This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Peters, D. G. Articles by Ferrell, R. E. Search for Related Content PubMed PubMed Citation Articles by Peters, D. G. Articles by Ferrell, R. E. Related Collections Cerebral Aneurysm, AVM, & Subarachnoid hemorrhage Genetics of Stroke Risk Factors for Stroke

(Stroke. 1999;30:2612.)
© 1999 American Heart Association, Inc.

Original Contributions

Functional Polymorphism in the Matrix Metalloproteinase-9 Promoter as a Potential Risk Factor for Intracranial Aneurysm

David G. Peters, PhD; Amin Kassam, MD; Pamela L. St. Jean, PhD; Howard Yonas, MD Robert E. Ferrell, PhD

From the Department of Human Genetics, Graduate School of Public Health (D.G.P., R.E.F.), Department of Neurosurgery, School of Medicine (A.K., H.Y.), University of Pittsburgh, Pittsburgh, Pa, and GlaxoWellcome, Inc, Research Triangle Park, NC (P.L.S.).

Correspondence to David G. Peters, PhD, Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261. E-mail dpeters{at}helix.hgen.pitt.edu

	Abstract

Top Abstract Introduction Materials and Methods Results Discussion References

 
Background and Purpose—There is convincing evidence that susceptibility to intracranial aneurysms (ICAs) has a genetic component. However, few studies have sought to identify functional variation in specific candidate genes that may predispose individuals to develop an ICA.

Methods—ICA cases and controls were genotyped for a simple length polymorphism in the promoter of matrix metalloproteinase-9 (MMP-9) to test for association between variation in the promoter and the occurrence of ICA. Alternative alleles were cloned into an in vitro reporter vector, transfected into human HT1080 fibroblasts, and assayed for promoter activity by ß-gal and luciferase assays. Electrophoretic gel shift assays were used to assess nuclear factor binding.

Results—A length polymorphism in the promoter of MMP-9 was nonrandomly associated with the occurrence of ICA in a case-control study. This polymorphism was shown, by direct sequencing of 36 individuals, to be the only sequence variation within a 736–base pair region proximal to the transcriptional start site of the gene. Variation in the length of this repetitive element was shown to modulate promoter activity in an in vitro reporter assay, with the highest promoter activity being observed in constructs bearing the longest [(CA)23] element. Electrophoretic mobility shift assays were used to show that the (CA) element is bound by a sequence-specific DNA-binding protein.

Conclusions—Genetic variation in the promoter of the MMP-9 gene results in variation in its expression at the level of transcription. This may result in subtle differences in MMP-9 activity within the circle of Willis, leading to increased susceptibility to ICA formation.

Key Words: biological markers • cerebral aneurysm • genetics • polymorphism

	Introduction

Top Abstract Introduction Materials and Methods Results Discussion References

 
Matrix metalloproteinase-9 (MMP-9; gelatinase B, type 4 collagenase) is a member of the MMP gene family, which encodes a family of zinc-dependent enzymes with proteolytic activity against connective tissue proteins, including collagens, elastin, and proteoglycans. MMP-9 plays an essential role in development and tissue remodeling.¹ MMP-9 overexpression has been reported in abdominal aortic and cerebral aneurysms,^{2 3 4 5} and its overexpression contributes to the formation of aneurysms through the degradation of type 4 collagen, proteoglycan core protein, and elastin, which are resistant to degradation by some other MMPs.⁶ MMP-9 is regulated primarily at the level of transcription in response to such regulatory molecules as tumor necrosis factor-, interleukin-1, platelet-derived growth factor, and epidermal growth factor.^{7 8}

There is significant evidence that susceptibility to cerebral aneurysms has an important genetic component,^{9 10} with an imbalance in the local expression of MMP-9 and tissue inhibitors of metalloproteinases being a contributing factor.⁴ We have previously described a simple sequence repeat polymorphism in the 5'-untranslated region of the human MMP-9 gene¹¹ within the regulatory domain. The present study was undertaken to test the hypothesis that polymorphic variation in this simple sequence repeat has a significant influence on MMP-9 expression.

	Materials and Methods

Top Abstract Introduction Materials and Methods Results Discussion References

 
Study Subjects
This research was approved by the Institutional Review Board of the University of Pittsburgh, and all participants gave written informed consent. Peripheral blood specimens and demographic, medical, and family histories were obtained from 76 sequentially ascertained, unrelated patients undergoing repair of a cerebral aneurysm at Presbyterian University Hospital, Pittsburgh, Pa. Eight (10%) of these patients reported a history of symptomatic intracranial aneurysm (ICA) among their first- and second-degree relatives, with no obvious pattern of occurrence. Among these cases, 70% were female and 30% were male, with a mean age of 54.9 and 46.6 years, respectively (P<0.005). All participants were of mixed west European white ancestry, and none had a personal or family history of connective tissue disorders or polycystic kidney disease. These cases were compared with an unselected sample of participants in observational epidemiological studies selected without reference to disease. The controls were drawn from the same population of mixed European ancestry as the cases (western Pennsylvania) and had a similar age and sex distribution. The controls were uncharacterized with respect to vascular disease.

