cook et al., 1996
).
However, the overexpression of PS1 in this system and its detection by
epitope tagging precluded the detection of endogenous PS1. In contrast,
our findings suggest that endogenous PS1 appears in both axons and
dendrites. Furthermore, the widespread distribution of PS1 in neurites
and growth cones during the early stages of neuronal differentiation
raises the possibility that PS1 may play a role in neuronal
differentiation. This possibility is supported by the observation that
proteolytic processing of PS1 is regulated by neuronal differentiation
and exhibits a brain-specific pattern (Hartmann et al., 1997
).
PS1 is constitutively cleaved to N- and C-terminal fragments in human
and rat neurons (Fig. 1). Although full-length PS1 is present at high
levels in transfected cells, it is present at low levels in cultured
neurons and other nontransfected cell lines. These results are in
agreement with recent reports that demonstrated constitutive cleavage
of PS1 in cell lines and in the mouse brain (Lee et al., 1996
;
Thinakaran et al., 1996
). Thus, it is likely that PS1 detected in
neuritic processes is composed predominantly of the N- and C-terminal
proteolytic cleavage products. Because both N- and C-terminal
antibodies show identical PS1 recognition patterns in culture and in
the normal adult human brain, it is likely that the N- and C-terminal
fragments are coordinately transported in neuritic processes. This
could occur if the N- and C-terminal fragments form a complex or are
complexed with other membrane proteins.
PS1 has previously been localized to the ER and Golgi complex in
transfected cells (Kovacs et al., 1996
). The results reported here
confirm an ER localization for endogenous PS1 in nontransfected SH-SY5Y
neuroblastoma cells. However, it remains to be determined whether PS1
in neurons is localized exclusively to the ER. We have observed that
the rough ER marker BiP does not co-localize with PS1 in the distal
neuritic processes of differentiated neurons (unpublished results).
However, PS1 may still be associated with smooth ER in these
compartments. Smooth ER has been demonstrated in all neuritic processes
in cultured rat hippocampal neurons, as well as in some growth cones
(Terasaki et al., 1994
; Krijnse-Locker et al., 1995
). Additional
ultrastructural studies will be required to determine the precise
localization of PS1 in neurites. Nevertheless, the presence of PS1 in
distal neurites suggests that PS1 may be involved in functions that are
unrelated to protein synthesis and processing in the ER.
In the brains of individuals with sporadic AD, PS1 is present in
neurons that are adjacent to and surround amyloid plaques. Using a new
technique for high-resolution immunofluorescence microscopy on paraffin
sections, we have localized PS1 in the dystrophic neurites of mature
plaques; much lower levels of PS1 immunoreactivity were detected in
plaque cores. It has been reported previously that significant
immunoreactivity for PS1 could be detected in amyloid plaque cores
(Wisniewski et al., 1995
). Although the difference between this result
and ours may reflect differences in antibody specificity, we were
unable to demonstrate high levels of PS1 immunoreactivity in plaque
cores with antibodies to either the PS1 N terminus or C-terminal loop.
However, the presence of PS1 in plaque dystrophic neurites raises the
possibility that PS1 may be involved in the process of amyloid
deposition. This possibility is supported by a recent report, which
showed that plasma levels of the highly amyloidogenic 42 amino acid
form of A
are increased in individuals that harbor PS1 mutations,
and that cultured fibroblasts from these individuals secrete higher
levels of A
42 than controls (Scheuner et al., 1996
).
PS1 co-localized with a subset of intraneuronal NFTs in the hippocampi
of patients with sporadic late-onset AD. The specificity of this
association was suggested by the antibody preabsorption controls. The
proportion of labeled NFTs (about 30%) was quite similar in three
separate cases of late-onset sporadic AD. It will be of interest to
determine whether the proportion of PS1-positive tangles is increased
in cases of early-onset familial AD associated with PS1 mutations.
