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Hendig D, Zarbock R, Szliska C, Kleesiek K, Götting C. The local calcification inhibitor matrix Gla protein in pseudoxanthoma elasticum. Clin Biochem 2008; 41:407-12. [PMID: 18222176 DOI: 10.1016/j.clinbiochem.2007.12.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Revised: 12/22/2007] [Accepted: 12/27/2007] [Indexed: 01/22/2023]
Abstract
OBJECTIVES Recent studies have revealed the involvement of calcification inhibitory proteins in the pathogenesis of pseudoxanthoma elasticum (PXE). DESIGN AND METHODS We analyzed serum concentrations of the calcification inhibitor matrix Gla protein (MGP) in a large cohort of patients suffering from PXE (n=101), 34 first-degree relatives and 67 healthy controls. Moreover, we determined the distribution of the two MGP promoter polymorphisms c.-7G>A and c.-138T>C in the three cohorts. RESULTS We found significantly lower total MGP concentrations in the sera of PXE patients compared to healthy controls (p=0.0002). Furthermore, higher serum MGP concentrations could be correlated with a later PXE onset. Analysis of MGP promoter polymorphism frequencies revealed one MGP haplotype to be a potential protective co-factor in PXE. CONCLUSIONS Our findings point to a role of the local calcification inhibitor MGP in PXE manifestation.
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Affiliation(s)
- Doris Hendig
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
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52
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Conceição N, Laizé V, Simões B, Pombinho AR, Cancela ML. Retinoic acid is a negative regulator of matrix Gla protein gene expression in teleost fish Sparus aurata. BIOCHIMICA ET BIOPHYSICA ACTA 2008; 1779:28-39. [PMID: 18078838 DOI: 10.1016/j.bbagrm.2007.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Revised: 11/05/2007] [Accepted: 11/06/2007] [Indexed: 01/26/2023]
Abstract
Matrix Gla protein (MGP) is an extracellular mineral-binding protein expressed in several tissues while accumulated only in bone and cartilage under physiological conditions. Although the precise molecular mechanism of action of MGP remains unknown, all available evidence indicates that it acts as a physiological inhibitor of mineralization. This work presents the cloning of gilthead seabream MGP gene (SaMGP) and the functional analysis of its promoter. SaMGP gene was found to be organized in five exons and to be under control of a distal and a proximal promoter, both, capable of activating SaMGP transcription in transient transfections. Furthermore, we present strong evidence that retinoic acid down-regulates SaMGP gene transcription by interacting, through binding of its receptor, with a specific region within distal promoter. Interestingly, the presence of repetitive motifs in the proximity of SaMGP gene regulatory regions suggests that they may modulate promoter accessibility to transcription machinery, as already seen for other genes. This work provides additional evidence of the usefulness of non-mammalian model systems to elucidate the complex regulation of MGP gene transcription.
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Affiliation(s)
- Natércia Conceição
- Centre of Marine Sciences (CCMAR), University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
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53
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Suliman ME, García-López E, Anderstam B, Lindholm B, Stenvinkel P. Vascular calcification inhibitors in relation to cardiovascular disease with special emphasis on fetuin-A in chronic kidney disease. Adv Clin Chem 2008; 46:217-62. [PMID: 19004191 DOI: 10.1016/s0065-2423(08)00406-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The mortality rate is extremely high in chronic kidney disease (CKD), primarily due to the high prevalence of cardiovascular disease (CVD) in this patient group. Apart from traditional Framingham risk factors, evidences suggest that nontraditional risk factors, such as inflammation, oxidative stress, endothelial dysfunction, and vascular calcification also contribute to this extremely high risk of CVD. Disturbance in the mineral metabolism, especially in the ions of Ca and PO4, are linked to enhanced calcification of blood vessels. Although the mechanism(s) of this enhanced calcification process are not fully understood, current knowledge suggests that a large number (and an imbalance between them) of circulating promoters and inhibitors of the calcification process, that is, fetuin-A (or alpha 2-Heremans-Schmid glycoprotein, AHSG), matrix-Gla protein (MGP), osteoprotegerin (OPG), osteopontin (OPN), bone morphogenetic proteins (BMPs), and inorganic pyrophosphate (PPi), are involved in the deterioration of vascular tissue. Thus, an imbalance in these factors may contribute to the high prevalence of vascular complications in CKD patients. Among these mediators, studies on fetuin-A deserve further attention as clinical studies consistently show that fetuin-A deficiency is associated with vascular calcification, all-cause and cardiovascular mortality in CKD patients. Both chronic inflammation and the uremic milieu per se may contribute to fetuin-A depletion, as well as specific mutations in the AHSG gene. Recent experimental and clinical studies also suggest an intriguing link between fetuin-A, insulin resistance, and the metabolic syndrome.
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Affiliation(s)
- Mohamed E Suliman
- Department of Clinical Science, Intervention and Technology, Divisions of Renal Medicine and Baxter Novum, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden
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Schurgers LJ, Spronk HMH, Skepper JN, Hackeng TM, Shanahan CM, Vermeer C, Weissberg PL, Proudfoot D. Post-translational modifications regulate matrix Gla protein function: importance for inhibition of vascular smooth muscle cell calcification. J Thromb Haemost 2007; 5:2503-11. [PMID: 17848178 DOI: 10.1111/j.1538-7836.2007.02758.x] [Citation(s) in RCA: 183] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Matrix Gla protein (MGP) is a small vitamin K-dependent protein containing five gamma-carboxyglutamic acid (Gla) residues that are believed to be important in binding Ca(2+), calcium crystals and bone morphogenetic protein. In addition, MGP contains phosphorylated serine residues that may further regulate its activity. In vivo, MGP has been shown to be a potent inhibitor of vascular calcification; however, the precise molecular mechanism underlying the function of MGP is not yet fully understood. METHODS AND RESULTS We investigated the effects of MGP in human vascular smooth muscle cell (VSMC) monolayers that undergo calcification after exposure to an increase in Ca(2+) concentration. Increased calcium salt deposition was found in cells treated with the vitamin K antagonist warfarin as compared to controls, whereas cells treated with vitamin K(1) showed decreased calcification as compared to controls. With conformation-specific antibodies, it was confirmed that warfarin treatment of VSMCs resulted in uncarboxylated (Gla-deficient) MGP. To specifically test the effects of MGP on VSMC calcification, we used full-length synthetic MGP and MGP-derived peptides representing various domains in MGP. Full length MGP, the gamma-carboxylated motif (Gla) (amino acids 35-54) and the phosphorylated serine motif (amino acids 3-15) inhibited calcification. Furthermore, we showed that the peptides were not taken up by VSMCs but bound to the cell surface and to vesicle-like structures. CONCLUSIONS These data demonstrate that both gamma-glutamyl carboxylation and serine phosphorylation of MGP contribute to its function as a calcification inhibitor and that MGP may inhibit calcification via binding to VSMC-derived vesicles.
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Affiliation(s)
- L J Schurgers
- Cardiovascular Research Institute Maastricht and VitaK, University of Maastricht, Universiteitssingel 50, Maastricht, The Netherlands.
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55
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Ashley EA, Spin JM, Tabibiazar R, Quertermous T. Frontiers in nephrology: genomic approaches to understanding the molecular basis of atherosclerosis. J Am Soc Nephrol 2007; 18:2853-62. [PMID: 17942952 DOI: 10.1681/asn.2007040514] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Atherosclerosis is a complex multicellular disease that is responsible for pathology in various organ systems. The understanding of its initiation and progression has been enhanced in recent years by the application of high-throughput genomic tools such as the microarray. Increasing in genomic coverage, such tools allow a view of the disease unaffected by previous conjecture as to the primary signal of interest. New statistical tools and pathway modeling techniques have established definitively for the first time the central role of inflammation in this process. This article reviews the genomic literature relating to atherosclerosis from cell culture, animal models, and human tissues. In this comparison of these differing approaches, the available data are synthesized to reach a new understanding of the complex interplay between vascular wall and immune system components.
