Human Molecular Genetics, 2000, Vol. 9, No. 3 325-331
© 2000 Oxford University Press
Genetic variability in the regulatory region of presenilin 1 associated with risk for Alzheimer’s disease and variable expression
Flanders Interuniversity Institute for Biotechnology (VIB), Born-Bunge Foundation (BBS), University of Antwerp (UIA), Department of Biochemistry, Antwerpen, Belgium and 1Department of Epidemiology and Biostatistics, Erasmus University Medical School, 3000 DR Rotterdam, The Netherlands
Received 10 September 1999; Revised and Accepted 30 November 1999.
 |
ABSTRACT |
|---|
 TOP ABSTRACT INTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
Mutations in the presenilin 1 (PSEN1) gene have been implicated in 18–50% of autosomal dominant cases with early-onset Alzheimer’s disease (EOAD). Also, PSEN1 has been suggested as a potential risk gene in late-onset AD cases. We recently showed genetic association in a population-based study of EOAD, pointing to the 5' regulatory region of PSEN1. In this study we systematically screened 3.5 kb of the PSEN1 upstream region and found four novel polymorphisms. Genetic analysis confirmed association of two polymorphisms with increased risk for EOAD. In addition, we detected two different mutations in EOAD cases at –280 and –2818 relative to the transcription initiation site in exon 1A of PSEN1. Analysis of the mutant and wild-type –280 variants using luciferase reporter gene expression in transiently transfected neuroblastoma cells showed a 30% decrease in transcriptional activity for the mutant –280G PSEN1 promoter variant compared with the wild-type variant –280C. Our data suggest that the increased risk for EOAD associated with PSEN1 may result from genetic variations in the regulatory region leading to altered expression levels of the PSEN1 protein.
|
INTRODUCTION |
|---|
|
TOPABSTRACTINTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
Alzheimer’s disease (AD) is the most common form of senile dementia and the fourth leading cause of death in western societies. Although AD occurs most frequently in the elderly population [late-onset or senile AD (LOAD)], in 1–2% of the cases the first symptoms become apparent before the age of 65 years [early-onset or presenile AD (EOAD)] (1). In 40–60% of AD cases a positive family history for dementia has been documented (2). In 10% of familial cases, AD is inherited as an autosomal dominant trait. Eighteen to fifty per cent of familial autosomal dominant EOAD cases can be explained by mutations in the presenilin 1 gene (PSEN1) (3–5). Other genes that are mutated in autosomal dominant EOAD cases are the amyloid precursor protein (APP) and presenilin 2 (PSEN2) genes (6,7). Also, the E4 allele of the apolipoprotein E gene (APOE4) was shown to increase risk for developing LOAD and EOAD (8,9).
No PSEN1 mutations were found in LOAD patients; however, a genetic association was reported between a di-allelic polymorphism in intron 8 of PSEN1 and LOAD (10). Association was present in a Caucasian North-American but not in an African-American population, suggesting that the intron 8 polymorphism may be in linkage disequilibrium with functionally more relevant sequence variations elsewhere in the PSEN1 gene (10). However, sequence analysis failed to detect sequence variations in the coding region. We recently analysed several polymorphisms within and near the PSEN1 gene for genetic association with EOAD in a population-based case–control sample (11). We found significant association with the intron 8 polymorphism (P = 0.05) as well as with a promoter polymorphism located 48 bp upstream of the transcription initiation site of PSEN1 (–48C
T; P = 0.03) (3,11) and a simple tandem repeat (STR) polymorphism D14S1028 located upstream of PSEN1 (11). However, the intron 8 association was fully explained by linkage disequilibrium with the dominant PSEN1 mutations. The association with the polymorphisms in the regulatory region remained after excluding PSEN1 mutation carriers from the analysis. Of the promoter polymorphism –48CT (3), the most frequent allele C was associated with an increased risk for EOAD [odds ratio (OR) = 2.6] due to over-representation of the CC genotype in the cases, independent of the APOE4 allele (11). These data suggested that genetic variants within the PSEN1 regulatory region might be implicated in AD pathogenesis. The PSEN1 gene consists of 13 exons, three non-coding exons (exons 1A, 1B and 2) and 10 coding exons (exons 3–12) (12). PSEN1 is ubiquitously expressed; however, exons 1A and 1B are alternatively used with the exon 1B transcript found only once in a colon adenocarcinoma cDNA library (13). We determined the genomic organization of PSEN1 by fibre-FISH analysis and restriction mapping of a clone contig spanning PSEN1 (14). In addition to the coding region the clone contig contains ~28 kb of sequences upstream of exon 1B. In this study we sequenced 6.7 kb of upstream sequences and systematically analysed 3.5 kb for genetic variations associated with EOAD.
