Serum matrix metalloproteinase‐9 is elevated in men with a history of myocardial infarction

Dose-Dependent Inhibitory Effect of Rosuvastatin in Japanese Patients with Acute Myocardial Infarction on Serum Concentration of Matrix Metalloproteinases-INVITATION Trial

Aim: Matrix metalloproteinases (MMPs) play critical roles in acute myocardial infarction (AMI). This trial was conducted to determine the potential effects of higher-dose rosuvastatin on circulating MMP levels in patients with AMI.

Methods: This was a multicenter, open-label, 1:1 randomized, parallel-group study. Patients with AMI were randomly assigned to the appropriate-dose group (10 mg rosuvastatin once daily) or the low-dose group (2.5 mg rosuvastatin once daily) within 24 hours after percutaneous coronary intervention. MMP-2 and MMP-9 levels were measured on day 1 and at week 4, 12, and 24 after enrollment. The primary endpoint was the change in MMP levels at 24 weeks after enrollment. The secondary endpoints were change in MMP levels at day 1 and weeks 4 and 12 after enrollment.

Results: Between August 2017 and October 2018, 120 patients with AMI from 19 institutions were randomly assigned to either the appropriate-dose or the low-dose group. There were 109 patients who completed the 24-week follow-up. The primary endpoint for both MMP-2 and MMP-9 was not significantly different between the two groups. The change in the active/total ratio of MMP-9 at week 12 after baseline was significantly lower in the appropriate-dose group compared with the low-dose group (0.81 [−52.8–60.1]% vs. 70.1 [−14.5–214.2]%, P =0.004), while the changes in MMP-2 were not significantly different between the two groups during the study period.

Conclusions: This study could not demonstrate the superiority of appropriate-dose of rosuvastatin in inhibiting serum MMPs levels in patients with AMI.

Oxidative/Antioxidative Status in Patients after Myocardial Infarction and in Those without Cardiovascular Event Depending on Anthropometric Factors Defining Body Weight

Obesity is one of the factors leading to the development of atherosclerosis. This metabolic disorder is associated with an increased production of reactive oxygen species, which affect the oxidative stress levels. The aim of this study was to evaluate oxidative/antioxidative status and to investigate the correlation between redox markers and anthropometric parameters and body composition in adult patients after myocardial infarction and in individuals without a cardiovascular event in the past. Descriptive data on socio-demographic, clinical, and anthropometric features and blood samples were collected and categorized into two equal groups: after myocardial infarction (study group (SG), n = 80) and without a cardiovascular event (control group (CG), n = 80). The oxidative/antioxidative status was assessed in plasma on the basis of total oxidative/capacitive status (PerOx), total antioxidative status/capacity (ImAnOx), and oxidized low-density lipoprotein (oxLDL). The oxLDL was significantly higher in the CG group compared to the SG group (p = 0.02). No significant differences were found with regard to PerOx and ImAnOx values between the groups studied. A significant positive correlation between PerOx and percentage of adipose tissue (FM%) and body adiposity index (BAI) was found in the two studied groups. ImAnOx significantly positively correlated with visceral adiposity indexes(VAIs) in SG and FM% in CG. OxLDL negatively correlated with body mass index and waist to hip circumference ratio in CG. The total oxidative/antioxidative status is related to the amount of adipose tissue and the BAIs of the subjects. It was observed that it correlates more frequently with the visceral distribution of body fat.

Reversal effect of Zhigancao decoction on myocardial fibrosis in a rapid pacing-induced atrial fibrillation model in New Zealand rabbits

Objective

To evaluate the effect of Zhigancao decoction on reversal of right atrial myocardial fibrosis after rapid atrial pacing (RAP)-induced atrial fibrillation (AF).