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Affiliation(s)
- Euan A Ashley
- Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California 94305, USA
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56
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Hermans MMH, Vermeer C, Kooman JP, Brandenburg V, Ketteler M, Gladziwa U, Rensma PL, Leunissen KML, Schurgers LJ. Undercarboxylated matrix GLA protein levels are decreased in dialysis patients and related to parameters of calcium-phosphate metabolism and aortic augmentation index. Blood Purif 2007; 25:395-401. [PMID: 17890861 DOI: 10.1159/000108629] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2007] [Accepted: 07/18/2007] [Indexed: 12/11/2022]
Abstract
BACKGROUND Vascular calcifications are related to cardiovascular mortality and morbidity in dialysis patients. Limited data exist on the role of calcification inhibitors, such as matrix-carboxyglutamic acid protein (MGP) in dialysis patients. METHODS In 120 dialysis patients and 41 age-matched healthy controls, circulating undercarboxylated (uc) MGP levels were measured with a novel ELISA-based competitive assay. The association between ucMGP levels and determinants of bone mineral metabolism, including the calcification inhibitor fetuin-A, was studied. Moreover, the relation between ucMGP levels and arterial stiffness was investigated. RESULTS The ucMGP level was significantly lower in dialysis patients compared to controls (173 +/- 70 vs. 424 +/- 126 nmol/l; p < 0.0001). After adjustment for age, sex and duration of dialysis an independent negative association between time-averaged phosphate levels [regression coefficient beta with 95% confidence interval = -64 (-107 to -21)] and a positive association between serum ucMGP and fetuin-A [131 (55-208)] was observed. Duration of dialysis was inversely correlated with ucMGP (r = -0.24, p = 0.007). ucMGP levels were not related to high-sensitivity C-reactive protein or time-averaged calcium levels. After adjustment for age, sex, cardiovascular disease, diabetes, height and mean arterial pressure, ucMGP level was negatively associated with the aortic augmentation index [-0.036 (-0.061 to -0.010)] but not with pulse wave velocity or pulse pressure. CONCLUSION Significantly lower serum ucMGP levels were observed in dialysis patients compared to healthy controls. ucMGP levels were inversely associated with phosphate and positively associated with serum fetuin-A levels. Furthermore, ucMGP levels were inversely associated with the aortic augmentation index. These data suggest that low ucMGP levels may be a marker of active calcification.
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Affiliation(s)
- Marc M H Hermans
- Department of Internal Medicine and Nephrology, Academic Hospital Maastricht, Maastricht, The Netherlands.
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57
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Gao B, Yasui T, Itoh Y, Tozawa K, Hayashi Y, Kohri K. A polymorphism of matrix Gla protein gene is associated with kidney stones. J Urol 2007; 177:2361-5. [PMID: 17509359 DOI: 10.1016/j.juro.2007.01.118] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2006] [Indexed: 11/21/2022]
Abstract
PURPOSE Matrix Gla protein, a potent calcification inhibitor in arterial vessels, is also expressed in the kidney and is up-regulated following the administration of ethylene glycol, a precursor of oxalate. Considering the analogous characteristics between arterial calcification and kidney stones, we identified variants of the human matrix Gla protein gene and investigated whether there is an association between MGP genetic polymorphisms and kidney stones. MATERIALS AND METHODS We studied single nucleotide polymorphisms in matrix Gla protein in 122 kidney stone cases and 125 controls. We resequenced the human genomic MGP gene, including the 1,000 bp promoter 5'-untranslated region, 4 exons and 3'-untranslated regions, and we performed systematic genetic analysis. A single nucleotide polymorphism was genotyped using a fluorescent 5'endonuclease assay and its association with kidney stones was analyzed. RESULTS We observed 19 polymorphisms. A single nucleotide polymorphism was associated with kidney stones (OR 0.51, 95% CI 0.30-0.87; p = 0.012). The G allele carrier had a 2-fold decreased kidney stone risk compared with A allele carriers in single nucleotide polymorphism 11 (OR 0.55, 95% CI 0.31-1.00, p = 0.047). We found no association between the polymorphism and kidney stone clinical characteristics. CONCLUSIONS Our findings show that an MGP gene polymorphism is associated with kidney stones and influences genetic susceptibility to kidney stones. In the future functional assays of the polymorphism should permit better understanding of the role of matrix Gla protein genetic variants and kidney stones.
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Affiliation(s)
- Bing Gao
- Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-ku, Nagoya 467-8601, Japan
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58
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Zhang L, Kasif S, Cantor ACR. Quantifying DNA-protein binding specificities by using oligonucleotide mass tags and mass spectroscopy. Proc Natl Acad Sci U S A 2007; 104:3061-6. [PMID: 17360609 PMCID: PMC1805538 DOI: 10.1073/pnas.0611075104] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The ability to determine the relative binding affinity of different transcription-factors (TF) to their DNA binding sites is fundamentally important for a comprehensive understanding of gene regulation. Here we present a general approach for multiplex quantification of DNA-TF binding specificities in vitro using oligonucleotide mass tag (OMT) labeling and mass spectroscopic quantification. An OMT is a short nucleic acid sequence with a distinct mass that can be resolved by a mass spectrometer. Each putative binding sequence is labeled with a unique OMT, and PCR amplification of OMTs is performed after removing nonbound DNA. Subsequently, a primer extension reaction is carried out, and the extension products are quantified by MALDI-TOF mass spectroscopy. Using the TF NF-kappaB P50, we have quantified the binding specificities of up to 15 binding sequences in a single assay. The results from the multiplex assay are consistent with data from the traditional gel shift assay. The approach allows the competitive binding of multiple DNA sequences to the given protein in a homogeneous reaction. By using the commercially available homogeneous MassEXTEND platform (SEQUENOM), it is scalable for high-throughput DNA-TF binding applications, including genome-wide TF binding site mapping and analyses of SNPs in promoter regions.
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Affiliation(s)
- Lingang Zhang
- *Center for Advanced Biotechnology
- Department of Biomedical Engineering
| | - Simon Kasif
- Department of Biomedical Engineering
- Bioinformatics Program, and
- Center for Advanced Genomic Technology, Boston University, Boston, MA 02215; and
| | - and Charles R. Cantor
- *Center for Advanced Biotechnology
- Department of Biomedical Engineering
- SEQUENOM, Inc., 3595 John Hopkins Court, San Diego, CA 92121
- To whom correspondence should be addressed. E-mail:
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Abstract
Vascular calcification is highly prevalent and correlated with high rates of cardiovascular mortality in chronic kidney disease patients. Recent evidence suggests that mineral, hormonal, and metabolic imbalances that promote phenotype change in vascular cells as well as deficiencies in specific mineralization inhibitory pathways may be important contributory factors for vascular calcification in these patients. This article reviews current mechanisms proposed for the regulation of vascular calcification and data supporting their potential contribution to this process in chronic kidney disease.
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Affiliation(s)
- Mohga El-Abbadi
- Department of Bioengineering, University of Washington, Seattle 98195, WA. USA
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60
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O'Donnell CJ, Shea MK, Price PA, Gagnon DR, Wilson PWF, Larson MG, Kiel DP, Hoffmann U, Ferencik M, Clouse ME, Williamson MK, Cupples LA, Dawson-Hughes B, Booth SL. Matrix Gla protein is associated with risk factors for atherosclerosis but not with coronary artery calcification. Arterioscler Thromb Vasc Biol 2006; 26:2769-74. [PMID: 16973975 PMCID: PMC2562549 DOI: 10.1161/01.atv.0000245793.83158.06] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
OBJECTIVE Atherosclerotic coronary artery calcification (CAC) is associated with increased coronary heart disease (CHD) risk. Matrix Gla protein (MGP) is an inhibitor of calcification in vivo. However, little is known regarding the distribution of circulating MGP and its associations with CHD risk factors or with CAC in humans. METHODS AND RESULTS Serum MGP concentrations were determined in 2 independent populations of men and women free of clinically apparent cardiovascular disease: study A, n=316, mean age 58 years, and study B, n=452, mean age 68 years. CAC was determined by computed tomography. Mean MGP concentrations were 98.4 and 198 ng/mL in men, and 97.4 and 201 ng/mL in women, in study A and study B, respectively. In both cohorts, MGP levels were higher with increasing age. In age-adjusted analyses, there was an association of circulating MGP with increasing Framingham CHD risk score (in study A, P=0.003 in men and P=0.016 in women, respectively; in study B, a nonsignificant increase in men and P=0.05 in women, respectively). Significant associations of circulating MGP with high-density lipoprotein and other individual CHD risk factors were also noted in both cohorts. There were no consistent associations between MGP and CAC after adjustment for CHD risk score in the 2 cohorts. CONCLUSIONS MGP is associated with individual CHD risk factors and the Framingham CHD risk score in men and women free of clinically apparent CHD. The relation of MGP with CAC deserves further study in larger populations.
