Matrix metalloproteinases and coronary artery diseases

Development of Matrix Metalloproteinases-Mediated Extracellular Matrix Remodeling in Regenerative Medicine: A Mini Review

Extracellular matrix (ECM) components confer biomechanical properties, maintain cell phenotype and mediate tissue homeostasis. ECM remodeling is complex and plays a key role in both physiological and pathological processes. Matrix metalloproteinases (MMPs) are a group of enzymes responsible for ECM degradation and have been accepted as a key regulator in ECM remodeling. In this mini-review, we summarize MMPs categories, functions and the targeted substrates. We then discuss current understanding of the role of MMPs-mediated events, including inflammation reaction, angiogenesis, cellular activities, etc., in ECM remodeling in the context of regenerative medicine.

Association of the Polymorphism rs3918242 of the Matrix Metalloproteinase-9 Gene with Coronary Artery Disease in a Younger Population

Coronary artery disease (CAD) is a complex disease resulting from the interaction of numerous so-called traditional risk factors and comorbid conditions on the one side (such as dyslipidemia, smoking, obesity, diabetes, hypertension) and genetic factors on the other. The evidence of a genetic contribution to the development of CAD, especially in the last 2 decades is consistent. It is important that a number of established gene polymorphisms in the younger CAD population are in the genes involved in the inflammatory response and tissue maintenance and remodeling processes. The aim of this study is to investigate the association of the rs3918242 polymorphism of the matrix metal-loproteinase 9 (MMP9) gene with the coronary artery disease in the younger population. In this observational genetic-association study of cases and controls, the demographic, clinical, laboratory and genetic data of the younger population in a group of selected 70 CAD patients aged up to 45 years were analyzed, of which 35 patients have negative and 35 have positive coronary angiography finding, and 43 are men and 27 are women. The analysis of the genotypic and allelic frequency determined an association of the polymorphism and the occurrence of the positive coronary angiographic findings in the population of patients under the age of 45. The carriers of the heterozygous genotype CT have almost 5 times higher probability of having a positive coronary angiography finding compared to the carriers of the reference homozygous genotype CC (p=0.012). Thus, this parameter could be used for clinical risk assessment for the development of CAD.

Transcription factors: key regulatory targets of vascular smooth muscle cell in atherosclerosis

Atherosclerosis (AS), leading to gradual occlusion of the arterial lumen, refers to the accumulation of lipids and inflammatory debris in the arterial wall. Despite therapeutic advances over past decades including intervention or surgery, atherosclerosis is still the most common cause of cardiovascular diseases and the main mechanism of death and disability worldwide. Vascular smooth muscle cells (VSMCs) play an imperative role in the occurrence of atherosclerosis and throughout the whole stages. In the past, there was a lack of comprehensive understanding of VSMCs, but the development of identification technology, including in vivo single-cell sequencing technology and lineage tracing with the CreERT2-loxP system, suggests that VSMCs have remarkable plasticity and reevaluates well-established concepts about the contribution of VSMCs. Transcription factors, a kind of protein molecule that specifically recognizes and binds DNA upstream promoter regions or distal enhancer DNA elements, play a key role in the transcription initiation of the coding genes and are necessary for RNA polymerase to bind gene promoters. In this review, we highlight that, except for environmental factors, VSMC genes are transcriptionally regulated through complex interactions of multiple conserved cis-regulatory elements and transcription factors. In addition, through a series of transcription-related regulatory processes, VSMCs could undergo phenotypic transformation, proliferation, migration, calcification and apoptosis. Finally, enhancing or inhibiting transcription factors can regulate the development of atherosclerotic lesions, and the downstream molecular mechanism of transcriptional regulation has also been widely studied.

To study the dynamics of serum levels of vascular remodeling in patients with hypertension, including in combination with type 2 diabetes mellitus during 12‑month therapy with perindopril A

Aim      To study the dynamics of serum markers for vascular remodeling in patients with arterial hypertension (AH), including AH associated with type 2 diabetes mellitus (DM2) during the 12-month treatment with the angiotensin-converting enzyme (ACE) inhibitor, perindopril A.Material and methods  The study included patients with grade 1-2 AH with or without type 2 DM (30 and 32, respectively). Perindopril A 10 mg/day was administered for the outpatient correction of previous, ineffective antihypertensive therapy. The following biomarkers were measured for all patients at baseline and at 12 months: matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), E-selectin, endothelin 1, transforming growth factor β-1 (TGF-β1), and von Willebrand factor (WF). Laboratory tests were performed with enzyme immunoassay.Results After 12 months of the perindopril A (perindopril arginine) 10 mg/day treatment, both groups achieved the goal blood pressure. Evaluation of biomarker dynamics during the perindopril A treatment showed significant decreases in MMP-9, TIMP-1, and endothelin 1 in the AH group; then the level of TIMP-1 returned to normal values (р<0.05). In the AH+DM2 group, the MMP-9 concentration was significantly decreased (р<0.05); the other values did not show any significant differences. In both groups, MMP-9 was significantly decreased (28.6 % (р=0.01) in group 1 and 33.2 % (р=0.00) in group 2. Notably, in none of these groups, did this index reach normal values. Also, there were no significant differences in this index between the groups (р=0.66). It should be noted that the decreases in TIMP-1 were significantly different between the groups (р=0.001). Thus, this biomarker did not significantly decrease in patients with AH and DM2 (р=0.26) whereas in group 1 (AH without DM2), the level of TIMP-1 decreased by 39.3 % and reached the normal range (р=0.005).Conclusion      Concentrations of biomarkers were decreased in both groups. However, in the AH group, there were statistically significant decreases in the markers that reflect processes of fibrosis and vasoconstriction. At the same time in the AH+DM2 group, there was no significant dynamics of the biomarkers, which was most likely due to more pronounced damage of blood vessels. However, the decrease in MMP-9 may indicate an alleviation of fibrotic processes in arterial walls. These results allow a conclusion that the long-term treatment with the ACE inhibitor, perindopril A, may reverse remodeling of the vascular changes that are called "early vascular ageing".r aging".

A High-Cholesterol Diet Increases Toll-like Receptors and Other Harmful Factors in the Rabbit Myocardium: The Beneficial Effect of Statins

Background: A high-cholesterol diet (HCD) induces vascular atherosclerosis through vascular inflammatory and immunological processes via TLRs. The aim of this study is to investigate the mRNA expression of TLRs and other noxious biomarkers expressing inflammation, fibrosis, apoptosis, and cardiac dysfunction in the rabbit myocardium during (a) high-cholesterol diet (HCD), (b) normal diet resumption and (c) fluvastatin or rosuvastatin treatment. Methods: Forty-eight male rabbits were randomly divided into eight groups (n = 6/group). In the first experiment, three groups were fed with HCD for 1, 2 and 3 months. In the second experiment, three groups were fed with HCD for 3 months, followed by normal chow for 1 month and administration of fluvastatin or rosuvastatin for 1 month. Control groups were fed with normal chow for 90 and 120 days. The whole myocardium was removed; total RNA was isolated from acquired samples, and polymerase chain reaction, reverse transcription PCR and quantitative real-time PCR were performed. Results: mRNA of TLRs 2, 3, 4 and 8; interleukin-6; TNF-a; metalloproteinase-2; tissue inhibitor of metalloproteinase-1; tumor protein 53; cysteinyl aspartate specific proteinase-3; and brain natriuretic peptide (BNP) increased in HCD. Statins but not resumption of a normal diet decreased levels of these biomarkers and increased levels of antifibrotic factors. Conclusions: HCD increases the levels of TLRs; inflammatory, fibrotic and apoptotic factors; and BNP in the rabbit myocardium. Atherogenic diets adversely affect the myocardium at a molecular level and are reversed by statins.