Methods

New Zealand white rabbits were randomly divided into four groups: sham operation group (Group A: implanted electrodes, no RAP), pacing group (Group B: RAP-induced AF), Zhigancao soup water decoction Yin group (Group C: RAP-induced AF followed by Zhigancao soup Yin prescription twice a day for 30 days), and Zhigancao soup group (Group D: RAP-induced AF followed by Zhigancao water decoction twice a day for 30 days). The atrial myocardium was then examined for myocardial fibrosis by Masson staining, and protein expression of matrix metalloproteinase-9 (MMP-9) was immunohistochemically assessed. The right atrial appendage tissue field action potential duration (fAPD) was measured by microelectrode arrays.

Results

RAP successfully induced AF. Myocardial fibrosis was more severe in Groups B and C and less severe in Group D. Protein expression of MMP-9 was strongly positive in Groups B and C and weakly positive in Group D. The fAPD was significantly decreased in Groups B and C, but the decrease in Group D was not significant.

Conclusion

Zhigancao decoction can reverse AF-induced myocardial fibrosis in rabbits and shorten the fAPD.

Lysophosphatidic Acid Is Associated with Atherosclerotic Plaque Instability by Regulating NF-κB Dependent Matrix Metalloproteinase-9 Expression via LPA2 in Macrophages

Lysophosphatidic acid (LPA), one of the simplest phospholipid signaling molecules, participates in formation and disruption of atherosclerotic plaque. Matrix metalloproteinases (MMPs) contribute to atherosclerotic plaque rupture by involving in extracellular matrix (ECM) degradation and then thinning fibrous cap. Our previous study demonstrated that macrophage-derived MMP-9 was associated with coronary plaque instability, but the relationship between LPA and MMP-9 remains unclear. The present work therefore aimed at elucidating association between LPA and MMP-9 and the regulation mechanism of LPA on MMP-9 in macrophages. We found that plasma LPA and MMP-9 levels were correlated positively (r = 0.31, P < 0.05) and both elevated significantly in patients with acute myocardial infarct (AMI). Consistent with peripheral blood levels, histochemical staining indicated that autotaxin (ATX), LPA-producing ectoenzyme, and MMP-9 were expressed frequently in the necrotic core and fibrous cap of human unstable plaques, which might increase the instability of plaque. Experiments in vitro were done with THP-1-derived macrophages and showed that LPA enhanced the expression, secretion and activity of MMP-9 in a time- and dose-dependent manner. Induction of LPA on pro-MMP-9 and active-MMP-9 was confirmed in human peripheral blood monocyte-derived macrophages. PDTC, NF-κB inhibitor, but not inhibitor of AP-1 and PPARγ, effectively prevented LPA-induced MMP-9 expression and NF-κB p65 siRNA decreased MMP-9 transcription, confirming that LPA might induce MMP-9 elevation by activating NF-κB pathway. In addition, knockdown of LPA₂ attenuated LPA-induced MMP-9 expression and nucleus p65 levels. These findings revealed that LPA upregulated the expression of MMP-9 through activating NF-κB pathway in the LPA₂ dependent manner, hence blocking LPA receptors signaling may provide therapeutic strategy to target plaque destabilization.

Neutrophil proteolytic activation cascades: a possible mechanistic link between chronic periodontitis and coronary heart disease

Cardiovascular diseases are chronic inflammatory diseases that affect a large segment of society. Coronary heart disease (CHD), the most common cardiovascular disease, progresses over several years and affects millions of people worldwide. Chronic infections may contribute to the systemic inflammation and enhance the risk for CHD. Periodontitis is one of the most common chronic infections that affects up to 50% of the adult population. Under inflammatory conditions the activation of endogenous degradation pathways mediated by immune responses leads to the release of destructive cellular molecules from both resident and immigrant cells. Matrix metalloproteinases (MMPs) and their regulators can activate each other and play an important role in immune response via degrading extracellular matrix components and modulating cytokines and chemokines. The action of MMPs is required for immigrant cell recruitment at the site of inflammation. Stimulated neutrophils represent the major pathogen-fighting immune cells that upregulate expression of several proteinases and oxidative enzymes, which can degrade extracellular matrix components (e.g. MMP-8, MMP-9 and neutrophil elastase). The activity of MMPs is regulated by endogenous inhibitors and/or candidate MMPs (e.g. MMP-7). The balance between MMPs and their inhibitors is thought to mirror the proteolytic burden. Thus, neutrophil-derived biomarkers, including myeloperoxidase, may activate proteolytic destructive cascades that are involved in subsequent immune-pathological events associated with both periodontitis and CHD. Here, we review the existing studies on the contribution of MMPs and their regulators to the infection-related pathology. Also, we discuss the possible proteolytic involvement and role of neutrophil-derived enzymes as an etiological link between chronic periodontitis and CHD.

