You are here

Article Text

Article menu

Download PDFPDF

Research paper
Plasma matrix metalloproteinases, cytokines and angiogenic factors in moyamoya disease
  1. Hyun-Seung Kang1,
  2. Jin Hyun Kim2,
  3. Ji Hoon Phi1,3,
  4. Young-Yim Kim1,
  5. Jeong Eun Kim1,
  6. Kyu-Chang Wang1,3,
  7. Byung-Kyu Cho1,3,
  8. Seung-Ki Kim1,3
  1. 1Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Korea
  2. 2Clinical Research Institute, Gyeongsang National University Hospital, Jinju, Gyeongnam, Korea
  3. 3Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, Korea
  1. Correspondence to Dr Seung-Ki Kim, Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, 101 Daehangno, Jongno-gu, Seoul, 110-744, Korea; nsthomas{at}snu.ac.kr

Abstract

Objective To document the expression patterns of various matrixins, cytokines and angiogenic factors in plasma to assess their involvement in the pathogenesis of moyamoya disease (MMD).

Methods This study included plasma samples from 20 MMD patients and nine healthy individuals. The plasma concentration of five matrix metalloproteinases (MMP-1, MMP-2, MMP-3, MMP-9, MMP-12), monocyte chemoattractant protein-1 (MCP-1), resistin, three interleukins (IL-1β, IL-6, IL-8), tumour necrosis factor-α, vascular endothelial growth factor (VEGF), platelet-derived growth factor BB (PDGF-BB) and basic fibroblast growth factor was determined using multianalyte profiling systems. The concentration of the tissue inhibitors of metalloproteinase (TIMP-1 and TIMP-2) was measured using ELISA. Gelatin zymography for MMP-2 and MMP-9 was also performed.

Results MMD patients exhibited significantly higher plasma concentrations of MMP-9, MCP-1, IL-1β, VEGF and PDGF-BB, and lower plasma concentrations of MMP-3, TIMP-1 and TIMP-2 compared with healthy controls. Significant correlations were found among MMP-9, MCP-1, VEGF, PDGF-BB and TIMP-2 in MMD patients.

Conclusion There were distinctive expression patterns of matrixins, cytokines and angiogenic factors in MMD patients, which seemed to correlate with disease pathogenesis. The balance between MMPs and TIMPs was disrupted in MMD and correlated with disease pathogenesis. Increased plasma levels of MCP-1 and VEGF in MMD patients may play a role in the recruitment of vascular progenitor cells and in the formation of collateral vessels.

  • Angiogenic factors
  • moyamoya disease
  • paediatric neurosurgery
  • stroke

https://doi.org/10.1136/jnnp.2009.191817

Statistics from Altmetric.com

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

    Introduction

    Moyamoya disease (MMD) is a disease characterised by idiopathic, chronic stenoocclusive changes in the intracranial arteries, and is a common cause of ischaemic and haemorrhagic stroke among East Asian people.1 The disease is also associated with rich collateral networks at the base of the brain (moyamoya vessels). The principal pathological changes in the major cerebral arteries in MMD patients are stenosis or occlusion associated with fibrocellular thickening of the intima, an irregular undulation of the internal elastic laminae and attenuation of the media.2–4 These features suggest that systemic factors related to pathophysiological alterations of endothelial and smooth muscle cells may be important for disease pathogenesis. A genetic study of familial MMD investigated the balance between matrix metalloproteinases (matrixins, MMPs) and their natural inhibitors (tissue inhibitors of metalloproteinase; TIMPs) and found that the presence of the G/C heterozygous genotype at position −418 bp of the TIMP2 promoter may be a genetic predisposing factor for familial MMD.5 The purpose of the present study was to document the expression patterns of various matrixins, cytokines and growth factors in plasma to assess their involvement in the pathogenesis of MMD.

    Methods

    Subjects and sample preparation

    This study included plasma samples from 20 consecutive patients diagnosed as having MMD (10 males and 10 females; 11.8±10.5 years of age) and nine healthy individuals (four males and five females; 23.6±0.9 years of age). We obtained approval from the institutional review board (#0705-020-208) and informed consent from the patients and/or the closest relatives. All patients underwent conventional angiography to confirm the diagnosis of MMD. Most of them presented with transient ischaemic attacks (with the exception of a case of intraventricular haemorrhage), and none of them showed acute cerebral infarction. Control subjects had no history of stroke, hypertension or smoking.