High-molecular-weight genomic DNA for genotyping and sequence analysis was prepared by standard methods.¹³ The MMP-9 CA-repeat polymorphism was genotyped as previously described.¹¹

Data Analysis
Allele frequencies were estimated by gene counting. Allele frequencies in cases and controls were compared by standard ² analysis. Means and SDs of luciferase assays were computed by standard methods, and significance of differences was assessed by ANOVA F test.

DNA Sequencing
CLG4B sequence was amplified from 50 ng of genomic DNA with Taq DNA polymerase (BRL) in 20 mmol/L Tris-HCl (pH 8.4), 500 mmol/L KCl, 1.5 mmol/L MgCl₂. Amplicons were purified to remove unincorporated primer and dNTPs with Microcon 100 spin columns (Amicon) and subjected to cycle sequencing on an ABI 9600 (PE Applied Biosystems) with dye-labeled terminators. Sequencing products were purified on Centricon columns (Princeton Separations) and analyzed on an ABI 377 automated sequencer (PE Applied Biosystems).

Subcloning Polymerase Chain Reaction Products of CLG4B Promoter Sequence
Polymerase chain reactions (PCRs) were performed with the high-fidelity thermostable DNA polymerase pfu (Stratagene) and 50 ng of genomic DNA in 100 mmol/L KCl, 100 mmol/L (NH₄)₂SO₄, 200 mmol/L Tris-Cl (pH 8.75), 20 mmol/L MgSO₄, 1% Triton X-100, 1000 µg/mL BSA. Primers were designed to incorporate either a SmaI or KpnI restriction recognition sequence at either end of the resulting PCR product and were identical to P1 and P2 (see below). The resulting 736-bp PCR products were purified on 1% agarose gels and subjected to restriction digestion. After an additional round of gel purification, fragments were ligated with SmaI/KpnI double-digested pGL3B reporter vector (Promega) and transformed into chemically competent XL1 Blue Escherichia coli (Stratagene). Recombinant plasmid DNA was purified by miniprep (Qiagen) and confirmed by sequencing. Large-scale preparations (Qiagen) of recombinant plasmid DNA were used for transfection of HT1080 (ATCC) human fibroblasts.

Transfection of Human HT1080 Fibroblasts
Cells were plated at a density of 0.75 cells/mL in 2 mL of DMEM containing 10% fetal bovine serum and penicillin/streptomycin (Life Technologies) and grown overnight until 70% confluent. Transfections were performed in either duplicate or triplicate with Lipofectamine (Life Technologies) according to the manufacturer’s instructions with a 5-hour incubation in the presence of the Lipofectamine. For each plate, 2 µg of reporter plasmid and 0.5 µg of a cytomegalovirus (CMV)-driven ß-gal positive control vector (pCMV, In Vitrogen) were used. Cell extracts were assayed for ß-gal and luciferase activity by use of commercially available kits (Promega). ß-Gal levels were measured by spectrophotometry, and luciferase activity was determined by use of a luminometer (Monolight).

Electrophoretic Mobility Shift Assay Probe Construction
CLG4B nucleotide numbers are assigned based on the sequence of Huhtala¹⁴ and assume a microsatellite length of 21 repeats. Double-stranded probes for electrophoretic mobility shift assays were constructed with a short common primer to fill in the second strand of a full-length single-stranded oligonucleotide. The common primer was radiolabeled at its 5' end with polynucleotide kinase (Boehringer Mannheim) in the presence of [³²P]-dCTP and purified by use of G25 spin columns (Boehringer Mannheim). Oligonucleotides were annealed by boiling for 3 minutes and cooling slowly to room temperature. Extension reactions were performed with the Klenow fragment of DNA polymerase I (Life Technologies). The (CA) element probe contains 23 CA repeats with 44 bp of flanking sequence corresponding to nucleotides -148 to -63.¹⁵ The "Replace" probe is identical except that the CA motif is replaced by a sequence of the same length derived from the polylinker of the pGL3Basic vector (nucleotides 31 to 66 [Promega]). Oligonucleotide sequences are as follows: (CA) element oligonucleotide: TCTCATGCTGGTGCTGCCACA-CACACACACACACACACACACACACACACACACACACAC-ACACCCTGACCCCTGAGTCAGCACTTGCCT.

Replace oligonucleotide: TCTCATGCTGGTGCTGCGCTCGA-GATCTGCGATCTAAGTAAGCTTGGCATTCCGGTACTGTTG-CCCTGACCCCTGAGTCAGCACTTGCCT.

Common primer: TCTCATGCTGGTG.