Matrix metalloproteinases are involved in cardiovascular diseases

This MiniReview describes the essential biochemical and molecular aspects of matrix metalloproteinases (MMPs) and briefly discusses how they engage in different diseases, with particular emphasis on cardiovascular diseases. There is compelling scientific evidence that many MMPs, especially MMP-2, play important roles in the development of cardiovascular diseases; inhibition of these enzymes is beneficial to many cardiovascular conditions, sometimes precluding or postponing end-organ damage and fatal outcomes. Conducting comprehensive discussions and further studies on how MMPs participate in cardiovascular diseases is important, because inhibition of these enzymes may be an alternative or an adjuvant for current cardiovascular disease therapy.

Changes in matrix metalloproteinase-9 levels during progression of atrial fibrillation

OBJECTIVES

To observe levels of matrix metalloproteinase (MMP)-9 and evaluate their significance in various stages of idiopathic atrial fibrillation (AF).

METHODS

Patients with idiopathic AF were recruited into this prospective study and classified into one of three groups according to stage of disease progression: paroxysmal AF; persistent AF; permanent AF. Healthy individuals were enrolled as control subjects. Serum levels of MMP-9 in all four groups were determined using a double-antibody sandwich enzyme-linked immunosorbent assay.

RESULTS

Each AF group included 25 patients; 40 healthy individuals were included as controls. MMP-9 levels in the three AF groups were significantly higher than in the control group: 168.72 ± 25.970, 201.36 ± 31.26 and 253.20 ± 22.99 ng/ml for the paroxysmal, persistent and permanent AF groups respectively, versus 76.80 ± 14.90 ng/ml for the control group. MMP-9 levels increased with idiopathic AF disease progression (P < 0.05).

CONCLUSIONS

An elevated MMP-9 level appears to be associated with a diagnosis of AF. MMP-9 levels appear to increase in relation to the stage of idiopathic AF progression.

Matrix metalloproteinases and myocardial infarction

Acute myocardial infarction (AMI) is currently one of the most important health problems in many countries around the world. Following AMI, many cytokines and proteolytic enzymes are released. Among these, matrix metalloproteinases (MMPs) are important proteolytic enzymes that lead to degradation of the extracellular matrix and to changes in cardiomyocytes in both infarcted and noninfarcted myocardium. This process is known as cardiac remodelling. It has been demonstrated that more than one type of MMP is present in the circulation after cardiomyocyte injury. A number of studies have demonstrated the correlations between these MMP levels and the severity of a coronary lesion, the progression of left ventricular dimension and the survival rate following AMI in both animal and human studies. MMPs have also been proposed as a possible novel prognostic indicator for myocardial infarction patients. Although the use of MMP inhibitors to improve cardiac outcome in AMI patients has been investigated, discrepancies in the results from those studies indicate that further research is still needed to warrant their beneficial effects. In the present review article, the roles of MMPs as prognostic indicators, as well as the factors influencing MMP expression, are discussed. Current findings on the role of MMP inhibitors in cardiac remodelling and the prognosis after AMI in both animal models and clinical studies are also examined.

