(Stroke. 1999;30:2277-2279.)
© 1999 American Heart Association, Inc.
Original Contributions |
A Deletion Polymorphism of 
2-Macroglobulin Gene and Cerebral Amyloid Angiopathy
From the Department of Neurology, Tokyo Medical and Dental University (M.Y., N. Sodeyama, H.M.); the Departments of Internal Medicine (Y.I., E.O.) and Pathology (N. Suematsu), Yokufukai Geriatric Hospital; and the Department of Neuropathology, Tokyo Institute of Psychiatry (M.M.), Tokyo, Japan.
Correspondence to Dr Masahito Yamada, Department of Neurology, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. E-mail m-yamada.nuro{at}med.tmd.ac.jp
 |
Abstract |
|---|
 Top Abstract IntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
Background and Purpose—
2-Macroglobulin may be implicated in
amyloid ß protein deposition. A deletion in the exon 18 splice
acceptor of the 2-macroglobulin gene
(A2M) has been reported to be associated with risk for
Alzheimer's disease (AD). In search of genetic risk factors
for cerebral amyloid angiopathy (CAA), we investigated association of
the A2M deletion polymorphism with CAA. Methods—The association between the severity of CAA and A2M deletion polymorphism was investigated in 178 autopsy cases of the elderly including 68 patients with AD.
Results—There was no significant difference in the severity of
CAA between individuals with the A2M deletion allele
and those without in the AD, non-AD, or total cases. Status for the
4 allele of the apolipoprotein E gene did not influence the
results.
Conclusions—Our results suggest that the A2M deletion polymorphism may not be a definitive risk factor of CAA in the elderly, although further study with larger samples is necessary to confirm this.
Key Words: Alzheimer's disease • amyloid • cerebrovascular disorders • polymorphism (genetics)
|
Introduction |
|---|
|
TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
Cerebral amyloid angiopathy (CAA) is commonly found in the elderly as well as in Alzheimer's disease (AD) and is associated with intracerebral hemorrhage and other cerebrovascular disorders.1 2 3 Some genetic risk factors for AD have been reported to be associated with sporadic CAA. The
4 allele of the apolipoprotein E (apoE) gene
(APOE), an established risk of AD, has been suggested to be
a risk of CAA,4 5 although this was not evident in
some populations and the APOE 2 allele may be
associated with CAA-related hemorrhage.6 7 8
We have reported that the polymorphisms in intron 8 of the
presenilin-1 gene and in the signal peptide sequence of
1-antichymotrypsin may be associated with
sporadic CAA.9 10 AD and CAA would share risk factors in
the common pathogenetic process of amyloid ß protein (Aß)
deposition.
2-Macroglobulin (2M)
is a major protease inhibitor and a ligand of the
low-density lipoprotein receptor–related protein (LRP) as apoE.
2M accumulates on senile
plaques11 and is implicated in binding, fibril formation,
neurotoxicity, degradation, and clearance of Aß.12 13 14 15 16
2M complexes with and mediates the endocytosis
of Aß through LRP.14 Internalization of Aß through LRP
by cerebrovascular smooth muscle cells may be important to the
pathogenesis of CAA.17 Recently, a deletion in the exon 18
splice acceptor of the 2M gene
(A2M) has been reported to be associated with risk for
AD.18 The association is independent of the effect of
APOE 4 and its magnitude is comparable to the association
of APOE 4 with AD,18 although
biological consequences of the 5' splice-site deletion in the exon 18
of A2M is unknown. Association of the A2M
polymorphism with CAA has not been reported as yet.
In the present study, we investigated whether the A2M polymorphism is associated with the severity of CAA in elderly individuals.
|
Subjects and Methods |
|---|
|
TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
We studied 178 patients (age 62 to 104 years; mean±SD, 85.8±7.9 years), all Japanese, from the autopsy series at Yokufukai Geriatric Hospital, Tokyo. The 178 patients included 68 patients with sporadic AD, in which the neuropathological findings satisfied the criteria of the Consortium to Establish a Registry for Alzheimer's Disease19 and 110 subjects without AD or other neurodegenerative disorders. All the AD patients clinically showed dementia on the criteria of DSM III-R.20 There was no significant difference in the age at death between AD (86.4±7.8 years) and non-AD groups (85.4±7.9 years). No familial case of AD or CAA was included in this series.
Neuropathological examinations and assessment of the severity of CAA were performed as previously described.9 10 Briefly, congophilic deposits with green birefringence under polarized light were identified as amyloid. With the use of a mouse monoclonal antibody to Aß,21 the cerebrovascular amyloid deposits were immunohistochemically confirmed to be Aß. Four patients with severe CAA were found to have CAA-related cerebral lobar hemorrhage.