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61
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Orakzai SH, Orakzai RH, Nasir K, Santos RD, Edmundowicz D, Budoff MJ, Blumenthal RS. Subclinical coronary atherosclerosis: racial profiling is necessary! Am Heart J 2006; 152:819-27. [PMID: 17070140 DOI: 10.1016/j.ahj.2006.08.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2006] [Accepted: 08/21/2006] [Indexed: 11/30/2022]
Abstract
OBJECTIVES We aim to review the studies comparing coronary calcification across different ethnic groups. BACKGROUND There is still uncertainty regarding ethnic differences in the prevalence, progression, and risk of coronary artery disease. Clues to possible racial differences in rates of coronary heart disease (CHD) may be found by identifying subclinical disease. Coronary artery calcification (CAC) can be used to predict risk of CHD in both symptomatic and asymptomatic subjects. METHODS Online databases were searched for studies assessing racial differences in CAC. RESULTS Most of the published studies have shown that racial differences exist in the prevalence and severity of CAC. Whites have a higher prevalence of CAC as compared to African Americans and other ethnic groups even after adjustment for risk factors. These differences in CAC are even more pronounced in men and in the elderly. Data regarding the distribution of CAC in ethnic groups outside the United States are limited. Emerging evidence indicates that while several ethnic groups outside the United States tend to have a greater prevalence of CHD risk factors, their prevalence of CAC is lower, as compared with Americans. Thus, the data obtained in the United States may not be able to be fully extrapolated to populations outside the United States for assessment of CHD risk. CONCLUSIONS The presence and extent of CAC varies among different racial groups within and outside the United States. The relationship between calcification and the incidence of CHD in these ethnic groups needs further exploration. Thus, it is important to develop ethnic specific CAC nomograms to more accurately determine the underlying CHD risk associated with CAC in these individuals. It will also be imperative to obtain outcome data and relate it to baseline levels of CAC to help us put in perspective the significance of racial differences in CAC and how they impact on cardiac risk prediction.
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Affiliation(s)
- Sarwar H Orakzai
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
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62
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Proudfoot D, Shanahan CM. Molecular mechanisms mediating vascular calcification: role of matrix Gla protein. Nephrology (Carlton) 2006; 11:455-61. [PMID: 17014561 DOI: 10.1111/j.1440-1797.2006.00660.x] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Patients with chronic kidney disease (CKD) have a higher incidence of vascular calcification and a greatly increased risk of cardiovascular death. The mechanisms involved in the accelerated vascular calcification observed in CKD have recently become clearer, leading to the hypothesis that a lack of natural inhibitors of calcification may trigger calcium deposition. One of these inhibitory factors, matrix Gla protein (MGP), is the focus of the present review. MGP, originally isolated from bone, is a vitamin K-dependent protein that is also highly expressed by vascular smooth muscle cells. MGP has been confirmed as a calcification-inhibitor in numerous studies; however, its mechanism of action is not completely understood. It potentially acts in several ways to regulate calcium deposition including: (i) binding calcium ions and crystals; (ii) antagonizing bone morphogenetic protein and altering cell differentiation; (iii) binding to extracellular matrix components; and (iv) regulating apoptosis. Its expression is regulated by several factors including retinoic acid, vitamin D and extracellular calcium ions, and a reduced form of vitamin K (KH2) is important in maintaining MGP in an active form. Therefore, strategies aimed at increasing its expression and activity may be beneficial in tipping the balance in favour of inhibition of calcification in CKD.
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Affiliation(s)
- Diane Proudfoot
- Division of Cardiovascular Medicine, University of Cambridge, Addenbrooke's Hospital (ACCI, Level 6), Cambridge, UK.
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63
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Atzeni F, Sarzi-Puttini P, Bevilacqua M. Calcium Deposition and Associated Chronic Diseases (Atherosclerosis, Diffuse Idiopathic Skeletal Hyperostosis, and Others). Rheum Dis Clin North Am 2006; 32:413-26, viii. [PMID: 16716887 DOI: 10.1016/j.rdc.2006.02.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Extracellular matrix mineralization or calcification occurs in many pathologic conditions, including atherosclerosis, medial wall calcification, diffuse idiopathic skeletal hyperostosis, and chondrocalcinosis. Vascular wall calcification is the most common and involves two mechanisms: passive calcification resulting from breakdown of the protection system and active calcification resulting from transdifferentiation of mesenchymal cells in the vascular wall to bone. Although reports are conflicting, several matrix proteins are identified as protective factors against dystrophic calcification in nonosseous tissues. Serum matrix Gla protein may be a marker of osteometabolic syndromes that cause hyperostosis and plays a role in Milwaukee shoulder syndrome.
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Affiliation(s)
- Fabiola Atzeni
- Rheumatology Unit, L Sacco University Hospital, Milan, Italy
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Takahashi T, Kato S, Suzuki N, Kawabata N, Takagi M. Autoregulatory mechanism of Runx2 through the expression of transcription factors and bone matrix proteins in multipotential mesenchymal cell line, ROB-C26. J Oral Sci 2006; 47:199-207. [PMID: 16415564 DOI: 10.2334/josnusd.47.199] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Runx2 is essential for osteoblast differentiation and gene expression of bone matrix proteins, however, little is known about the mechanism regulating its activity. In this study, the role of Runx2 on gene expression of transcription factors, AJ18, Msx2, and Dlx5, was examined in vitro. It is known that AJ18 and Msx2 act as repressors to inhibit activity of Runx2, whereas Dlx5 promotes its activity. An expression vector inserted Runx2 cDNA was transiently overexpressed in a rat multipotential mesenchymal cell line, ROB-C26 (C26). Real time reverse transcription-PCR analysis showed that, in exogenous Runx2-overexpressing C26 cells (C26-Rx), AJ18 expression increased 1.8-fold, Msx2 expression increased 3.0-fold, and Dlx5 expression increased 2.7-fold compared to the cells transfected with vector alone (C26-Co). Luciferase assay also showed that, in C26-Rx, AJ18 promoter activity increased 2.1-fold compared to C26-Co. Furthermore, gene expression of alkaline phosphatase (ALP) and bone matrix proteins including type I collagen (Col1), osteocalcin (OC), osteopontin (OPN), and matrix Gla protein (MGP) was examined. In C26-Rx, MGP expression increased 1.8-fold, and OPN expression increased 1.4-fold compared to C26-Co. However, no significant difference in Col1, ALP, and OC expressions was detected between C26-Rx and C26-Co. These results suggest that the existence of autoregulatory feed back loops, which inhibit Runx2 activity through the interaction of AJ18, Dlx5, and Msx2 cooperating with that of MGP and OPN, interferes with the differentiation of C26 cells toward mature osteoblasts.
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Affiliation(s)
- Tomihisa Takahashi
- Department of Anatomy, Nihon University School of Dentistry, Tokyo, Japan.
