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Cardiovascular Research 2006 70(1):158-164; doi:10.1016/j.cardiores.2006.02.003
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Copyright © 2006, European Society of Cardiology

Adrenomedullin in mast cells of abdominal aortic aneurysm

Toshihiro Tsurudaa,b,*, Johji Katoa, Kinta Hatakeyamac, Atsushi Yamashitac, Kunihide Nakamurad, Takuroh Imamuraa, Kazuo Kitamuraa, Toshio Onitsukad, Yujiro Asadac and Tanenao Etoa

aFirst Department of Internal Medicine, Miyazaki Medical College, University of Miyazaki, Japan
bDepartment of Nutrition Management, Faculty of Health and Nutrition, Minami-Kyushu University, Japan
cDepartment of Pathology, Miyazaki Medical College, University of Miyazaki, Japan
dSecond Department of Surgery, Miyazaki Medical College, University of Miyazaki, Japan

* Corresponding author. First Department of Internal Medicine, Miyazaki Medical College, University of Miyazaki, 5200 Kihara Kiyotake, Miyazaki 889-1692, Japan. Tel.: +81 985 85 0872; fax: +81 985 85 6596. Email address: ttsuruda{at}med.miyazaki-u.ac.jp

Received 24 September 2005; revised 26 January 2006; accepted 1 February 2006


   Abstract
Top
 Abstract
1. Introduction
 2. Materials and methods
 3. Results
 4. Discussion
 References
 
Objectives Produced by vascular walls, adrenomedullin (AM) exerts antifibrotic actions in the process of cardiovascular remodeling. The purpose of this study was to examine the pathophysiological role of AM in the development of human abdominal aortic aneurysm (AAA).

Methods and results Immunohistochemical analyses revealed that vascular smooth muscle cells in the media were positive for AM in the early stage of atherosclerotic aorta. Intense immunoreactivity was observed in mast cells of the outer media and adventitia of AAA, and the number of mast cells was greater (p<0.01) in AAA than in atherosclerotic aorta without any aneurysmal change. To determine the role of AM in mast cells, we examined cultured human mast cell leukemia line-1 (HMC-1) and fibroblasts isolated from AAA patients. Cultured HMC-1 cells were found to express preproAM gene and release AM peptide into the cultured media. When assessed by collagenase-sensitive [3H]proline incorporation and procollagen type I C-peptide secretion, collagen synthesis in co-culture of HMC-1 and the fibroblasts was reduced by 10– 6 mol/L synthetic AM, while conversely, it increased following blockade of the action of endogenous AM with 10µg/mL anti-AM monoclonal antibody.

Conclusion The present study suggests an anti-fibrotic role for AM released from mast cells, providing new insight into the biological actions of mast cell-derived AM in the development of AAA.

KEYWORDS Adrenomedullin; Abdominal aortic aneurysm; Mast cell; Fibrosis


   1. Introduction
Top
 Abstract
 1. Introduction
2. Materials and methods
 3. Results
 4. Discussion
 References
 
Abdominal aortic aneurysm (AAA) is a relatively common disorder in elderly patients with atherosclerosis [1,2]. AAA is characterized by an enlarged aortic lumen with a degenerated medial layer that is rearranged by disorganized collagen fibers, and in addition, either fibroblast proliferation with extracellular matrix formation or chronic inflammatory cellular infiltration is often observed in the outer media and adventitia [3]. A number of factors have been proposed as the cause of AAA [4–6]; however, the mechanisms underlying the development of the aneurysm remain unknown.

Adrenomedullin (AM), a 52-amino acid peptide originally isolated from human pheochromocytoma [7], has been shown to exert a wide range of cardiovascular actions, which are mostly protective for blood vessels, such as stimulation of nitric oxide production and inhibitions of oxidative stress and endothelial cell apoptosis [8]. Expression of the AM peptide was observed in the myocardium and in the vascular wall [9], suggesting a role for AM as a locally-acting humoral factor [10,11]. The magnitude of fibrosis of the cardiac or vascular tissues is determined by not only the mechanical stress but also the balance of humoral factors [12]. We have so far reported inhibitory effects of AM on fibroblast proliferation and extracellular matrix formation using cultured cells in vitro [13,14] and rodent models for hypertensive heart disease and myocardial infarction in vivo [15,16]. Based upon previous studies, we hypothesized that AM is involved in the development of AAA through modulation of fibroblast proliferation or extracellular matrix formation.

