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Short Communications |



From the Department of Neuroimmunology,*
Brain Research
Institute, University of Vienna, Vienna, Austria; IDUN Pharmaceuticals,
Inc.,
La Jolla, California; the Department of
Neurology,
Lainz Hospital, Vienna, Austria;
the Department of Neuropathology,§
University
of Göttingen, Göttingen, Germany; and the Ludwig Boltzmann
Institute for Clinical Neurobiology,¶
Vienna, Austria
| Abstract |
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| Introduction |
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To further investigate the extent and mode of neuronal death in AD, we performed immunohistochemical studies applying an antiserum against activated caspase-3.25 Caspase-3 is considered the central apoptotic effector enzyme responsible for many of the biochemical and morphological features of apoptosis.26,27 Activation of caspase-3 represents an irreversible step in the cell death pathway, and cells containing activated caspase-3 are prone to die. We found cytoplasmic immunoreactivity for activated caspase-3 in single apoptotic neurons in AD and DS, but not in controls. In addition, activated caspase-3 was found in cytoplasmic granules of granulovacuolar degeneration (GVD).28 This may indicate that the activation of the apoptotic cascade in affected neurons is counteracted by the seclusion of damaged areas into autophagic vacuoles.
| Materials and Methods |
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Brain tissues from nine cases of clinically diagnosed and neuropathologically confirmed AD, four cases of DS, and seven age-matched controls without neurological disease were obtained at autopsy, fixed in buffered formalin, and routinely embedded in paraffin. In addition, one similarly processed case of infantile pontosubicular neuron necrosis was included as positive control for apoptotic neuronal cell death in routinely processed human autopsy tissue.20,29,30 All AD cases fulfilled the quantitative neuropathological criteria for the diagnosis of AD according to Khatchaturian and the Consortium to Establish a Registry for Alzheimers Disease (CERAD).31,32 For immunohistochemistry, temporal lobe sections including temporal isocortex, hippocampus, and entorhinal cortex were used.
Immunohistochemistry
Immunohistochemistry was performed applying an affinity-purified rabbit polyclonal antiserum reactive against human activated caspase-3 (CM1; IDUN Pharmaceuticals, La Jolla, CA).25 In Western blots, this antiserum recognizes only the large (p18) subunit of processed caspase-3, but not the unprocessed zymogen or the processed small (p12) subunit. It is thus specific for the cleaved and thereby activated form of caspase-3. CM1 has previously been used to specifically detect apoptotic cells in vitro and in vivo.25,33 Briefly, after deparaffinization and blocking with 10% fetal calf serum (FCS)/phosphate buffered saline (PBS), we applied the primary antibody CM1 at a concentration of 0.1 µg/ml in 10% FCS/PBS and permitted it to bind over night at 4°C. Control sections were incubated without primary antibody or with polyclonal antisera against irrelevant antigens. A standard avidin-biotin-peroxidase method with DAB as the chromogenic substrate was used to visualize antibody binding.20 Alternatively, an alkaline phosphatase anti-alkaline phosphatase system (Dako, Glostrup, D) was used with Fast Red TR salt (Sigma) as chromogen. Pretreatment of the sections by microwaving 3x 5 minutes in 10 mmol/L citric acid buffer, pH 6.0, enhanced the sensitivity of CM1 for apoptotic cells but did not change the overall staining pattern. To assess the relationship between neuronal cell death and tau pathology, double-labeling experiments applying the mouse monoclonal antibody AT8 (1:1000; Innogenetics, Ghent, Belgium) against paired helical filament (PHF)-tau were performed.34-36 An alkaline phosphatase anti-alkaline phosphatase technique with Fast Blue BB salt (Sigma, St. Louis, MO) as chromogen was used for AT8 stainings.
| Results |
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In pontosubicular neuron necrosis, a disease condition resulting
from perinatal hypoxia-ischemia, a large number of apoptotic neurons
were present predominantly in pons and
hippocampus.20,29,30
Of these apoptotic neurons, 96.6%
contained activated caspase-3. Caspase-3 immunoreactivity was found
only in cells with chromatin condensation, nuclear fragmentation, and
cytoplasmic condensation (Figure 1a)
. No
other cells or structures were stained with the CM1 antiserum in these
sections.