    Blood samples (40 ml) were collected in heparinised syringes and processed within 1 h after collection. Plasma was isolated using density gradient centrifugation over Ficoll-1077 (Sigma, St Louis, Missouri) for 25 min at 2300 rpm and stored at −20°C until assayed.

    Biomarker analyses

    The plasma concentration of MMP-1, MMP-2, MMP-3, MMP-9, MMP-12, monocyte chemoattractant protein-1 (MCP-1) and resistin were quantified using a commercially available multiplex beads immunoassay, that is, fluorokine multianalyte profiling (Multiplex Human MMP and obesity panels; R&D Systems, Minneapolis, Minnesota), as previously described.6 Briefly, 50 μl of each plasma sample were incubated with fluorokine-coloured microspheres coated with specific antibodies, and analytes were allowed to bind to the specific antibody-coated microspheres. Samples were then washed and incubated with biotinylated antibodies and phycoerythrin-conjugated streptavidin. Finally, fluorescence was detected using a flow cytometry technique (Luminex 100, Luminex Corporation, Austin, Texas). The total amount of MMPs, including pro-, mature, and TIMP-1 complexed MMPs, was measured with this system. The plasma concentration of interleukins (IL)-1β, IL-6, IL-8, tumour necrosis factor (TNF)-α, vascular endothelial growth factor (VEGF), platelet-derived growth factor BB (PDGF-BB) and basic fibroblast growth factor (bFGF) was determined using the Bio-Plex assay system (Bio-Rad Laboratories, Hercules, California), as previously described.7 The concentration of TIMP-1 and TIMP-2 was measured by ELISA using commercially available kits (R&D Systems).

    Gelatin zymography

    To assess the expression of MMP-2 and MMP-9 in the plasma of MMD patients and controls, we performed gelatin zymography using the Bradford Reagent (Bio-Rad Protein Assay, Bio-Rad Laboratories). Each plasma sample (20 μl) was mixed with 2× sodium dodecyl sulfate sample buffer without prior heating or reduction. The samples were then run on 10% sodium dodecyl sulfate–polyacrylamide gel electrophoresis containing 0.1% gelatin. Electrophoresis was carried out at a constant voltage of 120 V. After electrophoresis, gels were soaked first in 2.5% Triton X-100 and then in developing buffer for 20 min. They were then incubated in developing buffer (500 mM Tris–HCl, 200 mM NaCl, 100 mM CaCl2, 100 μM ZnCl2 pH 7.4) at 37°C for 20 h. Gels were stained with 0.5% Coomassie Blue in 10% methanol and 10% acetic acid, and were then destained in the same solution without Coomassie Blue. The level of expression of the bands corresponding to 72 kDa and 92 kDa gelatinases was evaluated using the Digital Imaging system (My Imager SL-6, SeouLin Bioscience, Seoul, Korea). Relative optical density (OD) was calculated using the following formula: OD (relative)=OD (observed)/mean OD of controls.

    Measurement of active MMP-9

    We also measured active MMP-9 level in eight MMD patients and eight controls with a sandwich ELISA kit (RPN 2634; Amersham Biosciences, Piscataway, New Jersey) following the manufacturer's instructions. By excluding p-aminophenylmercuric acetate, we could measure the endogenous free active MMP-9 fraction.

    Statistical analyses

    The Mann–Whitney U test and the unpaired t test were performed using software available commercially (GraphPad Instat version 3.05, 32 bit for Windows 95/NT; GraphPad Software, San Diego, California). A Spearman correlation analysis was performed using the Statistical Package for the Social Sciences (SPSS; version 12.0 for PC; SPSS, Chicago, Illinois). Significance was set at p<0.05.