Preparation of Nuclear Extracts
HT1080 and bovine aortic endothelial cells (BAECs) were cultured to 70% confluence and crude nuclear extracts prepared by a modification of published methods.¹² Extracts were measured for protein content using the Bradford method (Bio-Rad) and frozen at -80°C.

Electrophoretic Mobility Shift Assays
Binding reactions were performed in binding buffer (25 mmol/L HEPES pH 7.9, 500 mmol/L KCl, 10 mmol/L DDT, 10 mg/mL BSA) containing 15% glycerol, 2 to 5 pmol of probe, and 2.0 µg of poly (dI-dC)(dI-dC) (Pharmacia). Either 1, 3, or 5 µg of crude nuclear extract was added to this, to a final volume of 20 µL. Reactions were incubated on ice for 30 minutes, run on 4% nondenaturing polyacrylamide gels, and electrophoresed for 2 to 3 hours at 4°C and 10 V/cm. After electrophoresis, gels were transferred to Whatman 3 MM paper, dried under vacuum at 80°C, and subjected to autoradiography.

	Results

Top Abstract Introduction Materials and Methods Results Discussion References

 
MMP-9 Genotyping and Sequencing
MMP-9 allele frequencies in cases and controls are shown in the Table. There is a significant difference in the allele frequency between cases and controls, with an excess of (CA)₂₃ alleles among cases.

View this table: [in this window] [in a new window]   Table 1. MMP-9 Allele Frequencies in ICA Patients and a Population Control Sample Showing a Significant Overrepresentation of the CA(23) Allele in Cases Compared With Controls

These cases were unrelated, sequentially ascertained subjects who were undergoing operative aneurysm repair. Approximately 10% of these cases report a history of an ICA in a first-degree relative, but the frequency of the (CA)₂₃ allele was not different between those with and those without a family history of ICA. The small number of cases with a positive family history (n=8) precludes the detection of small differences in allele frequency. The frequency of (CA)₂₃ homozygous individuals did not differ significantly between cases and controls. To test the hypothesis that the microsatellite variation in the regulatory region of MMP-9 is responsible for the association with ICA, we sequenced a 740-bp region of the MMP-9 promoter from 18 unrelated aneurysm cases and 18 control individuals. The only DNA sequence variation in this region was found to be within the (CA)n sequence that was used for the genotyping experiment. A schematic of the MMP-9 promoter is given in Figure 1, with the CA repeat and key promoter features shown. We reasoned that such placement of a variable-length repetitive sequence between both proximal and distal regulatory elements that may bind a variety of transcription factors¹⁴ may have a subtle, yet significant effect on transcription efficiency. To test this hypothesis, we tested multiple alleles of the CA element for transcriptional activity.

View larger version (8K): [in this window] [in a new window]   Figure 1. MMP-9 promoter region of interest amplified by PCR. Putative binding sites for transcription factors AP-1, GATA-1, SP-1, and nuclear factor-ß (NF-ß) are shown, as is the variable length (CA)n repeat element.

Transfection Analysis of Constructs Bearing Different Length (CA) Elements
To determine whether the variable length of (CA)n repeat is able to modulate transcription of the CLG4B gene, a 736-bp region of the CLG4B promoter encompassing the CA repeat sequence was amplified by PCR from individuals homozygous for microsatellite length and cloned into the luciferase reporter pGL3Basic (Promega). Constructs were assayed for their ability to drive expression of the reporter in human fibroblasts (HT1080). To ensure transfection of equal amounts of each construct, plasmid concentration was determined by quantification of UV-stained linearized vector with the Stratagene Eagle Eye System and also by spectrophotometry. Luciferase values were normalized to ß-gal activity generated by cotransfection of a CMV-driven internal control plasmid (In Vitrogen). We found consistent differences over 5 independent sets of experiments (F_3,16=8.78; P=0.001; see Materials and Methods) between MMP-9 constructs bearing inserts with different length microsatellite repeats (Figure 2). Specifically, promoters containing 14, 21, and 22 CA repeats gave 0.59-, 0.36-, and 0.61-fold (respectively) the activity of the promoter containing 23 CA repeats, which consistently resulted in the highest luciferase activity. These specific length repeats were chosen because they are the 4 most common alleles found in normal white populations¹¹ (see Table). Although the (CA)n sequence is able to modulate transcriptional activity in this in vitro system, it is unclear whether this effect is due to a direct interaction between the transcriptional machinery and the CA repeat or is merely due to a conformational change in the 3D structure of the active promoter caused by variation in its length.

View larger version (18K): [in this window] [in a new window]   Figure 2. Luciferase activity of constructs containing variable-length (CA) elements. Luciferase units are displayed relative to values obtained for the (CA)23 construct. Data are means of values obtained from 5 independent sets of experiments (P=0.001; see Materials and Methods).