OCT4 regulated neointimal formation in injured mouse arteries by matrix metalloproteinase 2-mediated smooth muscle cells proliferation and migration

The excessive proliferation and migration of vascular smooth muscle cells (VSMCs) play vital roles in neointimal hyperplasia and vascular restenosis. In the present study, we aimed to investigate the function and mechanism of octamer-binding transcription factor 4 (OCT4, a key transcription factor for maintaining stem cells in de-differentiated state) on neointima formation in response to vascular injury. Quantitative reverse-transcription polymerase chain reaction and western blot results displayed a significant increase of OCT4 levels in injured carotid arteries. Immunohistochemistry and immunofluorescence assays confirmed that the increased OCT4 expression was primarily localized in α-SMA-positive VSMCs from neointima, and colocalized with PCNA in the nuclei of VSMCs. Adenovirus-mediated OCT4 overexpression in injured carotid arteries exacerbated intimal thickening, while OCT4 knockdown significantly inhibited intimal thickening. In-vitro experiments confirmed that the increased OCT4 expression in VMSCs could be induced by platelet-derived growth factor-BB (PDGF-BB) in a time-dependent manner. Overexpression of OCT4 greatly promoted VSMCs proliferation and migration, while OCT4 knockdown significantly retarded the PDGF-BB-induced excessive proliferation and migration of VSMCs. Bioinformatics analysis, dual-luciferase reporter assay, and chromatin immunoprecipitation assay confirmed that OCT4 could upregulate matrix metalloproteinases 2 (MMP2) expression through promoting its transcription. Moreover, knockdown of MMP2 significantly attenuated OCT4-mediated VSMCs proliferation and migration. These results indicated that OCT4 facilitated neointimal formation in response to vascular injury by MMP2-mediated VSMCs proliferation and migration, and targeting OCT4 in VSMCs might be a novel therapeutic strategy for vascular restenosis.

Effects of moderate aerobic exercise on thoracic aortic remodeling of female LDL-receptor knockout ovariectomized mice

Menopause is a major factor involved in dyslipidemia increasing the risk of atherosclerosis which may be reversed by a routine of aerobic physical activity. Thus, this study aimed to analyze the effects of aerobic training on the thoracic aorta of female LDL-receptor knockout mice submitted to estrogen deprivation. Fifteen genetically modified female mice, knockout for the low-density lipoprotein receptor (LDL-Knockout group) were used as experimental groups and fifteen wild female mice (C57BL/6 J) were used as control groups. Animals were divided as (n = 5/per group): sedentary control (SC); sedentary control ovariectomized (SCO); trained control ovariectomized (TCO); LDL-Knockout sedentary (KS); LDL-Knockout sedentary ovariectomized (KOS); and LDL-Knockout trained ovariectomized (KOT). Immunohistochemical techniques for TIMP-1 and metalloproteinases 2 and 9 were used to evaluate thoracic aorta remodeling. Picrosirius stain was used to highlight the collagen fibers. Verhoff-Van Gienson was used for the quantitative analyses of elastic lamellae. Our results demonstrate a positive remodeling promoted by physical exercise in ovariectomized and dyslipidemic animals. However, further studies are needed including the evaluation of inflammatory markers present in dyslipidemia.

Exploring the role of extracellular matrix proteins to develop biomarkers of plaque vulnerability and outcome

Cardiovascular disease (CVD) is the most common cause of death in industrialized countries. One underlying cause is atherosclerosis, which is a systemic disease characterized by plaques of retained lipids, inflammatory cells, apoptotic cells, calcium and extracellular matrix (ECM) proteins in the arterial wall. The biologic composition of an atherosclerotic plaque determines whether the plaque is more or less vulnerable, that is prone to rupture or erosion. Here, the ECM and tissue repair play an important role in plaque stability, vulnerability and progression. This review will focus on ECM remodelling in atherosclerotic plaques, with focus on how ECM biomarkers might predict plaque vulnerability and outcome.

Does Arterial Hypertension Affect Plasma Levels of Matrix Metalloproteinases and Their Tissue Inhibitors in Patients with Stable Coronary Artery Disease? A Preliminary Study

Background

Arterial hypertension (HT) is a serious and prevalent epidemiological factor in the development of coronary artery disease (CAD). Metalloproteinases (MMPs), especially MMP-2 and MMP-9, and their natural endogenous tissue inhibitors (TIMPs) are involved in the pathogenesis of HT and its complications. MMPs are also involved in the development of diabetes (DM), a risk factor for CAD. The aim of the study was to explore the influence of CAD, HT, and DM on changes in plasma levels of MMP-2 and MMP-9 and their inhibitor TIMP-4.

Methods and Results

The study involved 70 patients with stable CAD admitted for coronary angiography and 15 healthy subjects. Whole blood samples were collected prior to angiography. MMP-2, MMP-9, and TIMP-4 levels in plasma were estimated using ELISA tests. CAD patients showed a significantly increased level of TIMP-4 and decreased level of MMP-2 in comparison to healthy controls (p=0.011 and p=0.037, respectively). Concentration of MMP-2, MMP-9, and TIMP-4 did not differ in the group with and without hypertension. Patients with DM presented higher MMP-2 level than patients without DM (p < 0.001). Multiple regression analysis of the influence of independent variables such as CAD stage, DM, and HT on MMP-2, MMP-9, and TIMP-4 showed that only DM was independently associated with a higher level of MMP-2 (β = 0.42, R² = 0.17, p < 0.001).

Conclusion

Data showed that patients with CAD presented higher TIMP-4 and lower MMP-2 concentration regardless of HT and DM. HT had no effect on MMP-2, MMP-9, and TIMP-4 levels in serum. DM was independently associated with higher MMP-2 concentration; however, co-occurrence of CAD and DM was associated with the balance in the MMP-2 level. Concentration of MMP-9 did not change significantly in any of the analysed groups.