Effect of a short-term diet and exercise intervention in youth on atherosclerotic risk factors

Early stages of atherosclerosis are commonly noted in youth. The present study was designed to examine the effects of lifestyle modification in 19 overweight children (age 8-17) who were placed on a high-fiber, low-fat diet in a 2-week residential program where food was provided ad libitum and daily exercise (2-2.5h) was performed. In each subject, pre- and post-intervention fasting blood was drawn to measure serum lipids, oxidative stress marker 8-isoprostaglandin F2alpha (8-iso-PGF2alpha) and generating enzyme myeloperoxidase (MPO), soluble intracellular adhesion molecule (sICAM)-1 and sE-selectin as indicators of endothelial activation, the inflammatory protein C-reactive protein (CRP) and total matrix metalloproteinase-9 (MMP-9). Using subject sera and human aortic endothelial cell (HAEC) culture systems, monocyte chemotactic protein-1 (MCP-1) production, as well as nitric oxide (NO), superoxide and hydrogen peroxide production were measured in vitro by fluorometric detection. After 2 weeks, significant reductions (p<0.05) in all serum lipids (except HDL cholesterol), 8-iso-PGF2alpha, MPO, sICAM-1, sE-selectin, CRP, MMP-9, and cellular MCP-1 production were noted. Additionally, there was a significant decrease in cultured, serum-stimulated HAEC production of superoxide and hydrogen peroxide, and a concomitant increase in NO production (all p<0.01), These results indicate amelioration of several traditional as well as novel factors associated with atherosclerosis after lifestyle modification, even in youth without documented disease.

Toll-like receptor 4 polymorphism is associated with coronary stenosis but not with the occurrence of acute or old myocardial infarctions

OBJECTIVE

Atherosclerosis is considered to be a chronic inflammatory disease. Toll-like receptor 4 (TLR-4), a key mediator in activating inflammatory cascade, has an A-to-G functional polymorphism that changes aspartic acid to glycine at position 299. TLR-4 is activated by, for example, lipopolysaccharides. The purpose of this study was to investigate the role of a common Asp299Gly polymorphism of the TLR-4 gene in atherosclerosis.

MATERIAL AND METHODS

The study comprised autopsy material from 657 men (the Helsinki Sudden Death Study; mean age 53, range 33-70 years).

RESULTS

Fewer G-allele carriers had 3-vessel coronary artery disease compared with AA homozygotes (OR 0.32; 95 % CI, 0.12-0.88, p = 0.027), and they also had a lower mean value for maximal coronary stenosis (p = 0.019). TLR-4 polymorphism was not significantly associated with the occurrence of acute or old myocardial infarction (MI).

CONCLUSIONS

The G allele of the TLR-4 gene, which is associated with a lower inflammation response, was associated with a lower risk of coronary stenosis but not with the occurrence of MI and hence is not a major factor in the development of coronary atherosclerosis.

Levels of matrix metalloproteinases-8 and -9 with simultaneous presence of periodontal pathogens in gingival crevicular fluid as well as matrix metalloproteinase-9 and cholesterol in blood

BACKGROUND AND OBJECTIVES

To investigate the levels of matrix metalloproteinase (MMP) -8 and -9 with the simultaneous presence of periodontal pathogens in gingival crevicular fluid (GCF) as well as MMP-9 and cholesterol in blood. Although bacterial pathogens are required to initiate the periodontal disease process, in some individuals the reaction to bacteria may lead to an excessive host response, resulting in a general inflammatory response.

METHODS

MMP-9 and lipids were analyzed from the blood samples of 33 subjects with a 16-year history and oral health records of periodontal disease as well as from 31 periodontally healthy controls. Information was obtained on education, body mass index, and family history of atherosclerosis. GCF was taken to determine MMP-8 and MMP-9 levels, and bacterial samples were simultaneously collected for polymerase chain reaction assessment of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, Tannerella forsythia, and Treponema denticola. Analysis of variance, chi-squared test, and multiple logistic regression analysis were used to analyze the results.