    Results

    Plasma assay

    Plasma assay results are summarised in table 1. Among the MMPs, the plasma level of MMP-9 was significantly elevated (control vs MMD, 3.53±1.34 ng/ml vs 115.53±23.43 ng/ml; p=0.0002), while the plasma level of MMP-3 was decreased (13.59±1.78 ng/ml vs 1.76±0.38 ng/ml; p<0.0001) in MMD patients compared with controls (figure 1). There were no significant differences in the levels of MMP-1 and MMP-2 between the two groups. Plasma levels of TIMP-1 and TIMP-2 were also decreased significantly in MMD patients. The levels of MMP-12 seemed to be elevated in MMD patients. The levels of MCP-1 and IL-1β were significantly elevated in MMD patients (p<0.0001 and p=0.0315, respectively), while IL-6 and TNFα levels showed no difference between the two groups. The levels of IL-8 seemed to be elevated in MMD patients. Plasma resistin levels were not different between MMD patients and the control group. The plasma levels of VEGF and PDGF-BB were elevated significantly in MMD patients (p=0.0018 and p=0.0123, respectively). The plasma levels of bFGF were below the measurement range in both groups.

    View this table:
    Table 1

    Plasma cytokine assays in moyamoya disease patients and controls

    Figure 1
    Figure 1

    Comparison of plasma levels of matrix metalloproteinase (MMP) 9 (A), MMP-3 (B), tissue inhibitors of metalloproteinase (TIMP) 1 (C), TIMP-2 (D), monocyte chemoattractant protein (MCP) 1 (E), interleukin (IL) 1β (F), vascular endothelial growth factor (VEGF) (G) and platelet-derived growth factor BB (PDGF-BB) (H). MMD, moyamoya disease.

    A correlation analysis revealed the presence of significant inter-relationships among MMP-9, MCP-1, VEGF and PDGF-BB in MMD patients (table 2). TIMP-2 exhibited a significant negative correlation with these factors.

    View this table:
    Table 2

    Significant Spearman correlations among the plasma cytokines in moyamoya disease

    Gelatin zymography and ELISA

    Distinct bands were observed at the molecular weights of 72 kDa (for MMP-2) and 92 kDa (for MMP-9). A significantly higher OD was observed for MMP-9 in MMD patients compared with controls. The mean relative OD (95% CI) in the patients was 3.83 (range 3.061 to 4.594) for MMP-9 (p<0.0001) and 1.35 (range 0.9776 to 1.713) for MMP-2 (p=0.0558). ELISA showed that there was no significant difference in active MMP-9 levels between the two groups (control vs MMD, 7.86±1.31 ng/ml vs 5.77±0.45 ng/ml; p=0.3282).

    Discussion

    To our knowledge, this is the most extensive study on plasma concentration of a variety of relevant matrixins, cytokines and angiogenic factors in patients with MMD. The principal vascular pathological features of MMD (arterial occlusive lesions and rich but fragile collateral networks) may be explained by the patterns of expression of the various factors. Increased MMP-9, decreased TIMP-1 and TIMP-2, increased IL-1β, and increased PDGF-BB may be related to smooth muscle cell mobilisation, migration and proliferation, which contribute to development of the arterial occlusive lesions. On the other hand, increased VEGF and MCP-1 may play an important role in inducing the extensive collateral network. Increased MMP-9 in combination with VEGF might help to facilitate a spontaneous haemorrhagic event by rupture of the fragile collateral vessels as well as the hyperperfusion syndrome after revascularisation surgery by increasing vascular permeability.8 9 The role of each factor in the pathogenesis of MMD is discussed below in detail.