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65
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Kumar A, Li Y, Patil S, Jain S. A haplotype of the angiotensinogen gene is associated with hypertension in african americans. Clin Exp Pharmacol Physiol 2006; 32:495-502. [PMID: 15854165 DOI: 10.1111/j.1440-1681.2005.04217.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
1. Hypertension is a serious risk factor for myocardial infarction, heart failure, vascular disease, stroke and renal failure. The incidence of hypertension is 25-30% in the adult Caucasian population and complications due to hypertension are even greater in African Americans. 2. The renin-angiotensin system plays an important role in the regulation of blood pressure and previous studies have suggested that angiotensinogen (AGT) gene locus is linked with human essential hypertension. Earlier studies suggested that a single nucleotide polymorphism (SNP) that converts methionine to threonine at amino acid 235 is associated with hypertension in the Caucasian population. However, this SNP is not associated with hypertension in African American and Chinese populations. 3. We have found an A/G polymorphism at -217 of the human AGT gene promoter and have shown that the frequency of allele A at -217 is significantly increased in the genomic DNA of African American hypertensive patients. 4. We have also shown that: (i) reporter constructs containing the AGT gene promoter with nucleoside A at -217 have increased promoter activity on transient transfection; and (ii) the CCAAT box enhancer binding protein (C/EBP) family of transcription factors and glucocorticoid receptor (GR) bind preferentially to this region of the promoter when nucleoside A is present at -217. In addition, variant -217A is always present with variants -532T, -793A and -1074T in the human AGT gene promoter. 5. These data suggest that the AGT haplotype containing -217A, -532T, -793A and -1074T may be involved in increased transcription of this gene and may play a role in human hypertension.
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Affiliation(s)
- Ashok Kumar
- Pathology Department, New York Medical College, Valhalla, New York 10595, USA.
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66
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Ma X, Ruan G, Wang Y, Li Q, Zhu P, Qin YZ, Li JL, Liu YR, Ma D, Zhao H. Two Single-Nucleotide Polymorphisms with Linkage Disequilibrium in the Human Programmed Cell Death 5 Gene 5′ Regulatory Region Affect Promoter Activity and the Susceptibility of Chronic Myelogenous Leukemia in Chinese Population. Clin Cancer Res 2005; 11:8592-9. [PMID: 16361542 DOI: 10.1158/1078-0432.ccr-05-0039] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Chronic myelogenous leukemia (CML) is a disease characterized cytogenetically by the presence of the Philadelphia chromosome. Recent studies suggested that altered PDCD5 expression may have significant implications in CML progression. The aim of this study was to identify single-nucleotide polymorphisms (SNP) within the programmed cell death 5 (PDCD5) promoter region and show their functional relevance to PDCD5 expression as well as their genetic susceptibility to CML. EXPERIMENTAL DESIGN One hundred twenty-nine CML subjects and 211 healthy controls were recruited for identification of SNPs and subsequent genetic analysis. Luciferase reporter assays were carried out to show the functional significance of the SNPs located in the promoter region to PDCD5 expression. Real-time quantitative PCR and Western blot analysis were done to determine the expression differences of PDCD5 in CML patients with different genotypes. RESULTS Two SNPs were identified within the PDCD5 promoter. They are -27A>G and -11G>A (transcription start site as position 1), respectively. The complete linkage disequilibrium was found between these two polymorphisms. The frequencies of -27G+/-11A+ genotype and -27G/-11A allele were significantly higher in CML patients than in healthy controls (genotype: 26.36% versus 11.85%, chi2=11.75, P<0.01; allele: 13.57% versus 6.40%, chi2=9.48, P<0.01). Luciferase reporter assays revealed that the promoter with -27G/-11A had significantly lower transcriptional activity and could not be up-regulated after apoptotic stimulations compared with the promoter with -27A/-11G. PDCD5 expression analysis in mononuclear cells derived from CML patients and cell lines with different -27/-11 genotypes showed consistent results with the reporter assays. CONCLUSIONS These data suggest that -27G/-11A is associated with reduced PDCD5 promoter activity and increased susceptibility to CML.
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MESH Headings
- 5' Flanking Region/genetics
- Apoptosis Regulatory Proteins/genetics
- Asian People/genetics
- Base Sequence
- Case-Control Studies
- Cell Line, Tumor
- China
- Gene Expression Regulation, Neoplastic
- Genes, Reporter/genetics
- Genetic Predisposition to Disease/genetics
- Humans
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukocytes, Mononuclear/metabolism
- Linkage Disequilibrium
- Molecular Sequence Data
- Neoplasm Proteins/genetics
- Polymorphism, Single Nucleotide
- Promoter Regions, Genetic/drug effects
- Promoter Regions, Genetic/genetics
- Tumor Necrosis Factor-alpha/pharmacology
- Up-Regulation
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Affiliation(s)
- Xi Ma
- Department of Immunology, School of Basic Medicine, Peking University Center for Human Disease Genomics, and Institute of Hematology, Peking University People's fHospital, P.R. China
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67
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Brancaccio D, Biondi ML, Gallieni M, Turri O, Galassi A, Cecchini F, Russo D, Andreucci V, Cozzolino M. Matrix GLA protein gene polymorphisms: clinical correlates and cardiovascular mortality in chronic kidney disease patients. Am J Nephrol 2005; 25:548-52. [PMID: 16210837 DOI: 10.1159/000088809] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2005] [Accepted: 08/22/2005] [Indexed: 11/19/2022]
Abstract
BACKGROUND Increased vascular calcification plays an important role in the pathogenesis of cardiovascular events in chronic kidney disease (CKD) patients. It is the result of an active ossification process counteracted by 'protective' proteins, such as matrix GLA protein (MGP). Polymorphisms of MGP have been identified. METHODS The aim of this study was to define the distribution of two MGP polymorphisms (-7, -138) in 99 hemodialysis (HD) patients, in 26 patients with CKD stage 3 and in 135 age- and sex-matched healthy controls. Patients were followed up for 12 months to record any cardiovascular deaths. The cause of death was determined by medical doctors, considering the medical history of each patient. The primers were designed with Primer Express software. RESULTS MGP -138TT homozygotes were more frequent in the HD group versus controls (p = 0.0004). Additionally, the frequency of the T allele was significantly higher in the HD group (p = 0.0006). The frequency of the A allele of MGP-7 was significantly higher both in the HD group (p = 0.033) and in the CKD group (p = 0.0017) versus controls. MGP-7 GG homozygotes were significantly less common in the CKD group than in controls (p = 0.037). Combination -138TT -7AA was significantly more frequent in both CKD patients (p = 0.001) and in HD patients (p = 0.029) than in controls. Seventeen out of 99 HD patients experienced fatal cardiovascular events. Sixteen (94.1%) were -138TT homozygotes and either -7AA homozygotes or -7GA heterozygotes. CONCLUSION This study suggests that CKD and HD patients have a different distribution of MGP gene polymorphism as compared with the normal population. Altered MGP gene polymorphism may be a negative prognostic factor for the progression to end-stage renal disease and for cardiovascular events in CKD patients.
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Affiliation(s)
- Diego Brancaccio
- Renal Division and Clinical Chemistry and Microbiology, S. Paolo Hospital, University of Milan, Italy.
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68
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Schurgers LJ, Teunissen KJF, Knapen MHJ, Kwaijtaal M, van Diest R, Appels A, Reutelingsperger CP, Cleutjens JPM, Vermeer C. Novel conformation-specific antibodies against matrix gamma-carboxyglutamic acid (Gla) protein: undercarboxylated matrix Gla protein as marker for vascular calcification. Arterioscler Thromb Vasc Biol 2005; 25:1629-33. [PMID: 15961706 DOI: 10.1161/01.atv.0000173313.46222.43] [Citation(s) in RCA: 228] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Matrix gamma-carboxyglutamic acid (Gla) protein (MGP), a vitamin K-dependent protein, is a potent in vivo inhibitor of arterial calcification. We hypothesized that low endogenous production of MGP and impaired carboxylation of MGP may contribute to the development or the progression of vascular disease. METHODS AND RESULTS Novel conformation-specific antibodies against MGP were used for immunohistochemistry of healthy and sclerotic arteries. In healthy arteries, MGP was mainly displayed around the elastin fibers in the tunica media. The staining colocalized with that for carboxylated MGP, whereas undercarboxylated MGP (ucMGP) was not detected. In atherosclerotic arteries, ucMGP was found in the intima, where it was associated with vesicular structures. In Mönckeberg's sclerosis of the media, ucMGP was localized around all areas of calcification. The results indicate that ucMGP is strongly associated with vascular calcification of different etiologies. In a separate study, serum MGP concentrations in a cohort of 172 subjects who had undergone percutaneous coronary intervention were significantly reduced compared with an apparently healthy population. CONCLUSIONS These data show that impaired carboxylation of MGP is associated with intimal and medial vascular calcification and suggest the essentiality of the vitamin K modification to the function of MGP as an inhibitor of ectopic calcification.