Electrophoretic Mobility Shift Assays
To further investigate whether the CA repeat has direct involvement in modulating transcriptional activity, we investigated site-specific DNA binding activity in HT1080 cells and BAECs using a 90-bp DNA sequence encompassing the CA repeat (see Figure 1). As a control probe, we used a sequence of identical length in which the (CA) element was replaced by a "benign" sequence derived from the pGL3Basic polylinker, which has no ability to drive luciferase expression in HT1080 cells (not shown). Sequence-specific DNA binding involving the CA repeat sequence (complex E and possibly complex B in Figure 3) was observed in both cell types. Complex E appears at the lowest concentration of protein and is eliminated (or reduced) at higher concentrations, whereupon complex B seems to become more prominent. This suggests a concentration-dependent cooperative binding effect. Other complexes (A, C, and D) appear to be shared between probes and may therefore involve the putative activator protein-1 (AP-1) binding site immediately downstream of the (CA) element (Figure 1).

View larger version (32K): [in this window] [in a new window]   Figure 3. Electrophoretic mobility shift assays showing binding of high (5 µg), medium (3 µg), and low (1 µg) (H, M, and L, respectively) of HT1080 (a) and BAEC (b) nuclear proteins to probes containing either the (CA)23 element or a control sequence of the same length (CA Replace). (CA)23 element-specific binding is represented by complexes E and B. AP-1-specific binding is represented by complexes A, C, and D.

The probe sequences used in the above experiment encompass the adjacent downstream putative AP-1 binding site.¹⁵ To confirm that the observed sequence-specific DNA-binding activity was not simply due to the AP-1 site, we performed the assays using probes lacking the AP-1 site. This approach did not result in any loss of complex E, which indicates that it does not involve AP-1 (data not shown).

	Discussion

Top Abstract Introduction Materials and Methods Results Discussion References

 
We report that variation within the regulatory region of the MMP-9 gene may be associated with ICA. A microsatellite marker used for typing MMP-9 variation in our sample and control populations was found to be the only polymorphic site within a 736-bp region upstream of the MMP-9 coding sequence. Differences in the length of this repeat sequence vary in the human population between 13 and 23 repeats. The (CA)₂₃ repeat was nonrandomly associated with the occurrence of aneurysm in our case-control study. The repetitive element is situated in the MMP-9 promoter in a region previously shown to be essential for transactivation.¹⁵ Not only did variation in (CA)n element length modulate transcriptional activity in vitro, but the highest activity was seen with reporter constructs containing the (CA)₂₃ allele associated with ICA. Furthermore, we found that the effect of this repetitive element in MMP-9 transcriptional regulation may be mediated directly by a sequence-specific DNA binding protein. Electrophoretic mobility shift assay probes containing the (CA) element and adjacent downstream putative AP-1 site were bound by a sequence-specific factor, as were probes lacking the AP-1 element. Such interactions were not seen when identical probes were used in which the (CA) element was replaced by a benign sequence of equal length and therefore represented CA-specific DNA binding factors. These interactions do not depend on the presence of the AP-1 site. These data suggest that (CA) element length has a subtle, yet significant effect on MMP-9 promoter activity. This effect may be due in part to variation in the spacing between the proximal and distal regulatory elements and may be mediated by a (CA) element sequence-specific DNA-binding protein.

There has been limited and inconclusive experimentation to identify an underlying biochemical imbalance that may be significant in ICA development. This effort has largely focused on factors that are either constituents of the extracellular matrix or are involved in its homeostasis. Such interest is not surprising given that ICAs are the result of an acute lesion at sites subject to considerable hemodynamic insult, which implies fundamental weakness due to structural defects or dysregulation of normal turnover in the arterial wall. A number of epidemiological risk factors are consistent with such a pathogenic model. For example, the increased risk of ICA conferred by cigarette smoking^{16 17} may be related to inactivation of -1-antitrypsin,¹⁸ a major circulating inhibitor of serine proteases, including elastase. This is supported by the finding that increased risk of ICA is associated with genetically determined -1-antitrypsin deficiency.^{19 20 21} Imbalances in levels of proteases and antiproteases may lead to increased proteolysis of connective tissue elements of the arterial wall. This could have catastrophic consequences within the circle of Willis, where local hemodynamic stresses could easily undermine the integrity of a weakened arterial wall. The involvement of dysregulated protease activity is suggested in a number of studies that have shown collagenase levels to be elevated in both the temporal arteries⁴ and serum⁵ of ICA patients.