    Among the MMPs, the expression of MMP-9 was increased (more than 30-fold; p=0.0002), while MMP-3 was significantly decreased in MMD patients (p<0.0001). Gelatin zymography also showed a significantly higher production of MMP-9 (p<0.0001). Fujimura et al reported on the increased expression of MMP-9 in the serum of MMD patients.10 Matrixins contribute to both pro- and antiangiogenic processes.11 MMP-9 is also known as gelatinase B, and its substrates include gelatins (denatured collagens), native type IV, V and XI collagens, laminin and the aggrecan core protein.12 MMP-9 knockout mice exhibit significantly reduced carotid artery intimal hyperplasia,13 and thus, upregulation of MMP-9 may contribute to the exaggerated intimal hyperplasia observed in MMD pathology. MMP-9 also hydrolyses plasminogen to form angiostatin, which is a strong inhibitor of angiogenesis,14 and stable overexpression of MMP-9 results in increased angiostatin levels and decreased angiogenesis in a mouse model of colon cancer.15 Other angiogenesis inhibitors such as endostatin and tumstatin can be generated from the C-terminal domain of collagen chains via the action of MMP-9.16 17 Endostatin inhibits VEGF- and bFGF-induced endothelial cell migration and induces apoptosis; tumstatin inhibits endothelial cell proliferation and promotes apoptosis.18 On the other hand, increased MMP-9 may contribute to the extensive collateral vessel formation (eg, moyamoya vessels), as angiogenesis requires degradation of the vascular basement membrane and remodelling of the extracellular matrix. A ‘vascular injury repair model’ has been suggested as a putative pathogenetic mechanism for MMD.5 According to this model, an imbalance between MMPs and their natural inhibitors, TIMPs, would result in intimal thickening because of excessive smooth muscle cell migration and proliferation. The finding of increased plasma levels MMP-9 in MMD patients constitutes additional supportive evidence of the model. Interestingly, we found that the active MMP-9 levels in MMD patients were no different from those of controls. Thus, in MMD patients, the higher expression of proMMP-9 seems to play a role in a specific local environment which is capable of activating the proenzyme (such as the terminus of the internal carotid artery and sites of collateral vessel development), and a systemic effect can be avoided by maintaining adequate the plasma level of active MMP-9.

    We also demonstrated that the levels of TIMP-1 and TIMP-2 were significantly decreased in MMD patients (p=0.0180 and p=0.0460, respectively). These results, together with the finding of elevated MMP-9 levels in MMD patients, also support the hypothesis of an MMP/TIMP imbalance as a pathogenic mechanism of MMD.

    MMP-3 (stromelysin-1) has a broad substrate specificity (its substrates include the proteoglycan core protein, fibronectin, laminin, collagens IV, V, XI and X, and elastin) and plays a central role in the activation of other pro-MMPs. Overexpression of MMP-3 leads to inhibition of smooth muscle cell migration and neointima formation in a rabbit vein graft model.19 The extrapolation of this result to our study implies that decreased MMP-3 levels may result in the facilitation of the smooth muscle cell migration and intimal hyperplasia found in MMD.

    MMP-12, which is one of the macrophage elastases, seemed to be elevated among MMD patients. MMP-12 is expressed in human vascular smooth muscle cells.14 MMP-12 degrades elastin, which is abundant in the arterial wall, and a number of other extracellular matrix molecules, and is essential for macrophage migration.12 In the presence of granulocyte macrophage colony stimulating factor, treatment with IL-1β or MCP-1 results in an increase in MMP-12 expression in human peripheral blood monocytes and monocyte-derived macrophages.20 Both IL-1β and MCP-1 were significantly elevated in MMD patients in our study. Thus, increased levels of IL-1β and MCP-1 may facilitate smooth muscle cell migration via MMP-12 expression in MMD.

    Among the cytokines tested, the plasma levels of MCP-1 were significantly elevated in MMD patients (15-fold; p<0.0001). MCP-1 is a pivotal proarteriogenic molecule that plays a major role in collateral artery growth.21–25 MCP-1 enhances the migration of bone marrow stromal cells in a rat ischaemic brain model.22 We believe that the upregulation of MCP-1 may be a hallmark of MMD, and that it may contribute to the formation of collateral vessels, including moyamoya vessels.