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Affiliation(s)
- Leon J Schurgers
- Cardiovascular Research Institute, Maastricht University, Maastricht, The Netherlands.
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69
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Conceição N, Silva AC, Fidalgo J, Belo JA, Cancela ML. Identification of alternative promoter usage for the matrix Gla protein gene. Evidence for differential expression during early development in Xenopus laevis. FEBS J 2005; 272:1501-10. [PMID: 15752365 DOI: 10.1111/j.1742-4658.2005.04590.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Recent cloning of the Xenopus laevis (Xl) matrix Gla protein (MGP) gene indicated the presence of a conserved overall structure for this gene between mammals and amphibians but identified an additional 5'-exon, not detected in mammals, flanked by a functional, calcium-sensitive promoter, 3042 bp distant from the ATG initiation codon. DNA sequence analysis identified a second TATA-like DNA motif located at the 3' end of intron 1 and adjacent to the ATG-containing second exon. This putative proximal promoter was found to direct transcription of the luciferase reporter gene in the X. laevis A6 cell line, a result confirmed by subsequent deletion mutant analysis. RT-PCR analysis of XlMGP gene expression during early development identified a different temporal expression of the two transcripts, strongly suggesting differential promoter activation under the control of either maternally inherited or developmentally induced regulatory factors. Our results provide further evidence of the usefulness of nonmammalian model systems to elucidate the complex regulation of MGP gene transcription and raise the possibility that a similar mechanism of regulation may also exist in mammals.
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70
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Schurgers LJ, Teunissen KJF, Knapen MHJ, Geusens P, van der Heijde D, Kwaijtaal M, van Diest R, Ketteler M, Vermeer C. Characteristics and performance of an immunosorbent assay for human matrix Gla-protein. Clin Chim Acta 2005; 351:131-8. [PMID: 15563881 DOI: 10.1016/j.cccn.2004.08.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2004] [Revised: 08/19/2004] [Accepted: 08/19/2004] [Indexed: 11/16/2022]
Abstract
BACKGROUND Matrix gammacarboxyglutamate (Gla)-protein (MGP) is a strong inhibitor of soft tissue calcification and is mainly produced by chondrocytes and vascular smooth muscle cells (VSMCs). MGP-deficient mice have extensive calcifications of cartilage and arteries leading to osteopenia, fractures and blood vessel ruptures. Promotor polymorphisms resulting in decreased expression levels were found to be associated with an increased risk for cardiovascular disease in humans. METHODS Recently, an ELISA-based assay has become available with which MGP may be detected in the circulation. The principle of the test kit is that of a competitive immunoassay using a monoclonal antibody against MGP bound to the microtiter plate. RESULTS Here, we report on a critical evaluation of this assay and its potential diagnostic utility in diseases associated with the degeneration of the arterial vessel wall and cartilage. The biochemical performance of the kit is satisfactory, and significant differences were found between a number of patient cohorts and the reference population. Serum MGP concentrations were significantly decreased in patients with angina pectoris and in various cartilage diseases. CONCLUSIONS The assay allows comparison of groups and may become a suitable marker for risk assessment or diagnosis in cardiovascular disease and osteoarthritis.
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Affiliation(s)
- Leon J Schurgers
- VitaK and Department of Biochemistry, Maastricht University, The Netherlands
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71
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Cobellis G, Lombardi M, Scarpa D, Izzo G, Fienga G, Meccariello R, Pierantoni R, Fasano S. Fra1 activity in the frog, Rana esculenta, testis: a new potential role in sperm transport. Biol Reprod 2004; 72:1101-8. [PMID: 15625234 DOI: 10.1095/biolreprod.104.036541] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Using an anti-Fos family member antibody, we have previously described in Rana esculenta testis the presence of a nuclear, 43 kDa protein that we hypothesized to be Fra1. With the assistance of an antibody against Fra1 that does not cross-react with other Fos family members, here we report data on Fra1 expression, localization, and putative activity in Rana esculenta testis during its annual reproductive cycle. Western blot analysis confirms that the nuclear, 43 kDa protein is Fra1. Immunocytochemistry validates the Western blot results and shows cytoplasmic and nuclear immunostaining of Fra1 in peritubular myoid cells, efferent ducts, and blood vessels. We report for the first time in a vertebrate, experimental evidence showing that the expression of Fra1 is related to peritubular myoid cells during sperm transport from the tubular compartment to efferent ducts.
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Affiliation(s)
- Gilda Cobellis
- Dipartimento di Medicina Sperimentale, Sezione F. Bottazzi, II Università di Napoli, 80138 Naples, Italy
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72
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Berkner KL, Runge KW. The physiology of vitamin K nutriture and vitamin K-dependent protein function in atherosclerosis. J Thromb Haemost 2004; 2:2118-32. [PMID: 15613016 DOI: 10.1111/j.1538-7836.2004.00968.x] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Recent advances in the discovery of new functions for vitamin K-dependent (VKD) proteins and in defining vitamin K nutriture have led to a substantial revision in our understanding of vitamin K physiology. The only unequivocal function for vitamin K is as a cofactor for the carboxylation of VKD proteins which renders them active. While vitamin K was originally associated only with hepatic VKD proteins that participate in hemostasis, VKD proteins are now known to be present in virtually every tissue and to be important to bone mineralization, arterial calcification, apoptosis, phagocytosis, growth control, chemotaxis, and signal transduction. The development of improved methods for analyzing vitamin K has shed considerable insight into the relative importance of different vitamin K forms in the diet and their contribution to hepatic vs. non-hepatic tissue. New assays that measure the extent of carboxylation in VKD proteins have revealed that while the current recommended daily allowance for vitamin K is sufficient for maintaining functional hemostasis, the undercarboxylation of at least one non-hemostatic protein is frequently observed in the general population. The advances in defining VKD protein function and vitamin K nutriture are described, as is the potential impact of VKD proteins on atherosclerosis. Many of the VKD proteins contribute to atherogenesis. Recent studies suggest involvement in arterial calcification, which may be influenced by dietary levels of vitamin K and by anticoagulant drugs such as warfarin that antagonize vitamin K action.
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Affiliation(s)
- K L Berkner
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, OH 44195, USA.
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73
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Al Aly Z, Edwards JC. Vascular biology in uremia: insights into novel mechanisms of vascular injury. Adv Chronic Kidney Dis 2004; 11:310-8. [PMID: 15241745 DOI: 10.1053/j.arrt.2004.04.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Cardiovascular disease is the leading cause of death in patients with end-stage renal disease. Although the prevalence of traditional atherosclerotic risk factors is increased in patients with chronic kidney disease, these traditional risk factors alone do not seem to account for the increased cardiovascular mortality. It has been proposed that additional risk factors may play a role in vascular injury. Among nontraditional risk factors, chronic inflammation, oxidative stress, and vascular calcification have been implicated in the accelerated athersclerosis of chronic kidney disease. Uremia is a proinflammatory state. Elevated levels of the proinflammatory cytokine interleukin-6 and suppressed levels of the anti-inflammatory cytokine interleukin-10 are present in chronic kidney disease and have been implicated in accelerated atherosclerosis. Uremia also results in increased oxidative stress. Asymmetric dimethyl arginine and myeloperoxidase may be critical mediators of the endothelial damage that results from oxidative stress. Finally, the uremic milieu seems to promote vascular calcification. The abundance of proinflammatory cytokines, the possible deficiency in calcification inhibitory proteins and the high phosphorus that are often present in uremia contribute to vascular calcification. Smooth muscle cells in calcifying lesions undergo phenotypic changes and molecular reprogramming that are reminiscent of endochondral bone formation during embryogenesis.