Another recent study suggested that NFTs are labeled by an antibody to
PS1 (Murphy et al., 1996
). These authors did not detect PS1 labeling in
any normal brain structures, a result that is difficult to interpret
given the widespread distribution of PS1 in the brain, as demonstrated
in this report and in other studies (Cribbs et al., 1996
; Kovacs et
al., 1996
; Lee et al., 1996
; Giannakopoulos et al., 1997). NFTs were
specifically labeled by our antibody to the PS1 C-terminal loop but not
by our antibody to the PS1 N terminus. Because PS1 is constitutively
cleaved to N- and C-terminal fragments, our results are consistent with
the possibility that the C-terminal fragment may selectively associate with cytoskeletal elements. Recent analysis of the membrane topography of PS1 suggests that the large hydrophilic loop is cytoplasmic (Doan et
al., 1996
; Li and Greenwald, 1996
). The hydrophilic loop may therefore
be accessible to the cytoskeleton. Further biochemical studies will be
required to determine whether PS1 binds directly to NFTs or
cytoskeletal elements, and whether PS1 plays a role in cytoskeletal
function. The association of PS1 with amyloid plaques and NFTs raises
the possibility that PS1 may be involved in the pathogenesis of both of
these degenerative lesions.
FOOTNOTES
Received March 12, 1997; revised April 21, 1997; accepted April 23, 1997.
This work was supported by National Institutes of Health Grants NS33325
and NS30352, Alzheimer's Association Grant IIRG-95-009, and a grant
from Sandoz Pharma Ltd. to B.A.Y. and by National Institutes of Health
Mental Retardation Research Center Core Grant P30-HD18655. H.H. is a
fellow of the Deutsche Forschungsgemeinschaft. J.B. was supported in
part by the University of Connecticut. We thank Pieter Dikkes for
assistance and Joseph Rogers, Lucie Sue, and the Sun Health Research
Institute for supplying autopsy human brain tissue.
Correspondence should be addressed to Dr. Bruce A. Yankner, The
Children's Hospital, Enders 260, 300 Longwood Avenue, Boston, MA
02115.
Dr. Busciglio's present address: University of Connecticut Health
Center, 263 Farmington Avenue, Farmington CT 06030.
REFERENCES
-
Busciglio J,
Yankner BA
(1995)
Apoptosis and increased generation of reactive oxygen species in Down's syndrome neurons in vitro.
Nature
378:776-779[Medline].
-
Busciglio J,
Gabuzda DH,
Matsudaira P,
Yankner BA
(1993)
Generation of
-amyloid in the secretory pathway in neuronal and non-neuronal cells.
Proc Natl Acad Sci USA
90:2092-2096[Abstract/Free Full Text]. -
Cook DG,
Sung JC,
Golde TE,
Felsenstein KM,
Wolczyk BS,
Tanzi RE,
Trojanowski JQ,
Lee VM-Y,
Doms RW
(1996)
Expression and analysis of presenilin 1 in a human neuronal system: localization in cell bodies and dendrites.
Proc Natl Acad Sci USA
93:9223-9226[Abstract/Free Full Text].
-
Cribbs DH,
Chen LS,
Bende SM,
LaFerla FM
(1996)
Widespread neuronal expression of the presenilin-1 early-onset Alzheimer's disease gene in murine brain.
Am J Pathol
148:1797-1806[Abstract].
-
Doan A,
Thinakaran G,
Borchelt DR,
Slunt HH,
Ratovitsky T,
Podlisny M,
Selkoe DJ,
Seeger M,
Gandy SE,
Price DL,
Sisodia SS
(1996)
Protein topology of presenilin 1.
Neuron
17:1023-1030[Web of Science][Medline].
-
Gabuzda D,
Busciglio J,
Chen LB,
Matsudaira P,
Yankner BA
(1994)
Inhibition of energy metabolism alters the processing of amyloid precursor protein and induces a potentially amyloidogenic derivative.
J Biol Chem
269:13623-13628[Abstract/Free Full Text].
-
Gorman CM,
Gies DR,
McCray G
(1990)
Transient production of proteins using an Adenovirus transformed cell line.
DNA Prot Eng Techn
2:3-10.