    The levels of IL-1β were elevated in MMD patients (p=0.0315). IL-1 is produced by endothelial cells, smooth muscle cells and macrophages, and its secretion is induced by microbial products that stimulate toll-like receptors via stimulation of the inflammasome and caspase-1.26 The presence of detectable levels of IL-1β among MMD patients implies that an inflammatory molecule may be involved in the disease process. Elevated levels of IL-1 result in activation of endothelial and smooth muscle cell proliferation, macrophage activation, increased vascular permeability and endothelial dysfunction, which could be related to the MMD disease process.27 A previous study showed that the release of prostaglandin E2 (which is a potent vasodilator) into the culture medium was significantly greater in moyamoya smooth muscle cells than in control smooth muscle cells after stimulation with IL-1β.28 Thus, we speculate that the upregulation of IL-1β may contribute to the increased release of prostaglandin E2, resulting in greater vasodilation and pial hyperaemia in MMD patients. IL-8 seemed to be elevated in these patients, while the levels of IL-6 and TNFα were not significantly different from those of controls. The recruitment of inflammatory cells into the intima is an important step in the development and progression of atherosclerosis, and various cytokines, including IL-6 and IL-8, are implicated in these processes.29–31 In contrast, systemic inflammatory responses do not seem to be essential in the pathogenesis of MMD.

    In our study, the levels of VEGF and PDGF-BB were significantly increased in MMD patients (p=0.0018 and p=0.0123, respectively). Rafat et al reported increased levels of VEGF in MMD patients (control vs MMD, 35.9±20.4 pg/ml vs 299.4±131.1 pg/ml; p<0.0001), which was inversely correlated with the number of circulating endothelial progenitor cells.32 In our study, VEGF levels were similar to those of the previous study (control vs MMD, 24.22±7.18 pg/ml vs 482.09±120.77 pg/ml). Previously, we noted that circulating endothelial progenitor cells were decreased in number as well as defective in function among MMD patients.33 For this reason, we hypothesise that increased plasma levels of VEGF may contribute to the formation of fragile collateral vessels in MMD patients, which occasionally results in intracranial bleeding.

    Smooth muscle cells from MMD patients exhibit different responses to PDGF compared with those of normal controls, and receptors for PDGF are downregulated in these cells.34–36 We found that plasma PDGF-BB levels were significantly increased in MMD patients (more than 18-fold). Increased levels of PDGF-BB may predispose vascular progenitor cells to differentiating into a smooth muscle cell lineage, which would produce the primary pathology of MMD (ie, intimal hyperplasia).

    It is notable that bFGF was not detected in the plasma of MMD patients in our study. Previous reports showed strong immunoreactivity of bFGF in endothelial and smooth muscle cells of the superficial temporal arteries, and elevation of the number of meningeal and vascular cells of dura mater and of bFGF levels in the cerebrospinal fluid of MMD patients.37 38 However, we failed to detect bFGF in the plasma of MMD patients, despite repeated measurements. This finding suggests that there is a discrepancy in the levels of bFGF between the plasma and the cerebrospinal fluid of MMD patients. The efficiency of bFGF transport through the blood–brain barrier is very low (<1% of doses infused intravenously).39 Capillary endothelial cells produce and release bFGF, which acts as a self-stimulating growth factor.40 We suppose that bFGF production and release in MMD patients are local rather than systemic phenomena.

    A correlation analysis showed that relevant factors, which included MMP-9, MCP-1, VEGF, PDGF-BB and TIMP-2, acted in a concerted fashion by recruiting vascular progenitor cells from the bone marrow, mobilising vascular smooth muscle cells and generating new vessels.

    Conclusions

    An extensive analysis of plasma matrixins, cytokines and angiogenic factors allowed us to demonstrate the presence of distinctive expression patterns of relevant factors in MMD patients, which seemed to be correlated with disease pathogenesis. The balance between MMPs and TIMPs was disrupted in MMD, which also seems to be correlated with disease pathogenesis. Increased plasma levels of MCP-1 and VEGF in MMD may play a role in the recruitment of vascular progenitor cells and in the formation of collateral vessels.

