Circulating matrix metalloproteinases and their inhibitors in hypertension

Features of The Dynamics of Profibrotic Markers and Regression of Left Ventricular Hypertrophy After Renal Denervation in Patients With Resistant Hypertension and Stenosing Atherosclerosis of the Coronary Arteries

AIM

To compare the changes in serum concentrations of matrix metalloproteinases (MMPs) and their tissue inhibitor (TIMP) to the dynamics of blood pressure (BP) and parameters of left ventricular hypertrophy (LVH) 6 months after renal denervation (RD) in patients with resistant arterial hypertension (RAH) and complicated coronary atherosclerosis.

MATERIAL AND METHODS

In 22 RAH patients with complicated coronary atherosclerosis (revascularization and/or history of myocardial infarction (MI)), 24-hour BP monitoring, echocardiography, and measurement of blood MMPs and TIMP were performed at baseline and six months after RD. The comparison group consisted of 48 RAH patients without a history of coronary revascularization or MI.

RESULTS

In 6 months after RD, BP was decreased comparably in both groups. In the group of complicated atherosclerosis, there were no significant changes in profibrotic markers or LVH parameters. Thus, at baseline and after 6 months, the values of the studied indicators were the following: left ventricular myocardial mass (LVMM) 233.1±48.1 and 243.0±52.0 g, LVMM index 60.6±14.5 and 62.8±10 .9 g/m2.7, proMMP-1 4.9 [2.1; 7.7] and 3.6 [2.0; 9.4]  ng/ml, MMP-2 290.4 [233.1; 352.5] and 352.2 [277.4; 402.9] ng/ml, MMP-9 220.6 [126.9; 476.7] and 263.5 [82.9; 726.2] ng/ml, TIMP-1 395.7 [124.7; 591.4] and 424.2 [118.2; 572.0] ng/ml, respectively. In the comparison group, on the contrary, there was a significant decrease in LVMM from 273.6±83.3 g to 254.1±70.4 g, LVMM index from 67.1±12.3 to 64.0±14.4 g/m2.7, proMMP-1 from 7.2 [3.6; 11.7] to 5.9 [3.5; 10.9] ng/ml, MMP-2 from 328.9 [257.1; 378.1] to 272.8 [230.2; 343.2] ng/ml, MMP-9 from 277.9 [137.0; 524.0] to 85.5 [34.2; 225.9] ng/ml, and the MMP-9/TIMP-1 ratio from 0.80 [0.31; 1.30] to 0.24 [0.07; 0.76]. The BP dynamics in this group was inversely correlated with MMP-2 at 6 months (r=-0.38), and the MMP-9/TIMP-1 ratio was correlated with LVMM and the LVMM index at baseline (r=0.39 and r=0.39) and at 6 months (r=0.37 and r=0.32). The change in TIMP-1 from 543.9 [277.5; 674.1] to 469.8 [289.7; 643.6] ng/ml was not significant (p=0.060).

CONCLUSION

In RAH patients with complicated coronary atherosclerosis, the dynamics of profibrotic biomarkers and LVH parameters after RD was absent despite the pronounced antihypertensive effect, probably due to the low reversibility of cardiovascular remodeling processes or more complex regulatory mechanisms of the MMP system.

Plasma Levels of Matrix Metalloproteinases 2 and 9 in Patients with Chronic Chagas Heart Disease and Systemic Arterial Hypertension: Correlation with TGF-Beta Plasma Levels

Background

Chronic Chagas heart disease (CCHD) and systemic arterial hypertension (SAH) frequently coexists in areas where Chagas disease is endemic. The effects of the association of both conditions (CCHD-SAH) on the extracellular matrix (ECM) remodeling are unknown. Matrix metalloproteinases (MMP) 2 and 9 are involved in ECM remodeling. The aim of this study was to evaluate MMP 2 and MMP9 in CCHD-SAH patients and to correlate their levels with those of the profibrogenic cytokine TGF-beta.

Methods

We included 19 patients with CCHD-SAH, 14 patients with CCHD alone, and 19 controls matched by sex and age. MMP-2 and MMP-9 plasma levels were studied by gel zymography and showed as optical densities (OD). TGF-beta plasma levels were measured by double-ligand ELISA and expressed as pg/mL.

Results

Median (5^th, 95^th) MMP-2 plasma levels were 1224.7 OD (1160, 1433.5) in patients with CCHD alone, 1424.1 OD (1267.5, 1561) in patients with CCHD-SAH, and 940 OD (898.1, 1000.8) in controls (p=0.001). MMP-9 plasma levels were 1870 OD (1740, 1904.1) in patients with CCHD alone, 1754.6 OD (1650, 2049) in those with CCHD-SAH and 89.7 OD (80, 96) in controls (p=0.0003). MMP-9 plasma levels were higher than those of MMP 2 in patients with CCHD-SAH (p=0.01). No correlation was found between TGF-beta plasma levels with MMP-2 serum levels (r = 0.12; p=0.7), but a moderate negative correlation (r = -0.46; p=0.048) was observed between TGF-beta and MMP-9 plasma levels.

Conclusions

MMP-2 and especially MMP-9 may play a role in the ECM remodeling process in patients with CCHD-SAH. TGF-Beta may counteract the MMP effect on the ECM remodeling process in patients with CCHD-SAH.

Cardiac markers: Role in the pathogenesis of arterial hypertension

Cardiac biomarkers may play unique roles in the prognostic evaluation of patients with hypertension, as many cardiac biomarker levels become abnormal long before the onset of obvious cardiovascular disease (CVD). There are numerous cardiac markers. However, this review article only reported the roles of creatinine kinase-MB, cardiac troponins, lipoprotein a, osteopontin, cardiac extracellular matrix, C-reactive protein, cardiac matrix metalloproteinases, cardiac natriuretic peptides, myoglobin, renin, and dynorphin in the pathogenesis of hypertension. This article explained recent major advances, as well as discoveries, significant gaps, and current debates and outlined possible directions for future research. Further studies are required to determine the association between myoglobin and other cardiac markers in hypertension. Moreover, therapeutic approaches are required to determine the early control of these cardiac markers, which ultimately reduce the prevalence of CVDs.