In the first part of the present study, to examine the role of AM in AAA, we characterized its expression in the aneurysmal aorta obtained from patients with AAA on surgical repair, and found that AM was present in mast cells in the outer media and adventitia. In the second part, we explored whether or not mast cell-derived AM modulates production of the extracellular matrix, by using a human mast cell line and cultured human fibroblasts isolated from the AAA tissue.


   2. Materials and methods
Top
 Abstract
 1. Introduction
 2. Materials and methods
3. Results
 4. Discussion
 References
 
The present study is approved by the Human Investigation Review Committee of the University of Miyazaki (Nos. 99 and 177) and conforms with the principles outlined in the Declaration of Helsinki (Cardiovasc Res 1997; 35: 2–4).

2.1 Reagents
Synthetic human AM was purchased from Peptide Institute, Inc. (Osaka, Japan). Dulbecco's modified Eagle's medium (DMEM)/F-12, Iscove's modified Dulbecco's medium, fetal bovine serum and antibiotics were obtained from GIBCO BRL. Collagenase (type IV) and insulin-transferrin-sodium selenite media supplement were from Sigma.

2.2 Tissue preparation
Aneurysmal tissues was obtained from the anterior part of aortic walls of 28 patients with AAA associated with atherosclerosis (75±1years; male, 71%) during elective repair surgery with written informed consent. The AAA tissues were fixed in 10% formalin immediately after resection. Aortic tissues with various degrees of atherosclerosis were collected from the anterior part of aorta of 20 patients (64±3years; male, 80%) at autopsy performed within 6h post-mortemly. Tissues of 10 of them showed diffuse intimal thickening or fatty streak and those of 10 advanced atherosclerosis.

2.3 Cell culture
Cultured fibroblasts were isolated from aorta of patients with AAA as described previously with minor modification [13]. In brief, minced aortic tissues digested with 0.12% trypsin and 0.03% collagenase type IV were placed in DMEM/F-12 medium with 10% fetal bovine serum in 10-cm culture plates for 2h at 37°C, and the adherent cells were further incubated until confluent. The human mast cell leukemia line, HMC-1, was kindly provided by Dr. J.H. Butterfield (Mayo Clinic, Rochester, MN, USA) [17] and cultured in Iscove's modified Dulbecco's medium.

2.4 Immunohistochemical analysis
Aortic tissues fixed in 10% formalin and embedded in paraffin wax. Sections (3µm thick) were immunohistochemically examined as previously described [18], with monoclonal antibodies against human {alpha}-smooth muscle actin or tryptase (DAKO cytomation) or with anti-human AM monoclonal antibody [19,20]. For detection of mast cell tryptase, the tissue sections were microwaved at 95°C for 1.0h in 10mmol/L citrate buffer (pH 6.0) prior to incubation with the primary antibody. As a negative control, non-immune IgG of mouse was used instead of the primary antibodies. Mast cell numbers of at least 6 fields in total areas of the outer-media and adventitia in atherosclerosis and AAA were counted at the magnification of x 400 and expressed as a density of mast cell number per mm2. The intracellular localization of AM and tryptase in HMC-1 cells was evaluated by double immunofluorescence staining with the anti-human AM antibody and goat anti-human tryptase polyclonal antibody (Santa Cruz Biotechnology) overnight at 4°C, followed by staining with fluorescein isothiocyanate-conjugated anti-mouse IgG and Cy3-conjugated anti-goat IgG (Jackson ImmunoResearch) for 20min. Immunofluorescent images were analyzed with a spectral confocal scanning system (TCS SP2, Leica).

2.5 Gene expression and assay for AM
Gene expression of AM in total RNA isolated from HMC-1 was analyzed by using a reverse transcription-polymerase chain reaction (RT-PCR) method [15,21]. The amplification protocol was 94°C for 2min, then 26cycles of 94°C for 30s, 62°C for 30s and 72°C for 1min, and finally 72°C for 5min. The PCR products were electrophoresed on 3.0% agarose gel with ethidium bromide. The concentration of AM in the conditioned medium as well as in the cells was measured with an immunoenzymometric assay, as previously described [22].