The influence of low-grade inflammation on platelets in patients with stable coronary artery disease

Inflammation is likely to be involved in all stages of atherosclerosis. Numerous inflammatory biomarkers are currently being studied, and even subtle increases in inflammatory biomarkers have been associated with increased risk of cardiovascular events in patients with coronary artery disease (CAD). Low-grade inflammation may influence both platelet production and platelet activation potentially leading to enhanced platelet aggregation. Thrombopoietin is considered the primary regulator of platelet production, but it likely acts in conjunction with numerous cytokines, of which many have altered levels in CAD. Previous studies have shown that high-sensitive C-reactive protein (CRP) independently predicts increased platelet aggregation in stable CAD patients. Increased levels of CRP, fibrinogen, interleukin-6, stromal cell-derived factor-1, CXC motif ligand 16, macrophage migration inhibitory factor, RANTES, calprotectin, and copeptin have been associated with increased risk of cardiovascular events in CAD patients. Additionally, some of these inflammatory markers have been associated with enhanced platelet activation and aggregation. However, CRP and other inflammatory markers provide only limited additional predictive value to classical risk factors such as smoking, blood pressure, and cholesterol levels. Existing data do not clarify whether inflammation simply accompanies CAD and increased production and aggregation of platelets, or whether a causal relationship exists. In this review, we provide a comprehensive overview of inflammatory markers in stable CAD with particular emphasis on platelet production, activation, and aggregation in CAD patients.

Matrix Metalloproteinases, Vascular Remodeling, and Vascular Disease

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that degrade various proteins in the extracellular matrix (ECM). Typically, MMPs have a propeptide sequence, a catalytic metalloproteinase domain with catalytic zinc, a hinge region or linker peptide, and a hemopexin domain. MMPs are commonly classified on the basis of their substrates and the organization of their structural domains into collagenases, gelatinases, stromelysins, matrilysins, membrane-type (MT)-MMPs, and other MMPs. MMPs are secreted by many cells including fibroblasts, vascular smooth muscle (VSM), and leukocytes. MMPs are regulated at the level of mRNA expression and by activation through removal of the propeptide domain from their latent zymogen form. MMPs are often secreted in an inactive proMMP form, which is cleaved to the active form by various proteinases including other MMPs. MMPs degrade various protein substrates in ECM including collagen and elastin. MMPs could also influence endothelial cell function as well as VSM cell migration, proliferation, Ca²⁺ signaling, and contraction. MMPs play a role in vascular tissue remodeling during various biological processes such as angiogenesis, embryogenesis, morphogenesis, and wound repair. Alterations in specific MMPs could influence arterial remodeling and lead to various pathological disorders such as hypertension, preeclampsia, atherosclerosis, aneurysm formation, as well as excessive venous dilation and lower extremity venous disease. MMPs are often regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs), and the MMP/TIMP ratio often determines the extent of ECM protein degradation and tissue remodeling. MMPs may serve as biomarkers and potential therapeutic targets for certain vascular disorders.

Matrix Metalloproteinase Inhibitors as Investigational and Therapeutic Tools in Unrestrained Tissue Remodeling and Pathological Disorders

Matrix metalloproteinases (MMPs) are zinc-dependent proteolytic enzymes that degrade various proteins in the extracellular matrix (ECM). MMPs may also regulate the activity of membrane receptors and postreceptor signaling mechanisms and thereby affect cell function. The MMP family includes collagenases, gelatinases, stromelysins, matrilysins, membrane-type MMPs, and other MMPs. Inactive proMMPs are cleaved by other MMPs or proteases into active MMPs, which interact with various protein substrates in ECM and cell surface. MMPs regulate important biological processes such as vascular remodeling and angiogenesis and may be involved in the pathogenesis of cardiovascular disorders such as hypertension, atherosclerosis, and aneurysm. The role of MMPs is often assessed by measuring their mRNA expression, protein levels, and proteolytic activity using gel zymography. MMP inhibitors are also used to assess the role of MMPs in different biological processes and pathological conditions. MMP activity is regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs), and the MMP/TIMP balance could determine the net MMP activity, ECM turnover, and tissue remodeling. Also, several synthetic MMP inhibitors have been developed. Synthetic MMP inhibitors include a large number of zinc-binding globulins (ZBGs), in addition to non-ZBGs and mechanism-based inhibitors. MMP inhibitors have been proposed as potential tools in the management of osteoarthritis, cancer, and cardiovascular disorders. However, most MMP inhibitors have broad-spectrum actions on multiple MMPs and could cause undesirable musculoskeletal side effects. Currently, doxycycline is the only MMP inhibitor approved by the Food and Drug Administration. New generation biological and synthetic MMP inhibitors may show greater MMP specificity and fewer side effects and could be useful in targeting specific MMPs, reducing unrestrained tissue remodeling, and the management of MMP-related pathological disorders.

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

Matrix metalloproteinase (MMP) and tissue inhibitors of metalloproteinase (TIMP) have a significant role in tissue remodeling related to cardiac function. In earlier studies, MMP-7 A-181G (rs11568818), C-153T (rs11568819), C-115T (rs17886546), and TIMP-2 G-418C (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-7 C-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.

Role of proteases in the pathophysiology of cardiac disease

Cardiovascular disease is a major cause of death and thus a great deal of effort has been made in salvaging the diseased myocardium. Although various factors have been identified as possible causes of different cardiac diseases such as heart failure and ischemic heart disease, there is a real need to elucidate their role for the better understanding of the cardiac disease pathology and formulation of strategies for developing newer therapeutic interventions. In view of the intimate involvement of different types of proteases in maintaining cellular structure, the role of proteases in various cardiac diseases has become the focus of recent research. Proteases are present in the cytosol as well as are localized in a number of subcellular organelles in the cell. These are known to use extracellular matrix, cytoskeletal, sarcolemmal, sarcoplasmic reticular, mitochondrial and myofibrillar proteins as substrates. Work from different laboratories using a wide variety of techniques has shown that the activation of proteases causes alterations of a number of specific proteins leading to subcellular remodeling and cardiac dysfunction. Inhibition of protease action by different drugs and agents, therefore, has a clinical relevance and is expected to form a part of new treatment paradigm for improving heart function. This review examines the biochemistry and localization of some of the proteases in the cardiac tissue in addition to identification of the sites of action of some protease inhibitors. (Mol Cell Biochem 263: 241-256, 2004).

Effect of improving dietary quality on carotid intima media thickness in subjects with type 1 and type 2 diabetes: a 12-mo randomized controlled trial

BACKGROUND

People with diabetes are at a heightened risk of cardiovascular disease compared with the general population. To our knowledge, randomized controlled trials investigating the effect of improving dietary quality on carotid intima media thickness, a marker of subclinical atherosclerosis and predictor of cardiovascular disease, have not been conducted in populations with diabetes.

OBJECTIVE

We aimed to determine whether increasing fruit (+1 serving; 150 g/d), vegetable (+2 servings; 150 g/d), and dairy (+1 serving; 200-250 g/d) intakes slows 12-mo common carotid artery intima media thickness (CCA IMT) progression, compared with a control group continuing to consume their usual diet, in people with type 1 and type 2 diabetes.