Despite their high frequency in the human genome, the potential functional role of simple dinucleotide repeats remains largely unexplored, although a number of studies suggest that such motifs may have functional effects. For example, the TG element, which is estimated to be present at 10⁵ copies per genome, with lengths of between 20 and 60 bp, is able to form unusual DNA conformations, such as Z-DNA^{22 23 24} and other left-handed helical structures,²⁵ that may modulate transcriptional activity²⁶ and be involved homologous recombination.²⁷

Although the differences in length of the MMP-9 CA repeat alleles are small, there are a number of reasons why they may be significant. For example, we have shown that the (CA) element may serve as a binding site for a specific regulatory protein. This concept is not without precedence, because it has been suggested that the estrogen receptor may form interactions with sequences able to form Z-DNA–like structures,²⁸ and a GC-binding transcription factor may regulate SV-40 promoter activity in a model system.²⁹ Variation in the length of the repeat within the promoter element may have a dramatic effect on the dynamics of DNA-protein interactions and lead to altered MMP-9 expression. In addition, there is considerable evidence that transcriptional regulation involves a complex 3-dimensional interaction between transcription factors at numerous sites along the DNA. It is possible that small alterations in these structures may have a significant impact on gene expression. Of particular significance with respect to MMP-9 regulation is the discovery that the transcription factor AP-1 is able to interact with other components of the transcriptional machinery, including GATA-2.³⁰ It is intriguing that the CA repeat found in the MMP-9 promoter sits between putative binding sites for these factors and an adjacent AP-1 site (Figure 1). The fact that simple dinucleotide repeats can form unusual Z-DNA–like conformations supports these notions. Subtle alterations in conformations of protein-protein interactions may thus modulate transcriptional activity and moderate levels of MMP-9 mRNA.

Although the association between trinucleotide repeat length and human disease is well characterized,^{31 32} this is the first reported example of which we are aware of the modulation of promoter function by a dinucleotide repeat within the context of normal human variation. Because microsatellite sequences are commonly found in human gene promoters, their ability to modulate transcription may be significant with respect to the susceptibility to and pathogenesis of a number of complex multigenic diseases. The relatively low frequency of the (CA)₂₃ allele in the general population means that this variation may represent only one of multiple genetic and environmental factors that contribute to the risk of ICA. These findings now require confirmation in other ICA populations.

	Acknowledgments

 
This work was supported in part by NIH grant No. HL44682.

Received April 22, 1999; revision received September 24, 1999; accepted September 24, 1999.

	References

Top Abstract Introduction Materials and Methods Results Discussion References

 
1. Vu TH, Shipley JM, Bergers G, Berger JE, Helms JA, Hanahan D, Shaprio SD, Senior RM, Werb Z. MMP-9/gelatinase B is a key regulator of growth plate angiogenesis and apoptosis of hypertropic chondrocytes. Cell. 1998;93:411–422.[Medline] [Order article via Infotrieve]

2. Thompson RW, Holmes DR, Mertens RA, Liao S, Botney MD, Mecham RP, Welgus HG, Parks WC. Production and localization of 92-kilodalton gelatinase in abdominal aortic aneurysms. J Clin Invest. 1995;96:318–326.

3. Tamarina NA, McMillan WD, Shilvey VP, Pearce WH. Expression of matrix metalloproteinases and their inhibitors in aneurysms and normal aorta. Surgery. 1997;122:264–271.[Medline] [Order article via Infotrieve]

4. Kim SC, Singh M, Huang J, Prestigiacomo CJ, Winfree CJ, Solomon RA, Connolly ES. Matrix metalloproteinase-9 in cerebral aneurysms. Neurosurgery. 1997;41:642–646.[Medline] [Order article via Infotrieve]

5. Chyatte D, Lewis I. Gelatinase activity in the occurrence of cerebral aneurysms. Stroke. 1997;28:799–804.[Abstract/Free Full Text]

6. Birkedal-Hansen H, Moore WG, Bodden MK, Windsor LJ, Birkedal-Hansen B, DeCarlo A, Engler JA. Matrix metalloproteinases: a review. Crit Rev Oral Biol Med. 1993;4:197–250.[Abstract/Free Full Text]

7. Fabunmi RP, Baker AH, Murray EJ, Booth RF, Newby AC. Divergent regulation by growth factors and cytokines of 95 kDa and 72 kDa gelatinases and tissue inhibitors of metalloproteinases-1, -2 and -3 in rabbit aortic smooth muscle cells. Biochem J. 1996;315:335–342.

8. Kondapaka SB, Fridman R, Reddy KB. Epidermal growth factor and amphiregulin upregulate matrix metalloproteinase 9 (MMP-9) in human breast cancer cells. Int J Cancer. 1997;70:722–726.[Medline] [Order article via Infotrieve]

9. Shievink WI. Genetics of intracranial aneurysms. Neurosurgery. 1997;40:651–663.[Medline] [Order article via Infotrieve]

10. Shievink WI. Genetics and aneurysm formation. Neurosurg Clin N Am. 1998;9:485–495.[Medline] [Order article via Infotrieve]

11. St. Jean PL, Zhang XC, Hart BK, Lamlum H, Webster MW, Steed DL, Henney AM, Ferrell RE. Characterization of a dinucleotide repeat in the 92 kDa type IV collagenase gene, localization of CLG4B to chromosome 20 and the role of CLG4B in aortic aneurysmal disease. Ann Hum Genet. 1995;59:17–24.[Medline] [Order article via Infotrieve]