2.6 Measurement of collagen synthesis de novo
The synthesis of collagen de novo was assessed by collagen-sensitive proline incorporation into the cells [23,24] and by procollagen type I C-peptide (PICP), a peptide cleaved from the carboxy terminus of procollagen type I during posttranslational processing into the collagen fibers [25], in the conditioned medium. After the confluent fibroblasts were incubated with serum-free DMEM/F-12 medium for 48h, HMC-1 cells (1 x 106/cm3) were placed on the fibroblasts with or without of 10– 6 mol/L synthetic AM in the absence or presence of 10µg/mL purified anti-AM monoclonal antibody or purified non-immune mouse IgG (Zymed Laboratories, Inc., San Francisco, USA). To measure collagen-sensitive proline incorporation, the cultured cells were incubated with 5.0µCi/mL of [3H]proline (Amersham Bioscience) for a further 24h. The concentrations of PICP secreted in the conditioned media during the 24-h incubation with or without synthetic AM or anti-AM antibody were determined with commercially available enzyme immunoassay (Takara).

2.7 Statistical analysis
All data were analyzed with the SPSS software of version 11.0 (SPSS Inc., Chicago, IL) and expressed as the median with the 10–90% range and extreme values. Two data were compared with Student's t-test, and comparisons among multiple groups were assessed with a one-way ANOVA followed by Sheffè's test. Statistical significance was accepted at p<0.05.


   3. Results
Top
 Abstract
 1. Introduction
 2. Materials and methods
 3. Results
4. Discussion
 References
 
3.1 Localization of immunoreactive AM
Fig. 1 illustrates the immunoreactive localization for AM and {alpha}-smooth muscle actin in the aortic walls of AAA or of diffuse intimal thickening. In the aneurysmal wall, immunoreactivity for AM was detected in the degenerated media replaced by fibrous tissues, where the residual smooth muscle cells, mural vessels, and fibroblast-like cells were weakly stained. In the aortic wall with diffuse intimal thickening, immunoreactivity for AM was located mainly in the media.


Figure 1
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  		Fig. 1 Localization of immunoreactive AM (b and e) or {alpha}-smooth muscle actin (c and f) and negative control (a and d) of aortic tissues with AAA (d–f) and with diffuse intimal thickening (DIT, a–c). Bar, 100µm.

 
3.2 Immunoreactivity for AM in mast cells of AAA
We further examined the aortic sections from AAA patients stained with anti-AM monoclonal antibody. Fig. 2A illustrates the representative localizations of immunoreactive AM and tryptase in the adventitia of AAA. The immunoreactivity for AM was abundantly present in the cells located in connective tissue, which were identified as mast cells in the serial sections, based on positive staining for tryptase, a specific marker for mast cells. Next, a comparison was made of the number of mast cells between the aortic tissues with and without AAA. As shown in Fig. 2B, the number of mast cells was significantly (p<0.01) increased in the outer media and adventitia in cases of AAA, compared to atherosclerotic aorta without AAA.


Figure 2
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  		Fig. 2 (A) Localization of immunoreactive AM (a and c) and tryptase (b and d) of two serial sections of AAA. Arrows indicate mast cells positive for AM or tryptase. Bar, 100µm. (B) Number of mast cells in atherosclerotic aorta and AAA. Mast cells immunostained with anti-human mast cell tryptase antibody were counted at magnification of x 400 under the microscope. Values are shown as the median with 10–90% range (n); **p<0.01, vs. atherosclerotic aorta.

 
3.3 AM production in mast cell line
We examined the human mast cell leukemia line HMC-1 to see whether or not mast cells can produce and secrete AM. RT-PCR revealed expression of the preproAM gene in cultured HMC-1 cells (Fig. 3A), and immunohistochemical studies showed that AM (green) and tryptase (red) were positive in a granular pattern, co-localizing partially in merging images (yellow) (Fig. 3B). As shown in Fig. 4A, HMC-1 cells secreted AM into the medium in a time-dependent manner for up to 72h, with unchanged intracellular AM levels (Fig. 4B). To examine the molecular forms of secreted AM, we analyzed immunoreactive AM secreted from co-culture of the mast cells and fibroblasts over an incubation period of 24h with reverse phase high-performance liquid chromatography (RP-HPLC). The RP-HPLC analysis showed that immunoreactive AM consisted of a single peak eluting at the position of human AM(1–52)-NH2.