DESIGN

A 12-mo randomized controlled trial was conducted. The primary outcome was mean CCA IMT, measured at baseline and 12 mo, with B-mode ultrasound. Participants in the intervention group received counseling from a dietitian at baseline and 1, 3, 6, and 9 mo, and compliance was measured with a food-frequency questionnaire at baseline, 3 mo, and 12 mo. The control group continued consuming their usual diet.

RESULTS

In total, 118 participants completed the study. Vegetable (46 g/d; 95% CI: 14, 77 g/d; P < 0.001) and fruit (179 g/d; 95% CI: 119, 239 g/d; P < 0.001) intakes were increased at 3 mo in the intervention group compared with the control group. This increase was not maintained at 12 mo, but intake increased overall in the cohort (fruit, 48 g/d; vegetables, 14 g/d). An increase in dairy consumption was not achieved, but yogurt intake was higher in the intervention group at 3 mo (38 g; 95% CI: 12, 65 g; P < 0.001); this was not maintained at 12 mo. At 12 mo, CCA IMT regressed (mean ± SD: -0.01 ± 0.04 mm; P < 0.001), with a greater effect in the treatment group (mean ± SD: -0.02 ± 0.04 mm compared with -0.004 ± 0.04 mm; P = 0.009).

CONCLUSION

Improving dietary quality in people with well-controlled type 1 and type 2 diabetes may slow CCA IMT progression. This trial was registered at https://www.anzctr.org.au as ACTRN12613000251729.

Matrix metalloproteinases in biologic samples

Matrix metalloproteinases (MMPs) are an important class of endopeptidases, having a role in a diverse range of physiological and pathological processes. This chapter provides an overview of the key regulatory processes in MMP production and activation. The common techniques used to assess MMP activity are discussed and their various strengths and weaknesses presented. This comparison of methodologies is specifically intended to aid any investigator who wishes to determine the most appropriate analytical method for their future studies because any investigation of MMPs in biological samples should be cognizant of the key mechanisms influencing the expression and activity of these proteinases. The endogenous, preanalytic and analytic chemistry of MMP activation influences the interpretation of the various techniques widely employed throughout the literature. Therefore, the ability to accurately evaluate the true endogenous activity of MMPs is heavily dependent on a clear understanding of these processes.

Pharmacogenomics in the development and characterization of atheroprotective drugs

Atherosclerosis is the main cause of cardiovascular disease (CVD) and can lead to stroke, myocardial infarction, and death. The clinically available atheroprotective drugs aim mainly at reducing the levels of circulating low-density lipoprotein (LDL), increasing high-density lipoprotein (HDL), and attenuating inflammation. However, the cardiovascular risk remains high, along with morbidity, mortality, and incidence of adverse drug events. Pharmacogenomics is increasingly contributing towards the characterization of existing atheroprotective drugs, the evaluation of novel ones, and the identification of promising, unexplored therapeutic targets, at the global molecular pathway level. This chapter presents highlights of pharmacogenomics investigations and discoveries that have contributed towards the elucidation of pharmacological atheroprotection, while opening the way to new therapeutic approaches.

Clinical study of the hypothesis of endogenous collateral wind on acute coronary syndrome: a review

BACKGROUND

Acute Coronary Syndrome (ACS), is a serious threat to people's health, and life, and in recent years, the incidence has increased yearly. This study was to propose the hypothesis of "endogenous collateral wind" based on the patho-mechanism of thrombogenesis complicated by ruptured plaque on ACS, and the theory of traditional Chinese medicine.

MATERIALS AND METHODS

Through successful coronary angiography (CAG), and intravascular ultrasound (IVUS), patients with coronary artery disease were made the differential diagnosis such as blood stasis, blood stasis due to phlegm obstruction, and endogenous collateral wind. The levels of plasma inflammatory marker were measured to study on the characteristics of "endogenous collateral wind". Luo heng dripping pills with promoting blood circulation to expel wind-evil, and remove wetness were made based on the hypothesis of "endogenous collateral wind" on ACS. Patients with unstable angina were randomly divided into 3, groups based on therapeutic methods: conventional therapy group, Luo Heng dripping pills group and Tongxinluo caps. Differences among groups were compared.

RESULTS

There were great changes in number and degree of coronary arteriostenosis confirmed by CAG, the types of ACC/AHA lesion and Levin lesion confirmed by CAG, remodeling index, positive or negative remodeling percentage measured by IVUS, the plasma levels of plasma inflammatory marker measured by ELLSA in the patients with endogenous collateral wind, compared with patients with blood stasis and blood stasis due to phlegm obstruction. The total effective rate of improved angina in Luo Heng dripping pills group was significantly higher than those in other two groups. The levels of plasma inflammatory marker were significantly lower in Luo Heng dripping pills group.

CONCLUSION

There were some pathological basis which were found about the hypothesis of "endogenous collateral wind" on acute coronary syndrome. It provided evidences for patients with coronary artery disease treated by medicines with expelling evil-wind, and removing wetness.

Inflammatory biomarkers for predicting cardiovascular disease

The pathology of cardiovascular disease (CVD) is complex; multiple biological pathways have been implicated, including, but not limited to, inflammation and oxidative stress. Biomarkers of inflammation and oxidative stress may serve to help identify patients at risk for CVD, to monitor the efficacy of treatments, and to develop new pharmacological tools. However, due to the complexities of CVD pathogenesis there is no single biomarker available to estimate absolute risk of future cardiovascular events. Furthermore, not all biomarkers are equal; the functions of many biomarkers overlap, some offer better prognostic information than others, and some are better suited to identify/predict the pathogenesis of particular cardiovascular events. The identification of the most appropriate set of biomarkers can provide a detailed picture of the specific nature of the cardiovascular event. The following review provides an overview of existing and emerging inflammatory biomarkers, pro-inflammatory cytokines, anti-inflammatory cytokines, chemokines, oxidative stress biomarkers, and antioxidant biomarkers. The functions of each biomarker are discussed, and prognostic data are provided where available.