|
RESULTS |
|---|
|
TOPABSTRACTINTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
PSEN1 promoter polymorphisms
We subcloned four restriction fragments of plasmid B22 (14), representing a 6.7 kb sequence upstream of exon 1B in the pOCUS-2 vector for transposon-based genomic sequencing: the 3.2 kb EcoRI–PstI, 2.1 kb PstI, 2.5 kb PstI and 2.2 kb HindIII–EcoRI fragments (Fig. 1A). In total, 9642 bp were sequenced (GenBank accession no. AF205592), of which 6698 bp were upstream of exon 1B.
|
We systematically screened 3.5 kb upstream of exon 1B (Fig. 1B) in 10 randomly selected control individuals by polymerase chain reaction–single-strand conformation polymorphism (PCR–SSCP) analysis using 16 overlapping primer sets. Four PCR fragments gave altered SSCP patterns and cycle sequencing revealed five polymorphisms (Table 1). One is –48C
T that we reported previously (3) (Table 1), abolishing an HgaI site allowing for its detection by PCR–restriction fragment length polymorphism (RFLP) analysis (Fig. 2). The other four are novel polymorphisms: two single nucleotide changes at positions –1789 (–1789GA) and –2154 (–2154GA); and two complex variations, i.e. a T-stretch at –2319 (–2319Tn) and a 13 bp insertion/deletion at –2823 (–2823I/D) (Table 1). –2154GA and –2823I/D involve restriction enzyme recognition sites for BsmBI and NlaIII, respectively, and can be detected by a PCR–RFLP assay (Fig. 2). For –1789GA we developed an HgaI mismatch PCR–RFLP assay (Fig. 2). SSCP analysis of –2319Tn was complex, also because the T-stretch is contained in the same PCR fragment comprising the –2154GA polymorphism. Sequencing indicated that the T-stretch is highly polymorphic although the number of T alleles could not be determined exactly.
|
|
Genetic association
We analysed the EOAD case–control sample for genetic association with the three novel polymorphisms: –1789G
A, –2154GA and –2823I/D. In the same EOAD case–control sample we have previously analysed –48CT and found positive association with the C-allele and an over-representation of the CC genotype in cases versus controls (Table 2) (11). For all three polymorphisms, genotype frequencies were in Hardy–Weinberg equilibrium in the control population (Table 2). Also, –2154GA and –2823I/D were in nearly complete linkage disequilibrium with –48CT (P < 6.10–15): the risk allele C of –48CT is linked to the G allele of –2154GA and the deletion allele of –2823I/D resulting in similar ORs for these polymorphisms (Table 2). No association was detected with –1789GA (Table 2).
|
PSEN1 promoter mutations
When analysing –2823I/D by PCR–SSCP in the EOAD case–control sample, an additional variation was observed in one EOAD patient. Sequence analysis demonstrated a heterozygous A
G transition at position –2818 (–2818AG) creating a BanI site (Table 1; Fig. 2). PCR–RFLP analysis of the EOAD case–control sample confirmed the presence of –2818AG in the one patient, whereas all other patients and controls were homozygous for the A allele. In addition, we systematically analysed the –372 to –33 promoter fragment by PCR–SSCP analysis for mutations in the EOAD cases. In our previous study we had already analysed the –134 to +163 fragment revealing –48CT but no mutations (3). In one patient, we detected a heterozygous CG transversion at position –280 (–280CG), creating an NcoI site (Table 1; Fig. 2). Again, PCR–RFLP analysis confirmed the presence of the mutation in the one patient with all other patients and controls being homozygous for the C allele.
Reporter gene analysis
We cloned the 1554 bp KpnI–HindIII fragment of B22 corresponding to the –318 to +1226 region (14) into the luciferase reporter vector pGL3-basic. The G allele of –280CG was introduced in the construct by in vitro mutagenesis and sequence integrity was confirmed by sequencing. The effect of the wild-type (–280C) and mutant (–280G) alleles on the transcriptional activity of the PSEN1 promoter was studied in transiently transfected cells. In human embryonic kidney (HEK293) cells no significant differences in expression levels were detected between –280G and –280C (Fig. 3). In mouse Neuro2A-neuroblastoma (N2A) cells, however, a 30% decrease was detected for –280G (Fig. 3). Notably, the promoter activity of –280C in N2A cells and HEK293 cells was comparable (data not shown).
|
|
DISCUSSION |
|---|
|
TOPABSTRACTINTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
Following our previous observation of genetic association of the PSEN1 –48C
T promoter polymorphism with increased risk for EOAD (11), we aimed in this study at analysing systematically the regulatory region of PSEN1 for genetic variations. Starting from a clone contig of PSEN1 that we had previously constructed (14), we determined 6.7 kb of genomic sequence upstream of PSEN1 exon 1B. No TATA box or initiator sequences were found within the 200 bp upstream promoter region. Also, the overall GC content of the 6.7 kb sequence was 48.5%, which is slightly higher than what is expected on average (40%). The GC content was significantly higher (60–70%) in regions upstream of exons 1A and 1B, and highest (73%) in the 100 bp region 5' of exon 1A. Here the GpC:CpG ratio was 1:1 because of the presence of CpG islands representing SP1 recognition sites. All these features are typical for promoters of housekeeping genes corroborating previous findings showing ubiquitous expression of PSEN1 (13). Next, we systematically screened 3.5 kb of upstream sequences by PCR–SSCP analysis and found four novel polymorphisms upstream of exon 1A: two simple base changes (–1789GA and –2154GA) and two complex polymorphisms (a T-stretch at –2319Tn and an insertion/deletion at –2823I/D). When we compared our data with the sequence AF109907 published in GenBank, five differences were observed in the 6.7 kb upstream sequence, of which three were in the 3.5 kb systematically screened by us. Two of these represent the poly- morphisms –1789GA and –2319Tn. The other three (–179C, –3744insT and –4853A) are most likely to be sequencing errors in AF109907 since: (i) they are located in regions that we sequenced at least twice; and (ii) we could not confirm their presence by PCR–RFLP analysis of 10 unrelated individuals.