    References

    1. ↵
      1. Kuroda S,
      2. Houkin K
      . Moyamoya disease: current concepts and future perspectives. Lancet Neurol 2008;7:1056–66.
      OpenUrlCrossRefPubMedWeb of Science
    2. ↵
      1. Hosoda Y
      . Pathology of so-called ‘spontaneous occlusion of the circle of Willis’. Pathol Annu 1984;19:221–44.
      OpenUrl
    3. ↵
      1. Kono S,
      2. Oka K,
      3. Sueishi K
      . Histopathologic and morphometric studies of leptomeningeal vessels in moyamoya disease. Stroke 1990;21:1044–50.
      OpenUrlAbstract/FREE Full Text
    4. ↵
      1. Hosoda Y,
      2. Ikeda E,
      3. Hirose S
      . Histopathological studies on spontaneous occlusion of the circle of Willis (cerebrovascular moyamoya disease). Clin Neurol Neurosurg 1997;99(Suppl 2):203–8.
      OpenUrl
    5. ↵
      1. Kang HS,
      2. Kim SK,
      3. Kim YY,
      4. et al
      . Single nucleotide polymorphisms of tissue inhibitor of metalloproteinase genes in familial moyamoya disease. Neurosurgery 2006;58:1074–80.
      OpenUrlCrossRefPubMedWeb of Science
    6. ↵
      1. Vignali DA
      . Multiplexed particle-based flow cytometric assays. J Immunol Methods 2000;243:243–55.
      OpenUrlCrossRefPubMedWeb of Science
    7. ↵
      1. de Jager W,
      2. te Velthuis H,
      3. Prakken BJ,
      4. et al
      . Simultaneous detection of 15 human cytokines in a single sample of stimulated peripheral blood mononuclear cells. Clin Diagn Lab Immunol 2003;10:133–9.
      OpenUrlCrossRefPubMed
    8. ↵
      1. Kim JE,
      2. Oh CW,
      3. Kwon OK,
      4. et al
      . Transient hyperperfusion after superficial temporal artery/middle cerebral artery bypass surgery as a possible cause of postoperative transient neurological deterioration. Cerebrovasc Dis 2008;25:580–6.
      OpenUrlCrossRefPubMed
    9. ↵
      1. Fujimura M,
      2. Mugikura S,
      3. Kaneta T,
      4. et al
      . Incidence and risk factors for symptomatic cerebral hyperperfusion after superficial temporal artery-middle cerebral artery anastomosis in patients with moyamoya disease. Surg Neurol 2009;71:442–7.
      OpenUrlCrossRefPubMed
    10. ↵
      1. Fujimura M,
      2. Watanabe M,
      3. Narisawa A,
      4. et al
      . Increased expression of serum matrix metalloproteinase-9 in patients with moyamoya disease. Surg Neurol 2009;72:476–80.
      OpenUrlCrossRefPubMed
    11. ↵
      1. Rundhaug JE
      . Matrix metalloproteinases and angiogenesis. J Cell Mol Med 2005;9:267–85.
      OpenUrlPubMedWeb of Science
    12. ↵
      1. Murphy G,
      2. Nagase H
      . Progress in matrix metalloproteinase research. Mol Aspects Med 2008;29:290–308.
      OpenUrlCrossRefPubMedWeb of Science
    13. ↵
      1. Johnson C,
      2. Galis ZS
      . Matrix metalloproteinase-2 and -9 differentially regulate smooth muscle cell migration and cell-mediated collagen organization. Arterioscler Thromb Vasc Biol 2004;24:54–60.
      OpenUrlAbstract/FREE Full Text
    14. ↵
      1. Wu L,
      2. Tanimoto A,
      3. Murata Y,
      4. et al
      . Matrix metalloproteinase-12 gene expression in human vascular smooth muscle cells. Genes Cells 2003;8:225–34.
      OpenUrlCrossRefPubMedWeb of Science
    15. ↵
      1. Pozzi A,
      2. LeVine WF,
      3. Gardner HA
      . Low plasma levels of matrix metalloproteinase 9 permit increased tumor angiogenesis. Oncogene 2002;21:272–81.
      OpenUrlCrossRefPubMedWeb of Science
    16. ↵
      1. Ferreras M,
      2. Felbor U,
      3. Lenhard T,
      4. et al
      . Generation and degradation of human endostatin proteins by various proteinases. FEBS Lett 2000;486:247–51.