Angiotensin II enhances AT1-Nox1 binding and stimulates arterial smooth muscle cell migration and proliferation through AT1, Nox1, and interleukin-18

The redox-sensitive transcription factors NF-κB and activator protein-1 (AP-1) are critical mediators of ANG II signaling. The promitogenic and promigratory factor interleukin (IL)-18 is an NF-κB- and AP-1-responsive gene. Therefore, we investigated whether ANG II-mediated smooth muscle cell (SMC) migration and proliferation involve IL-18. ANG II induced rat carotid artery SMC migration and proliferation and IL-18 and metalloproteinase (MMP)-9 expression via ANG II type 1 (AT(1)) receptor. ANG II-induced superoxide generation, NF-κB and AP-1 activation, and IL-18 and MMP-9 induction were all markedly attenuated by losartan, diphenyleneiodonium chloride (DPI), and Nox1 knockdown. Similar to ANG II, addition of IL-18 also induced superoxide generation, activated NF-κB and AP-1, and stimulated SMC migration and proliferation, in part via Nox1, and both ANG II and IL-18 induced NOX1 transcription in an AP-1-dependent manner. AT(1) physically associates with Nox1 in SMC, and ANG II enhanced this binding. Interestingly, exogenous IL-18 neither induced AT(1) binding to Nox1 nor enhanced the ANG II-induced increase in AT(1)/Nox1 binding. Importantly, IL-18 knockdown, or pretreatment with IL-18 neutralizing antibodies, or IL-18 binding protein, all attenuated the migratory and mitogenic effects of ANG II. Continuous infusion of ANG II for 7 days induced carotid artery hyperplasia in rats via AT(1) and was associated with increased AT(1)/Nox1 binding (despite lower AT(1) levels); increased DPI-inhibitable superoxide production; increased phospho-IKKβ, JNK, p65, and c-Jun; and induction of IL-18 and MMP-9 in endothelium-denuded carotid arteries. These results indicate that IL-18 amplifies the ANG II-induced, redox-dependent inflammatory cascades by activating similar promitogenic and promigratory signal transduction pathways. The ANG II/Nox1/IL-18 pathway may be critical in hyperplastic vascular diseases, including atherosclerosis and restenosis.

Matrix metalloproteinase inhibitors as investigative tools in the pathogenesis and management of vascular disease

Matrix metalloproteinases (MMPs) are proteolytic enzymes that degrade various components of the extracellular matrix (ECM). MMPs could also regulate the activity of several non-ECM bioactive substrates and consequently affect different cellular functions. Members of the MMPs family include collagenases, gelatinases, stromelysins, matrilysins, membrane-type MMPs, and others. Pro-MMPs are cleaved into active MMPs, which in turn act on various substrates in the ECM and on the cell surface. MMPs play an important role in the regulation of numerous physiological processes including vascular remodeling and angiogenesis. MMPs may also be involved in vascular diseases such as hypertension, atherosclerosis, aortic aneurysm, and varicose veins. MMPs also play a role in the hemodynamic and vascular changes associated with pregnancy and preeclampsia. The role of MMPs is commonly assessed by measuring their gene expression, protein amount, and proteolytic activity using gel zymography. Because there are no specific activators of MMPs, MMP inhibitors are often used to investigate the role of MMPs in different physiologic processes and in the pathogenesis of specific diseases. MMP inhibitors include endogenous tissue inhibitors (TIMPs) and pharmacological inhibitors such as zinc chelators, doxycycline, and marimastat. MMP inhibitors have been evaluated as diagnostic and therapeutic tools in cancer, autoimmune disease, and cardiovascular disease. Although several MMP inhibitors have been synthesized and tested both experimentally and clinically, only one MMP inhibitor, i.e., doxycycline, is currently approved by the Food and Drug Administration. This is mainly due to the undesirable side effects of MMP inhibitors especially on the musculoskeletal system. While most experimental and clinical trials of MMP inhibitors have not demonstrated significant benefits, some trials still showed promising results. With the advent of new genetic and pharmacological tools, disease-specific MMP inhibitors with fewer undesirable effects are being developed and could be useful in the management of vascular disease.

Involvement of calcium-sensing receptor in oxLDL-induced MMP-2 production in vascular smooth muscle cells via PI3K/Akt pathway

Matrix metalloproteinase-2 (MMP-2) is constitutively expressed in vascular smooth muscle cells (VSMCs) and up-regulated in atherosclerotic lesion by various stimuli, such as oxidized low-density lipoprotein (oxLDL). Calcium-sensing receptor (CaSR) is also expressed in VSMCs, but it remains unclear whether CaSR is associated with overproduction of MMP-2 in VSMCs. In this study, the expression of MMP-2 was detected by real-time PCR and Western blot analysis, and the gelatinolytic activity of MMP-2 was measured using gelatin zymography. Our results showed that oxLDL enhanced MMP-2 expression and activity in rat aortic VSMCs in a time- and dose-dependent manner. In addition, CaSR expression was up-regulated by oxLDL. Manipulating CaSR function in these cells by NPS2390 (an antagonist of CaSR) or GdCl(3) (an agonist of CaSR) affected the oxLDL-induced MMP-2 production. In VSMCs, oxLDL stimulated the rapid activation of phosphatidylinositol 3-kinase (PI3K)/Akt signal pathway, as determined by Western blot analysis. Phosphorylation of Akt and MMP-2 production stimulated by oxLDL were attenuated by LY294002 (a specific inhibitor of PI3K). Activation of Akt was suppressed by NPS2390 but enhanced by GdCl(3). In contrast, oxLDL had no stimulatory effect on the phosphorylation of JNK, and pretreatment with SP600125 (an inhibitor of JNK) produced no significant effect on oxLDL-induced MMP-2 production. These results suggest that CaSR mediates oxLDL-induced MMP-2 production in VSMCs via PI3K/Akt signal pathway.

The effect of the expression of angiotensin II on extracellular matrix metalloproteinase inducer (EMMPRIN) in macrophages is mediated via the AT1/COX-2/PGE2 pathway

AIM

To explore the expression of extracellular matrix metalloproteinase inducer (EMMPRIN) in THP-1 macrophages induced by angiotensin II (Ang II) and the mechanism of EMMPRIN expression.

METHODS

THP-1 cells were cultured and induced into macrophages, then stimulated with 10(-6) mol/L Ang II. Levels of EMMPRIN gene and its protein were measured by real-time polymerase chain reaction and western blotting. Prostaglandin E(2) (PGE(2)) expression was assayed by enzyme-linked immunosorbent assay. Antagonists of the angiotensin type-1 receptor (AT(1)R) and angiotensin type-2 receptor (AT(2)R) were used to inhibit the effect of Ang II, and PGE(2) added to detail the mechanism of Ang II-induced EMMPRIN expression.

RESULTS

Ang II clearly induced the expression of EMMPRIN mRNA and protein in macrophages; this expression peaked at 12 h and declined after 24 h. The tendency of enhancement of the levels of cyclooxygenase-2 (COX-2) and PGE(2) was coincident with EMMPRIN expression. AT(1)-receptor antagonists and COX-2 inhibitors inhibited the effect of Ang II, but AT(2)-receptor antagonists did not.

CONCLUSION

Ang II can up-regulate EMMPRIN expression in THP-1 macrophages via the AT(1)/COX-2/PGE(2) signal transduction pathway, and the effect can be inhibited by losartan and NS-398.