We analysed the novel polymorphisms, except –2319Tn, in the EOAD cases and controls. The –2154GA and –2823I/D polymorphisms are in nearly complete linkage disequilibrium (P < 6.10–15) with the –48CT polymorphism that we previously identified (3). Also, strong linkage disequilibrium was found between the PSEN1 intron 8 and –48CT (P = 0.001). The –2823D and –2154G alleles co-existed with the –48C risk allele. As a result, the genetic association analysis of these two polymorphisms gave almost identical ORs of 3.0 and 2.9, respectively. The –1789GA polymorphism was not associated with EOAD, suggesting that it arose more recently in history on the risk haplotype.
The association with multiple markers in the region upstream of PSEN1 described in this study is caused mainly by patients homozygous for the risk haplotype (–48C/–2154G/–2823D). In homozygous patients the effect of a PSEN1 promoter polymorphism may lead to important changes in PSEN1 expression levels contributing to the development of AD pathophysiology. Since all three polymorphisms associated with an increased risk for EOAD are located in the regulatory region of PSEN1, each one separately or together may be influencing PSEN1 expression levels. Moreover, all three polymorphisms alter predicted binding properties of potential transcription factor binding sites. The –48CT alters the matrix similarity of three transcription factor binding sites: c-myb, Th1/E47 and zinc finger protein with interaction domain (ZID) (Fig. 1B). The matrix similarity of c-myb at position –57 is decreased from 0.857 for –48C to 0.853 for –48T, suggesting better binding of the transcription factor to the C allele. The binding of Th1/E47 is predicted to be less strong for –48C (0.882 versus 0.909 for –48T). E47 is a basic helix–loop–helix transcription factor, which is expressed in various tissues including brain. In brain, E47 forms a complex with brain-specific proteins and is implicated in the development and maintenance of the mammalian nervous system (15–17). The binding site for ZID is only present for the T allele. In the case of –2823I/D, the last 10 nucleotides of the 13 bp insertion sequence are identical to the 10 nucleotides preceding the insertion site. These 10 nucleotides contain an Ets-1 binding site, although the sequence of the core-binding region does not match the consensus sequence completely (0.926 core similarity/0.888 matrix similarity). However, it is possible that the two Ets-1 sites in the insertion allele –2823I exert a cooperative binding effect and that deletion of one Ets-1 in the –2823D risk allele decreases PSEN1 expression by >2-fold. Also, the Ets-1 sites may interact with the Ets site at position –40 influencing basal promoter activity (18). The core similarity of the binding sequence of GKLF at the –2154GA is decreased from 1 to 0.885 when the –2154G risk allele is present. GKLF belongs to a family of tissue-specific proteins, some of which were shown to influence transcriptional activation by SP1 (19). Since multiple SP1 sites are present in the PSEN1 regulatory region, a comparable brain-specific scenario may be implicated.
Another possibility is that it is not the polymorphisms per se that are biologically relevant, but that they are landmarks for other functionally more important variations in the PSEN1 regulatory region. In this context, it is interesting that we found two different sequence variations in EOAD patients not present in controls: –280CG and –2818AG. Both patients were homozygous for the risk haplotype but heterozygous for the mutation. The mutations were present in patients with onset ages of 63 and 56 years, respectively, and a first degree positive family history of disease, but no family members were available for segregation studies. We studied the effect of –280CG located in the proximal promoter region on PSEN1 promoter activity using a luciferase reporter gene analysis and provided evidence that –280CG modifies transcriptional activity of the PSEN1 promoter in a cell-type-specific manner. In mouse neuroblastoma cells, a decrease in transcriptional activity of >30% was detected for the G allele compared with the C allele, whereas no effect was seen in human kidney cells. These data suggest that –280CG alters or creates a cis element important for transcriptional activity in neuron-like cells, but not in kidney cells. The –280G mutation creates a potential NF1-binding site (core similarity 1/matrix similarity 0.872), which may influence the expression of PSEN1. It has been shown that NF-I proteins play an important role in the regulation of tissue-specific gene expression during mammalian embryogenesis (20).