RESULTS

Demographic data showed significant differences between patients and controls in smoking (P < 0.01), body mass index (P < 0.05), family history of atherosclerotic disease (P < 0.01), and education (P < 0.01). Significant differences were also observed in oral health data, in the detection of P. gingivalis (P < 0.001), P. intermedia (P < 0.01), P. nigrescens (P < 0.001), and T. forsythia (P < 0.001) and in the levels of MMP-8 and MMP-9 in GCF between patients and controls. T. forsythia[odds ratio(OR) 10.1; P = 0.001] and age (OR 5.54; P = 0.008) appeared to be the main independent predictors for high MMP-8 in GCF. Patients had significantly higher total cholesterol (P < 0.01), low-density lipoprotein cholesterol (P = 0.05), and triglycerides (P < = 0.01) than controls. Plasma levels of MMP-9 were significantly higher in patients than in controls (P = 0.001).

CONCLUSIONS

Specific periodontal microorganisms appeared to induce host response, with increased release of MMP-8 and MMP-9 in gingival pockets as well as of MMP-9 in plasma, possibly triggering its up-regulation in blood.

Matrix metalloproteinases in cerebral ischemia

Matrix metalloproteinases (MMPs) are involved in the pathophysiology of several central nervous system diseases that share common pathogeneses, such as disruption of the blood-brain barrier (BBB), neuroinflammation, oxidative stress, and remodeling of the extracellular matrix (ECM). In early ischemic injury, MMPs participate in disruption of the BBB by digesting the basal lamina of capillaries and ECM, leading to vasogenic edema and hemorrhagic transformation. However, ECM degradation and remodeling are essential for tissue recovery, with MMPs having a key role as modulators of homeostasis between neuronal death and tissue regeneration. Thus, MMPs may be a double-edged sword that has a deleterious or beneficial role depending on the stage of brain injury.

Effect of a short-term diet and exercise intervention on oxidative stress, inflammation, MMP-9, and monocyte chemotactic activity in men with metabolic syndrome factors

The present study was designed to examine the effects of lifestyle modification on key contributing factors to atherogenesis, including oxidative stress, inflammation, chemotaxis, and cell adhesion. Obese men ( n = 31), 15 of whom had metabolic syndrome, were placed on a high-fiber, low-fat diet in a 3-wk residential program where food was provided ad libitum and daily aerobic exercise was performed. In each subject, pre- and postintervention fasting blood was drawn for circulating levels of serum lipids, glucose and insulin (for estimation of insulin sensitivity), oxidative stress-generating enzyme myeloperoxidase and marker 8-isoprostaglandin F2α, the inflammatory protein C-reactive protein, soluble ICAM-1 as an indicator of endothelial activation, sP-selectin as a marker of platelet activation, the chemokine macrophage inflammatory protein-1α, and total matrix metalloproteinase-9. Using subject sera and human aortic endothelial cell culture systems, we measured VCAM-1 cell surface abundance and monocyte chemotactic protein-1, nitric oxide, superoxide, and hydrogen peroxide production in vitro by fluorometric detection. Also determined in vitro was serum-induced, monocyte adhesion and monocyte chemotactic activity. After 3 wk, significant reductions ( P < 0.05) in body mass index, all serum lipids and lipid ratios, fasting glucose, insulin, homeostasis model assessment for insulin resistance, myeloperoxidase, 8-isoprostaglandin F2α, C-reactive protein, soluble ICAM-1, soluble P-selectin, macrophage inflammatory protein-1α, and matrix metalloproteinase-9 were noted. In vitro, serum-stimulated cellular VCAM-1 expression, monocyte chemotactic protein-1 production, and fluorometric detection of superoxide and hydrogen peroxide production decreased, whereas a concomitant increase in NO production was noted (all P < 0.01). Additionally, both monocyte adhesion ( P < 0.05) and MCA ( P < 0.01) decreased. Nine of 15 were no longer positive for metabolic syndrome postintervention. Intensive lifestyle modification may ameliorate novel coronary artery disease risk factors in men with metabolic syndrome factors before reversal of obesity.

