Matrix degrading proteases in vascular disease

Diverse processes of vascular disease including lesion growth, plaque rupture and abdominal aortic aneurysm formation are influenced by protease expression. Arteries undergo compensatory remodelling when the mechanical forces that are imposed on them are altered. During growth of an atherosclerotic lesion there is an accumulation of inflammatory cells and extracellular matrix. The neointima formation with accumulation of macrophages and smooth muscle cells has been associated with increased amounts of proteases in the vascular wall. However, further investigation of the proteases are necessary to determine their diverse and overlapping roles in the progression of vascular disease. In the present studies, we have identified three functional polymorphisms within the promoter regions of MMP-7 and MMP-12. In the MMP-7 promoter we found two polymorphisms located at -181 with an A to G substitution and the other one at -153 with a C to T substitution. Both of the MMP-7 polymorphisms were associated with a higher transcription rate in vitro together with smaller coronary artery luminal dimensions in vivo in a subgroup of hypercholesterolaemic patients. The MMP-12 promoter polymorphism is an A to G substitution located at -82. The polymorphism influences the binding of transcription factor activator protein-1, which is an important regulator of MMP transcription. Further, this allele specific regulation is influenced by insulin in vitro, and in a preliminary study, the polymorphism influenced luminal diameter in patients with diabetes. When examining the differential expression of proteases during the progression of atherosclerosis, we found that the expression levels of cathepsins were high, and varied over time and location. In particular, cathepsins S showed an extensive expression in the fibrous plaque and medial smooth muscle cell layer. These results indicate that there may be a role for the cysteine and aspartic proteases in atherogenesis and plaque rupture. When investigating the impact of functional polymorphisms in the promoter regions of three different MMPs on abdominal aortic aneurysm, we found that the growth rate of aneurysms appears to be influenced by a variation in the MMP-2 gene. These results indicate that there is a causative relationship between MMP-2 activity and abdominal aortic aneurysm progression. Taken together, the results support the hypothesis that matrix-degrading proteases may influence the progression of vascular disease. In addition, we show that there are other proteases, the cathepsins, with a potential role in the process of atherosclerosis. Taken together, the importance of individual proteases seems to vary at different stages of vascular disease

Differential Expression of Cysteine and Aspartic Proteases during Progression of Atherosclerosis in Apolipoprotein E-Deficient Mice

Several groups of proteolytic enzymes are able to degrade components of the extracellular matrix. During atherosclerosis, matrix remodeling is believed to influence the migration and proliferation of cells within the plaque. In the present study, gene expression of several proteases and their inhibitors was analyzed during the development of atherosclerosis in apolipoprotein E-deficient (ApoE−/−) mice. Quantitative real-time polymerase chain reaction was used to study gene expression of proteases after 10 and 20 weeks in ApoE−/− and C57BL/6 mice and in atherosclerotic lesions and nonaffected regions of the same ApoE−/− mouse. Some of the differentially expressed proteolytic enzymes were studied by immunohistochemistry. The matrix metalloproteinase (MMP)-9 and its inhibitor TIMP-1 were differentially expressed and the expression increased with time. Urokinase-type plasminogen activator showed no major expression. In contrast, cathepsins B, D, L, and S all showed strong and increased expression in ApoE−/− mice compared to C57BL/6 mice whereas the expression of their inhibitor, cystatin C, did not differ between the two mouse strains. The expression of cathepsins was mainly localized to the lesions and not to nonaffected regions of the aorta of ApoE−/− mice. Furthermore, cathepsin expression was similar to the expression of the macrophage marker macrosialin (CD68) although expression of cathepsins B, D, and L could be demonstrated in healthy C57BL/6 mice and in nonaffected vessel segments of atherosclerotic ApoE−/− mice. Cathepsin S mRNA expression was restricted to lesions of ApoE−/− mice. Furthermore, cathepsin S was the only cathepsin that was expressed in the media and absent in lipid-rich regions. All cathepsins studied showed intimal expression, the degree and localization of which differed between individual cathepsins. In conclusion, increased expression of several cathepsins in atherosclerotic lesions suggests that these proteases may participate in the remodeling of extracellular matrix associated with the atherosclerotic process

Analysis of MMP-7 and TIMP-2 gene polymorphisms in coronary artery disease and myocardial infarction: A Turkish case-control study

YILMAZ, AKIN/0000-0002-4368-0777WOS: 000394727100004PubMed: 28137415Matrix metalloproteinase (MMP) and tissue inhibitors of metalloproteinase (TIMP) have a significant role in tissue remodeling related to cardiac function. In earlier studies, MMP-7A-181G (rs11568818), C-153T (rs11568819), C-115T (rs17886546), and TIMP-2 G-418-C (rs8179090) polymorphisms have been studied in various diseases. However, association between coronary artery disease (CAD) and these polymorphisms has been poorly studied. The goal of this study is to investigate the association of CAD and myocardial infarction (MI) with MMP-7 or TIMP-2 polymorphisms. This study included 122 CAD patients and 132 control individuals. DNA was extracted from whole blood. Polymerase chain reaction-restriction fragment length polymorphism and automated direct sequencing method were used for genotyping of these polymorphisms. No significant differences were found between MMP-7 A-181G, C-115T, and TIMP-2 G-418C polymorphism and CAD or MI in a Turkish population. Despite the fact that the genotypes of MMP-7C-153T polymorphism had no significant differences among MI and control groups, allele frequencies of C-153T polymorphism were significantly different between the two groups. Our study is the first report to clarify the appreciable relationship between MMP-7 C-153T polymorphism and MI development in CAD patients. However, these findings also need to be confirmed in other populations so we can improve our knowledge about the genetic factors affecting the development of CAD. Copyright (C) 2017, Kaohsiung Medical University. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Gazi University Research FundGazi University [11/2004-84]The authors are very thankful to all volunteers who participated in this study. We are also thankful to Hacer Ilke Onen and Mehmet Galip Icduygu for valuable contribution. This study was partially supported by Gazi University Research Fund as a project with code number 11/2004-84