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Temporal lobe sections of AD, DS, and age-matched controls were
analyzed for the presence of CM1 immunopositive cells indicating the
presence of activated caspase-3. Sections contained hippocampal
allocortex, entorhinal cortex, and temporal isocortex. A total area per
section of 171.18 ± 16.62 mm2
in AD,
219.14 ± 33.76 mm2
in DS, and 197.77
± 22.09 mm2
in age-matched controls was screened
and the number of cells with distinct and strong cytoplasmic labeling
with CM1 was determined. In 2/9 cases of AD and 1/4 cases of DS,
cytoplasmic immunoreactivity for activated caspase-3 was detected in
single CA1, subicular, and isocortical neurons: two CM1-positive
neurons in the CA1 region were found in case AD 1, two CM1 positive
cells in layer 2 of temporal isocortex in case AD 9, and three
CM-1-immunopositive cells in the subiculum and in CA1 in case DS 1
(Figure 1, b
-d, and Table 1
). Unlike
unstained neurons, neurons containing activated caspase-3 had shrunken,
condensed, and sometimes fragmented nuclei and a condensed cytoplasm,
thus displaying features typical for apoptosis (Figure 1, b
-d). No
CM1-immunoreactive neurons were found in age-matched controls.
Apart from neurons, few apoptotic white matter cells identified as
oligodendrocytes and few intra- and perivascular apoptotic leukocytes
were immunoreactive for activated caspase-3 in AD, DS, and controls
(Table 1)
. The occurrence of apoptotic neurons in AD and DS was not
related to postmortem time and cause of death in the respective cases
(Table 1)
.
|
Activated Caspase-3 Is Present in Granules of GVD
In addition to the cytoplasmic immunoreactivity observed in
apoptotic neurons in AD and DS, activated caspase-3 was detected in
granules of GVD (Figure 1, e
-g). GVD was present in 11.69 ±
2.48% (all percentages are ± SE) of subicular and CA1
neurons in AD, and in 21.7 ± 6.89% of subicular and CA1 neurons
in DS (Table 1)
. Neurons harbored from one to more than 20 vacuoles
with the characteristic basophilic core. GVD was scarce in subiculum
and CA1 of age-matched controls, and a total of 5 neurons with GVD were
found in the 7 control cases. Direct counting of CM1 immunoreactivity
in GVD-positive neurons revealed that in AD, 54.87 ± 9.99% of
GVD-positive neurons contained CM1 immunopositive granules. In DS,
39.4 ± 20.42% of GVD-positive neurons revealed granules stained
with CM1. Neurons were counted positive if at least one of the granules
was stained; however, in most cases, more than 50% of granules were
immunoreactive. We noted a marked variability in the number of neurons
containing CM1-immunopositive GVD, ranging from 2.14 to 90.9% in
different cases of AD and DS. This may be attributable to different
stages of GVD formation found in individual cases of AD and DS. CM1
immunoreactivity was restricted to the granulovacuoles of GVD and not
present in other cytoplasmic compartments of the corresponding neurons.
In particular, lipofuscin granules and neurofibrillary tangles were not
labeled (Figure 1, e and f)
. Furthermore, neurons with CM1-positive GVD
did not display nuclear alterations indicative of apoptosis. Some of
the few GVD vacuoles found in age matched controls equally contained
immunoreactivity for activated caspase-3. Double-labeling experiments
with AT8 revealed neurons harboring AT8-positive neurofibrillary
tangles and CM1-positive GVD (Figure 1g)
.