Serum matrix metalloproteinase-9 and venous bypass graft occlusion

OBJECTIVE

The primary results after coronary artery bypass grafting are good, but early clinical events as a result of graft occlusion are still a problem. Early occlusions are thought to be due to thrombosis or fibrointimal hyperplasia superimposed by thrombosis, but the etiology of these phenomena is not fully understood. Matrix metalloproteinase-9 has been suggested to have a role in graft occlusion ex vivo.

MATERIAL AND METHODS

We investigated whether the level of serum matrix metalloproteinase-9 reflects its proposed role in occlusion of vein grafts. The study population consisted of 30 men with a history of myocardial infarction and 31 men without myocardial infarction who had undergone coronary artery bypass grafting. All the men were asymptomatic.

RESULTS

Among the patients with no previous myocardial infarction, serum matrix metalloproteinase-9 level was significantly higher in those with graft occlusion than in those without occlusion (54.0+/-11.0 microg/L and 41.7+/-10.4 microg/L, respectively, p = 0.006), and it correlated positively with the number of occluded grafts (R = 0.55, p = 0.001). In the patients with myocardial infarction, this effect was not detected.

CONCLUSIONS

Serum matrix metalloproteinase-9 reflected the occurrence of vein graft occlusion in subjects with no previous history of myocardial infarction.

Physiological matrix metalloproteinase concentrations in serum during childhood and adolescence, using Luminex Multiplex technology

Matrix metalloproteinases are a family of zinc-dependent proteinases which are involved in the breakdown and remodeling of extracellular matrix. As children grow and adolescents reach pubescence, their bodies undergo changes that require age-related morphogenesis of the extracellular matrix, possibly requiring unique patterns of matrix metalloproteinase (MMP) expression during periods of rapid tissue growth (i.e., childhood) or accelerated tissue remodeling and expansion (i.e., adolescence). Therefore, we have characterized age-specific and gender-specific differences in circulating concentrations of MMPs (specifically MMP-1, -2, -3, -8 and -9) in 189 serum samples obtained from healthy subjects, aged 2-18 years. MMP concentrations were measured using Fluorokine MultiAnalyte Profiling kits and a Luminex Bioanalyzer, as well as by commercial ELISA. Serum levels of MMP-1, -2, -3, -8, and -9 in healthy pediatric subjects represent log-normal distributions. MMP-2 was significantly negatively correlated with age (r=-0.29; p<0.001), while MMP-3 was significantly positively correlated with age (r=0.38; p<0.001). Although plasma, not serum, is considered the appropriate blood sample for measurement of MMP-8 and -9, serum levels of MMP-8 and -9 were also found to be highly positively correlated with each other (r=0.76; p<0.01). MMP results obtained by Fluorokin MultiAnalyte Profiling methods correlated well with conventional ELISA methods and use of this technology provided several advantages over ELISA.

Decursin Inhibits Induction of Inflammatory Mediators by Blocking Nuclear Factor-κB Activation in Macrophages