12. Hagenbüchle, O, Wellauer PK. A rapid method for the isolation of DNA-binding proteins from purified nuclei of tissues and cells in culture. Nucleic Acids Res. 1992;20:3555–3559.[Abstract/Free Full Text]

13. Miller SA, Dykes DD, Polesky HF. A simple salting-out procedure for extracting DNA from human nucleated cells. Nucleic Acids Res. 1988;16:1215.[Free Full Text]

14. Huhtala P, Tuuttila A, Chow LT, Lohi J, Keski-Oja K, Tryggvason K. Complete structure of the human gene for 92 kDA type IV collagenase: divergent regulation of expression for the 92- and 72-kilodalton enzyme genes in HT-1080 cells. J Biol Chem. 1991;266:16485–16490.[Abstract/Free Full Text]

15. Sato H, Kita M, Seiki M. v-Src activates the expression of 92-kDa type IV collagenase gene through the AP-1 site and the GT box homologous to retinoblastoma control elements: a mechanism regulating gene expression independent of that by inflammatory cytokines. J Biol Chem. 1993;268:23460–23468.[Abstract/Free Full Text]

16. Bonita R. Cigarette smoking, hypertension and the risk of subarachnoid hemorrhage: a population-based case-control study. Stroke. 1986;17:831–835.[Abstract/Free Full Text]

17. Juvela S, Hillbom M, Numminen H, Koskinen P. Cigarette smoking and alcohol consumption as risk factors for aneurysmal subarachnoid hemorrhage. Stroke. 1993;24:639–646.[Abstract/Free Full Text]

18. Gaetani P, Tartara F, Tancioni F, Klersy C, Forlino A, Buena RR. Activity of -1-antitrypsin and cigarette smoking in subarachnoid haemorrhage from ruptured aneurysm. J Neurol Sci. 1996;141:33–38.[Medline] [Order article via Infotrieve]

19. Schievink WI, Prakash UBS, Piepgras DG, Makri B. -1-Antitrypsin deficiency in intracranial aneurysms and cervical artery dissection. Lancet. 1994;343:452–453.[Medline] [Order article via Infotrieve]

20. Schievink WI, Katzmann JA, Piepgras DG, Schaid DJ. Alpha-1-antitrypsin phenotypes among patients with intracranial aneurysms. J Neurosurg. 1996;84:781–784.[Medline] [Order article via Infotrieve]

21. St. Jean PL, Hart B, Webster M, Steed D, Adamson J, Powell J, Ferrell R. Alpha-1-antitrypsin deficiency in aneurysmal disease. Hum Hered. 1996;46:92–97.[Medline] [Order article via Infotrieve]

22. Hamada H, Kakunage T. Potential Z-DNA forming sequences are highly dispersed in the human genome. Nature. 1982;298:396–398.[Medline] [Order article via Infotrieve]

23. Haniford DB, Pulleyblank DE. Facile transition of poly[d(TG) x d(CA)] into a left-handed helix in physiological conditions. Nature. 1983;302:632–634.[Medline] [Order article via Infotrieve]

24. Nordheim A, Rich A. The sequence (dC-dA)n x (dG-dT)n forms left-handed Z-DNA in negatively supercoiled plasmids. Proc Natl Acad Sci U S A. 1983;80:1821–1825.[Abstract/Free Full Text]

25. Kladde MP, Kohwi Y, Kowhi-Shigematsu T, Gorski J. The non-B-DNA structure of d(CA/TG)n differs from that of Z-DNA. Proc Natl Acad Sci U S A. 1994;91:1898–1902.[Abstract/Free Full Text]

26. Hamada H, Seidman M, Howard B, Gorman CM. Enhanced gene expression by the poly(dT-dG) poly(dC-dA) sequence. Mol Cell Biol. 1984;4:2622–2630.[Abstract/Free Full Text]

27. Weinreb A, Katzenberg DR, Gilmore GL, Birshtein BK. Site of unequal sister chromatid exchange contains a potential Z-DNA-forming tract. Proc Natl Acad Sci U S A. 1988;85:529–533.[Abstract/Free Full Text]

28. Thomas T, Thomas TJ. Structural specificity of polyamines in modulating the binding of the estrogen receptor to potential z-DNA forming sequences. J Recept Res. 1993;13:1115–1133.[Medline] [Order article via Infotrieve]

29. Amirhaeri S, Wohlrab F, Wells RD. Differential effects of simple repeating DNA sequences on gene expression from the SV40 early promoter. J Biol Chem. 1995;270:3313–3319.[Abstract/Free Full Text]

30. Kawana M, Lee ME, Quertermous EE, Quertermous T. Cooperative interaction of GATA-2 and AP1 regulates transcription of the endothelin-1 gene. Mol Cell Biol. 1995;15:4225–4231.[Abstract]

31. Coles R, Leggo J, Rubinsztein DC. Analysis of the 5' upstream sequence of the Huntington’s disease (HD) gene shows six new rare alleles which are unrelated to the age at onset of HD. J Med Genet. 1997;34:371–374.[Abstract/Free Full Text]