      OpenUrlCrossRefPubMedWeb of Science
    17. ↵
      1. Hamano Y,
      2. Zeisberg M,
      3. Sugimoto H,
      4. et al
      . Physiological levels of tumstatin, a fragment of collagen IV alpha3 chain, are generated by MMP-9 proteolysis and suppress angiogenesis via alphaV beta3 integrin. Cancer Cell 2003;3:589–601.
      OpenUrlCrossRefPubMedWeb of Science
    18. ↵
      1. Sudhakar A,
      2. Sugimoto H,
      3. Yang C,
      4. et al
      . Human tumstatin and human endostatin exhibit distinct antiangiogenic activities mediated by alpha v beta 3 and alpha 5 beta 1 integrins. Proc Natl Acad Sci U S A 2003;100:4766–71.
      OpenUrlAbstract/FREE Full Text
    19. ↵
      1. Kallenbach K,
      2. Salcher R,
      3. Heim A,
      4. et al
      . Inhibition of smooth muscle cell migration and neointima formation in vein grafts by overexpression of matrix metalloproteinase-3. J Vasc Surg 2009;49:750–8.
      OpenUrlCrossRefPubMedWeb of Science
    20. ↵
      1. Wu L,
      2. Fan J,
      3. Matsumoto S,
      4. et al
      . Induction and regulation of matrix metalloproteinase-12 by cytokines and CD40 signaling in monocyte/macrophages. Biochem Biophys Res Commun 2000;269:808–15.
      OpenUrlCrossRefPubMedWeb of Science
    21. ↵
      1. Leonard EJ,
      2. Yoshimura T
      . Human monocyte chemoattractant protein-1 (MCP-1). Immunol Today 1990;11:97–101.
      OpenUrlCrossRefPubMedWeb of Science
    22. ↵
      1. Wang L,
      2. Li Y,
      3. Chen J,
      4. et al
      . Ischemic cerebral tissue and MCP-1 enhance rat bone marrow stromal cell migration in interface culture. Exp Hematol 2002;30:831–6.
      OpenUrlCrossRefPubMedWeb of Science
    23. ↵
      1. Fujii T,
      2. Yonemitsu Y,
      3. Onimaru M,
      4. et al
      . Nonendothelial mesenchymal cell-derived MCP-1 is required for FGF-2-mediated therapeutic neovascularization: critical role of the inflammatory/arteriogenic pathway. Arterioscler Thromb Vasc Biol 2006;26:2483–9.
      OpenUrlAbstract/FREE Full Text
    24. ↵
      1. Capoccia BJ,
      2. Gregory AD,
      3. Link DC
      . Recruitment of the inflammatory subset of monocytes to sites of ischemia induces angiogenesis in a monocyte chemoattractant protein-1-dependent fashion. J Leukoc Biol 2008;84:760–8.
      OpenUrlAbstract/FREE Full Text
    25. ↵
      1. Demicheva E,
      2. Hecker M,
      3. Korff T
      . Stretch-induced activation of the transcription factor activator protein-1 controls monocyte chemoattractant protein-1 expression during arteriogenesis. Circ Res 2008;103:477–84.
      OpenUrlAbstract/FREE Full Text
    26. ↵
      1. Muruve DA,
      2. Pétrilli V,
      3. Zaiss AK,
      4. et al
      . The inflammasome recognizes cytosolic microbial and host DNA and triggers an innate immune response. Nature 2008;452:103–7.
      OpenUrlCrossRefPubMedWeb of Science
    27. ↵
      1. Fearon WF,
      2. Fearon DT
      . Inflammation and cardiovascular disease: role of the interleukin-1 receptor antagonist. Circulation 2008;117:2577–9.
      OpenUrlFREE Full Text
    28. ↵
      1. Yamamoto M,
      2. Aoyagi M,
      3. Fukai N,
      4. et al
      . Increase in prostaglandin E(2) production by interleukin-1beta in arterial smooth muscle cells derived from patients with moyamoya disease. Circ Res 1999;85:912–18.
      OpenUrlAbstract/FREE Full Text
    29. ↵
      1. Braunersreuther V,
      2. Mach F,
      3. Steffens S
      . The specific role of chemokines in atherosclerosis. Thromb Haemost 2007;97:714–21.
      OpenUrlPubMedWeb of Science
    30. ↵
      1. Dorweiler B,
      2. Torzewski M,
      3. Dahm M,