Leukocyte subtypes, gelatinases, and their tissue inhibitors in a group of subjects with asymptomatic carotid atherosclerosis

In a cohort of subjects with asymptomatic carotid atherosclerosis (ACA), we have evaluated the neutrophil and lymphocyte count and their ratio (NLR), the gelatinases (MMP-2 and MMP-9) and their tissue inhibitors (TIMP-1 and TIMP-2). At baseline, no difference was observed between ACA subjects and subject control group regarding neutrophil and lymphocyte count while was evident in ACA subjects a significant increase in MMP-2, MMP-9 and TIMP-2 associated to a significant decrease in TIMP-1. Dividing the ACA according to the number of cardiovascular risk factors (CRFs) we have observed an increase in lymphocyte count in the subgroup with 3-5 CRFs. Evaluating the leukocyte subtypes according to all the surrogate markers of insulin resistance has been noted, in the subgroups that exceed the medians of these markers, a significant increase in neutrophil and lymphocyte count without any variation of the NLR. Effecting the same evaluation for the MMP/TIMP pattern we observed, instead, that the same subgroups tend to show a decrease in MMP-2 and an increase in MMP-9. No difference instead for TIMP-1 and TIMP-2. The abnormality of the MMP/TIMP pattern, bearing in mind the cardiometabolic clustering present in this cohort of ACA subjects, would induce to use drugs able not only to cure the cardiometabolic risk factors but also to influence the MMP/TIMP profile.

Matrix Metalloproteinases: From Molecular Mechanisms to Physiology, Pathophysiology, and Pharmacology

The first matrix metalloproteinase (MMP) was discovered in 1962 from the tail of a tadpole by its ability to degrade collagen. As their name suggests, matrix metalloproteinases are proteases capable of remodeling the extracellular matrix. More recently, MMPs have been demonstrated to play numerous additional biologic roles in cell signaling, immune regulation, and transcriptional control, all of which are unrelated to the degradation of the extracellular matrix. In this review, we will present milestones and major discoveries of MMP research, including various clinical trials for the use of MMP inhibitors. We will discuss the reasons behind the failures of most MMP inhibitors for the treatment of cancer and inflammatory diseases. There are still misconceptions about the pathophysiological roles of MMPs and the best strategies to inhibit their detrimental functions. This review aims to discuss MMPs in preclinical models and human pathologies. We will discuss new biochemical tools to track their proteolytic activity in vivo and ex vivo, in addition to future pharmacological alternatives to inhibit their detrimental functions in diseases. SIGNIFICANCE STATEMENT: Matrix metalloproteinases (MMPs) have been implicated in most inflammatory, autoimmune, cancers, and pathogen-mediated diseases. Initially overlooked, MMP contributions can be both beneficial and detrimental in disease progression and resolution. Thousands of MMP substrates have been suggested, and a few hundred have been validated. After more than 60 years of MMP research, there remain intriguing enigmas to solve regarding their biological functions in diseases.

Association of matrix metalloproteinase‐9 and nitric oxide with hypertension in obstructive sleep apnea

Background

Patients with obstructive sleep apnea (OSA) are more likely to suffer from hypertension. At the same time, the serum levels of matrix metalloproteinase‐9 (MMP‐9) and nitric oxide (NO) in patients with OSA are also changed in OSA patients. We investigated the correlation between serum levels of MMP‐9, NO in patients with OSA and their association with hypertension in those patients, and the effects of continuous positive airway pressure therapy (CPAP) on these serum biomarkers and blood pressure.

Methods

Serum MMP‐9 and NO levels and blood pressure of 57 patients with newly diagnosed OSA and 30 controls were measured; among them, 30 patients with moderate to severe OSA underwent 3‐month CPAP treatment.

Results

In comparison to the control group, the MMP‐9 serum levels were higher (232.8 ± 103.2 ng/ml versus 161.6 ± 56.5 ng/ml, p < .001*), there was no statistical significance difference among serum NO (26.7 ± 9.1 IU/ml versus 31.0 ± 11.7 IU/ml, p = .06), and MMP‐9 was negatively correlated to NO, especially in patients with hypertension (r = −.644, p = .02*). MMP‐9, NO, and blood pressure were significantly recovered in the patients with OSA after CPAP treatment for 3 months (p < .05*).

Conclusion

The MMP‐9 level and the NO level were altered in OSA patients. The relationship between the two especially in patients with hypertension suggests the potential mechanism of OSA‐induced hypertension.

MMPs and TIMPs levels are correlated with anthropometric parameters, blood pressure, and endothelial function in obesity

The association between matrix metalloproteinases (MMPs), tissue inhibitor of metalloproteinases (TIMPs) and obesity as well as obesity-related disease including metabolic syndrome is not fully explored. Our aims are that: (i) to evaluate the plasma levels of MMP-1, MMP-2, MMP-3, MMP-9, TIMP-1, TIMP-2 and their ratios in non-obese people, overweight and obese people with or without metabolic syndrome, (ii) to investigate correlations between MMPs or TIMPs levels and several anthropometric parameters, blood pressure, endothelial function. Anthropometric and biochemical parameters were determined in 479 randomly selected participants, subdividing according to body mass index (BMI) and metabolic syndrome status. Plasma MMPs and TIMPs levels were measured. The assessment of endothelial function was characterized in people with obesity, overweight and non-obese, using laser Doppler Flowmetry. Obese people have elevated MMP-1, MMP-2, TIMP-1, TIMP-2 levels and decreased MMP-3/TIMP-1 and MMP-9/TIMP-1 ratios compared with non-obese people. MMP-1 levels and MMP-1/TIMP-1 ratio were positively correlated with BMI and waist circumference (WC) while MMP-2 levels were negatively correlated with BMI and WC values in obese people. MMP-3 levels and MMP-3/TIMP-1 ratio were positively correlated with systolic blood pressure (SBP) or diastolic blood pressure (DBP) in obese and metabolic syndrome people. Additionally, MMP-9 levels and MMP-9/TIMP-1 ratio were negatively correlated with endothelium-dependent response in obese and metabolic syndrome people. MMP-1, MMP-2, TIMP-1, TIMP-2 levels were increased in obese subjects. Significant correlations between anthropometric parameters and MMP-1 as well as MMP-1/TIMP-1 ratio supported these results. MMP-3 and -9 levels as well as their ratios with TIMP-1 were associated with blood pressure and endothelial-dependent response, respectively. In conclusion, our results demonstrated that MMP-1, MMP-3 and MMP-9 levels were correlated with several obesity-related parameters including BMI, WC, blood pressure and endothelial-dependent response. Our findings will hopefully provide new aspects for the use of MMPs and TIMPs as clinical biomarkers in obesity-related cardiovascular diseases such as metabolic syndrome and hypertension. The lack of measure of MMPs activity in plasma and relevant organs/tissues in obesity and metabolic syndrome is considered as a limitation in this report.