In conclusion, our study is the first one systematically analysing the PSEN1 regulatory region for genetic variability contributing to the genetic risk for AD. In addition to –48CT, which we identified earlier (3), we found two novel polymorphisms (–2154GA and –2823I/D) associated with increased risk for developing EOAD independently of APOE4, and two potentially EOAD-related mutations (–280CG and –2818AG). Both polymorphisms are in nearly complete linkage disequilibrium with –48CT previously associated with EOAD (3) independently of APOE4. However, it will be important to test the polymorphisms for association in other epidemiological studies to confirm that PSEN1 is a risk gene for EOAD. Also, it will be of interest to determine whether the association previously observed with the intron 8 polymorphism can be explained by genetic variability of the PSEN1 promoter in LOAD. The genome scan in LOAD reported by Kehoe et al. (21) provided significant evidence neither for nor against the notion that PSEN1 may contribute to the risk of developing LOAD. However, the power of the linkage methods to detect genes of small effect is limited (22), and under the conditions used by Kehoe et al. (21) only genes of an effect size equal to or greater than APOE were detected.
Each one of the polymorphisms and mutations involve consensus sequences of potential transcriptional regulatory elements (Fig. 1B) and therefore may modulate PSEN1 transcription. It will be essential to study the functionality of these transcription factor binding sites in vitro and in vivo. Missense mutations in PSEN1 were shown to lead to autosomal dominant EOAD by pathways depending on the production of increased amounts of the amyloidogenic peptide Aß42 (23), a proteolysis product of APP deposited in brain. Also, 50% antisense inhibition of PSEN1 expression in cultured cells resulted in increased Aß42 production (24). On the other hand, in neuronal cell cultures derived from PSEN1 deficient mice, APP processing into Aß peptides was prevented (25). Together, these observations suggest that variable expression levels of PSEN1 may modulate Aß production. Our finding that the –280G mutation, creating a potential NF1-binding site, decreases PSEN1 transcriptional activity in neuroblastoma cells by 30%, suggests that the increased risk associated with PSEN1 can be explained by decreased PSEN1 expression. However, it is important to note that the –280G mutation appeared in the heterozygous state although the patient was homozygous for the risk haplotype. Therefore, more data on the functionality of the PSEN1 promoter are needed before concluding that altered PSEN1 transcription contributes to disease risk. The importance of these studies is demonstrated by recent findings of polymorphisms in the APOE promoter modulating risk for LOAD (26,27) by altering APOE4 expression levels (28). Also, contribution of genetic variability in the APP promoter to increased risk for LOAD was recently suggested (29), possibly by increasing APP expression leading to increased Aß production as in Down’s syndrome cases. Together, these studies suggest an important role for variability in regulatory elements in the genetic predisposition for developing AD.
|
MATERIALS AND METHODS |
|---|
|
TOPABSTRACTINTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
Subjects
Patients were derived from a population-based epidemiological study of EOAD within metropolitan Rotterdam and the four northern provinces of The Netherlands (30). Blood samples for DNA extraction were collected from 102 (52%) of the participating patients. The mean age at onset of the patients was 56.7 ± 5.4 years and the mean age at the time of the study was 63 ± 4.4 years. Patients were compared with an age- and sex-matched control series (n = 118; mean age 63 ± 4.4 years) that was drawn randomly from the Rotterdam Study (30–32). Based on family history up to two degrees, these subjects were not related. None of the control subjects showed symptoms of dementia and none had cognitive test scores suspect for dementia (30,32).
Sequencing of the PSEN1 5' upstream region
Plasmid B22 (14) was subcloned into the pOCUS-2 vector for transposon-based genomic sequencing (Novagen, Madison, WI). The pOCUS-2 constructs were transferred into chemically competent donor cells, which carry the transposon on an F factor, and one of the resulting colonies was mated with the recipient cells according to the manufacturer’s protocol. For each fragment, 96 colonies were randomly selected and stored in a 96-well plate containing LB medium supplemented with 20% glycerol. The transposition site of the different clones was mapped by colony PCR combining one of the two vector-specific primers (POCUSUP or POCUSDOWN) with a transposon-specific primer (GDIR) in separate reactions (33). Colonies were selected based on their site of transposition and DNA was prepared for sequencing using the Wizard Plus SV Minipreps DNA Purification System (Promega, Madison, WI). Plasmid sequencing was performed using the Thermo Sequenase II Dye Terminator Cycle Sequencing kit (Amersham Life Science, Cleveland, OH) according to the supplier’s protocol using primers GD1 and GD2 (33). The sequences were assembled using the Lasergene software for Windows (DNASTAR, Madison, WI). Gaps in the sequence were completed by targeted cycle sequencing using primers directed against sequences flanking the gaps.