IL-17 stimulates migration of carotid artery vascular smooth muscle cells in an MMP-9 dependent manner via p38 MAPK and ERK1/2-dependent NF-kappaB and AP-1 activation

Inappropriate vascular remodeling is thought to be the main cause of restenosis following angioplasty. Migration of vascular smooth muscle cells (VSMC) into lumina, which is promoted by degradation of the extracellular matrix by matrix metalloproteinases (MMPs) plays a causal role in pathological vascular remodeling. The aim of the present research is to explore the effects of a novel cytokine, IL-17, on migration of VSMC and MMP-9 secretion. Carotid artery VSMC was isolated from Sprague-Dawley rats. Expression of MMP-9 and cell migration induced by IL-17 and its related signal pathway were detected. The results showed that IL-17-induced migration of VSMC in an MMP-9-dependent manner. IL-17-induced MMP-9 expression was via p38 MAPK and ERK1/2 dependent NF-kappaB and AP-1 activation. The present results demonstrated that IL-17 may play a role in vascular remodeling and targeting IL-17 or its specific downstream mediators is a potentially novel therapeutic pathway for attenuating the post-angioplastic restenosis.

Genetic and cellular evidence of vascular inflammation in neurofibromin-deficient mice and humans

Neurofibromatosis type 1 (NF1) results from mutations in the NF1 tumor suppressor gene, which encodes the protein neurofibromin. NF1 patients display diverse clinical manifestations, including vascular disease, which results from neointima formation and vessel occlusion. However, the pathogenesis of NF1 vascular disease remains unclear. Vessel wall homeostasis is maintained by complex interactions between vascular and bone marrow-derived cells (BMDCs), and neurofibromin regulates the function of each cell type. Therefore, utilizing cre/lox techniques and hematopoietic stem cell transplantation to delete 1 allele of Nf1 in endothelial cells, vascular smooth muscle cells, and BMDCs alone, we determined which cell lineage is critical for neointima formation in vivo in mice. Here we demonstrate that heterozygous inactivation of Nf1 in BMDCs alone was necessary and sufficient for neointima formation after vascular injury and provide evidence of vascular inflammation in Nf1+/- mice. Further, analysis of peripheral blood from NF1 patients without overt vascular disease revealed increased concentrations of inflammatory cells and cytokines previously linked to vascular inflammation and vasoocclusive disease. These data provide genetic and cellular evidence of vascular inflammation in NF1 patients and Nf1+/- mice and provide a framework for understanding the pathogenesis of NF1 vasculopathy and potential therapeutic and diagnostic interventions.

Modification of vascular and inflammation biomarkers after OGTT in overweight healthy and diabetic subjects

We evaluated the effect of an oral glucose tolerance test (OGTT) on the level of biomarkers of vascular remodelling. We enrolled 256 Caucasian overweight healthy subjects (H) and 274 overweight type 2 diabetic patients (D). All patients underwent basal measurements of blood glucose (BG), nitrites/nitrates, adiponectin (ADP), matrix metalloproteinase-2 (MMP-2), and matrix metalloproteinase-9 (MMP-9) before and after OGTT. Nitrites/nitrates decrease was present after 60, 90, 120, and 180 min in both groups. Nitrite/nitrate levels were decreased at baseline, after 30 and 60 min in D group compared to H group. ADP decrease was present after 90, 120, and 180 min, in both groups. ADP levels were lower in D group than in H group during OGTT. MMP-2 increase was present after 60, 90, and 120 min in H group, while MMP-2 increase was observed after 90, 120, and 180 min in D group. MMP-2 levels were higher in D group than in H group during OGTT. MMP-9 increase was present in H group after 60, 90, 120, and 180 min, while MMP-9 increase was observed after 90, 120, and 180 min in D group. MMP-9 levels were higher in D group than in H group during OGTT. Postprandial glycemia induces an acute increase in biomarkers of vascular remodelling.

Total panax notoginsenosides prevent atherosclerosis in apolipoprotein E-knockout mice: Role of downregulation of CD40 and MMP-9 expression

Total panax notoginsenosides (TPNS) are the main active ingredients in San-Chi, the root of Panax notoginseng (Burk) F.H. Chen, which belongs to the Araliaceae family and has been used in traditional Chinese medicine to treat atherosclerosis. We investigated the effect of TPNS on serum lipid levels and cell differentiation antigen 40 (CD40) and matrix metalloproteinase 9 (MMP-9) expression in atherosclerosis in apolipoprotein E-knockout (apoE-KO) mice fed a high-fat, high-cholesterol diet. Twenty-four apoE-KO mice were divided into two groups, the ApoE-KO group and the ApoE-KO + TPNS group. TPNS (60 mg/kg) was orally administered daily for 12 weeks in ApoE-KO + TPNS group. After 12 weeks, blood and aortas were obtained. Serum levels of lipid were analyzed, serum oxidized low density lipoprotein (oxLDL) concentration, ratio of plaque area-to-vessel area and the expression of CD40 and MMP-9 were examined by ELISA, histological staining, immunohistochemistry and real-time PCR, respectively. It was observed in our study that serum levels of lipid and oxLDL, ratio of plaque area to vessel area, and expression of CD40 and MMP-9 were lower in the ApoE-KO + TPNS group than in the ApoE-KO group. These results suggest that TPNS could prevent atherosclerosis by lowering serum lipid levels and regulating vascular CD40 and MMP-9 expression. TPNS may have implications for clinical treatment of atherosclerosis vascular disease.

Effects of long chain omega-3 fatty acids on metalloproteinases and their inhibitors in combined dyslipidemia patients

We evaluate the effect of a standardized dietary supplementation with omega-3 polyunsaturated fatty acids (n-3 PUFAs) on the level of some markers of vascular remodeling in patients with combined dyslipidemia. Three hundred and thirty-three patients received placebo or n-3 PUFAs for 6 months. We evaluated body mass index, glycemic profile, blood pressure, lipid profile, lipoprotein(a), plasminogen activator inhibitor-1, homocysteine, fibrinogen, high-sensitivity C reactive protein, ADP, MMP-2 and MMP-9, and tissue inhibitors of metalloproteinase-1 and -2. A significant increase of high-density lipoprotein-cholesterol, and a significant decrease of triglycerides were present after 3 and 6 months with n-3 PUFAs intake. A significant plasminogen activator inhibitor-1, fibrinogen and high-sensitivity C reactive protein decrease was obtained after 3 and 6 months and a significant ADP increase was observed after 3 and 6 months of n-3 PUFAs. A significant MMP-2, MMP-9, tissue inhibitors of metalloproteinase-1 and tissue inhibitors of metalloproteinase-2 decrease was obtained after 6 months compared to the baseline value with n-3 PUFAs intake. n-3 PUFAs give a better lipid profile and a better improvement of coagulation, fibrinolytic and inflammatory parameters than placebo. Furthermore, lowers levels of MMP-2, MMP-9 and their tissue inhibitors are obtained with n-3 PUFAs compared to placebo.

Ceramide: a common pathway for atherosclerosis?

Plasma sphingomyelin concentration is correlated with the development of atherosclerosis. It has been found to exist in significantly higher concentrations in aortic plaque. This appears to have clinical relevance as well as it has been shown to be an independent predictor of coronary artery disease. Ceramide, the backbone of sphingolipids, is the key component which affects atherosclerotic changes through its important second-messenger role. This paper sheds light on some of the current literature supporting the significance of ceramide with respect to its interactions with lipids, inflammatory cytokines, homocysteine and matrix metalloproteinases. Furthermore, the potential therapeutic implications of modulating ceramide concentrations are also discussed.