MMP-2 and MMP-9 levels in plasma are altered and associated with mortality in COVID-19 patients

Respiratory symptoms are one of COVID-19 manifestations, and the metalloproteinases (MMPs) have essential roles in the lung physiology. We sought to characterize the plasmatic levels of matrix metalloproteinase-2 and 9 (MMP-2 and MMP-9) in patients with severe COVID-19 and to investigate an association between plasma MMP-2 and MMP-9 levels and clinical outcomes and mortality. MMP-2 and MMP-9 levels in plasma from patients with COVID-19 treated in the ICU (COVID-19 group) and Control patients were measured with the zymography. The study groups were matched for age, sex, hypertension, diabetes, BMI, and obesity profile. MMP-2 levels were lower and MMP-9 levels were higher in a COVID-19 group (p < 0.0001) compared to Controls. MMP-9 levels in COVID-19 patients were not affected by comorbidity such as hypertension or obesity. MMP-2 levels were affected by hypertension (p < 0.05), but unaffected by obesity status. Notably, hypertensive COVID-19 patients had higher MMP-2 levels compared to the non-hypertensive COVID-19 group, albeit still lower than Controls (p < 0.05). No association between MMP-2 and MMP-9 plasmatic levels and corticosteroid treatment or acute kidney injury was found in COVID-19 patients. The survival analysis showed that COVID-19 mortality was associated with increased MMP-2 and MMP-9 levels. Age, hypertension, BMI, and MMP-2 and MMP-9 were better predictors of mortality during hospitalization than SAPS3 and SOFA scores at hospital admission. In conclusion, a significant association between MMP-2 and MMP-9 levels and COVID-19 was found. Notably, MMP-2 and MMP-9 levels predicted the risk of in-hospital death suggesting possible pathophysiologic and prognostic roles.

Effects of physical exercise combined with captopril or losartan on left ventricular hypertrophy of hypertensive rats

Background: Left ventricular hypertrophy (LVH) is an endpoint of hypertensive cardiac alterations. Renin-angiotensin-aldosterone system (RAAS) blockers are among the most effective on LVH regression. Physical exercise combined to antihypertensive drug contributes to arterial pressure (AP) control and LVH prevention. We evaluated the effects of physical exercise combined to captopril or losartan during eight weeks for spontaneously hypertensive rats (SHR) on some cardiac parameters.Methods: SHR (n=5-6 per group) were sedentary or trained 5 days a week in treadmill during 8 weeks; and they were treated with daily oral captopril (12.5, 25, or 50mg/kg), losartan (2.5, 5, or 10mg/kg), or vehicle. At the end, it was obtained systolic AP (SAP), electrocardiogram (ECG), and hearts metalloproteinase 2 (MMP-2) activity and histology.Results: Captopril 25 and 50 mg/kg, and losartan 10 mg/kg lowered SAP of sedentary and trained SHR. Losartan 5 mg/kg combined with physical exercise also lowered SAP. Combined with exercise, captopril 50 mg/kg lowered 13.6% of QT interval, 14.2% of QTc interval, and 22.8% of Tpeak-Tend compared to sedentary SHR. Losartan 5 and 10mg/kg lowered QT interval of sedentary and trained SHR. Losartan 2.5, 5 and 10mg/kg combined with physical exercise lowered respectively 25.4%, 24.8%, and 31.8% of MMP-2 activity. Losartan (10mg/kg) combined with exercise reduced cardiomyocyte diameter.Conclusion: These data support the hypothesis of physical exercise combined with RAAS blockers could improve the benefits on hypertensive LVH treatment.

Matrix Metalloproteinases and Hypertension-Mediated Organ Damage: Current Insights

Matrix metalloproteinases (MMPs) are important extracellular enzymes involved in many physiological and pathological processes. Changes in the activity and concentration of specific MMPs, as well as the unbalance with their inhibitors (tissue inhibitors of metalloproteinases – TIMPs), have been described as a part of the pathogenic cascade promoted by arterial hypertension. MMPs are able to degrade various protein substrates in the extracellular matrix, to influence endothelial cells function, vascular smooth muscle cells migration, proliferation and contraction, and to stimulate cardiomyocytes changes. All these processes can be activated by chronically elevated blood pressure values. Animal and human studies demonstrated the key function of MMPs in the pathogenesis of hypertension-mediated vascular, cardiac, and renal damage, besides age and blood pressure values. Thus, the role of MMPs as biomarkers of hypertension-mediated organ damage and potential pharmacological treatment targets to prevent further cardiovascular and renal complications in hypertensive population is increasingly supported. In this review, we aimed to describe the main scientific evidence about the behavior of MMPs in the development of vascular, cardiac, and renal damage in hypertensive patients.

Prediction of the early response to spironolactone in resistant hypertension by the combination of matrix metalloproteinase-9 activity and arterial stiffness parameters

AIMS

The aim of present study was to determine whether arterial stiffness assessed with the biochemical parameter active matrix metalloproteinase (MMP)-9 and the clinical parameters pulse pressure (PP) and pulse wave velocity predicts the response to spironolactone in resistant hypertension (RH).

METHODS AND RESULTS

Ambulatory blood pressure (BP) and active MMP-9 (measured by zymography and ELISA) were measured at baseline, and patients were classified as having pseudo-RH or RH. Patients with RH received spironolactone and the response was determined after 8 weeks by ambulatory BP monitoring: those who achieved BP goals were considered controlled (CRH) and those who did not were considered uncontrolled (UCRH). Plasma active MMP-9 was significantly higher in patients with RH than with pseudo-RH, and correlated with 24-hour systolic BP and PP. Receiver operating characteristic analysis indicated that active MMP-9 could predict the response to spironolactone, and its combination with 24-hour PP and pulse wave velocity significantly improved this prediction. Moreover, plasma of patients with UCRH induced the MMP-9 expression pathway.