Figure 3
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  		Fig. 3 (A) Expression of preproAM mRNA in the HMC-1 cell line. (B) Localization of immunoreactive AM (a, green) or tryptase (b, red) and a merged image (c, yellow) in HMC-1 cells. Bar, 10µm.

 

Figure 4
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  		Fig. 4 (A) Secretion of AM from HMC-1 cells into the conditioned media. (B) Intracellular concentration of AM in HMC-1 cells. HMC-1 cells were cultured in serum-free media for the indicated time period. Values are shown as the median with 10–90% range and the numbers of samples are 4–7 for secretion and 4 for AM content measurements.

 
3.4 Effect of AM on protein and collagen synthesis
Fig. 5 shows the effects of exogenous and endogenous AM on collagenase-sensitive proline incorporation (A), PICP level in the conditioned media (B) and cellular protein content (C) of cultured HMC-1 cells and fibroblasts isolated from aorta with AAA. Although AM had little effect on the total protein content, 10– 6 mol/L AM significantly (p<0.05) decreased the proline incorporation and PICP level in co-culture of HMC-1 and fibroblasts. In contrast, blockade of the action of endogenous AM with 10µg/mL of purified anti-AM monoclonal antibody resulted in increased proline incorporation and PICP level.


Figure 5
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  		Fig. 5 [3H]proline incorporation (A), procollagen type I C-peptide (PICP) (B) and cellular protein levels (C) of co-culture of HMC-1 cells and fibroblasts incubated with or without 10– 6 mol/L synthetic AM in the absence or presence of 10µg/mL purified anti-AM monoclonal antibody or 10 µg/mL purified non-immune mouse IgG. Values are shown as the median with 10–90% range, and the number of samples are 8–12 for proline incorporation, 6 for PICP and 6 for cellular protein. *p<0.05, **p<0.01, vs. fibroblasts alone; ##p<0.01, vs. HMC-1 alone; +p<0.05, ++p<0.01 vs. control co-culture of fibroblasts and HMC-1 cells.

 

   4. Discussion
Top
 Abstract
 1. Introduction
 2. Materials and methods
 3. Results
 4. Discussion
References
 
Here, we demonstrated the presence of AM in mast cells of the outer media and adventitia of patients with AAA as well as in the human mast cell line HMC-1. Second, AM was released from HMC-1 and suppressed the synthesis of collagen in co-culture of HMC-1 cells and fibroblasts in vitro. The present study suggests a role for mast cell-derived AM in modulating production of the extracellular matrix of AAA.

AM has been reported to be found in various tissues and organs [9], but in particular, locally produced AM in the heart and vasculature has gained attention because of its role as an autocrine or paracrine factor [10,11]. AM exerted anti-fibrotic effects on the heart and blood vessels in vitro and in vivo, attenuating myofibroblastic differentiation and collagen synthesis and stimulating matrix metalloproteinase-2 (MMP-2) activity [14,15]. In the present study, the medial and adventitial layers of the aortic aneurysmal wall were replaced by fibrous tissue, where the residual smooth muscle cells and fibroblast-like cells were weakly positive for AM. Unexpectedly, during the microscopic observation, intense immunoreactivity for AM was observed in mast cells, number of which markedly increased in the outer media and adventitia of AAA. In accord with this, the cultured mast cell line was found to express preproAM mRNA and to contain the AM peptide in the secretory granules.

Accumulation of mast cells is observed in fibrotic tissues of idiopathic cardiomyopathy [26] and of vascular walls with atherosclerotic changes [27], suggesting a potential role of this type of cells in the pathogenesis. Mast cells can directly exert fibrogenic effects by releasing or activating several mediators such as histamine and tryptase [28,29]. To look at the role of AM on extracellular matrix formation in the aneurysmal walls, we treated co-culture of the mast cells and fibroblasts with synthetic AM or purified anti-AM monoclonal antibody which binds to the ring structure, critical for the biological activity of this peptide. When assessed with collagenase-sensitive proline incorporation and with PICP secretion, collagen synthesis de novo in the cells was reduced by synthetic AM, while conversely, increased by the blockade of action of endogenous AM by the anti-AM antibody. These results clearly suggest an inhibitory action of exogenous and endogenous AM on collagen synthesis in the cultured cells. The intracellular mechanisms of action for AM are not completely understood, while accumulation of intracellular cAMP has been proposed as a mechanism [7,8]. Indeed, AM has been shown to inhibit collagen synthesis via elevation of cAMP levels in cultured fibroblasts [30] and this mechanism is considered for the AM action observed in the present cell-culture study.