-
Greenberg SG,
Davies P
(1990)
A preparation of Alzheimer paired helical filaments that displays distinct tau proteins by polyacrylamide gel electrophoresis.
Proc Natl Acad Sci USA
87:5827-5831[Abstract/Free Full Text].
-
Harlow E,
Lane D
(1988)
In: Antibodies: a laboratory manual. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory.
-
Hartmann H, Busciglio J, Baumann K-H, Staufenbiel M, Yankner
BA (1997) Developmental regulation of presenilin-1 processing
in the brain suggests a role in neuronal differentiation. J Biol
Chem, in press.
-
Kovacs DM,
Fausett HJ,
Page KJ,
Kim T-W,
Moir RD,
Merriam DE,
Hollister RD,
Hallmark OG,
Mancini R,
Felsenstein KM,
Hyman BT,
Tanzi RE,
Wasco W
(1996)
Alzheimer-associated presenilins 1 and 2: neuronal expression in brain and localization to intracellular membranes in mammalian cells.
Nat Med
2:224-229[Web of Science][Medline].
-
Krijnse-Locker J,
Parton RG,
Fuller SD,
Griffiths G,
Dotti CG
(1995)
The organization of the endoplasmic reticulum and the intermediate compartment in cultured rat hippocampal neurons.
Mol Biol Cell
6:1315-1332[Abstract].
-
Lee MK,
Slunt HH,
Martin LJ,
Thinakaran G,
Kim G,
Gandy SE,
Seeger M,
Koo E,
Price DL,
Sisodia SS
(1996)
Expression of presenilin 1 and 2 (PS1 and PS2) in human and murine tissues.
J Neurosci
16:7513-7525[Abstract/Free Full Text].
-
Levitan D,
Greenwald I
(1995)
Facilitation of lin-12-mediated signalling by sel-12, a Caenorhabditis elegans S182 Alzheimer's disease gene.
Nature
377:351-354[Medline].
-
Levy-Lahad E,
Wasco W,
Poorkaj P,
Romano DM,
Oshima J,
Pettingell WH,
Yu C-E,
Jondro PD,
Schmidt SD,
Wang K,
Crowley AC,
Fu Y-H,
Guenette SY,
Galas D,
Nemens E,
Wijsman EM,
Bird TD,
Schellenberg GD,
Tanzi RE
(1995)
Candidate gene for the chromosome 1 familial Alzheimer's disease locus.
Science
269:973-977[Abstract/Free Full Text].
-
L'Hernault SW,
Arduengo PM
(1992)
Mutation of a putative sperm membrane protein in Caenorhabditis elegans prevents sperm differentiation but not its associated meiotic divisions.
J Cell Biol
119:55-68[Abstract/Free Full Text].
-
Li X,
Greenwald I
(1996)
Membrane topology of the C. elegans SEL-12 presenilin.
Neuron
17:1015-1021[Web of Science][Medline].
-
Li J,
Ma J,
Potter H
(1995)
Identification and expression analysis of a potential familial Alzheimer disease gene on chromosome 1 related to AD3.
Proc Natl Acad Sci USA
92:12180-12184[Abstract/Free Full Text].
-
Lorenzo A,
Yankner BA
(1994)
Beta-amyloid neurotoxicity requires fibril formation and is inhibited by Congo red.
Proc Natl Acad Sci USA
91:12243-12247[Abstract/Free Full Text].
-
Murphy GM,
Forno LS,
Ellis WG,
Nochlin D,
Levy-Lahad E,
Poorkaj P,
Bird TD,
Jiang Z,
Cordell B
(1996)
Antibodies to presenilin proteins degect neurofibrillary tangles in Alzheimer's disease.
Am J Pathol
149:1839-1846[Abstract].
-
Rogaev EI,
Sherrington R,
Rogaeva EA,
Levesque G,
Ikeda M,
Liang Y,
Chi H,
Lin C,
Holman K,
Tsuda T,
Mar L,
Sorbi S,
Nacmias B,
Placentini S,
Amaducci L,
Chumakov I,
Cohen D,
Lannfelt L,
Fraser PE,
Rommens JM,
St. George-Hyslop PH
(1995)
Familial Alzheimer's disease in kindred with missense mutations in a gene on chromosome 1 related to the Alzheimer's disease type 3 gene.