CONCLUSION

We propose active MMP-9 as a useful biomarker to identify patients with RH who will not respond to spironolactone. Combining MMP-9 activity with classical arterial stiffness parameters improves the prediction of the clinical response to spironolactone and might contribute to guide the most appropriate therapeutic decisions for patients with RH.

Treatment strategies for isolated systolic hypertension in elderly patients

INTRODUCTION

Hypertension is a major and modifiable risk factor for cardiovascular disease. Its prevalence is rising as the result of population aging. Isolated systolic hypertension mostly occurs in older patients accounting for up to 80% of cases.

AREAS COVERED

The authors systematically review published studies to appraise the scientific and clinical evidence supporting the role of blood pressure control in elderly patients with isolated systolic hypertension, and to assess the influence of different drug treatment regimens on outcomes.

EXPERT OPINION

Antihypertensive treatment of isolated systolic hypertension significantly reduces the risk of morbidity and mortality in elderly patients. Thiazide diuretics and dihydropyridine calcium-channel blockers are the primary compounds used in randomized clinical trials. These drugs can be considered as first-line agents for the management of isolated systolic hypertension. Free or fixed combination therapy with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers and calcium-channel blockers or thiazide-like diuretics should also be considered, particularly when compelling indications such as coronary artery disease, chronic kidney disease, diabetes, and congestive heart failure coexist. There is also hot scientific debate on the optimal blood pressure target to be achieved in elderly patients with isolated systolic hypertension, but current recommendations are scarcely supported by evidence.

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.

Matrix metalloproteinase-2 knockout prevents angiotensin II-induced vascular injury

Aims

Matrix metalloproteinases (MMPs) have been implicated in the development of hypertension in animal models and humans. Mmp2 deletion did not change Ang II-induced blood pressure (BP) rise. However, whether Mmp2 knockout affects angiotensin (Ang) II-induced vascular injury has not been tested. We sought to determine whether Mmp2 knockout will prevent Ang II-induced vascular injury.

Methods and results

A fourteen-day Ang II infusion (1000 ng/kg/min, SC) increased systolic BP, decreased vasodilatory responses to acetylcholine, induced mesenteric artery (MA) hypertrophic remodelling, and enhanced MA stiffness in wild-type (WT) mice. Ang II enhanced aortic media and perivascular reactive oxygen species generation, aortic vascular cell adhesion molecule-1 and monocyte chemotactic protein-1 expression, perivascular monocyte/macrophage and T cell infiltration, and the fraction of spleen activated CD4+CD69+ and CD8+CD69+ T cells, and Ly-6Chi monocytes. Study of intracellular signalling showed that Ang II increased phosphorylation of epidermal growth factor receptor and extracellular-signal-regulated kinase 1/2 in vascular smooth muscle cells isolated from WT mice. All these effects were reduced or prevented by Mmp2 knockout, except for systolic BP elevation. Ang II increased Mmp2 expression in immune cells infiltrating the aorta and perivascular fat. Bone marrow (BM) transplantation experiments revealed that in absence of MMP2 in immune cells, Ang II-induced BP elevation was decreased, and that when MMP2 was deficient in either immune or vascular cells, Ang II-induced endothelial dysfunction was blunted.

Conclusions

Mmp2 knockout impaired Ang II-induced vascular injury but not BP elevation. BM transplantation revealed a role for immune cells in Ang II-induced BP elevation, and for both vascular and immune cell MMP2 in Ang II-induced endothelial dysfunction.

Circulating matrix metalloproteinases are associated with arterial stiffness in patients with type 1 diabetes: pooled analysis of three cohort studies

Background

Altered regulation of extracellular matrix (ECM) composition by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) may contribute to arterial stiffening. We investigated associations between circulating MMP-1, -2, -3, -9, -10 and TIMP-1, and carotid-femoral pulse wave velocity (cfPWV) and pulse pressure (PP), as markers of arterial stiffness in type 1 diabetic patients.

Methods

Individuals with type 1 diabetes from three different cohorts were included in this study: EURODIAB Prospective Complications study (n = 509), LEACE (n = 370) and PROFIL (n = 638). Linear regression analyses were used to investigate cross-sectional associations between circulating levels of MMP-1, -2, -3, -9, -10, and TIMP-1 and cfPWV (n = 614) as well as office PP (n = 1517). Data on 24-h brachial and 24-h central PP were available in 638 individuals from PROFIL. Analyses were adjusted for age, sex, duration of diabetes, HbA1c, mean arterial pressure (MAP), and eGFR, and additionally for other cardiovascular risk factors and presence of vascular complications.

Results

After adjustment for potential confounders and presence of vascular complications, circulating MMP-3 was associated with cfPWV [β per 1 SD higher lnMMP3 0.29 m/s (0.02; 0.55)]. In addition, brachial and central 24-h PP measurements in PROFIL were significantly associated with MMP-2 [(1.40 (0.47:2.33) and 1.43 (0.63:2.23)]. Pooled data analysis showed significant associations of circulating levels of MMP-1 and MMP-2 with office PP [β per 1 SD higher lnMMP-1 and lnMMP-2 = − 0.83 mmHg (95% CI − 1.50; − 0.16) and = 1.33 mmHg (0.55; 2.10), respectively].

Conclusions

MMPs-1, -2, and -3 are independently associated with markers of arterial stiffening in patients with type 1 diabetes and may become therapeutic targets.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0620-9) contains supplementary material, which is available to authorized users.

Changes in activities of circulating MMP-2 and MMP-9 in patients suffering from heart failure in relation to gender, hypertension and treatment: a cross-sectional study

Matrix metalloproteinases (MMPs) play an important role in the pathogenesis of heart failure (HF). Our aim was to determine the activities of circulating MMP-2 and MMP-9 in patients with HF in respect of gender, comorbidities and treatment (n=51). We did not reveal any differences in circulating pro-MMP-2 and pro-MMP-9 activities between the patients with HF and without it. However, there was a decrease in activity of pro-MMP-2 in treated hypertensive participants versus healthy ones. In contrast, we observed increased pro-MMP-2 activity in hypertensive participants with coexistent HF versus hypertensive participants without HF. In addition, a decrease in pro-MMP-2 activity was shown in women suffering from HF versus men suffering from HF. In conclusion, potential inhibitory effect of antihypertensive treatment on pro-MMP-2 activity was found. Coexistent HF with hypertension probably reduces the inhibitory effect of antihypertensive treatment on pro-MMP-2 activity. Our data also suggest the role of potential cardioprotective factors influencing the activity of pro-MMP-2 in women.