For evaluation of the severity of CAA, the number of amyloid-bearing vessels was counted for randomly chosen 100 meningeal and cortical vessels of the occipital lobe in each case (CAA count was equal to the percentage of the amyloid-laden vessels). The occipital lobe was most commonly affected with CAA in the elderly individuals, as shown in our previous study.2 The quantification was performed without knowledge of A2M and APOE genotypes. Severe vascular wall involvement by CAA was commonly found in patients with high CAA counts.
The A2M polymorphism was detected by the amplification-created restriction site method. Genomic DNA was isolated from the frozen brain tissue of all patients. A2M was amplified with primers described by Matthijs and Marynen.22 The amplification product (326 bp) was digested with Hph I (BioLabs) and electrophoresed on a 2% agarose gel. The A2M polymorphism consists of 2 alleles, the normal allele without deletion (A2M-1) and mutant allele with the 5 nucleotide deletion (A2M-2). The A2M-1 allele was cleaved by Hph I to 2 fragments; the A2M-2 allele was not cleaved. The APOE genotype was also examined as reported previously.6
For statistical analyses, the CAA counts were compared between A2M genotypes in AD, non-AD, and total cases. Because the counts did not follow a normal distribution in any group, we used the Mann-Whitney test for comparison as a nonparametric test.
In our previous studies,2 3 intracerebral
hemorrhage, a major complication of CAA, was found to be
associated only with moderate or severe CAA (affected vessels 
40%)
but not with CAA of the lower degree. Therefore we decided in advance
to compare frequencies of the A2M-2 allele between
patients with severe or moderate CAA (affected vessels 40%) and
those with slight or no CAA (affected vessels <40%). The
2 test was used for the comparison.
Statistical significance was defined as P<0.05. The statistical analyses were performed with the use of computer software (StatView J-7.5, Abacus Concepts).
|
Results |
|---|
|
TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
Among the 178 patients examined, A2M-1/A2M-1 and A2M-1/A2M-2 genotypes were found in 160 and 18 individuals, respectively (0.05 in A2M-2 allele frequency). There was no case of A2M-2/A2M-2 genotype. The age did not differ significantly between the genotypes. The A2M genotype or allele frequencies were not significantly different between AD (0.02 in A2M-2 allele frequency) and non-AD subjects (0.07 in A2M-2 allele frequency), although there was strong association between AD and the APOE
4 allele in this population
(P=0.0004). When the subjects were divided by their
APOE 4 status, there was also no significant difference
in the A2M genotype or allele frequencies
between AD and non-AD cases (data not shown).
The average values (mean±SE) of the CAA counts in the A2M
genotypes are shown in Table 1
. There was no significant
difference in the CAA counts between the
A2M-1/A2M-2 (A2M-2 carriers) and
A2M-1/A2M-1 genotypes (A2M-2
noncarriers). Further, when the subjects were divided by the status of
the APOE 4, the A2M genotype was not
significantly associated with the CAA counts (Table 1). In this
population, the CAA counts in the AD group was significantly higher
compared with the non-AD group (P<0.0001) (Table 1).
The CAA counts in the APOE 4 carriers was higher than
those in non-4 carriers in the total cases (P=0.0154)
(Table 1); within the AD or non-AD group, however, the CAA
counts were not significantly different between the 4 carriers and
non-4 carriers.
|
Severe or moderate CAA was found in 22 (32.4%) of the 68 AD patients
and in 16 (14.5%) of the 110 non-AD subjects (AD vs non-AD,
P=0.0048 by 2 test). The
A2M genotype or allele frequencies were not
significantly different between severe or moderate CAA and slight or no
CAA (Table 2).
|
|
Discussion |
|---|
|
TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
There was no significant association between A2M genotype and severity of CAA in the AD, non-AD, or total cases. Further, in the subgroups divided by the APOE
4 status,
A2M genotype was not associated with severity of
CAA. Our results with elderly Japanese subjects suggest that
A2M polymorphism may not be a risk factor of CAA in the
elderly. However, because the size of our sample is relatively small,
further study with larger samples is necessary to rule out a
statistical error. The low frequency of the A2M-2 allele
in our sample population prevented analysis for the association
of A2M-2/A2M-2 genotype with the severity
of CAA.
Our study confirmed strong association of CAA with AD, as shown in many
studies.1 2 Blacker et al18 reported that the
A2M-2 allele was associated with AD as comparable to the
association of APOE 4 with AD. In our study with
pathologically confirmed patients, however, A2M-2 allele
was not associated with AD irrespective of the APOE 4
status. It should be noted that the results by Blacker et
al18 were from family-based association studies.