Nature
376:775-778[Medline].
-
Scheuner D,
Eckman M,
Jensen X,
Song M,
Citron N,
Suzuki TD,
Bird J,
Hardy M,
Hutton W,
Kukull E,
Larson E,
Levy-Lahad M,
Viitanen E,
Peskind P,
Poorkaj G,
Schellenberg R,
Tanzi W,
Wasco L,
Lanfelt Selkoe D,
Younkin S
(1996)
Secreted amyloid
-protein similar to that in the senile plagues of Alzheimer's disease is increased in vivo by the presenilin 1 and 2 and APP mutations linked to familial Alzheimer's disease.
Nature
2:864-870. -
Schrader-Fischer G,
Paganetti P
(1996)
Effect of alkalinizing agents on the processing of the
-amyloid precursor protein.
Brain Res
716:91-100[Web of Science][Medline]. -
Sherrington R,
Rogaev EI,
Liang Y,
Rogaeva EA,
Levesque G,
Ikeda M,
Chi H,
Li G,
Holman K,
Tsuda T,
Mar L,
Foncin J-F,
Bruni AC,
Montesi MP,
Sorbi S,
Rainero I,
Pinessi L,
Nee L,
Chumakov I,
Pollen D,
Brookes A,
Sanseau P,
Polinsky RJ,
Wasco W,
Da Silva HA,
Haines JL,
Pericak-Vance MA,
Tanzi RE,
Roses AD,
Fraser PE,
Rommens JM,
St. George-Hyslop PH
(1995)
Cloning of a gene bearing missense mutations in early-onset familial Alzheimer's disease.
Nature
375:754-760[Medline].
-
Terasaki M,
Traverse Slater N,
Fein A,
Schmidek A,
Reese TS
(1994)
Continuous network of endoplasmic reticulum in cerebellar Purkinje neurons.
Proc Natl Acad Sci USA
91:7510-7514[Abstract/Free Full Text].
-
Thinakaran G,
Borcheit DR,
Lee MK,
Ratovitsky T,
Davenport F,
Nordstedt C,
Seeger M,
Hardy J,
Levey A,
Gandy SE,
Jenkins NA,
Copeland NG,
Price DL,
Sisodia SS
(1996)
Endoproteolysis of presenilin 1 and accumulation of processed derivatives in vivo.
Neuron
17:181-190[Web of Science][Medline].
-
Wisniewski T,
Palha JA,
Ghiso J,
Frangione B
(1995)
S182 protein in Alzheimer's disease neuritic plaques.
Lancet
346:1366[Web of Science][Medline].
-
Yankner BA
(1996)
Mechanisms of neuronal degeneration in Alzheimer's disease.
Neuron
16:921-932[Web of Science][Medline].