Association of MMP-9 gene polymorphisms with nephrolithiasis patients

BACKGROUND

Nephrolithiasis is one of the causes which lead to chronic kidney disease (CKD). Matrix metalloproteinases (MMPs) are endopeptidases degrading extracellular matrix which correlate with the pathogenesis of atherosclerosis. The current study was designed to analyze the association of (R279Q, C1562T) polymorphism of MMP-9 with nephrolithiasis patients.

METHODS

Genotyping of MMP-9/R279Q and of MMP-9/C1562T polymorphism were carried out by PCR-based restriction digestion method. Serum level of MMP-9, oxidative stress marker, MDA, and uric acid were measured in patients and control.

RESULTS

Allele frequencies of the MMP-9/C1562T polymorphism for C and T allele were 71.25% and 28.75% in patients, 87.08% and 12.92% in control respectively. The homozygote TT was more frequent in the nephrolithiasis patients group, while T allele frequency was significantly higher in the nephrolithiasis patients group than in the control group. The patients with CT and TT genotype showed a significant increase in serum MMP-9, Total Oxidant Status (TOS), Oxidative Stress Index (OSI), Malondialdehyde (MDA), and uric acid when compared to CC genotype in patients with nephrolithiasis. The R279Q polymorphism site with regard to the relationship with nephrolithiasis was not significant.

CONCLUSION

The result indicates that patients with TT genotype had an increased risk of stones. Also, the results demonstrate that TT allele of the C1562T polymorphism in the MMP-9gene is related with an increase of oxidative stress in nephrolithiasis patients and may possibly impose a risk for cardiovascular diseases in patients with TT genotype of MMP-9.

Isolated Systolic Hypertension: An Update After SPRINT

Isolated systolic hypertension is the most common hemodynamic form of hypertension in the elderly. With a rapidly aging population, the prevalence of hypertension, particularly isolated systolic hypertension, is expected to increase substantially. This phenomenon of increasing systolic pressure in the elderly is believed to be secondary to pathophysiological changes of aging as well as modifiable risk factors. Isolated systolic hypertension is associated with substantial mortality and morbidity, particularly of cerebrovascular disease. It is a rapidly growing public health concern and its management continues to remain a challenge to practicing physicians. Recent studies like the Systolic Blood Pressure Intervention Trial (SPRINT) and Heart Outcomes Prevention Evaluation (HOPE)-3 have implications for antihypertensive therapy in general and for the management of isolated systolic hypertension in particular. In this article we will review: 1) epidemiology and pathophysiologic mechanisms, 2) impact of isolated systolic hypertension on cardiovascular outcomes, 3) optimal management strategies, and 4) systolic blood pressure goals in the light of SPRINT and HOPE 3 trials.

Increased Circulating Tissue Inhibitor of Metalloproteinase-2 Is Associated With Resistant Hypertension

Resistant hypertension (RH) is associated with organ damage and cardiovascular risk. Evidence suggests the involvement of matrix metalloproteinase 2 (MMP-2) and tissue inhibitor of metalloproteinase 2 (TIMP-2) in hypertension and in cardiovascular remodeling. The aim of this study was to assess the levels of MMP-2 and TIMP-2 in RH and its relation with organ damage, including arterial stiffness and cardiac hypertrophy. MMP-2 and TIMP-2 levels were compared among 19 patients with normotension (NT), 116 with nonresistant hypertension (HTN) and 116 patients with resistant HTN (RH). MMP-2 levels showed no differences among NT, HTN, and RH groups, while TIMP-2 levels were higher in RH compared with HTN and NT groups (90.0 [76.1-107.3] vs 70.1 [57.7-88.3] vs 54.7 [40.9-58.1] ng/mL, P<.01), respectively. MMP-2/TIMP-2 ratio was reduced in the RH group compared with the HTN and NT groups (2.7 [1.9-3.4] vs 3.3 [2.6-4.2] vs 4.9 [4.5-5.3], P<.01), respectively. No associations were found between MMP-2 levels, TIMP-2, and MMP-2/TIMP-2 ratio with cardiac hypertrophy and arterial stiffness in the RH and HTN groups. Finally, in a regression analysis, reduced MMP-2/TIMP-2 ratio and increased TIMP-2 levels were independently associated with RH. The present findings provide evidence that TIMP-2 is associated with RH and might be a possible biomarker for screening RH patients.

Levels of matrix metalloproteinases differ in plasma and serum - aspects regarding analysis of biological markers in cancer

BACKGROUND

There are inconsistencies in the use of serum or plasma when analysing the matrix metalloproteinases (MMPs) as diagnostic or prognostic markers. The purpose of this study was to compare the concentration of MMP-1, -2, -7, -8, -9 and -13 in serum vs plasma samples.

METHODS

Blood samples were obtained from sixty-five men and women. Samples were analysed for levels of MMPs in corresponding citrate plasma and serum.

RESULTS

All MMPs expressed higher concentration in serum compared with plasma (P<0.01). There were no differences between genders.

CONCLUSIONS

Present study demonstrated significant differences regarding concentrations of some MMPs using plasma vs serum. We conclude that future studies regarding MMPs as biological markers in cancer should consider the use of citrate plasma instead of serum.