In the course of screening inhibitors of matrix metalloproteinase (MMP)-9 induction in macrophages, we isolated decursin, a coumarin compound, from the roots of Angelicae gigas. As a marker for the screening and isolation, we tested expression of MMP-9 in RAW264.7 cells and THP-1 cells after treatment with bacterial lipopolysaccharide (LPS), the TLR-4 ligand. Decursin suppressed MMP-9 expression in cells stimulated by LPS in a dose-dependent manner at concentrations below 60 microM with no sign of cytotoxicity. The suppressive effect of decursin was observed not only in cells stimulated with ligands for TLR4, TLR2, TLR3, and TLR9 but also in cells stimulated with interleukin (IL)-1beta, and tumor necrosis factor (TNF)-alpha, indicating that the molecular target of decursin is common signaling molecules induced by these stimulants. In addition to the suppression of MMP-9 expression, decursin blocked nitric oxide production and cytokine (IL-8, MCP-1, IL-1beta, and TNF-alpha) secretion induced by LPS. To find out the molecular mechanism responsible for the suppressive effect of decursin, we analyzed signaling molecules involved in the TLR-mediated activation of MMP-9 and cytokines. Decursin blocked phosphorylation of IkappaB and nuclear translocation of NF-kappaB in THP-1 cells activated with LPS. Furthermore, expression of a luciferase reporter gene under the promoter containing NF-kappaB binding sites was blocked by decursin. These data indicate that decursin is a novel inhibitor of NF-kappaB activation in signaling induced by TLR ligands and cytokines.

Matrix Metalloproteinase-9 Is a Marker of Heart Failure After Acute Myocardial Infarction

BACKGROUND

Matrix metalloproteinases (MMPs) have been associated with the development of left ventricular remodeling after myocardial infarction (MI). We sought to determine whether peripheral levels of MMPs can be used as a risk marker for the development of congestive heart failure (CHF) after acute MI.

METHODS AND RESULTS

Plasma levels of MMP-2, MMP-9, C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-alpha), and pro-brain natriuretic peptide (pro-BNP) were measured in 109 consecutive patients with acute MI treated with primary mechanical reperfusion. Echocardiographic assessment of left ventricular wall motion index was performed during admission. Patients were followed for the development of CHF. Left ventricular function and volumes were determined after 2 years with radionuclide ventriculography. During 2-year follow-up, 15 patients developed congestive heart failure (CHF). Using multivariate analysis, MMP-9 levels were the only circulating factor predictive of late onset CHF. Patients who had high MMP-9 levels had a significant risk of late onset CHF (OR of 6.5, P < or = .006) and left ventricular remodeling (DeltaEF = -9%, P = .03, and Deltaend-diastolic volume = +13 mL, P = .03). MMP-2, TNF-alpha, hs-CRP, creatine kinase, and pro-BNP were not predictive of late onset CHF.

CONCLUSION

MMP-9 levels may hold prognostic significance in MI patients.

Matrix Metalloproteinase-9 (MMP-9), MMP-2, and Serum Elastase Activity Are Associated With Systolic Hypertension and Arterial Stiffness

Background— Arterial stiffness is an independent determinant of cardiovascular risk, and arterial stiffening is the predominant abnormality in systolic hypertension. Elastin is the main elastic component of the arterial wall and can be degraded by a number of enzymes, including matrix metalloproteinase-9 (MMP-9) and MMP-2. We hypothesized that elastase activity would be related to arterial stiffness and tested this using isolated systolic hypertension (ISH) as a model of stiffening and separately in a large cohort of healthy individuals.

Methods and Results— A total of 116 subjects with ISH and 114 matched controls, as well as 447 individuals free from cardiovascular disease were studied. Aortic and brachial pulse wave velocity (PWV) and augmentation index were determined. Blood pressure, lipids, C-reactive protein, MMP-9, MMP-2, serum elastase activity (SEA), and tissue-specific inhibitor 2 of metalloproteinases were measured. Aortic and brachial PWV, MMP-9, MMP-2, and SEA levels were increased in ISH subjects compared with controls ( P =0.001). MMP-9 levels correlated linearly and significantly with aortic ( r =0.45; P =0.001) and brachial PWV ( r =0.22; P =0.002), even after adjustments for confounding variables. In the younger, healthy subjects, MMP-9 and SEA were also independently associated with aortic PWV.

Conclusions— Aortic stiffness is related to MMP-9 levels and SEA, not only in ISH, but also in younger, apparently healthy individuals. This suggests that elastases including MMP-9 may be involved in the process of arterial stiffening and development of ISH.