This article has been cited by other articles:

|
 |

|
 |
 
N. L. Chevallier, S. Soriano, D. E. Kang, E. Masliah, G. Hu, and E. H. Koo
Perturbed Neurogenesis in the Adult Hippocampus Associated with Presenilin-1 A246E Mutation
Am. J. Pathol.,
July 1, 2005;
167(1):
151 - 159.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
G. Pigino, G. Morfini, A. Pelsman, M. P. Mattson, S. T. Brady, and J. Busciglio
Alzheimer's Presenilin 1 Mutations Impair Kinesin-Based Axonal Transport
J. Neurosci.,
June 1, 2003;
23(11):
4499 - 4508.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
E. A. Grace and J. Busciglio
Aberrant Activation of Focal Adhesion Proteins Mediates Fibrillar Amyloid beta -Induced Neuronal Dystrophy
J. Neurosci.,
January 15, 2003;
23(2):
493 - 502.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. N. Prasad, W. C. Cole, and K. C. Prasad
Risk Factors for Alzheimer's Disease: Role of Multiple Antioxidants, Non-Steroidal Anti-inflammatory and Cholinergic Agents Alone or in Combination in Prevention and Treatment
J. Am. Coll. Nutr.,
December 1, 2002;
21(6):
506 - 522.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Y.-H. Suh and F. Checler
Amyloid Precursor Protein, Presenilins, and alpha -Synuclein: Molecular Pathogenesis and Pharmacological Applications in Alzheimer's Disease
Pharmacol. Rev.,
September 1, 2002;
54(3):
469 - 525.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. J. Palacino, M. P. Murphy, O. Murayama, K. Iwasaki, M. Fujiwara, A. Takashima, T. E. Golde, and B. Wolozin
Presenilin 1 Regulates beta -Catenin-mediated Transcription in a Glycogen Synthase Kinase-3-independent Fashion
J. Biol. Chem.,
October 12, 2001;
276(42):
38563 - 38569.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
D. M. A. Mann, S. M. Pickering-Brown, A. Takeuchi, and T. Iwatsubo
Amyloid Angiopathy and Variability in Amyloid {beta} Deposition Is Determined by Mutation Position in Presenilin-1-Linked Alzheimer's Disease
Am. J. Pathol.,
June 1, 2001;
158(6):
2165 - 2175.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
G. Pigino, A. Pelsman, H. Mori, and J. Busciglio
Presenilin-1 Mutations Reduce Cytoskeletal Association, Deregulate Neurite Growth, and Potentiate Neuronal Dystrophy and Tau Phosphorylation
J. Neurosci.,
February 1, 2001;
21(3):
834 - 842.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. Theuns and C. Van Broeckhoven
Transcriptional regulation of Alzheimer's disease genes: implications for susceptibility
Hum. Mol. Genet.,
October 1, 2000;
9(16):
2383 - 2394.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
W. G. Annaert, L. Levesque, K. Craessaerts, I. Dierinck, G. Snellings, D. Westaway, P. St. George-Hyslop, B. Cordell, P. Fraser, and B. De Strooper
Presenilin 1 Controls {gamma}-Secretase Processing of Amyloid Precursor Protein in Pre-Golgi Compartments of Hippocampal Neurons
J. Cell Biol.,
October 18, 1999;
147(2):
277 - 294.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. L. Schwarzman, N. Singh, M. Tsiper, L. Gregori, A. Dranovsky, M. P. Vitek, C. G. Glabe, P. H. St. George-Hyslop, and D. Goldgaber
Endogenous presenilin 1 redistributes to the surface of lamellipodia upon adhesion of Jurkat cells to a collagen matrix
PNAS,
July 6, 1999;
96(14):
7932 - 7937.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. M. Stabler, L. L. Ostrowski, S. M. Janicki, and M. J. Monteiro
A Myristoylated Calcium-binding Protein that Preferentially Interacts with the Alzheimer's Disease Presenilin 2 Protein
J. Cell Biol.,
June 14, 1999;
145(6):
1277 - 1292.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. P. Mattson and Qing Guo
{blacksquare} REVIEW : The Presenilins
Neuroscientist,
March 1, 1999;
5(2):
112 - 124.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
J. A. Johnston, C. L. Ward, and R. R. Kopito
Aggresomes: A Cellular Response to Misfolded Proteins
J. Cell Biol.,
December 28, 1998;
143(7):
1883 - 1898.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Takashima, M. Murayama, O. Murayama, T. Kohno, T. Honda, K. Yasutake, N. Nihonmatsu, M. Mercken, H. Yamaguchi, S. Sugihara, et al.
Presenilin 1 associates with glycogen synthase kinase-3beta and its substrate tau
PNAS,
August 4, 1998;
95(16):
9637 - 9641.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Q. Guo, N. Robinson, and M. P. Mattson
Secreted beta -Amyloid Precursor Protein Counteracts the Proapoptotic Action of Mutant Presenilin-1 by Activation of NF-kappa B and Stabilization of Calcium Homeostasis
J. Biol. Chem.,
May 15, 1998;
273(20):
12341 - 12351.
[Abstract]
[Full Text]
[PDF]
|
 |
|