Recent population-based case-control studies as well as family-based
studies failed to replicate the association of the A2M-2
allele with AD,23 24 25 although a family-based
study24 indicated significant but weaker associations than
those observed by Blacker et al.18
As mentioned above, the low frequency of the A2M-2 allele in our Japanese population is remarkable compared with those in Europeans and Mediterraneans (0.18)22 and the United Kingdom (0.18).23 There is the possibility that association of the A2M-2 allele with CAA as well as AD may be different between different ethnic groups, requiring further study with larger samples from populations with different ethnic backgrounds.
|
Acknowledgments |
|---|
This study was supported in part by a Health Science Research Grant (to M.Y.) and a Grant for the Amyloidosis Research Committee (to M.Y.) from the Ministry of Health and Welfare, Japan, by a Grant-in-Aid for Scientific Research (to M.Y.) from the Ministry of Education, Science, Sports, and Culture, Japan, and by a Grant (to M.Y.) from Novartis Foundation for Gerontological Research. The authors are grateful to I. Isahai, M. Takeda, and H. Konuma for expert technical assistance.
Received July 26, 1999; revision received August 24, 1999; accepted August 24, 1999.
|
References |
|---|
|
TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
-
Vinters HV. Cerebral amyloid angiopathy: a
critical review. Stroke. 1987;18:311–324.
[Free Full Text] - Yamada M, Tsukagoshi H, Otomo E, Hayakawa M. Cerebral amyloid angiopathy in the aged. J Neurol. 1987;234:371–376.[Medline] [Order article via Infotrieve]
- Itoh Y, Yamada M, Hayakawa M, Otomo E, Miyatake T. Cerebral amyloid angiopathy: a significant cause of cerebellar as well as lobar cerebral hemorrhage in the elderly. J Neurol Sci. 1993;116:135–141.[Medline] [Order article via Infotrieve]
-
Greenberg SG, Rebeck GW, Vonsattel JPG, Gomez-Isla T,
Hyman BT. Apolipoprotein E 4 and cerebral hemorrhage
associated with amyloid angiopathy. Ann Neurol. 1995;38:254–259.[Medline]
[Order article via Infotrieve]
-
Premkumar DRD, Cohen DL, Hedera P, Friedland RP,
Kalaria RN. Apolipoprotein E 4 alleles in cerebral amyloid
angiopathy and cerebrovascular pathology associated with
Alzheimer's disease. Am J Pathol. 1996;148:2083–2095.[Abstract]
-
Itoh Y, Yamada M, Suematsu N, Matsushita M, Otomo E.
Influence of apolipoprotein E genotype on cerebral amyloid
angiopathy in the elderly. Stroke. 1996;27:216–218.
[Abstract/Free Full Text] -
Yamada M, Itoh Y, Suematsu N, Matsushita M, Otomo E.
Lack of an association between apolipoprotein E 4 and cerebral
amyloid angiopathy in elderly Japanese. Ann Neurol. 1996;39:683.[Medline]
[Order article via Infotrieve]
-
Nicoll JAR, Burnett C, Love S, Graham DI, Dewar D,
Ironside JW, Steward J, Vinters HV. High frequency of apolipoprotein
E 2 in hemorrhage due to cerebral amyloid angiopathy.
Ann Neurol. 1997;41:716–721.[Medline]
[Order article via Infotrieve]
-
Yamada M, Sodeyama N, Itoh Y, Suematsu N, Otomo E,
Matsushita M, Mizusawa H. Association of presenilin-1 polymorphism
with cerebral amyloid angiopathy in the elderly. Stroke. 1997;28:2219–2221.
[Abstract/Free Full Text] -
Yamada M, Sodeyama N, Itoh Y, Suematsu N, Otomo E,
Matsushita M, Mizusawa H. Association of 1-antichymotrypsin
polymorphism with cerebral amyloid angiopathy. Ann
Neurol. 1998;44:129–131.[Medline]
[Order article via Infotrieve]
-
Rebeck GW, Harr SD, Strickland DK, Hyman BT. Multiple,
diverse senile plaque-associated proteins are ligands of an
apolipoprotein E receptor, the 2-macroglobulin
receptor/low-density-lipoprotein receptor-related protein. Ann
Neurol. 1995;37:211–217.[Medline]
[Order article via Infotrieve]
-
Qiu WQ, Borth W, Ye Z, Haass C, Teplow DB, Selkoe DJ.
Degradation of amyloid ß-protein by a serine
protease-2-macroglobulin complex. J
Biol Chem. 1996;271:8443–8451.