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Affiliation(s)
- Ziyad Al Aly
- Division of Nephrology, St Louis University, MO 63110, USA.
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74
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Eferl R, Hoebertz A, Schilling AF, Rath M, Karreth F, Kenner L, Amling M, Wagner EF. The Fos-related antigen Fra-1 is an activator of bone matrix formation. EMBO J 2004; 23:2789-99. [PMID: 15229648 PMCID: PMC514946 DOI: 10.1038/sj.emboj.7600282] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2004] [Accepted: 05/28/2004] [Indexed: 01/10/2023] Open
Abstract
Ectopic expression of the transcription factor Fra-1 in transgenic mice leads to osteosclerosis, a bone disorder characterized by increased bone mass. The molecular basis for this phenotype is unknown and Fra-1 functions cannot be studied by a conventional loss-of-function approach, since fra-1-knockout mice die in utero likely due to placental defects. Here we show that the lethality of fra-1-knockout mice can be rescued by specific deletion of Fra-1 only in the mouse embryo and not in the placenta. Mice lacking Fra-1 (fra-1(delta/delta)) are viable and develop osteopenia, a low bone mass disease. Long bones of fra-1(delta/delta) mice appear to have normal osteoclasts but express reduced amounts of bone matrix components produced by osteoblasts and chondrocytes such as osteocalcin, collagen1a2 and matrix Gla protein. The gene for matrix Gla protein seems to be a specific target of Fra-1 since its expression was markedly increased in the long bones of fra-1-transgenic mice. These results uncover a novel function of Fra-1 in regulating bone mass through bone matrix production by osteoblasts and chondrocytes.
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Affiliation(s)
- Robert Eferl
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | - Astrid Hoebertz
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | - Arndt F Schilling
- Department of Trauma, Hand and Reconstructive Surgery, Hamburg, University School of Medicine, Hamburg, Germany
| | - Martina Rath
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | - Florian Karreth
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | - Lukas Kenner
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | - Michael Amling
- Department of Trauma, Hand and Reconstructive Surgery, Hamburg, University School of Medicine, Hamburg, Germany
| | - Erwin F Wagner
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
- Research Institute of Molecular Pathology (IMP), Dr Bohr-Gasse 7, 1030 Vienna, Austria. Tel.: +43 1 79730; Fax: +43 1 7989390; E-mail:
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75
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Nobata S, Mogi H, Shinozawa T. Exon skipping of midkine pre-mRNA is enhanced by intronic polymorphism in a colon cancer cell line. Cancer Lett 2004; 207:89-93. [PMID: 15050737 DOI: 10.1016/j.canlet.2003.10.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2003] [Revised: 09/24/2003] [Accepted: 10/02/2003] [Indexed: 10/26/2022]
Abstract
A correlation between the polymorphism, heterogeneous G/T at the 62nd site of intron 3 in the midkine gene, and the induction of colorectal cancer has been reported [Cancer Lett. 180 (2002) 159]. The minigene containing exons 2, 3 and 4, as well as intronic sequences flanking exon 3, was transfected into COLO205 colon cancer cells. When the base of the site was G, correctly spliced mRNA was strongly detected. However in case of a G to T substitution, a truncated exon 3 mRNA was strongly detected. In this case, the detection of correctly spliced mRNA was weak. When the minigene was transfected into HCT-15 colon cancer cells, correctly spliced mRNA was strongly detected in the cases of both minigenes. This indicates the possibility that a G to T substitution at the 62nd site of intron 3 in the midkine gene enhances the expression of truncated midkine in colon cancer.
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Affiliation(s)
- Shigenori Nobata
- Department of Biological and Chemical Engineering, Faculty of Engineering, Gunma University, 1-5-1 Tenjincho, Kiryu, Gunma 376-8515, Japan
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76
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Goodman WG, London G, Amann K, Block GA, Giachelli C, Hruska KA, Ketteler M, Levin A, Massy Z, McCarron DA, Raggi P, Shanahan CM, Yorioka N. Vascular calcification in chronic kidney disease. Am J Kidney Dis 2004; 43:572-9. [PMID: 14981617 DOI: 10.1053/j.ajkd.2003.12.005] [Citation(s) in RCA: 283] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- William G Goodman
- Division of Nephrology, UCLA Medical Center, Los Angeles, CA 90095, USA.
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77
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Doherty TM, Fitzpatrick LA, Shaheen A, Rajavashisth TB, Detrano RC. Genetic determinants of arterial calcification associated with atherosclerosis. Mayo Clin Proc 2004; 79:197-210. [PMID: 14959915 DOI: 10.4065/79.2.197] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Increasing research interest has focused on arterial calcification in the setting of atherosclerosis. Many features of atherosclerosis-related calcification provide useful clinical information. For example, calcium mineral deposits frequently form in atherosclerotic plaque, and intimal arterial calcification can be used as a surrogate marker for atherosclerosis; also, calcium deposits are readily and noninvasively quantified, which is useful because greater amounts of coronary calcification predict a higher risk of myocardial infarction and death. Several mechanisms leading to calcification associated with atherosclerosis have been proposed; however, no direct testing of proposed mechanisms has yet been reported. Studies in genetically altered animals and in humans have shed light on potential genetic determinants, which in turn could form the basis for a more comprehensive understanding of the factors affecting calcification within plaque and the associated pathobiologic implications. We review proposed molecular and cellular mechanisms of atherosclerosis-associated arterial calcification, summarize genetic influences, and suggest areas in which further investigation is needed. Understanding the molecular and genetic determinants of specific structural plaque components such as calcification can provide a solid foundation for the development of novel therapeutic approaches to favorably alter plaque structure and minimize vulnerability to arterial rupture.
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Affiliation(s)
- Terence M Doherty
- Burns and Allen Research Institute, Department of Medicine, Cedars-Sinai Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, Calif, USA
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78
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Rusovici R, LaVoie HA. Expression and distribution of AP-1 transcription factors in the porcine ovary. Biol Reprod 2003; 69:64-74. [PMID: 12606371 DOI: 10.1095/biolreprod.102.013995] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The activator protein-1 (AP-1) transcription factors are important regulators of cell proliferation and differentiation. The developmental distribution of AP-1 family members in porcine ovary has not been previously investigated. We examined the expression of AP-1 factors in porcine ovarian follicles, granulosa cells, and corpora lutea at different stages of development. Immunoblot analyses confirmed that c-Jun, JunD, JunB, c-Fos, Fra-1, Fra-2, and FosB immunoreactive proteins were present in whole-cell extracts (WCE) of all antral follicles and midluteal phase corpora lutea (CL) as well as granulosa cells (GC) isolated from different-sized antral follicles. The intensities of c-Jun and c-Fos protein bands were decreased in CL WCE compared to antral follicles. In granulosa cells from preovulatory follicles (8-10 mm), Fra-2 exhibited a shift from 43 kDa to 46 kDa when compared to granulosa cells from smaller antral follicles. Separation of cytoplasmic and nuclear extracts was performed to determine if developmental differences between these fractions existed. Most AP-1 factors predominated in the nuclear fraction with notable exceptions. c-Fos predominated in the nucleus in GC and follicles but predominated in the cytoplasmic fraction of CL. With the exception of GC from 1-2-mm follicles, in which expression was similar between fractions, Fos-B was found predominantly in the cytoplasmic fraction. Fra-1 exhibited similar expression between cytoplasmic and nuclear fractions for all tissues. Immunohistochemical (IHC) analyses of porcine ovary sections were performed to determine the cellular distribution of these factors at different follicular stages, and immunopositive nuclei were evaluated. In primordial and primary unilaminar follicles, all AP-1 factors studied except for FosB were detected in granulosa nuclei. Granulosa cell nuclei of multilaminar preantral follicles were immunopositive for all factors, with lower expression of FosB. Antral follicles exhibited GC and thecal cell nuclear staining for all factors with the exception of FosB in theca. Luteal cells exhibited the most intense nuclear staining for JunD and Fra-2, whereas all other factors were present in luteal cell nuclei although to a lesser extent. IHC with FosB antibodies yielded mostly cytoplasmic staining but only weak luteal nuclear staining. In corpora albicantia, low levels of staining were seen for all AP-1 factors. The DNA-binding abilities of these factors in granulosa cells and CL were evaluated by EMSA. Nuclear extracts from granulosa cells from 1-2-mm or 8-10-mm antral follicles bound an AP-1 DNA consensus sequence and complexes consisted predominantly of c-Jun, JunD, JunB, c-Fos, and Fra-2. In CL, c-Jun, JunD, JunB, and Fra-2 were present in DNA-binding complexes, and c-Fos binding was not detected. In conclusion, our results suggest that expression and DNA-binding activity of AP-1 factors in follicular structures changes with luteinization. Differentiation to the luteal phenotype involves a reduction in nuclear c-Jun and c-Fos and a predominance of JunD and Fra-2.