Neurons Bearing Abnormally Phosphorylated Tau Are More Likely to Also Harbor GVD
Neurons containing neurofibrillary tangles (NFTs) have been
suggested to be prone to cell death in AD.16,37
Given the
presence of activated caspase-3 in GVD, we examined the relationship
between AT8 positive inclusions (tangles and pretangle
changes38,39
) and the concomitant presence of GVD in
subicular and CA1 neurons in cases AD 1 to 8 and DS 1 to 4. Of neurons
with abnormally phosphorylated cytoskeletal components as demonstrated
by AT8 immunoreactivity, 25.99 ± 5.25% also harbored GVD as
compared to only 4.69 ± 1.47% of neurons without AT8-positive
inclusions (Figure 2)
. GVD was much more
likely to occur in AT8-positive (78.25% ± 7.76) than in AT8-negative
(21.75% ± 7.76) neurons. The granules of GVD are not labeled by the
AT8 antibody (Figure 1g)
.34
|
| Discussion |
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There are, however, reservations about the notion that cells with DNA fragmentation are necessarily apoptotic. The incidence of cells with DNA fragmentation is, by several magnitudes, higher than would be expected in a disease with an average duration of 10 years.16,23,24 Furthermore, cells with DNA fragmentation in AD do not show the classical morphological changes of apoptosis, ie, chromatin condensation and nuclear fragmentation, although these changes are readily detectable in human autopsy conditions where apoptosis occurs at a high frequency.16,17,20,22,29 In a recent study, we found that the expression of an apoptosis-specific protein in AD is restricted to exceptional neurons in AD, which actually show typical alterations of apoptosis, and is absent in all other cells with DNA fragmentation.20
In the present study, we used an antiserum against activated caspase-3
to unequivocally identify cells where activation of the apoptotic cell
death program has taken place. Caspase activation is considered
specific to the apoptotic process and defines an irreversible stage in
the cell death process. Caspase-3 activation leads to the cleavage of
so-called cell death substrates, such as fodrin, gelsolin, lamin,
ICAD/DFF45, DNA-PK, PK
, PARP, and many
others.26
This contributes to the disassembly of cell
structures, the reorganization of the cytoskeleton, deficits in DNA
repair and replication, and the cleavage of DNA into 180- to 200-bp
fragments. Caspases have been shown to cleave the presenilins and APP
during apoptotic cell death.53-58
Recently, Masliah et al
reported the presence of nonactivated caspase-3 in AD and control
brains and established a correlation between the number of neurons with
DNA fragmentation and the intensity of caspase-3
immunolabeling.59
Gervais et al observed numerous labeled
nonapoptotic CA3 neurons in AD using their antiserum against activated
caspase-3.58
We found activated caspase-3 in the cytoplasm
of the vast majority of apoptotic neurons in pontosubicular neuron
necrosis, demonstrating that detection of apoptotic neurons in human
autopsy tissue is feasible, specific, and sensitive. In AD and DS, only
exceptional neurons revealed strong cytoplasmic labeling for activated
caspase-3; neurons immunopositive for activated caspase-3 displayed the
full morphological spectrum of apoptosis. This is in contrast to
studies using DNA fragmentation techniques15-22
or
immunohistochemistry for nonactivated caspase-3,59
where
numbers of positive neurons are high and concordance with apoptotic
morphology is absent. Our data suggest that, indeed, some cells (though
in exceptionally low numbers) die in the brains of patients with AD and
DS at a given time point by apoptosis.
The incidence of approximately one apoptotic neuron in 1100 to 5000 neurons, found in this study, matches the recent estimate by Perry et al23,24 and seems fairly realistic, given the short time required to complete apoptosis and the protracted course of AD. On the other hand, the significantly increased incidence of cells with DNA fragmentation, together with the proapoptotic phenotype of neurons in AD brains in comparison to age-matched controls, indicates that, overall, neurons in AD may be more vulnerable20,42,43 and generally subject to a proapoptotic (micro)environment.