Collagen deposition in tissues is determined not only by its production but also by enzymatic degradation, and AM was found to augment MMP-2 activity in cultured aortic adventitial fibroblasts of rats [14]. We therefore measured MMP-2 activity in conditioned media of the mast cells and fibroblasts, but found that neither synthetic AM nor anti-AM antibody had effect on the enzymatic activity (data not shown). Recently, Martínez et al. [31] reported cleavage of the AM peptide into smaller fragments by MMP-2; however RP-HPLC analysis showed that the major molecular form of AM secreted from the mast cells and fibroblasts was the full-length human AM(1–52)-NH2. Therefore, it seems unlikely that the anti-fibrotic effect of exogenous or endogenous AM is modulated by alteration of MMP-2 activity.

The clinical significance of mast cells in the development of AAA has yet to be defined, though several studies have shown possible activation of chymase and matrix metalloproteinases by the cells [32,33]. In the present study, we observed a significant increase in mast cell number in the outer media and adventitia of AAA. As mentioned above, mast cells are assumed to release pro-fibrotic factors, compensating for the loss of structural integrity in the aneurysmal wall. According to the present experiments in vitro, AM released from mast cells may have potency to suppress deposition of extracellular matrix; however, it is unclear whether or not suppressed extracellular matrix formation by AM is beneficial in preventing AAA from enlarging. Indeed, we found no significant correlation between the AM levels and collagen contents or wall thickness of the AAA tissues (data not shown), partly because of the limited number of samples or of the removal of intima or part of media during the operation. Thus, further studies, particularly in vivo, are needed to answer this important question.

In summary, AM was found to be produced by mast cells in the outer media and adventitia of AAA, and the cell culture experiments showed an anti-fibrotic action of AM released from a human mast cell line. This study provides new insight into the biological action of mast cell-derived AM in modulating formation of the extracellular matrix in the development of AAA.


   Acknowledgements
 
This study was supported by grants-in-aid for Scientific Research on Priority Areas and for the 21st Century Centers of Excellence Program (Life Science) from the Ministry of Education, Culture, Sport, Science and Technology, Japan, a grant-in-aid from the Suzuken Memorial Foundation, the Mochida Memorial Foundation for Medical and Pharmaceutical Research, and an incentive grant from Minami-Kyushu University. We are thankful to Dr. J.H. Butterfield, Mayo Clinic, Rochester, MN, USA for providing the mast cell line HMC-1. We also thank Drs. Kazushi Kojima, Mitsuhiro Yano, Yoshikazu Yano, Second Department of Surgery for their help to collect the AAA samples, Drs. Fukumi Nakamura-Uchiyama and Yukifumi Nawa, Department of Parasitology, Dr. Kousuke Marutsuka, Department of Pathology, University of Miyazaki for their helpful discussion, and Ms. Ritsuko Sotomura and Ms. Mariko Tokashiki for their technical assistance.


   Notes
 
Time for primary review 22 days


   References
Top
 Abstract
 1. Introduction
 2. Materials and methods
 3. Results
 4. Discussion
 References
 