Association of Common Variants in MMPs with Periodontitis Risk

Background. Matrix metalloproteinases (MMPs) are considered to play an important role during tissue remodeling and extracellular matrix degradation. And functional polymorphisms in MMPs genes have been reported to be associated with the increased risk of periodontitis. Recently, many studies have investigated the association between MMPs polymorphisms and periodontitis risk. However, the results remain inconclusive. In order to quantify the influence of MMPs polymorphisms on the susceptibility to periodontitis, we performed a meta-analysis and systematic review. Results. Overall, this comprehensive meta-analysis included a total of 17 related studies, including 2399 cases and 2002 healthy control subjects. Our results revealed that although studies of the association between MMP-8 −799 C/T variant and the susceptibility to periodontitis have not yielded consistent results, MMP-1 (−1607 1G/2G, −519 A/G, and −422 A/T), MMP-2 (−1575 G/A, −1306 C/T, −790 T/G, and −735 C/T), MMP-3 (−1171 5A/6A), MMP-8 (−381 A/G and +17 C/G), MMP-9 (−1562 C/T and +279 R/Q), and MMP-12 (−357 Asn/Ser), as well as MMP-13 (−77 A/G, 11A/12A) SNPs are not related to periodontitis risk. Conclusions. No association of these common MMPs variants with the susceptibility to periodontitis was found; however, further larger-scale and multiethnic genetic studies on this topic are expected to be conducted to validate our results.

Matrix Metalloproteinase 2 as a Potential Mediator of Vascular Smooth Muscle Cell Migration and Chronic Vascular Remodeling in Hypertension

For vascular remodeling in hypertension, it is essential that vascular smooth muscle cells (VSMCs) reshape in order to proliferate and migrate. The extracellular matrix (ECM) needs to be degraded to favor VSMC migration. Many proteases, including matrix metalloproteinases (MMPs), contribute to ECM proteolysis and VSMC migration. Bioactive peptides, hemodynamic forces and reactive oxygen-nitrogen species regulate MMP-2 expression and activity. Increased MMP-2 activity contributes to hypertension-induced maladaptive arterial changes and sustained hypertension. New ECM is synthesized to supply VSMCs with bioactive mediators, which stimulate hypertrophy. MMP-2 stimulates the interaction of VSMCs with newly formed ECM, which triggers intracellular signaling via integrins to induce a phenotypic switch and persistent migration. VSMCs switch from a contractile to a synthetic phenotype in order to migrate and contribute to vascular remodeling in hypertension. MMPs also disrupt growth factors bound to ECM, thus contributing to their capacity to regulate VSMC migration. This review sheds light on the proteolytic effects of MMP-2 on ECM and non-ECM substrates in the vasculature and how these effects contribute to VSMC migration in hypertension. The inhibition of MMP activity as a therapeutic target may make it possible to reduce arterial maladaptation caused by hypertension and prevent the resulting fatal cardiovascular events.

Angiotensin-II induced hypertension and renovascular remodelling in tissue inhibitor of metalloproteinase 2 knockout mice

BACKGROUND

Sustained hypertension induces renovascular remodelling by altering extracellular matrix (ECM) components. Matrix metalloproteinases (MMPs) are Zn-dependent enzymes that regulate ECM turnover in concert with their inhibitors, tissue inhibitors of metalloproteinases (TIMPs). Increased MMP-2 and MMP-9 have been implicated in hypertensive complications; however, the contribution of individual MMPs/TIMPs in renal remodelling has not been fully elucidated. The purpose of this study was to determine the effect of TIMP2 deficiency and thus MMP-2 on angiotensin-II (Ang-II) induced renal remodelling.

METHOD

C57BL/6J (wild-type) and TIMP2 knockout mice were infused with Ang-II at 250 ng/kg per min for 4 weeks. Blood pressure was measured weekly and end-point laser Doppler flowmetry was done to assess cortical blood flow. Immunohistochemical staining was performed for collagen and elastin analyses. The activity of MMP-9 and MMP-2 was determined by Gelatin zymography.

RESULTS

Ang-II induced similar elevation in mean blood pressure in TIMP2 and wild-type mice. In TIMP2 mice, Ang-II treatment was associated with a greater reduction in renal cortical blood flow and barium angiography demonstrated decreased vascular density compared with Ang-II treated wild-type mice. Peri-glomerular and vascular collagen deposition was increased and elastin content was decreased causing increased wall-to-lumen ratio in TIMP2 mice compared with wild-type mice receiving Ang-II. Ang-II increased the expression and activity of MMP-9 predominantly in TIMP2 mice than in wild-type mice.

CONCLUSION

These results suggest that TIMP2 deficiency exacerbates renovascular remodelling in agonist-induced hypertension by a mechanism that may, in part, be attributed to increased activity of MMP-9.

Screening of the binding of small molecules to proteins by desorption electrospray ionization mass spectrometry combined with protein microarray

The interaction between bioactive small molecule ligands and proteins is one of the important research areas in proteomics. Herein, a simple and rapid method is established to screen small ligands that bind to proteins. We designed an agarose slide to immobilize different proteins. The protein microarrays were allowed to interact with different small ligands, and after washing, the microarrays were screened by desorption electrospray ionization mass spectrometry (DESI MS). This method can be applied to screen specific protein binding ligands and was shown for seven proteins and 34 known ligands for these proteins. In addition, a high-throughput screening was achieved, with the analysis requiring approximately 4 s for one sample spot. We then applied this method to determine the binding between the important protein matrix metalloproteinase-9 (MMP-9) and 88 small compounds. The molecular docking results confirmed the MS results, demonstrating that this method is suitable for the rapid and accurate screening of ligands binding to proteins. Graphical Abstract ᅟ.

Role of MMP-2 and MMP-9 in resistance to drug therapy in patients with resistant hypertension

Background

Despite the increased evidence of the important role of matrix metalloproteinases (MMP-9 and MMP‑2) in the pathophysiology of hypertension, the profile of these molecules in resistant hypertension (RHTN) remains unknown.

Objectives

To compare the plasma levels of MMP-9 and MMP-2 and of their tissue inhibitors (TIMP-1 and TIMP-2, respectively), as well as their MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios, between patients with controlled RHTN (CRHTN, n=41) and uncontrolled RHTN (UCRHTN, n=35). In addition, the association of those parameters with clinical characteristics, office blood pressure (BP) and arterial stiffness (determined by pulse wave velocity) was evaluate in those subgroups.

Methods

This study included 76 individuals diagnosed with RHTN and submitted to physical examination, electrocardiogram, and laboratory tests to assess biochemical parameters.

Results

Similar values of MMP-9, MMP-2, TIMP-1, TIMP-2, and MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios were found in the UCRHTN and CRHTN subgroups (P>0.05). A significant correlation was found between diastolic BP (DBP) and MMP-9/TIMP-1 ratio (r=0.37; P=0.02) and DPB and MMP-2 (r=-0.40; P=0.02) in the UCRHTN subgroup. On the other hand, no correlation was observed in the CRHTN subgroup. Logistic regression models demonstrated that MMP-9, MMP-2, TIMP-1, TIMP-2 and their ratios were not associated with the lack of BP control.