The finding of activated caspase-3 in the granulovacuoles of neurons with GVD, which were abundant in AD and DS but also present in age-matched controls in low incidence, may represent another footprint of the metabolic battle of neurons between proapoptotic signals and compensatory mechanisms. Granules of GVD are believed to be autophagic in origin.60-63 The activation of caspase-3 in GVD could indicate the presence of cellular self-repair mechanisms, leading to the sequestration in autophagic vacuoles of cytoplasmic compartments where the potentially disastrous activation of proapoptotic enzymes has occurred. This notion is indirectly supported by elegant work on the ultrastructure of GVD by Okamoto et al demonstrating the sequestration of electron-dense cytoplasmic material by endoplasmic reticulum membranes, leading to the formation of vacuoles of GVD.63 The presence of activated caspase-3 in granules of GVD may also be explained by an activation of caspases by lysosomal enzymes,64-66 implying an activation of the apoptotic cascade in a subcellular compartment, thus providing relative safety to the affected neuron. It must also be considered that caspase-3 is activated during the process of lysosomal degradation of caspase-3-containing organelles or even exerts some function in the removal of damaged cellular constituents. However, evidence is accumulating that autophagy and apoptosis are, at least in some respect, related processes, and that autophagic forms of apoptosis exist.67,68 Recently, a protein accumulating specifically in apoptotic cells was found to be related to a gene product essential for yeast autophagy.69
NFTs have been considered a risk factor for neuronal death in AD.16,37 In our study, no neurons double-labeled for diffuse cytoplasmic CM1 and AT8 (PHF-tau) could be identified. The number of CM1-positive neurons found in our cases of AD and DS, however, is too small to support any conclusions about the role of abnormally phosphorylated cytoskeletal components in neuronal death. The reported association between NFTs and neuronal death, together with our finding of activated caspase-3 in GVD, prompted us to examine the relationship between AT8 positivity and GVD in hippocampal AD and DS neurons. The 5.5 times higher risk that AT8-positive neurons (tangles and pretangle changes) will contain GVD and the vulnerability of certain brain regions (CA1, subiculum) to both NFTs and GVD70,71 suggest an association between these two pathological alterations in AD neurons. So far, little is known about the relationship between neurofibrillary tangles and GVD. PHF-tau degradation (as well as formation) has been suggested to occur in GVD.72,73 Immunohistochemical studies have shown the presence of neurofilament proteins, ubiquitin, tropomyosin, and various tau epitopes in both GVD and NFTs and have indicated the sequestration of undegraded tau in GVD.74 We found GVD in 26% of neurons with AT8 reactivity as compared to 4.7% without pathological tau protein. Together with our finding of activated caspase-3 in GVD, this supports the notion that relatively early damage, as manifested by abnormally phosphorylated cytoplasmic inclusions, may lead to the induction or activation of cell death-related compounds, eg, activated caspase-3, which are then sequestered into the membrane-bound vesicles of GVD, temporarily delaying neuronal demise.
Our work supports the notion that neuronal apoptosis occurs in the AD and DS brain, albeit at exceedingly low levels. The presence of a multitude of proapoptotic factors in AD together with the high amount of neurons with DNA fragmentation indicates, on the one hand, an ongoing proapoptotic challenge of AD neurons and, on the other hand, an enhanced vulnerability of AD neurons to a variety of noxious factors. The presence of activated caspase-3 in autophagic vacuoles of GVD may serve as evidence for neuronal mechanisms counteracting the apoptotic process in the AD brain.
| Acknowledgements |
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| Footnotes |
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Supported by European Community concerted action grant BMH4-CT960162.
Accepted for publication July 30, 1999.
| References |
|---|
|
|
|---|
precedes the formation of neurofibrillary tangles in Alzheimers disease. Brain Res 1989, 477:90-99[Medline]
-induced production of ceramide, activation of caspase-3 and apoptosis. Eur J Biochem 1998, 251:295-303[Medline]
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