  1. Hallett J.W. Jr. Management of abdominal aortic aneurysms. Mayo Clin Proc (2000) 75:395–399.[ISI][Medline]
  2. Brady A.R., Fowkes F.G., Thompson S.G., Powell J.T. Aortic aneurysm diameter and risk of cardiovascular mortality. Arterioscler Thromb Vasc Biol (2001) 21:1203–1207.[Abstract/Free Full Text]
  3. Rosai J. Rosai and Ackerman's surgical pathology, 9th ed. Rosai, ed. (2004) Philadelphia: Elsevier Inc. 2438–2439.
  4. Lindholt J.S., St{oslash}vring J., Østergaard L., Urbonavicius S., Henneberg E.W., Honoré B., et al. Serum antibodies against Chlamydia pneumoniae outer membrane protein cross-react with the heavy chain of immunoglobulin in the wall of abdominal aortic aneurysms. Circulation (2004) 109:2097–2102.[Abstract/Free Full Text]
  5. Freestone T., Turner R.J., Coady A., Higman D.J., Greenhalgh R.M., Powell J.T. Inflammation and matrix metalloproteinases in the enlarging abdominal aortic aneurysm. Arterioscler Thromb Vasc Biol (1995) 15:1145–1151.[Abstract/Free Full Text]
  6. Leskinen M., Wang Y., Leszczynski D., Lindstedt K.A., Kovanen P.T. Mast cell chymase induces apoptosis of vascular smooth muscle cells. Arterioscler Thromb Vasc Biol (2001) 21:516–522.[Abstract/Free Full Text]
  7. Kitamura K., Kangawa K., Kawamoto M., Ichiki Y., Nakamura S., Matsuo H., et al. Adrenomedullin: a novel hypotensive peptide isolated from human pheochromocytoma. Biochem Biophys Res Commun (1993) 192:553–560.[CrossRef][ISI][Medline]
  8. Kato J., Tsuruda T., Kita T., Kitamura K., Eto T. Adrenomedullin: a protective factor for blood vessels. Arterioscler Thromb Vasc Biol (2005) 12:2480–2487.
  9. Eto T., Kato J., Kitamura K. Regulation of production and secretion of adrenomedullin in the cardiovascular system. Regul Pept (2003) 112:61–69.[CrossRef][ISI][Medline]
  10. Kato J., Tsuruda T., Kitamura K., Eto T. Adrenomedullin: a possible autocrine or paracrine hormone in the cardiac ventricles. Hypertens Res (2003) 26:S113–S119.[CrossRef][ISI][Medline]
  11. Tsuruda T., Burnett J.C. Jr. Adrenomedullin: an autocrine/paracrine factor for cardiorenal protection. Circ Res (2002) 90:625–627.[Free Full Text]
  12. Weber K.T. Targeting pathological remodeling: concepts of cardioprotection and reparation. Circulation (2000) 102:1342–1345.[Free Full Text]
  13. Tsuruda T., Kato J., Kitamura K., Kawamoto M., Kuwasako K., Imamura T., et al. An autocrine or a paracrine role of adrenomedullin in modulating cardiac fibroblast growth. Cardiovasc Res (1999) 43:958–967.[Abstract/Free Full Text]
  14. Tsuruda T., Kato J., Cao Y.N., Hatakeyama K., Masuyama H., Imamura T., et al. Adrenomedullin induces matrix metalloproteinase-2 activity in rat aortic adventitial fibroblasts. Biochem Biophys Res Commun (2004) 325:80–84.[CrossRef][ISI][Medline]
  15. Tsuruda T., Kato J., Hatakeyama K., Masuyama H., Cao Y.N., Imamura T., et al. Antifibrotic effect of adrenomedullin on coronary adventitia in angiotensin II-induced hypertensive rats. Cardiovasc Res (2005) 65:921–929.[Abstract/Free Full Text]
  16. Nakamura R., Kato J., Kitamura K., Onitsuka H., Imamura T., Cao Y., et al. Adrenomedullin administration immediately after myocardial infarction ameliorates progression of heart failure in rats. Circulation (2004) 110:426–431.[Abstract/Free Full Text]
  17. Butterfield J.H., Weiler D., Dewald G., Gleich G.J. Establishment of an immature mast cell line from a patient with mast cell leukemia. Leuk Res (1988) 12:345–355.[CrossRef][ISI][Medline]
  18. Ishikawa T., Hatakeyama K., Imamura T., Ito K., Hara S., Date H., et al. Increased adrenomedullin immunoreactivity and mRNA expression in coronary plaques obtained from patients with unstable angina. Heart (2004) 90:1206–1210.[Abstract/Free Full Text]