Conclusion

These findings suggest that neither MMP-2 nor MMP-9 affect BP control in RHTN subjects.

Expression of matrix metalloproteinases in patients with bipolar disorder

OBJECTIVE

High cardiovascular mortality rates have been reported in patients with bipolar disorder (BD). Studies indicate that matrix metalloproteinases (MMPs) are implicated in cardiovascular diseases. We evaluated the expression pattern of MMP-2 and MMP-9 in blood from patients with BD during acute mania and after euthymia, in comparison with healthy controls.

METHODS

Twenty patients and 20 controls were recruited and matched for sex and age. MMP messenger RNA (mRNA) levels were measured using real-time quantitative polymerase chain reaction (PCR). Body mass index (BMI) was calculated for all subjects.

RESULTS

There were no significant differences in MMP-2 and MMP-9 mRNA expression between patients and controls. mRNA levels were not significantly different during mania and euthymia. However, MMP-2 mRNA levels were negatively associated with BMI in BD patients and positively associated with BMI in controls. There was no difference in the pattern of MMP-9 expression between patients and controls.

CONCLUSIONS

Our results suggest a different pattern of association between MMP-2 and BMI in BD patients as compared with controls. Despite some study limitations, we believe that the role of MMPs in BD should be further investigated to elucidate its relationship with cardiovascular risk.

Nebivolol attenuates prooxidant and profibrotic mechanisms involving TGF-β and MMPs, and decreases vascular remodeling in renovascular hypertension

Nebivolol and metoprolol are β1-adrenergic receptor blockers with different properties. We hypothesized that nebivolol, but not metoprolol, could attenuate prooxidant and profibrotic mechanisms of hypertension and therefore protect against the vascular remodeling associated with hypertension. Hypertension was induced in male Wistar rats by clipping the left renal artery. Six weeks after surgery, hypertensive and sham rats were treated with nebivolol (10 mg kg(-1) day(-1)) or metoprolol (20 mg kg(-1) day(-1)) for 4 weeks. Systolic blood pressure was monitored weekly. Morphologic changes in the aortic wall were studied in hematoxylin/eosin and picrosirius red sections. Aortic NAD(P)H activity and superoxide production were evaluated by luminescence and dihydroethidium, respectively, and TBARS levels were measured in plasma. Aortic nitrotyrosine staining was evaluated to assess peroxynitrite formation. TGF-β levels and p-ERK 1/2 expression were determined by immunofluorescence and Western blotting, respectively. Matrix metalloproteinase (MMP) activity and expression were determined by in situ zymography, gel zymography, Western blotting, and immunofluorescence, and TIMP-1 was assessed by immunohistochemistry. Both β1-receptor antagonists exerted very similar antihypertensive effects. However, while metoprolol had no significant effects, nebivolol significantly attenuated vascular remodeling and collagen deposition associated with hypertension. Moreover, nebivolol, but not metoprolol, attenuated hypertension-induced increases in aortic NAD(P)H oxidase activity, superoxide production, TBARS concentrations, nitrotyrosine levels, TGF-β upregulation, and MMP-2 and -9 expression/activity. No effects on p-ERK 1/2 and TIMP-1 expression were found. These results show for the first time that nebivolol, but not metoprolol, attenuates prooxidant and profibrotic mechanisms involving TGF-β and MMP-2 and MMP-9, which promote vascular remodeling in hypertension.

Antioxidant effect of doxycycline decreases MMP activity and blood pressure in SHR

Increased matrix metalloproteinase (MMP) levels are involved in vascular remodeling of hypertension. In this study, we hypothesized that doxycycline (a MMP inhibitor) could exert antioxidant effects, reverse establish vascular remodeling, and lower blood pressure in spontaneously hypertensive rats (SHR). SHR and Wistar-Kyoto rats received either doxycycline at 30 mg/kg/day by gavage or vehicle. Systolic blood pressure (SBP) was assessed weekly by tail cuff. After 5 weeks of treatment, morphologic changes in the aortic wall were studied in hematoxylin/eosin sections. MMP activity and expression were determined by in situ zymography using DQ gelatin and immunofluorescence for MMP-2. Dihydroethidium was used to evaluate aortic reactive oxygen species (ROS) production by fluorescence microscopy. Doxycycline reduced SBP by 25 mmHg. However, the antihypertensive effects were not associated with significant reversal of hypertension-induced vascular hypertrophy. SHR showed increased aortic MMP-2 levels which co-localized with higher aortic MMP activity and ROS levels, and all those biochemical alterations associated with hypertension were blunted by treatment with doxycycline. These results show that MMP inhibition with doxycycline in SHR with established hypertension resulted in antioxidant effects, lower gelatinolytic activity, and antihypertensive effects which were not associated with reversal of hypertension-induced vascular remodeling.

Matrix metalloproteinases as drug targets in preeclampsia

Preeclampsia is an important syndrome complicating pregnancy. While the pathogenesis of preeclampsia is not entirely known, poor placental perfusion leading to widespread maternal endothelial dysfunction is accepted as a major mechanism. It has been suggested that altered placental expression of matrix metalloproteinases (MMPs) may cause shallow cytotrophoblastic invasion and incomplete remodeling of the spiral arteries. MMPs are also thought to link placental ischemia to the cardiovascular alterations of preeclampsia. In fact, MMPs may promote vasoconstriction and surface receptors cleavage affecting the vasculature. Therefore, the overall goal of this review article is to provide an overview of the pathophisiology of preeclampsia, more specifically regarding the role of MMPs in the pathogenesis of preeclampsia and the potential of MMP inhibitors as therapeutic options.