32. Sandberg G, Schalling M. Effect of in vitro promoter methylation and CGG repeat expansion on FMR-1 expression. Nucleic Acids Res. 1997;25:2883–2887.[Abstract/Free Full Text]

This article has been cited by other articles:

				T. Aoki, H. Kataoka, T. Moriwaki, K. Nozaki, and N. Hashimoto Role of TIMP-1 and TIMP-2 in the Progression of Cerebral Aneurysms Stroke, August 1, 2007; 38(8): 2337 - 2345. [Abstract] [Full Text] [PDF]

				W.I. Mangrum, F. Farassati, R. Kadirvel, C.P. Kolbert, S. Raghavakaimal, D. Dai, Y.H. Ding, D. Grill, V.G. Khurana, and D.F. Kallmes mRNA Expression in Rabbit Experimental Aneurysms: A Study Using Gene Chip Microarrays AJNR Am. J. Neuroradiol., May 1, 2007; 28(5): 864 - 869. [Abstract] [Full Text] [PDF]

				A. K. Kader, J. Liu, L. Shao, C. P. Dinney, J. Lin, Y. Wang, J. Gu, H. B. Grossman, and X. Wu Matrix Metalloproteinase Polymorphisms Are Associated with Bladder Cancer Invasiveness Clin. Cancer Res., May 1, 2007; 13(9): 2614 - 2620. [Abstract] [Full Text] [PDF]

				A. K. Kader, L. Shao, C. P. Dinney, M. B. Schabath, Y. Wang, J. Liu, J. Gu, H. B. Grossman, and X. Wu Matrix Metalloproteinase Polymorphisms and Bladder Cancer Risk Cancer Res., December 15, 2006; 66(24): 11644 - 11648. [Abstract] [Full Text] [PDF]

				M. Sugimoto, S. Yoshida, S. Kennedy, M. Deguchi, N. Ohara, and T. Maruo Matrix Metalloproteinase-1 and -9 Promoter Polymorphisms and Endometrial Carcinoma Risk in a Japanese Population Reproductive Sciences, October 1, 2006; 13(7): 523 - 529. [Abstract] [PDF]

				H Senzaki The pathophysiology of coronary artery aneurysms in Kawasaki disease: role of matrix metalloproteinases Arch. Dis. Child., October 1, 2006; 91(10): 847 - 851. [Abstract] [Full Text] [PDF]

				H. Akagawa, A. Tajima, Y. Sakamoto, B. Krischek, T. Yoneyama, H. Kasuya, H. Onda, T. Hori, M. Kubota, T. Machida, et al. A haplotype spanning two genes, ELN and LIMK1, decreases their transcripts and confers susceptibility to intracranial aneurysms Hum. Mol. Genet., May 15, 2006; 15(10): 1722 - 1734. [Abstract] [Full Text] [PDF]

				S. Ye Influence of matrix metalloproteinase genotype on cardiovascular disease susceptibility and outcome Cardiovasc Res, February 15, 2006; 69(3): 636 - 645. [Abstract] [Full Text] [PDF]

				S. Wagner, B. Kluge, J. A. Koziol, A. J. Grau, and C. Grond-Ginsbach MMP-9 Polymorphisms Are Not Associated With Spontaneous Cervical Artery Dissection Stroke, March 1, 2004; 35 (3): e62 - e64. [Abstract] [Full Text] [PDF]

				D. Krex, H. Rohl, I. R. Konig, A. Ziegler, H. K. Schackert, and G. Schackert Tissue Inhibitor of Metalloproteinases-1, -2, and -3 Polymorphisms in a White Population With Intracranial Aneurysms Stroke, December 1, 2003; 34(12): 2817 - 2821. [Abstract] [Full Text] [PDF]

				V. G. Khurana, Y. R. Sohni, W. I. Mangrum, R. L. McClelland, D. J. O'Kane, F. B. Meyer, and I. Meissner Endothelial Nitric Oxide Synthase T-786C Single Nucleotide Polymorphism: A Putative Genetic Marker Differentiating Small Versus Large Ruptured Intracranial Aneurysms Stroke, November 1, 2003; 34(11): 2555 - 2559. [Abstract] [Full Text] [PDF]

				A. Hofer, M. Hermans, N. Kubassek, M. Sitzer, H. Funke, F. Stogbauer, V. Ivaskevicius, J. Oldenburg, J. Burtscher, U. Knopp, et al. Elastin Polymorphism Haplotype and Intracranial Aneurysms Are Not Associated in Central Europe Stroke, May 1, 2003; 34(5): 1207 - 1211. [Abstract] [Full Text] [PDF]