      4. et al
      . Subendothelial infiltration of neutrophil granulocytes and liberation of matrix-destabilizing enzymes in an experimental model of human neo-intima. Thromb Haemost 2008;99:373–81.
      OpenUrlPubMedWeb of Science
    31. ↵
      1. Papadopoulou C,
      2. Corrigall V,
      3. Taylor PR,
      4. et al
      . The role of the chemokines MCP-1, GRO-alpha, IL-8 and their receptors in the adhesion of monocytic cells to human atherosclerotic plaques. Cytokine 2008;43:181–6.
      OpenUrlCrossRefPubMedWeb of Science
    32. ↵
      1. Rafat N,
      2. Beck GCh,
      3. Peña-Tapia PG,
      4. et al
      . Increased levels of circulating endothelial progenitor cells in patients with Moyamoya disease. Stroke 2009;40:432–8.
      OpenUrlAbstract/FREE Full Text
    33. ↵
      1. Kim JH,
      2. Jung JH,
      3. Phi JH,
      4. et al
      . Decreased level and defective function of circulating endothelial progenitor cells in children with moyamoya disease. J Neurosci Res 2010;88:510–18.
      OpenUrlPubMedWeb of Science
    34. ↵
      1. Aoyagi M,
      2. Fukai N,
      3. Sakamoto H,
      4. et al
      . Altered cellular responses to serum mitogens, including platelet-derived growth factor, in cultured smooth muscle cells derived from arteries of patients with moyamoya disease. J Cell Physiol 1991;147:191–8.
      OpenUrlCrossRefPubMedWeb of Science
    35. ↵
      1. Aoyagi M,
      2. Fukai N,
      3. Matsushima Y,
      4. et al
      . Kinetics of 125I-PDGF binding and down-regulation of PDGF receptor in arterial smooth muscle cells derived from patients with moyamoya disease. J Cell Physiol 1993;154:281–8.
      OpenUrlCrossRefPubMed
    36. ↵
      1. Yamamoto M,
      2. Aoyagi M,
      3. Fukai N,
      4. et al
      . Differences in cellular responses to mitogens in arterial smooth muscle cells derived from patients with moyamoya disease. Stroke 1998;29:1188–93.
      OpenUrlAbstract/FREE Full Text
    37. ↵
      1. Hoshimaru M,
      2. Takahashi JA,
      3. Kikuchi H,
      4. et al
      . Possible roles of basic fibroblast growth factor in the pathogenesis of moyamoya disease: an immunohistochemical study. J Neurosurg 1991;75:267–70.
      OpenUrlCrossRefPubMed
    38. ↵
      1. Takahashi A,
      2. Sawamura Y,
      3. Houkin K,
      4. et al
      . The cerebrospinal fluid in patients with moyamoya disease (spontaneous occlusion of the circle of Willis) contains high level of basic fibroblast growth factor. Neurosci Lett 1993;160:214–16.
      OpenUrlCrossRefPubMed
    39. ↵
      1. Deguchi Y,
      2. Naito T,
      3. Yuge T,
      4. et al
      . Blood–brain barrier transport of 125I-labeled basic fibroblast growth factor. Pharm Res 2000;17:63–9.
      OpenUrlCrossRefPubMedWeb of Science
    40. ↵
      1. Schweigerer L,
      2. Neufeld G,
      3. Friedman J,
      4. et al
      . Capillary endothelial cells express basic fibroblast growth factor, a mitogen that promotes their own growth. Nature 1987;325:257–9.
      OpenUrlCrossRefPubMed

    Footnotes

    • Funding This study was supported by a grant from the Korea Healthcare Technology R&D Project, Ministry for Health, Welfare and Family Affairs, Republic of Korea (A080588-8) and by an SBS Grant-in-Aid from the Seoul National University Children's Hospital Research Fund (06-2008-195-9).

    • Competing interests None.

    • Patient consent Obtained.

    • Ethics approval Ethics approval was provided by the Seoul National University Hospital Institutional Review Board (#0705-020-208).

    • Provenance and peer review Not commissioned; externally peer reviewed.