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Affiliation(s)
- Raluca Rusovici
- Department of Cell and Developmental Biology and Anatomy, University of South Carolina School of Medicine, Columbia, South Carolina 29208, USA
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79
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Rutsch F, Terkeltaub R. Parallels between arterial and cartilage calcification: what understanding artery calcification can teach us about chondrocalcinosis. Curr Opin Rheumatol 2003; 15:302-10. [PMID: 12707585 DOI: 10.1097/00002281-200305000-00019] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The pathogenesis of arterial calcification and chondrocalcinosis has become concurrently illuminated in recent years. For example, both processes occur in chronic inflammation-mediated degenerative diseases associated with aging (including atherosclerosis and osteoarthritis). Both processes are also modulated by altered gene expression by resident cells and by the release of mineralization-competent cell fragments (matrix vesicles and apoptotic bodies). Among the variety of genetic diseases associated with artery calcification are disorders that also promote cartilage calcification and/or dysregulated bone formation. Our discussion highlights that pathologic arterial and articular cartilage calcification both can be owing to genetic deficiencies of calcification inhibitors such as the inorganic pyrophosphate-generating ectoenzyme PC-1/nucleotide pyrophosphatase phosphodiesterase 1. Conversely, pathologic arterial and articular cartilage calcification also can primarily arise as a consequence of active processes driven by inflammatory cytokines and by disordered calcium and inorganic phosphate homeostasis. As discussed in this review, recent developments in the pathogenesis of arterial calcification provide valuable information pertinent to potential future advances in controlling chondrocalcinosis.
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Affiliation(s)
- Frank Rutsch
- Veterans Affairs Medical Center, University of California, San Diego School of Medicine, San Diego, California 92161, USA
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80
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Ketteler M, Wanner C, Metzger T, Bongartz P, Westenfeld R, Gladziwa U, Schurgers LJ, Vermeer C, Jahnen-Dechent W, Floege J. Deficiencies of calcium-regulatory proteins in dialysis patients: a novel concept of cardiovascular calcification in uremia. KIDNEY INTERNATIONAL. SUPPLEMENT 2003; 63:S84-7. [PMID: 12694317 DOI: 10.1046/j.1523-1755.63.s84.21.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Dialysis patients suffer a manifold increase in cardiovascular mortality when compared to a nonuremic population, while this phenomenon is not sufficiently explained by an increased prevalence of traditional risk factors, such as hypercholesterolemia and hypertension. The presence of hyperphosphatemia, of an increased calcium x phosphate product, as well as the magnitude of vascular and valvular calcifications, were recently identified as specific major risk factors of cardiovascular mortality in the uremic population. Furthermore, hyperphosphatemia and an increased calcium x phosphate product could be quantitatively linked to the burden of coronary artery calcification in young dialysis patients, suggesting the correction of hyperphosphatemia as the central target for preventive therapeutic intervention. Recent studies in knockout mice, however, point to the alternative possibility that deficiencies in calcium-regulatory proteins may represent important pathomechanisms leading to extraosseous calcifications. alpha 2-Heremans Schmid glycoprotein (Ahsg/fetuin) and matrix Gla protein (MGP) are strong inhibitors of calcification in vivo. Novel evidence that deficiencies of such proteins may be involved in the pathogenesis of cardiovascular calcifications in dialysis patients will be discussed.
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Affiliation(s)
- Markus Ketteler
- Department of Nephrology and Clinical Immunology, and IZKF BioMAT, University Hospital Aachen, Germany.
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Lee TC, O'Malley PG, Feuerstein I, Taylor AJ. The prevalence and severity of coronary artery calcification on coronary artery computed tomography in black and white subjects. J Am Coll Cardiol 2003; 41:39-44. [PMID: 12570942 DOI: 10.1016/s0735-1097(02)02618-9] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES We studied the relationship between coronary artery calcium (CAC) and race in asymptomatic, active-duty personnel in the Prospective Army Coronary Calcium (PACC) project. BACKGROUND Valid cardiovascular risk assessments in black Americans using coronary artery computed tomography (coronary CT) require the generalizability of population-based CAC score distributions derived from primarily white patient populations. METHODS Among 1,000 consecutive participants (mean age, 42 +/- 2 years; range, 40 to 45 years), 999 participants underwent coronary CT and indicated a specific racial affiliation. This included white, non-Hispanic in 699 (69.9%) participants and black, non-Hispanic in 194 (19.4%) participants. Univariate associations between race and cardiovascular risk variables were entered into a logistic regression model for CAC that also controlled for socioeconomic status and education. RESULTS Coronary artery calcium was nearly twice as prevalent in white (19.2%) than in black participants (10.3%) (p = 0.004). Black individuals had a threefold greater prevalence of hypertension, left ventricular hypertrophy, ST-T-wave abnormalities, and current cigarette smoking. Black subjects also had significantly greater blood pressure, high-density lipoprotein cholesterol, glycosylated hemoglobin, lipoprotein(a) and fibrinogen levels, and lower triglyceride levels and waist girth than white subjects. After adjustment for these differences, and socioeconomic adjusters, black individuals were 39% as likely to have any CAC present (odds ratio, 0.39; 95% confidence interval, 0.20 to 0.78; p = 0.007). CONCLUSIONS Despite a worse cardiovascular risk profile, black Americans have significantly less CAC than white Americans. The use of coronary CT as an accurate risk prediction tool in black Americans will require ethnic-specific data on the presence and severity of CAC.
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Affiliation(s)
- Timothy C Lee
- Cardiology, Walter Reed Army Medical Center, Washington, DC 20307, USA
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82
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Abstract
Changes in gene expression and regulation--due in particular to the evolution of cis-regulatory DNA sequences--may underlie many evolutionary changes in phenotypes, yet little is known about the distribution of such variation in populations. We present in this study the first survey of experimentally validated functional cis-regulatory polymorphism. These data are derived from more than 140 polymorphisms involved in the regulation of 107 genes in Homo sapiens, the eukaryote species with the most available data. We find that functional cis-regulatory variation is widespread in the human genome and that the consequent variation in gene expression is twofold or greater for 63% of the genes surveyed. Transcription factor-DNA interactions are highly polymorphic, and regulatory interactions have been gained and lost within human populations. On average, humans are heterozygous at more functional cis-regulatory sites (>16,000) than at amino acid positions (<13,000), in part because of an overrepresentation among the former in multiallelic tandem repeat variation, especially (AC)(n) dinucleotide microsatellites. The role of microsatellites in gene expression variation may provide a larger store of heritable phenotypic variation, and a more rapid mutational input of such variation, than has been realized. Finally, we outline the distinctive consequences of cis-regulatory variation for the genotype-phenotype relationship, including ubiquitous epistasis and genotype-by-environment interactions, as well as underappreciated modes of pleiotropy and overdominance. Ordinary small-scale mutations contribute to pervasive variation in transcription rates and consequently to patterns of human phenotypic variation.