				S. Yamada, M. Utsunomiya, K. Inoue, K. Nozaki, S. Miyamoto, N. Hashimoto, K. Takenaka, T. Yoshinaga, and A. Koizumi Absence of Linkage of Familial Intracranial Aneurysms to 7q11 in Highly Aggregated Japanese Families Stroke, April 1, 2003; 34(4): 892 - 900. [Abstract] [Full Text] [PDF]

				S. Blankenberg, H. J. Rupprecht, O. Poirier, C. Bickel, M. Smieja, G. Hafner, J. Meyer, F. Cambien, L. Tiret, and for the AtheroGene Investigators Plasma Concentrations and Genetic Variation of Matrix Metalloproteinase 9 and Prognosis of Patients With Cardiovascular Disease Circulation, April 1, 2003; 107(12): 1579 - 1585. [Abstract] [Full Text] [PDF]

				P. K. Chua, M. E. Melish, Q. Yu, R. Yanagihara, K. S. Yamamoto, and V. R. Nerurkar Elevated Levels of Matrix Metalloproteinase 9 and Tissue Inhibitor of Metalloproteinase 1 during the Acute Phase of Kawasaki Disease Clin. Vaccine Immunol., March 1, 2003; 10(2): 308 - 314. [Abstract] [Full Text] [PDF]

				O. CHIBA-FALEK and R.L. NUSSBAUM Regulation of {alpha}-Synuclein Expression: Implications for Parkinson's Disease Cold Spring Harb Symp Quant Biol, January 1, 2003; 68(0): 409 - 416. [Abstract] [PDF]

				A. Fornoni, Y. Wang, O. Lenz, L. J. Striker, and G. E. Striker Association of a Decreased Number of d(CA) Repeats in the Matrix Metalloproteinase-9 Promoter with Glomerulosclerosis Susceptibility in Mice J. Am. Soc. Nephrol., August 1, 2002; 13(8): 2068 - 2076. [Abstract] [Full Text] [PDF]

				N. Lamblin, C. Bauters, X. Hermant, J.-M. Lablanche, N. Helbecque, and P. Amouyel Polymorphisms in the promoter regions of MMP-2, MMP-3, MMP-9 and MMP-12 genes as determinants of aneurysmal coronary artery disease J. Am. Coll. Cardiol., July 3, 2002; 40(1): 43 - 48. [Abstract] [Full Text] [PDF]

				I. Loftus and M. Thompson The role of matrix metalloproteinases in vascular disease Vascular Medicine, May 1, 2002; 7(2): 117 - 133. [Abstract] [PDF]

				P. E. Ferrand, S. Parry, M. Sammel, G. A. Macones, H. Kuivaniemi, R. Romero, and J. F. Strauss III A polymorphism in the matrix metalloproteinase-9 promoter is associated with increased risk of preterm premature rupture of membranes in African Americans Mol. Hum. Reprod., May 1, 2002; 8(5): 494 - 501. [Abstract] [Full Text] [PDF]

				L. Joos, J.-Q. He, M. B. Shepherdson, J. E. Connett, N. R. Anthonisen, P. D. Pare, and A. J. Sandford The role of matrix metalloproteinase polymorphisms in the rate of decline in lung function Hum. Mol. Genet., March 1, 2002; 11(5): 569 - 576. [Abstract] [Full Text] [PDF]

				O. Chiba-Falek and R. L. Nussbaum Effect of allelic variation at the NACP-Rep1 repeat upstream of the {alpha}-synuclein gene (SNCA) on transcription in a cell culture luciferase reporter system Hum. Mol. Genet., December 1, 2001; 10(26): 3101 - 3109. [Abstract] [Full Text] [PDF]

				V. Obach, M. Revilla, N. Vila, A. Cervera, and A. Chamorro {alpha}1-Antichymotrypsin Polymorphism: A Risk Factor for Hemorrhagic Stroke in Normotensive Subjects Stroke, November 1, 2001; 32(11): 2588 - 2591. [Abstract] [Full Text] [PDF]

				B. Zhang, S. Dhillon, I. Geary, W. M. Howell, F. Iannotti, I. N.M. Day, and S. Ye Polymorphisms in Matrix Metalloproteinase-1, -3, -9, and -12 Genes in Relation to Subarachnoid Hemorrhage Stroke, September 1, 2001; 32(9): 2198 - 2202. [Abstract] [Full Text] [PDF]

				N. H. Fujiwara, H. J. Cloft, W. F. Marx, J. G. Short, M. E. Jensen, and D. F. Kallmes Serial Angiography in an Elastase-induced Aneurysm Model in Rabbits: Evidence for Progressive Aneurysm Enlargement after Creation AJNR Am. J. Neuroradiol., April 1, 2001; 22(4): 698 - 703. [Abstract] [Full Text]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Peters, D. G. Articles by Ferrell, R. E. Search for Related Content PubMed PubMed Citation Articles by Peters, D. G. Articles by Ferrell, R. E. Related Collections Cerebral Aneurysm, AVM, & Subarachnoid hemorrhage Genetics of Stroke Risk Factors for Stroke