  19. Marutsuka K., Hatakeyama K., Sato Y., Yamashita A., Sumiyoshi A., Asada Y. Immunohistological localization and possible functions of adrenomedullin. Hypertens Res (2003) 26:S33–S40.[CrossRef][ISI][Medline]
  20. Ohta H., Tsuji T., Asai S., Sasakura K., Teraoka H., Kitamura K., et al. One-step direct assay for mature-type adrenomedullin with monoclonal antibodies. Clin Chem (1999) 45:244–251.[Abstract/Free Full Text]
  21. Uemura T., Kato J., Kuwasako K., Kitamura K., Kangawa K., Eto T. Aldosterone augments adrenomedullin production without stimulating pro-adrenomedullin N-terminal 20 peptide secretion in vascular smooth muscle cells. J Hypertens (2002) 20:1209–1214.[CrossRef][ISI][Medline]
  22. Kita T., Kitamura K., Hashida S., Morishita K., Eto T. Plasma adrenomedullin is closely correlated with pulse wave velocity in middle-aged and elderly patients. Hypertens Res (2003) 26:887–893.[CrossRef][ISI][Medline]
  23. Ostrom R.S., Naugle J.E., Hase M., Gregorian C., Swaney J.S., Insel P.A., et al. Angiotensin II enhances adenylyl cyclase signaling via Ca2+/calmodulin. Gq-Gs cross-talk regulates collagen production in cardiac fibroblasts. J Biol Chem (2003) 278:24461–24468.[Abstract/Free Full Text]
  24. Tsuruda T., Boerrigter G., Huntley B.K., Noser J.A., Cataliotti A., Costello-Boerrigter L.C., et al. Brain natriuretic peptide is produced in cardiac fibroblasts and induces matrix metalloproteinases. Circ Res (2002) 91:1127–1134.[Abstract/Free Full Text]
  25. Taubman M.B., Goldberg B., Sherr C. Radioimmunoassay for human procollagen. Science (1974) 186:1115–1117.[Abstract/Free Full Text]
  26. Patella V., Marinò I., Arbustini E., Lamparter-Schummert B., Verga L., Adt M., et al. Stem cell factor in mast cells and increased mast cell density in idiopathic and ischemic cardiomyopathy. Circulation (1998) 97:971–978.[Abstract/Free Full Text]
  27. Atkinson J.B., Harlan C.W., Harlan G.C., Virmani R. The association of mast cells and atherosclerosis: a morphologic study of early atherosclerotic lesions in young people. Hum Pathol (1994) 25:154–159.[CrossRef][ISI][Medline]
  28. Levi-Schaffer F., Piliponsky A.M. Tryptase, a novel link between allergic inflammation and fibrosis. Trends Immunol (2003) 24:158–161.[CrossRef][ISI][Medline]
  29. Garbuzenko E., Nagler A., Pickholtz D., Gillery P., Reich R., Maquart F.X., et al. Human mast cells stimulate fibroblast proliferation, collagen synthesis and lattice contraction: a direct role for mast cells in skin fibrosis. Clin Exp Allergy (2002) 32:237–246.[CrossRef][ISI][Medline]
  30. Horio T., Nishikimi T., Yoshihara F., Matsuo H., Takishita S., Kangawa K. Effects of adrenomedullin on cultured rat cardiac myocytes and fibroblasts. Eur J Pharmacol (1999) 382:1–9.[CrossRef][ISI][Medline]
  31. Martínez A., Oh H.R., Unsworth E.J., Bregonzio C., Saavedra J.M., Stetler-Stevenson W.G., et al. Matrix metalloproteinase-2 cleavage of adrenomedullin produces a vasoconstrictor out of a vasodilator. Biochem J (2004) 383:413–418.[CrossRef][ISI][Medline]
  32. Tsunemi K., Takai S., Nishimoto M., Yuda A., Hasegawa S., Sawada Y., et al. Possible roles of angiotensin II-forming enzymes, angiotensin converting enzyme and chymase-like enzyme, in the human aneurysmal aorta. Hypertens Res (2002) 25:817–822.[CrossRef][ISI][Medline]
  33. Baram D., Vaday G.G., Salamon P., Drucker I., Hershkoviz R., Mekori Y.A. Human mast cells release metalloproteinase-9 on contact with activated T cells: Juxtacrine regulation by TNF-{alpha}. J Immunol (2001) 167:4008–4016.[Abstract/Free Full Text]

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