DNA analysis
Standard PCR was performed using 16 overlapping primer sets covering the 3.5 kb sequence upstream of exon 1B. Two additional primer sets were designed to analyse the two sequence differences –3744insT and –4853GA. In the SSCP analyses, heat-denatured and renatured PCR products were electrophoresed on precast ExcelGel gels (Pharmacia Biotech, Uppsala, Sweden) for 3.5 h at 600 V using the MultiPhorII electrophoresis system (Pharmacia Biotech) and visualized by silver staining. Products with aberrant SSCP patterns were sequenced as described above. Polymorphisms were analysed by restriction enzyme digestion of the PCR products amplified from genomic DNA, when they produced an RFLP. In case no RFLP was present, mismatch primers were designed or samples were analysed by PCR–SSCP analysis. Fragments were separated on a 1.5–3% agarose gel and visualized on an ultraviolet trans-illuminator after ethidium bromide staining. Alternatively, fragments were separated on precast ExcelGel gels and visualized by silver staining.
Statistical analysis
Allele and genotype distributions in patients and controls, excluding the six patients with PSEN1 mutations, were compared using Fisher’s exact test (34). Hardy–Weinberg equilibrium and linkage disequilibrium were tested using the HWE and EH programs as described by Terwilliger and Ott (34). Since the markers tested were in strong linkage disequilibrium, adjustment for multiple testing is not straightforward, as statistical tests are not independent. Therefore, exact P values were calculated. The strength of association between alleles or genotypes and EOAD was evaluated with the OR presented with 95% confidence intervals.
Construction of reporter plasmids
The PSEN1 5' upstream region from –323 to +1231 was cloned into the promoterless pGL3-basic vector (Promega) upstream of the firefly luciferase gene. The Quick-change in vitro mutagenesis kit (Stratagene, La Jolla, CA) was used to introduce the –280G mutation using primer 5'-ATTTAGGATGGCCATGGCTTGTATGCCGGGAGAAGCACACGCTG-3' and its reverse complement. A mutant clone was selected by NcoI digestion and the integrity of the complete insert was confirmed by sequence analysis as described above using vector- and PSEN1-specific primers designed for screening of the PSEN1 5' upstream region.
Eukaryotic cell culture and transient transfection
Mouse N2A cells were propagated in a minimal essential medium with Earle’s salt, 10% fetal bovine serum, 2 mM L-glutamine, 200 IU/ml penicillin, 200 g/ml streptomycin and 0.1 mM non-essential amino acids (Life Technologies, Gaithersburg, MD). HEK293 cells were propagated in Optimem with 10% fetal bovine serum, 200 IU/ml penicillin and 200 g/ml streptomycin (Life Technologies). For transient transfection, N2A and HEK293 cells were seeded in 6-well tissue culture dishes, at 9 x 104 and 7 x 105 cells/well, respectively, and allowed to recover for 24 h. Cells were co-transfected with 20 ng of pRL-TK plasmid containing the herpes simplex virus thymidine kinase promoter upstream of the renilla luciferase gene (Promega) and 1 g of either one of the PSEN1 promoter constructs or one of the control plasmids, using the Lipofectamine procedure (Life Technologies) as described in the manufacturer’s protocol. Empty pGL3-basic vector was used as a negative control, pGL3-promoter plasmid containing the SV40 promoter upstream of the firefly luciferase gene (Promega) as a positive control.
Relative luciferase activity measures
Transfected cells were cultured for 48 h, washed with 1 ml of phosphate-buffered saline (Life Technologies), and lysed with Passive lysis buffer (Promega). Firefly luciferase activities (LAF) and renilla luciferase activities (LAR) were measured sequentially using a Dual-Luciferase reporter assay system (Promega) and a model TD-20E Luminometer (Turner Design, Sunnyvale, CA). To correct for transfection efficiency and DNA uptake, the relative luciferase activity (RLA) was calculated as: RLA = LAF/LAR. To compare the RLA of a sample in one cell line with another, relative RLA was calculated as a percentage of the RLA of the wild-type construct: %RLA = (RLAmt/RLAwt) x 100.
|
ACKNOWLEDGEMENTS |
|---|
We thank J. Remacle for his kind advice and inspiring discussions. This work was supported by the Fund for Scientific Research-Flanders (Belgium; FWO-F), DWTC Interuniversity Attractionpoles (IUAP P4/17), the International Alzheimer’s Research Foundation (IARF) and grants from the Netherlands Organisation for Scientific Research (NWO), The Netherlands Institute for Health Sciences (NIHES) and the Hersenstichting Nederland (HsN). M.C. is a postdoctoral fellow and B.D. a PhD fellow of the FWO-F.
|
FOOTNOTES |
|---|
+ To whom correspondence should be addressed at: Laboratory of Molecular Genetics, Neurogenetics Group, University of Antwerp (UIA), Department of Biochemistry, Universiteitsplein 1, B-2610 Antwerpen, Belgium. Tel: +32 3 8202333; Fax: +32 3 8202541; Email: cruts@uia.ua.ac.be
|
REFERENCES |
|---|
|
TOPABSTRACTINTRODUCTIONRESULTSDISCUSSIONMATERIALS AND METHODSREFERENCES |
|---|
1 Ott, A., Breteler, M.M., Van Harskamp, F., Stijnen, T. and Hofman, A. (1998) Incidence and risk of dementia. The Rotterdam Study. Am. J. Epidemiol., 147, 574–580.
