Lercanidipine reduces matrix metalloproteinase-9 activity in patients with hypertension

Treating hypertension while protecting the vulnerable islet in the cardiometabolic syndrome

Hypertension, a multifactorial-polygenic disease, interacts with multiple environmental stressors and results in functional and structural changes in numerous end organs, including the cardiovascular system. This can result in coronary heart disease, stroke, peripheral vascular disease, congestive heart failure, end-stage renal disease, insulin resistance, and damage to the pancreatic islet. Hypertension is the most important modifiable risk factor for major health problems encountered in clinical practice. Whereas hypertension was once thought to be a medical condition based on discrete blood pressure readings, a new concept has emerged defining hypertension as part of a complex and progressive metabolic and cardiovascular disease, an important part of a cardiometabolic syndrome. The central role of insulin resistance, oxidative stress, endothelial dysfunction, metabolic signaling defects within tissues, and the role of enhanced tissue renin-angiotensin-aldosterone system activity as it relates to hypertension and type 2 diabetes mellitus are emphasized. Additionally, this review focuses on the effect of hypertension on functional and structural changes associated with the vulnerable pancreatic islet. Various classes of antihypertensive drugs are reviewed, especially their roles in delaying or preventing damage to the vulnerable pancreatic islet, and thus delaying the development of type 2 diabetes mellitus.

Redox signaling, vascular function, and hypertension

Accumulating evidence supports the importance of redox signaling in the pathogenesis and progression of hypertension. Redox signaling is implicated in many different physiological and pathological processes in the vasculature. High blood pressure is in part determined by elevated total peripheral vascular resistance, which is ascribed to dysregulation of vasomotor function and structural remodeling of blood vessels. Aberrant redox signaling, usually induced by excessive production of reactive oxygen species (ROS) and/or by decreases in antioxidant activity, can induce alteration of vascular function. ROS increase vascular tone by influencing the regulatory role of endothelium and by direct effects on the contractility of vascular smooth muscle. ROS contribute to vascular remodeling by influencing phenotype modulation of vascular smooth muscle cells, aberrant growth and death of vascular cells, cell migration, and extracellular matrix (ECM) reorganization. Thus, there are diverse roles of the vascular redox system in hypertension, suggesting that the complexity of redox signaling in distinct spatial spectrums should be considered for a better understanding of hypertension.

Comparative assessment of matrix metalloproteinase (MMP)-2 and MMP-9, and their inhibitors, tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 in preeclampsia and gestational hypertension

OBJECTIVES

To compare the circulating levels of matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitors of metalloproteinase (TIMP)-1, TIMP-2, and the MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios in preeclampsia and gestational hypertension with those found in normotensive pregnancies.

DESIGN AND METHODS

We studied 83 pregnant women (30 healthy pregnant women with uncomplicated pregnancies, 26 with gestational hypertension, and 27 with preeclampsia) and 30 healthy nonpregnant women in a cross-sectional study. MMP and TIMP concentrations were measured in plasma samples by gelatin zymography and ELISA, respectively.

RESULTS

We found higher plasma pro-MMP-9 levels, and higher pro-MMP-9/TIMP-1 ratios in women with gestational hypertension (95%-CI: 1.031 to 2.357, and 0.012 to 0.031, respectively), but not with preeclampsia, compared with those found in normotensive pregnant women (95%-CI: 0.810 to 1.350, and 0.006 to 0.013, respectively; both P<0.05). We found no significant differences in pro-MMP-2 levels (P>0.05).

CONCLUSIONS

The higher net MMP-9 (but not MMP-2) activity in gestational hypertension compared with normotensive pregnancy suggests that MMP-9 plays a role in the pathophysiology of gestational hypertension. Conversely, the lack of such alterations in preeclampsia is consistent with the notion that different pathophysiological mechanisms are involved in these hypertensive disorders.