Matrix metalloproteinases and their inhibitors in vascular remodeling and vascular disease

Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes that degrade various components of the extracellular matrix (ECM). Members of the MMP family include collagenases, gelatinases, stromelysins, matrilysins and membrane-type MMPs. ProMMPs are cleaved into active forms that promote degradation of ECM proteins. Also, recent evidence suggests direct or indirect effects of MMPs on ion channels in the endothelium and vascular smooth muscle, and on other mechanisms of vascular relaxation/contraction. Endogenous tissue inhibitors of metalloproteinases (TIMPs) reduce excessive proteolytic ECM degradation by MMPs. The balance between MMPs and TIMPs plays a major role in vascular remodeling, angiogenesis, and the uterine and systemic vasodilation during normal pregnancy. An imbalance in the MMPs/TIMPs activity ratio may underlie the pathogenesis of vascular diseases such as abdominal aortic aneurysm, varicose veins, hypertension and preeclampsia. Downregulation of MMPs using genetic manipulations of endogenous TIMPs, or synthetic pharmacological inhibitors such as BB-94 (Batimastat) and doxycycline, and Ro-28-2653, a more specific inhibitor of gelatinases and membrane type 1-MMP, could be beneficial in reducing the MMP-mediated vascular dysfunction and the progressive vessel wall damage associated with vascular disease.

Metalloproteinase-2 and -9 in diabetic and nondiabetic subjects during acute coronary syndromes

The authors hypothesized that matrix metalloproteinase (MMP)-2, -9, and tissue inhibitor metalloproteinase (TIMP)-1, -2 would be abnormal in acute coronary syndromes (ACSs). MMP-2, -9, and TIMP-1, -2 plasma levels were measured in diabetic patients with ACSs compared to nondiabetic patients with ACSs. A total of 46 diabetic and 78 nondiabetic patients with ACSs were enrolled. The following parameters were measured: body mass index (BMI), glycosylated hemoglobin (HbA1c), fasting plasma glucose (FPG), fasting plasma insulin (FPI), homeostasis model assessment index (HOMA index), systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (Tg), lipoprotein(a) [Lp(a)], plasminogen activator inhibitor-1 (PAI-1), homocysteine (Hct), fibrinogen (Fg), high-sensitivity C-reactive protein (hs-CRP), and plasma levels of MMP-2, MMP-9, TIMP-1, and TIMP-2. Significant HbA1c, FPG, FPI, HOMA index, DBP, Tg, Hct, and Fg increases were present in the diabetic group with ACSs, whereas hs-CRP was lower in these patients compared to nondiabetic patients with ACSs. MMP-9, TIMP-1, and TIMP-2 plasma levels were higher in diabetic patients with ACSs compared to nondiabetic patients with ACSs. MMP-9, TIMP-1, and TIMP-2 plasma levels were increased in diabetic patients with ACSs, which may reflect abnormal extracellular matrix metabolism in diabetes during acute event.

Evaluation of metalloproteinase 2 and 9 levels and their inhibitors in diabetic and healthy subjects

OBJECTIVES

We hypothesized that molecules active in vascular remodeling (i.e. MMPs and their TIMPs) could be modified in diabetic patients, as indirect markers of the diabetes related generalized abnormality of vascular activity. To test this hypothesis, we measured the plasma levels of MMP-2, MMP-9, TIMP-1, and TIMP-2 in type 2 diabetic patients and in healthy subjects.

METHODS

We enrolled 181 diabetic patients and 165 controls. We measured body mass index (BMI), glycosylated hemoglobin (HbA(1c)), fasting plasma glucose (FPG), fasting plasma insulin (FPI), homeostasis model assessment index (HOMA index), systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C), triglycerides (Tg), lipoprotein(a) [Lp(a)], plasminogen activator inhibitor-1 (PAI-1), homocysteine (Hct) fibrinogen (Fg), high sensitivity C-reactive protein (hs-CRP), and plasma levels of MMP-2, MMP-9, TIMP-1, and TIMP-2.

RESULTS

A significant increase (P<0.0001) of BMI, HbA(1c), FPG, FPI, HOMA index, SBP, DBP, TC, LDL-C, Tg, Lp(a), PAI-1, Hct, Fg, and hs-CRP was present in the diabetic group, with a significant decrease (P<0.0001) of HDL-C levels compared to healthy subjects. MMP-2 and MMP-9 levels were significantly higher (P<0.0001) in diabetic patients. Significant TIMP-1, and TIMP-2 increase was also observed (P<0.0001) in the diabetic group.

CONCLUSION

Plasma levels of MMP-2, MMP-9, TIMP-1, and TIMP-2 are increased in diabetic patients which may reflect abnormal extracellular matrix (ECM) metabolism.

Role for furin in tumor necrosis factor alpha-induced activation of the matrix metalloproteinase/sphingolipid mitogenic pathway

Neutral sphingomyelinase (nSMase), the initial enzyme of the sphingolipid signaling pathway, is thought to play a key role in cellular responses to tumor necrosis factor alpha (TNF-alpha), such as inflammation, proliferation, and apoptosis. The mechanism of TNF-alpha-induced nSMase activation is only partly understood. Using biochemical, molecular, and pharmacological approaches, we found that nSMase activation triggered by TNF-alpha is required for TNF-alpha-induced proliferation and in turn requires a proteolytic cascade involving furin, membrane type 1 matrix metalloproteinase (MT1-MMP), and MMP2, and leading finally to extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and DNA synthesis, in smooth muscle cells (SMC) and fibroblasts. Pharmacological and molecular inhibitors of MMPs (batimastat), furin (alpha1-PDX inhibitor-transfected SMC), MT1-MMP (SMC overexpressing a catalytically inactive MT1-MMP), MMP2 (fibroblasts from MMP2(-/-) mice), and small interfering RNA (siRNA) strategies (siRNAs targeting furin, MT1-MMP, MMP2, and nSMase) resulted in near-complete inhibition of the activation of nSMase, sphingosine kinase-1, and ERK1/2 and of subsequent DNA synthesis. Exogenous MT1-MMP activated nSMase and SMC proliferation in normal but not in MMP2(-/-) fibroblasts, whereas exogenous MMP2 was active on both normal and MMP2(-/-) fibroblasts. Altogether these findings highlight a pivotal role for furin, MT1-MMP, and MMP2 in TNF-alpha-induced sphingolipid signaling, and they identify this system as a possible target to inhibit SMC proliferation in vascular diseases.