2 Slooter, A.J. and van Duijn, C.M. (1997) Genetic epidemiology of Alzheimer disease. Epidemiol. Rev., 19, 107–119.
3 Cruts, M., van Duijn, C.M., Backhovens, H., Van den Broeck, M., Wehnert, A., Serneels, S., Sherrington, R., Hutton, M., Hardy, J., St-George Hyslop, P.H. et al. (1998) Estimation of the genetic contribution of presenilin-1 and -2 mutations in a population-based study of presenile Alzheimer disease. Hum. Mol. Genet., 7, 43–51.
4 Campion, D., Flaman, J.-M., Brice, A., Hannequin, D., Dubois, B., Martin, C., Moreau, V., Charbonnier, F., Didierjean, O., Tardieu, S. et al. (1995) Mutations of the presenilin 1 gene in families with early-onset Alzheimer’s disease. Hum. Mol. Genet., 4, 2373–2377.
5 Hutton, M., Busfield, F., Wragg, M., Crook, R., Perez, T.J., Clark, R.F., Prihar, G., Talbot, C., Phillips, H., Wright, K. et al. (1996) Complete analysis of the presenilin 1 gene in early onset Alzheimer’s disease. Neuroreport, 7, 801–805.[Web of Science][Medline]
6 Goate, A., Chartier-Harlin, M.-C., Mullan, M., Brown, J., Crawford, F., Fidani, L., Giuffra, L., Haynes, A., Irving, N., James, L. et al. (1991) Segregation of a missense mutation in the amyloid precursor protein gene with familial Alzheimer’s disease. Nature, 349, 704–706.[Medline]
7 Levy-Lahad, E., Wasco, W., Poorkaj, P., Romano, D.M., Oshima, J., Pettingell, W.H., Yu, C.-E., Jondro, P.D., Schmidt, S.D., Wang, K. et al. (1995) Candidate gene for the chromosome 1 familial Alzheimer’s disease locus. Science, 269, 973–977.
8 Strittmatter, W.J., Saunders, A.M., Schmechel, D., Pericak, V.M., Enghild, J., Salvesen, G.S. and Roses, A.D. (1993) Apolipoprotein E: high-avidity binding to ß-amyloid and increased frequency of type 4 allele in late-onset familial Alzheimer disease. Proc. Natl Acad. Sci. USA, 90, 1977–1981.
9 van Duijn, C., de Knijff, P., Cruts, M., Wehnert, A., Havekes, L.M., Hofman, A. and Van Broeckhoven, C. (1994) Apolipoprotein E4 allele in a population-based study of early-onset Alzheimer’s disease. Nature Genet., 7, 74–78.[Web of Science][Medline]
10 Wragg, M., Hutton, M. and Talbot, C. (1996) Genetic association between intronic polymorphism in presenilin-1 gene and late-onset Alzheimer’s disease. Alzheimer’s Disease Collaborative Group. Lancet, 347, 509–512.[Web of Science][Medline]
11 van Duijn, C., Cruts, M., Theuns, J., Van Gassen, G., Backhovens, H., Van den Broeck, M., Wehnert, A., Serneels, S., Hofman, A. and Van Broeckhoven, C. (1999) Genetic association of the presenilin-1 regulatory region with early-onset Alzheimer’s disease in a population-based sample. Eur. J. Hum. Genet., 7, 801–806.[Web of Science][Medline]
12 Clark, R.F., Hutton, M., Fuldner, R.A., Froelich, S., Karran, E., Talbot, C., Crook, R., Lendon, C., Prihar, G., He, C. et al. (1995) The structure of the presenilin 1 (S182) gene and identification of six novel mutations in early onset AD families. Alzheimer’s Disease Collaborative Group. Nature Genet., 11, 219–222.[Web of Science][Medline]
13 Rogaev, E.I., Sherrington, R., Wu, C., Levesque, G., Liang, Y., Rogaeva, E.A., Ikeda, M., Holman, K., Lin, C., Lukiw, W.J. et al. (1997) Analysis of the 5' sequence, genomic structure, and alternative splicing of the presenilin-1 gene (PSEN1) associated with early onset Alzheimer disease. Genomics, 40, 415–424.[Web of Science][Medline]
14 Theuns, J., Cruts, M., Del-Favero, J., Goossens, D., Dauwerse, H., Wehnert, A., den Dunnen, J.T. and Van Broeckhoven, C. (1999) Determination of the genomic organization of human presenilin 1 by fiber-FISH analysis and restriction mapping of cloned DNA. Mamm. Genome, 10, 410–414.[Web of Science][Medline]
15 Shimizu, C., Akazawa, C., Nakanishi, S. and Kageyama, R. (1995) MATH-2, a mammalian helix–loop–helix factor structurally related to the product of Drosophila proneural gene atonal, is specifically expressed in the nervous system. Eur. J. Biochem., 229, 239–248.[Web of Science][Medline]
16 Peyton, M., Stellrecht, C.M., Naya, F.J., Huang, H.P., Samora, P.J. and Tsai, M.J. (1996) BETA3, a novel helix–loop–helix protein, can act as a negative regulator of BETA2 and MyoD-responsive genes. Mol. Cell. Biol., 16, 626–633.[Abstract]
17 Akazawa, C., Ishibashi, M., Shimizu, C., Nakanishi, S. and Kageyama, R. (1995) A mammalian helix–loop–helix factor structurally related to the product of Drosophila proneural gene atonal is a positive transcriptional regulator expressed in the developing nervous system. J. Biol. Chem., 270, 8730–8738.