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83
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Jain S, Tang X, Narayanan CS, Agarwal Y, Peterson SM, Brown CD, Ott J, Kumar A. Angiotensinogen gene polymorphism at -217 affects basal promoter activity and is associated with hypertension in African-Americans. J Biol Chem 2002; 277:36889-96. [PMID: 12145290 DOI: 10.1074/jbc.m204732200] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hypertension is a serious health problem in Western society, in particular for the African-American population. Although previous studies have suggested that the angiotensinogen (AGT) gene locus is involved in human essential hypertension, the molecular mechanisms involved in hypertension in African-Americans remain unknown. We show that an A/G polymorphism at -217 in the promoter of the AGT gene plays a significant role in hypertension in African-Americans. The frequency of the -217A allele was increased significantly in African-American hypertensive subjects compared with normotensive controls. We also show that the nucleotide sequence of this region of the AGT gene promoter bound strongly to CAAT/enhancer-binding protein (C/EBP) family transcription factors when nucleoside A was present at -217. In addition, we show that reporter constructs containing the human AGT gene promoter with nucleoside A at -217 had increased basal transcriptional activity upon transient transfection in HepG2 cells compared with reporter constructs with nucleoside G at -217. Finally, we show that interleukin-6 treatment in the presence or absence of overexpressed C/EBPbeta increased the promoter activities of reporter constructs containing nucleoside A at -217 compared with reporter constructs containing nucleoside G at -217. Because the AGT gene is expressed primarily in liver and adipose tissue, and C/EBP family transcription factors play an important role in gene expression in these tissues, we propose that increased transcriptional activity of the -217A allele of the human AGT gene is associated with hypertension in African-Americans.
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Affiliation(s)
- Sudhir Jain
- Department of Pathology, New York Medical College, Valhalla, New York 10595, USA
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84
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Demer LL, Tintut Y, Parhami F. Novel mechanisms in accelerated vascular calcification in renal disease patients. Curr Opin Nephrol Hypertens 2002; 11:437-43. [PMID: 12105395 DOI: 10.1097/00041552-200207000-00011] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
PURPOSE OF REVIEW Vascular calcification occurs more often and earlier in patients with end-stage renal disease than in normal controls. It is a regulated biological process following many of the cellular and molecular programs in osteogenesis. This review summarizes some of the regulatory mechanisms that may explain its severity in renal patients. RECENT FINDINGS A subpopulation of cells from arteries and cardiac valves produce a mineralizing matrix and undergo osteoblastic differentiation. Osteogenic differentiation regulators are found in calcified but not normal arteries. Phosphate levels have dramatic effects on vascular calcification in vitro, through a sodium phosphate transporter signaling molecular changes. Atherogenic oxidized lipids promote osteoblastic differentiation of vascular cells and inhibit bone mineralization. In uremic patients, the severity of dyslipidemia corresponds with the progression of vascular calcification. Oxidative stress and inflammatory mediators may underlie the effects of oxidized lipids. In dialysis patients, the degree of cardiac valvular calcification corresponds with levels of C-reactive protein. Genetic factors may also contribute. Polymorphisms of the inflammatory adhesion molecule, E-selectin, associate with coronary calcification in young women. Mice deficient in matrix GLA protein, which inhibits bone morphogenetic protein activity, develop complete ossification of the aorta, presumably as a result of unopposed osteogenic activity on vascular mesenchyme. Since matrix GLA protein function requires gamma-carboxylation of its glutamate residues by a vitamin K dependent carboxylase, warfarin treatment may affect vascular calcification by blocking vitamin K and hence matrix GLA protein activity. SUMMARY These findings indicate that vascular calcification is regulated both positively and negatively by a wide variety of mechanisms affecting patients with renal disease.
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Affiliation(s)
- Linda L Demer
- Departments of Medicine and Physiology, UCLA School of Medicine, Los Angeles, California, USA.
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85
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Udalova IA, Mott R, Field D, Kwiatkowski D. Quantitative prediction of NF-kappa B DNA-protein interactions. Proc Natl Acad Sci U S A 2002; 99:8167-72. [PMID: 12048232 PMCID: PMC123039 DOI: 10.1073/pnas.102674699] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We describe a general method based on principal coordinates analysis to predict the effects of single-nucleotide polymorphisms within regulatory sequences on DNA-protein interactions. We use binding data for the transcription factor NF-kappaB as a test system. The method incorporates the effects of interactions between base pair positions in the binding site, and we demonstrate that such interactions are present for NF-kappaB. Prediction accuracy is higher than with profile models, confirmed by crossvalidation and by the experimental verification of our predictions for additional sequences. The binding affinities of all potential NF-kappaB sites on human chromosome 22, together with the effects of known single-nucleotide polymorphisms, are calculated to determine likely functional variants. We propose that this approach may be valuable, either on its own or in combination with other methods, when standard profile models are disadvantaged by complex internucleotide interactions.
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Affiliation(s)
- Irina A Udalova
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK. iudalova@
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86
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Conceição N, Henriques NM, Ohresser MCP, Hublitz P, Schüle R, Cancela ML. Molecular cloning of the Matrix Gla Protein gene from Xenopus laevis. Functional analysis of the promoter identifies a calcium sensitive region required for basal activity. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:1947-56. [PMID: 11952797 DOI: 10.1046/j.1432-1033.2002.02846.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To analyze the regulation of Matrix Gla Protein (MGP) gene expression in Xenopus laevis, we cloned the xMGP gene and its 5' region, determined their molecular organization, and characterized the transcriptional properties of the core promoter. The Xenopus MGP (xMGP) gene is organized into five exons, one more as its mammalian counterparts. The first two exons in the Xenopus gene encode the DNA sequence that corresponds to the first exon in mammals whereas the last three exons show homologous organization in the Xenopus MGP gene and in the mammalian orthologs. We characterized the transcriptional regulation of the xMGP gene in transient transfections using Xenopus A6 cells. In our assay system the identified promoter was shown to be transcriptionally active, resulting in a 12-fold induction of reporter gene expression. Deletional analysis of the 5' end of the xMGP promoter revealed a minimal activating element in the sequence from -70 to -36 bp. Synthetic reporter constructs containing three copies of the defined regulatory element delivered 400-fold superactivation, demonstrating its potential for the recruitment of transcriptional activators. In gel mobility shift assays we demonstrate binding of X. laevis nuclear factors to an extended regulatory element from -180 to -36, the specificity of the interaction was proven in competition experiments using different fragments of the xMGP promoter. By this approach the major site of factor binding was demonstrated to be included in the minimal activating promoter fragment from -70 to -36 bp. In addition, in transient transfection experiments we could show that this element mediates calcium dependent transcription and increasing concentrations of extracellular calcium lead to a significant dose dependent activation of reporter gene expression.
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Ketteler M, Vermeer C, Wanner C, Westenfeld R, Jahnen-Dechent W, Floege J. Novel insights into uremic vascular calcification: role of matrix Gla protein and alpha-2-Heremans Schmid glycoprotein/fetuin. Blood Purif 2002; 20:473-6. [PMID: 12207096 DOI: 10.1159/000063554] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Cardiovascular mortality is markedly increased in the dialysis population when compared to non-uremic subjects. Vascular and valvular calcifications are most frequently found in dialysis patients at risk and are independent predictors of cardiovascular death in this population. Traditionally, the presence of hyperphosphatemia and an increased calcium x phosphate product was considered a major pathomechanistic condition leading to excessive vascular and soft-tissue calcifications in uremic subjects. Recent studies in knockout mice, however, revealed that deficiencies in calcium-regulatory proteins may also directly contribute to the development of extraosseus calcifications. alpha(2)-Heremans Schmid glycoprotein and matrix Gla protein are important inhibitors of calcification in vivo and there is novel evidence available that a deficiency in such proteins is involved in the pathogenesis of cardiovascular calcifications in dialysis patients.
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Affiliation(s)
- Markus Ketteler
- Department of Nephrology and Clinical Immunology, University Hospital Aachen, Germany.
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