Resveratrol inhibits macrophage expression of EMMPRIN by activating PPARγ

The effect of resveratrol on macrophage EMMPRIN expression and its potential mechanism was investigated. Both EMMPRIN expression and MMP-9 activity, respectively assayed by Western blot and zymography, were greatly up-regulated during PMA-induced macrophage differentiation from THP-1 monocytes. Both resveratrol and a PPARgamma agonist, pioglitazone, significantly inhibited EMMPRIN expression and MMP-9 activity in a concentration-dependent manner. The effects of pioglitazone and resveratrol were reversed by pretreatment of THP-1 cells with a PPARgamma antagonist, GW9662, prior to PMA induction. Thus, data suggest that resveratrol may down-regulate EMMPRIN and MMP-9 through PPARgamma activation. This possibility was further examined in resveratrol-or pioglitazone-treated U937 cells, which had been co-transfected with a PPARgamma expression vector and a luciferase reporter vector containing three tandem repeats of PPRE in cis. Results of the agonist-activated luciferase assay showed that resveratrol activated PPARgamma in a concentration-dependent manner. Since EMMPRIN and MMP-9 up-regulation is associated with activation of the NF-kappaB pathway, we investigated the effect of pioglitazone and resveratrol on TNF-alpha-induced NF-kappaB activation. Western blot results indicated that both pioglitazone and resveratrol markedly inhibited the NF-kappaB pathway through suppressing IkappaB protein phosphorylation in macrophages, although this effect of resveratrol was not reversed by GW9662. In conclusion, resveratrol can down-regulate EMMPRIN expression by macrophages via activating PPARgamma. This may be a primary mechanism of its inhibitory effect on MMP-9.

High glucose and homocysteine synergistically affect the metalloproteinases-tissue inhibitors of metalloproteinases pattern, but not TGFB expression, in human fibroblasts

AIMS/HYPOTHESIS

Atherosclerosis is particularly aggressive in patients with diabetes. Hyperhomocysteinaemia causes oxidative stress and cytokine secretion: its atherogenic effect is mediated by an enhanced inflammatory response. Matrix metalloproteinases (MMPs) regulate extracellular matrix degradation and remodelling, and contribute to the vulnerability of the atherosclerotic lesion. Fibroblasts contribute to collagen biosynthesis and participate in plaque remodelling via expression and release of MMP2 and MMP9. To explore the role of hyperhomocysteinaemia in cellular pathways involved in plaque growth and stability in diabetic patients, we studied the effect of hyperhomocysteinaemia in human fibroblasts grown in the presence of normal or high glucose concentrations.

MATERIALS AND METHODS

In fibroblasts of five normal subjects, grown at 5.5 or 22 mmol/l glucose and treated with homocysteine, we determined: (1) MMP2, MMP9 and tissue inhibitor of metalloproteinases (TIMP)-1 (an MMP inhibitor) production by western blot analysis; (2) their activity by zymography; (3) TGFB1 expression by real-time PCR; and (4) TGFB, fibronectin and IL6 release by ELISA.

RESULTS

Hyperhomocysteinaemia increased the production and enzymatic activity of MMP2 and MMP9, the effect being more pronounced in high glucose. Conversely, TIMP1 production was reduced by hyperhomocysteinaemia in both conditions, especially in high glucose. Hyperhomocysteinaemia also stimulated IL6 release, at least in part through nuclear factor-kappaB activation. TGFB1 expression was not affected by hyperhomocysteinaemia either in normal or in high glucose.

CONCLUSIONS/INTERPRETATION

Homocysteine upregulates the MMP-TIMP pathway and IL6 release, the effect being stronger in the presence of high glucose. These actions of homocysteine may contribute to the increased atherogenesis observed in diabetic patients with poor metabolic control.

Elevated Plasma Active Matrix Metalloproteinase-9 Level Is Associated With Coronary Artery In-Stent Restenosis

Objective— This study aimed to determine whether the plasma levels of matrix metalloproteinase-9 (MMP-9) or tissue inhibitor of metalloproteinases-1 (TIMP-1) were altered in patients with a history of symptomatic in-stent restenosis (ISR).

Methods and Results— A group of 158 patients with a history of ISR were compared with 128 symptom-free patients. Plasma samples and a detailed risk factor history were collected. Plasma samples were analyzed for pro–MMP-9 and latent MMP-9 and active MMP-9, latent MMP-3, and TIMP-1. Several variables were associated with ISR, including index coronary disease extent and severity (number of diseased vessels and American College of Cardiology/American Heart Association lesion classification), number, diameter, and total length of stent(s) inserted, and plasma high-density lipoprotein cholesterol. Plasma active MMP-9 (odds ratio, 1.96; 95% CI, 1.43 to 2.69) showed independent risk association with ISR. Patients with multiple sites of ISR had significantly higher levels of active MMP-9 compared with patients with only a single ISR lesion or no ISR.

Conclusion— Plasma active MMP-9 levels may be a useful independent predictor of bare metal stent ISR.

Interleukin-18-induced human coronary artery smooth muscle cell migration is dependent on NF-kappaB- and AP-1-mediated matrix metalloproteinase-9 expression and is inhibited by atorvastatin

The proliferation and migration of arterial smooth muscle cells (SMCs) are key events in the vascular restenosis that frequently follows angioplasty. Furthermore, SMC migration and neointimal hyperplasia are promoted by degradation of the extracellular matrix by matrix metalloproteinases (MMPs). Because we demonstrated previously that the proinflammatory and proatherogenic cytokine interleukin-18 (IL-18) stimulates SMC proliferation (Chandrasekar, B., Mummidi, S., Valente, A. J., Patel, D. N., Bailey, S. R., Freeman, G. L., Hatano, M., Tokuhisa, T., and Jensen, L. E. (2005) J. Biol. Chem. 280, 26263-26277), we investigated whether IL-18 induces SMC migration in an MMP-dependent manner and whether the 3-hydroxy-3-methylglutaryl-CoA reductase inhibitor atorvastatin can inhibit this response. IL-18 treatment increased both mRNA and protein expression of MMP9 in human coronary artery SMCs. Gel shift, enzyme-linked immunosorbent, and chromatin immunoprecipitation assays revealed a strong induction of IL-18-mediated AP-1 (c-Fos, c-Jun, and Fra-1) and NF-kappaB (p50 and p65) activation and stimulation of MMP9 promoter-dependent reporter gene activity in an AP-1- and NF-kappaB-dependent manner. Ectopic expression of p65, c-Fos, c-Jun, and Fra-1 induced MMP9 promoter activity. Specific antisense or small interfering RNA reagents for these transcription factors reduced IL-18-mediated MMP9 transcription. Furthermore, IL-18 stimulated SMC migration in an MMP9-dependent manner. Atorvastatin effectively suppressed IL-18-mediated AP-1 and NF-kappaB activation, MMP9 expression, and SMC migration. Together, our results indicate for the first time that the proatherogenic cytokine IL-18 induces human coronary artery SMC migration in an MMP9-dependent manner. Atorvastatin inhibits IL-18-mediated aortic SMC migration and has therapeutic potential for attenuating the progression of atherosclerosis and restenosis.