Matrix metalloproteinases 2 and 9 are differentially expressed in patients with indeterminate and cardiac clinical forms of Chagas disease

Dilated chronic cardiomyopathy (DCC) from Chagas disease is associated with myocardial remodeling and interstitial fibrosis, resulting in extracellular matrix (ECM) changes. In this study, we characterized for the first time the serum matrix metalloproteinase 2 (MMP-2) and MMP-9 levels, as well as their main cell sources in peripheral blood mononuclear cells from patients presenting with the indeterminate (IND) or cardiac (CARD) clinical form of Chagas disease. Our results showed that serum levels of MMP-9 are associated with the severity of Chagas disease. The analysis of MMP production by T lymphocytes showed that CD8(+) T cells are the main mononuclear leukocyte source of both MMP-2 and MMP-9 molecules. Using a new 3-dimensional model of fibrosis, we observed that sera from patients with Chagas disease induced an increase in the extracellular matrix components in cardiac spheroids. Furthermore, MMP-2 and MMP-9 showed different correlations with matrix proteins and inflammatory cytokines in patients with Chagas disease. Our results suggest that MMP-2 and MMP-9 show distinct activities in Chagas disease pathogenesis. While MMP-9 seems to be involved in the inflammation and cardiac remodeling of Chagas disease, MMP-2 does not correlate with inflammatory molecules.

Application of quantitative proteomic analysis using tandem mass tags for discovery and identification of novel biomarkers in periodontal disease

Periodontal disease is a bacterial infection that destroys the gingiva and surrounding tissues of the oral cavity. Gingival crevicular fluid (GCF) is extracted from the gingival sulcus and pocket. Analysis of biochemical markers in GCF, which predict the progression of periodontal disease, may facilitate disease diagnosis. However, no useful GCF biochemical markers with high sensitivity for detecting periodontal disease have been identified. Thus, the search for biochemical markers of periodontal disease is of continued interest in experimental and clinical periodontal disease research. Using tandem mass tag (TMT) labeling, we analyzed GCF samples from healthy subjects and patients with periodontal disease, and identified a total of 619 GCF proteins based on proteomic analysis. Of these, we focused on two proteins, matrix metalloproteinase (MMP)-9 and neutrophil gelatinase-associated lipocalin (LCN2), which are involved in the progression of periodontal disease. Western blot analysis revealed that the levels of MMP-9 and LCN2 were significantly higher in patients with periodontal disease than in healthy subjects. In addition, ELISA also detected significantly higher levels of LCN2 in patients with periodontal disease than in healthy subjects. Thus, LC-MS/MS analyses of GCF using TMT labeling led to the identification of LCN2, which may be a promising GCF biomarker for the detection of periodontal disease.

Oscillometric measurement of brachial artery cross-sectional area and its relationship with cardiovascular risk factors and arterial stiffness in a middle-aged male population

An enlarged arterial diameter is associated with an increased risk for cardiovascular disease. This study examined the relationship of noninvasively measured brachial artery cross-sectional area with cardiovascular risk factors and arterial stiffness in a middle-aged male population. Absolute volumetric changes of the brachial artery were measured with a newly developed oscillometric method during a general health examination in 387 men (mean age: 38±9 years) without known cardiovascular disease. Based on the measurement, the estimated area (eA) of the brachial artery at end-diastole was obtained. Brachial artery volume elastic modulus (VE) and brachial-ankle pulse wave velocity (baPWV) were simultaneously measured as indices of arterial stiffness by the same device. The relationships of eA with cardiovascular risk factors, including age, obesity, hypertension, dyslipidemia, impaired fasting glucose/diabetes mellitus (IFG/DM), hyperuricemia, smoking and their associated continuous variables, as well as VE and baPWV, were examined. Overall, the mean eA was 12.9 ± 2.9 mm². The eA was significantly higher in subjects with obesity, hypertension or IFG/DM than in those without each of these risk factors. In a multiple linear regression analysis, body mass index (β=0.31, P<0.001), age (β=0.25, P<0.001), systolic blood pressure (β=0.16, P=0.004) and pulse rate (β=-0.13, P=0.005) were independent determinants of eA. In contrast, neither VE nor baPWV were selected as independent determinants of eA. In conclusion, enlarged brachial artery cross-sectional area was significantly associated with cardiovascular risk factors such as age, body mass index and systolic blood pressure, but it was not associated with increased arterial stiffness.

Nitric oxide attenuates matrix metalloproteinase-9 production by endothelial cells independent of cGMP- or NFκB-mediated mechanisms

Cardiovascular diseases involve critical mechanisms including impaired nitric oxide (NO) levels and abnormal matrix metalloproteinase (MMP) activity. While NO downregulates MMP expression in some cell types, no previous study has examined whether NO downregulates MMP levels in endothelial cells. We hypothesized that NO donors could attenuate MMP-9 production by human umbilical vein endothelial cells (HUVECs) as a result of less NFκB activation or cyclic GMP (cGMP)-mediated mechanisms. We studied the effects of DetaNONOate (10-400 μM) or SNAP (50-400 μM) on phorbol 12-myristate 13-acetate (PMA; 10 nM)-induced increases in MMP-9 activity (by gel zymography) or concentrations (by ELISA) as well as on a tissue inhibitor of MMPs' (TIMP)-1 concentrations (by ELISA) in the conditioned medium of HUVECs incubated for 24 h with these drugs. We also examined whether the irreversible inhibitor of soluble guanylyl cyclase ODQ modified the effects of SNAP or whether 8-bromo-cGMP (a cell-permeable analog of cGMP) influenced PMA-induced effects on MMP-9 expression. Total and phospho-NFκB p65 concentrations were measured in HUVEC lysates to assess NFκB activation. Both NO donors attenuated PMA-induced increases in MMP-9 activity and concentrations without significantly affecting TIMP-1 concentrations. This effect was not modified by ODQ, and 8-bromo-cGMP did not affect MMP-9 concentrations. While PMA increased phospho-NFκB p65 concentrations, SNAP had no influence on this effect. In conclusion, this study shows that NO donors may attenuate imbalanced MMP expression and activity in endothelial cells independent of cGMP- or NFκB-mediated mechanisms. Our results may offer an important pharmacological strategy to approach cardiovascular diseases.

Is isolated systolic hypertension worse than combined systolic/diastolic hypertension?

New developments in cardiovascular translational sciences have significantly advanced our understanding of the endovascular biology of blood pressure. Reductions in vascular elasticity and vessel compliance of conduit arteries are key components of both ISH and SDH. Vascular changes from the matrix metalloproteinase family of enzymes are involved in arterial wall remodeling and vascular stiffness. This new translational information helps further our understanding of both ISH and SDH.