[Abstract/Free Full Text] -
Du Y, Ni B, Glinn M, Dodel RC, Bales KR, Zhang Z,
Hyslop PA, Paul SM. 2-macroglobulin as a
ß-amyloid peptide-binding plasma protein. J
Neurochem. 1997;69:299–305.[Medline]
[Order article via Infotrieve]
-
Narita M, Holtzman DM, Schwartz AL, Bu G.
2-Macroglobulin complexes with and mediates
the endocytosis of ß-amyloid peptide via cell surface low-density
lipoprotein receptor-related protein. J Neurochem. 1997;69:1904–1911.[Medline]
[Order article via Infotrieve]
-
Du Y, Bales KR, Dodel RC, Liu X, Glinn MA, Horn JW,
Little SP, Paul SM. 2-Macroglobulin
attenuates ß-amyloid peptide 1–40 fibril formation and associated
neurotoxicity of cultured fetal rat cortical neurons. J
Neurochem. 1998;70:1182–1188.[Medline]
[Order article via Infotrieve]
-
Hughes SR, Khorkova O, Goyal S, Knaeblein J, Heroux J,
Riedel N, Sahasrabudhe S. 2-Macroglobulin
associates with ß-amyloid peptide and prevents fibril formation.
Proc Natl Acad Sci U S A. 1998;95:3275–3280.
[Abstract/Free Full Text] - Urmoneit B, Prikulis I, Wihl G, D'Urso D, Frank R, Heeren J, Beisiegel U, Prior R. Cerebrovascular smooth muscle cells internalize Alzheimer amyloid beta protein via a lipoprotein pathway: implications for cerebral amyloid angiopathy. Lab Invest. 1997;77:157–166.[Medline] [Order article via Infotrieve]
- Blacker D, Wilcox MA, Laird NM, Rodes L, Horvath SM, Go RCP, Perry R, Watson B Jr, Bassett SS, McInnis MG, Albert MS, Hyman BT, Tanzi RE. Alpha-2 macroglobulin is genetically associated with Alzheimer disease. Nature Genet. 1998;19:357–360.
-
Mirra S, Heyman A, McKeel D, Sumi SM, Crain BJ,
Brownlee LM, Vogel FS, Hughes JP, van Belle G, Berg L, participating
CERAD neuropathologists. The Consortium to Establish a Registry for
Alzheimer's Disease (CERAD), II: standardization of the
neuropathologic assessment of Alzheimer's disease.
Neurology. 1991;41:479–486.
[Abstract/Free Full Text] - American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 3rd ed. Washington DC: American Psychiatric Association; 1987.
-
Mori H, Takio K, Ogawara M, Selkoe DJ. Mass
spectrometry of purified amyloid beta protein in Alzheimer's
disease. J Biol Chem. 1992;267:17082–17086.
[Abstract/Free Full Text] -
Matthijs G, Marynen P. A deletion polymorphism in
the human alpha-2-macroglobulin (A2 M) gene. Nucleic Acids
Res. 1991;19:5102.
[Free Full Text] -
Dow DJ, Lindsey N, Cairns NJ, Brayne C, Robinson D,
Huppert FA, Paykel ES, Xuereb J, Wilcock G, Whittaker JL, Rubinsztein
DC. -2 Macroglobulin polymorphism and Alzheimer
disease risk in the UK. Nature Genet. 1999;22:16–17.[Medline]
[Order article via Infotrieve]
-
Rudrasingham V, Vriéze FW-D, Lambert J-C,
Chakraverty S, Kehoe P, Crook R, Amouyel P, Wu W, Rice F,
Pérez-Tur J, Frigard B, Morris JC, Carty S, Petersen R, Cottel D,
Tunstall N, Holmans P, Lovestone S, Chariter-Harlin M-C, Goate A, Hardy
J, Owen MJ, Williams J. -2 Macroglobulin gene and
Alzheimer disease. Nature Genet. 1999;22:17–19.[Medline]
[Order article via Infotrieve]
-
Rogaeva EA, Premkumar S, Grubber J, Serneels L, Scott
WK, Kawarai T, Song Y, Hill DM, Abou-Donia SM, Martin ER, Vance JJ, Yu
G, Orlacchio A, Pei Y, Nishimura M, Supala A, Roberge B, Saunders AM,
Roses AD, Schmechel D, Crane-Gatherum A, Sorbi S, Bruin A, Small GW,
Conneally PM, Haines JL, Van Leuven F, St. Geroge-Hyslop PH, Farrer LA,
Pericak-Vance MA. An -2 macroglobulin insertion-deletion
polymorphism in Alzheimer disease. Nature Genet. 1999;22:19–21.[Medline]
[Order article via Infotrieve]
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||