18 Pastorcic, M. and Das, H.K. (1999) An upstream element containing an ETS binding site is crucial for transcription of the human presenilin-1 gene. J. Biol. Chem., 274, 24297–24307.
19 Zhang, W., Shields, J.M., Sogawa, K., Fujii-Kuriyama, Y. and Yang, V.W. (1998) The gut-enriched Kruppel-like factor suppresses the activity of the CYP1A1 promoter in an Sp1-dependent fashion. J. Biol. Chem., 273, 17917–17925.
20 Chaudhry, A.Z., Lyons, G.E. and Gronostajski, R.M. (1997) Expression patterns of the four nuclear factor I genes during mouse embryogenesis indicate a potential role in development. Dev. Dyn., 208, 313–325.[Web of Science][Medline]
21 Kehoe, P., Wavrant-De Vrieze, F., Crook, R., Wu, W.S., Holmans, P., Fenton, I., Spurlock, G., Norton, N., Williams, H., Williams, N. et al. (1999) A full genome scan for late onset Alzheimer’s disease. Hum. Mol. Genet., 8, 237–245.
22 Hauser, E.R., Boehnke, M., Guo, S.W. and Risch, N. (1996) Affected-sib-pair interval mapping and exclusion for complex genetic traits: sampling considerations. Genet. Epidemiol., 13, 117–137.[Web of Science][Medline]
23 Hardy, J. (1997) Amyloid, the presenilins and Alzheimer’s disease. Trends Neurosci., 20, 154–159.[Web of Science][Medline]
24 Refolo, L., Eckman, C., Prada, C.M., Yager, D. and Younkin, S. (1998) Antisense reduction of presenilin 1 significantly increases Aß42 (43) secreted by human embryonic kidney cells. Neurobiol. Aging, 19, S63.
25 De Strooper, B., Saftig, P., Craessaerts, K., Vanderstichele, H., Guhde, G., Annaert, W., Von Figura, K. and Van Leuven, F. (1998) Deficiency of presenilin-1 inhibits the normal cleavage of amyloid precursor protein. Nature, 391, 387–390.[Medline]
26 Lambert, J.C., Pasquier, F., Cottel, D., Frigard, B., Amouyel, P. and Chartier-Harlin, M.C. (1998) A new polymorphism in the APOE promoter associated with risk of developing Alzheimer’s disease. Hum. Mol. Genet., 7, 533–540.
27 Lambert, J.C., Berr, C., Pasquier, F., Delacourte, A., Frigard, B., Cottel, D., Perez-Tur, J., Mouroux, V., Mohr, M., Cecyre, D. et al. (1998) Pronounced impact of Th1/E47cs mutation compared with –491 AT mutation on neural APOE gene expression and risk of developing Alzheimer’s disease. Hum. Mol. Genet., 7, 1511–1516.
28 Bullido, M.J., Artiga, M.J., Recuero, M., Sastre, I., Garcia, M.A., Aldudo, J., Lendon, C., Han, S.W., Morris, J.C., Frank, A. et al. (1998) A polymorphism in the regulatory region of APOE associated with risk for Alzheimer’s dementia. Nature Genet., 18, 69–71.[Web of Science][Medline]
29 Wavrant-De Vrieze, F., Crook, R., Holmans, P., Kehoe, P., Owen, M.J., Williams, J., Roehl, K., Laliiri, D.K., Shears, S., Booth, J. et al. (1999) Genetic variability at the amyloid-ß precursor protein locus may contribute to the risk of late-onset Alzheimer’s disease. Neurosci. Lett., 269, 67–70.[Web of Science][Medline]
30 van Duijn, C.M., Hendriks, L., Farrer, L.A., Backhovens, H., Cruts, M., Wehnert, A., Hofman, A. and Van Broeckhoven, C. (1994) A population-based study of familial Alzheimer disease: linkage to chromosomes 14, 19, and 21. Am. J. Hum. Genet., 55, 714–727.[Web of Science][Medline]
31 Hendriks, L., van Duijn, C.M., Cras, P., Cruts, M., Van Hul, W., Van Harskamp, F., Warren, A., McInnis, M.G., Antonarakis, S.E. and Martin, J.J. (1992) Presenile dementia and cerebral haemorrhage linked to a mutation at codon 692 of the ß-amyloid precursor protein gene. Nature Genet., 1, 218–221.[Web of Science][Medline]
32 Hofman, A., Grobbee, D.E., de Jong, P.T. and van den Ouweland, F.A. (1991) Determinants of disease and disability in the elderly: the Rotterdam Elderly Study. Eur. J. Epidemiol., 7, 403–422.[Web of Science][Medline]
33 Strathmann, M., Hamilton, B.A., Mayeda, C.A., Simon, M.I., Meyerowitz, E.M. and Palazzolo, M.J. (1991) Transposon-facilitated DNA sequencing. Proc. Natl Acad. Sci. USA, 88, 1247–1250.
34 Terwilliger, J.D. and Ott, J. (1994) Handbook of Human Genetic Linkage. John Hopkins University Press, New York, NY.
35 Quandt, K., Frech, K., Karas, H., Wingender, E. and Werner, T. (1995) MatInd and MatInspector: new fast and versatile tools for detection of consensus matches in nucleotide sequence data. Nucleic Acids Res., 23, 4878–4884.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  G. Bourque, B. Leong, V. B. Vega, X. Chen, Y. L. Lee, K. G. Srinivasan, J.-L. Chew, Y. Ruan, C.-L. Wei, H. H. Ng, et al. Evolution of the mammalian transcription factor binding repertoire via transposable elements Genome Res., November 1, 2008; 18(11): 1752 - 1762. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. M. Stylianou, J. P. Affourtit, K. R. Shockley, R. Y. Wilpan, F. A. Abdi, S. Bhardwaj, J. Rollins, G. A Churchill, and B. Paigen Applying Gene Expression, Proteomics and Single-Nucleotide Polymorphism Analysis for Complex Trait Gene Identification Genetics, March 1, 2008; 178(3): 1795 - 1805. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. B.H. Williams, E. K.F. Chan, M. J. Cowley, and P. F.R. Little The influence of genetic variation on gene expression Genome Res., December 1, 2007; 17(12): 1707 - 1716. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Shen and R. J. Kelleher III The presenilin hypothesis of Alzheimer's disease: Evidence for a loss-of-function pathogenic mechanism PNAS, January 9, 2007; 104(2): 403 - 409. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Thomas and M. Fenech A review of genome mutation and Alzheimer's disease Mutagenesis, January 1, 2007; 22(1): 15 - 33. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Theuns, J. Remacle, R. Killick, E. Corsmit, K.'l Vennekens, D. Huylebroeck, M. Cruts, and C. V. Broeckhoven Alzheimer-associated C allele of the promoter polymorphism -22C>T causes a critical neuron-specific decrease of presenilin 1 expression Hum. Mol. Genet., April 15, 2003; 12(8): 869 - 877. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. COTSAPAS, E. CHAN, M. KIRK, M. TANAKA, and P. LITTLE Genetic Variation and the Control of Transcription Cold Spring Harb Symp Quant Biol, January 1, 2003; 68(0): 109 - 114. [Abstract] [PDF]
|
|
|
|
 |
|
 S. Leonard, J. Gault, J. Hopkins, J. Logel, R. Vianzon, M. Short, C. Drebing, R. Berger, D. Venn, P. Sirota, et al. Association of Promoter Variants in the {alpha}7 Nicotinic Acetylcholine Receptor Subunit Gene With an Inhibitory Deficit Found in Schizophrenia Arch Gen Psychiatry, December 1, 2002; 59(12): 1085 - 1096. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. S. Athan, J. H. Lee, A. Arriaga, R. P. Mayeux, and B. Tycko Polymorphisms in the Promoter of the Human APP Gene: Functional Evaluation and Allele Frequencies in Alzheimer Disease Arch Neurol, November 1, 2002; 59(11): 1793 - 1799. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. A. Rogaeva, K.C. Fafel, Y.Q. Song, H. Medeiros, C. Sato, Y. Liang, E. Richard, E.I. Rogaev, P. Frommelt, A. D. Sadovnick, et al. Screening for PS1 mutations in a referral-based series of AD cases: 21 Novel mutations Neurology, August 28, 2001; 57(4): 621 - 625. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J.-C. Lambert, D. M A Mann, J. M Harris, M.-C. Chartier-Harlin, A. Cumming, J. Coates, H. Lemmon, D. StClair, T. Iwatsubo, and C. Lendon The {-}48 C/T polymorphism in the presenilin 1 promoter is associated with an increased risk of developing Alzheimer's disease and an increased A{beta} load in brain J. Med. Genet., June 1, 2001; 38(6): 353 - 355. [Abstract] [Full Text]
|
|
|
|
|
|
M. J Houseman, L. A Ellis, A. Pagnamenta, W.-L. Di, S. Rickard, A. H Osborn, H.-H. M Dahl, G. R Taylor, M. Bitner-Glindzicz, W. Reardon, et al. Genetic analysis of the connexin-26 M34T variant: identification of genotype M34T/M34T segregating with mild-moderate non-syndromic sensorineural hearing loss J. Med. Genet., January 1, 2001; 38(1): 20 - 25. [Abstract] [Full Text]
|
|
|
|
|
|
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]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||