Inverse relationship between markers of nitric oxide formation and plasma matrix metalloproteinase-9 levels in healthy volunteers

BACKGROUND

Nitric oxide (NO) is a major regulator of cardiovascular homeostasis and has anti-atherogenic properties. Reduced NO formation is associated with endothelial dysfunction and with cardiovascular risk factors. Although NO downregulates the expression and activity of the pro-atherogenic enzyme matrix metalloproteinase-9 (MMP-9), no previous clinical study has examined whether endogenous NO formation is inversely associated with the circulating levels of pro-MMP-9, which are associated with cardiovascular events. We examined this hypothesis in 175 healthy male subjects who were non-smokers.

METHODS

To assess NO bioavailability, the plasma concentrations of nitrite, nitrate, and cGMP were determined using an ozone-based chemiluminescence assay and an enzyme immunoassay. Pro-MMP-9 and pro-MMP-2 levels were measured in plasma samples by gelatin zymography.

RESULTS

We found significant negative correlations between pro-MMP-9 levels and plasma nitrite (P=0.035, rs= -0.159), nitrate (P=0.040, rs= -0.158), and cGMP (P=0.011, rs= -0.189) concentrations. However, no significant correlations were found between pro-MMP-2 levels and the plasma concentrations of markers of NO bioavailability (all P>0.05).

CONCLUSIONS

There is an inverse relationship between markers of NO formation and plasma MMP-9 levels. This finding may shed some light on the possible mechanisms involved in the increased cardiovascular risk of apparently healthy subjects with low NO bioavailability or high circulating levels of pro-MMP-9.

Myocardial Matrix Remodeling and the Matrix Metalloproteinases: Influence on Cardiac Form and Function

It is now becoming apparent that dynamic changes occur within the interstitium that directly contribute to adverse myocardial remodeling following myocardial infarction (MI), with hypertensive heart disease and with intrinsic myocardial disease such as cardiomyopathy. Furthermore, a family of matrix proteases, the matrix metalloproteinases (MMPs) and the tissue inhibitors of MMPs (TIMPs), has been recognized to play an important role in matrix remodeling in these cardiac disease states. The purpose of this review is fivefold: 1) to examine and redefine the myocardial matrix as a critical and dynamic entity with respect to the remodeling process encountered with MI, hypertension, or cardiomyopathic disease; 2) present the remarkable progress that has been made with respect to MMP/TIMP biology and how it relates to myocardial matrix remodeling; 3) to evaluate critical translational/clinical studies that have provided a cause-effect relationship between alterations in MMP/TIMP regulation and myocardial matrix remodeling; 4) to provide a critical review and analysis of current diagnostic, prognostic, and pharmacological approaches that utilized our basic understanding of MMP/TIMPs in the context of cardiac disease; and 5) most importantly, to dispel the historical belief that the myocardial matrix is a passive structure and supplant this belief that the regulation of matrix protease pathways such as the MMPs and TIMPs will likely yield a new avenue of diagnostic and therapeutic strategies for myocardial remodeling and the progression to heart failure.

Effects of long-term lercanidipine or hydrochlorothiazide administration on hypertension-related vascular structural changes

OBJECTIVES

Vascular remodelling and hypertrophy represent early therapeutic targets of antihypertensive treatment. The present study was aimed at assessing the effects of 1-year administration of the highly vasoselective calcium-channel blocker lercanidipine (10 mg/day) or the diuretic compound hydrochlorothiazide (25 mg/day) on hypertension-related vascular alterations. The study was also aimed at assessing whether and to what extent: (i) pharmacological regression of vascular hypertrophy is related only to the blood pressure (BP) reduction "per se" or also to the specific ancillary properties of a given drug and (ii) treatment provides restoration of vascular function indicative of normal vascular structure.

DESIGN AND METHODS

In 26 untreated patients with mild-to-moderate essential hypertension sphygmomanometric and finger BP, heart rate, forearm and calf blood flow (venous occlusion plethysmography) and corresponding vascular resistance (forearm and calf vascular resistance: FVR and CVR) were assessed before and following 6 and 12 months of either lercanidipine or hydrochlorothiazide administration. Vascular resistance was also evaluated following a local ischaemic stimulus (FVR(min) and CVR(min)) in order to assess the effects of treatment on arteriolar structural alterations.

RESULTS

For superimposable BP reductions, lercanidipine caused FVR and CVR to decrease significantly more than hydrochlorothiazide. Similarly, the FVR(min) and CVR(min) reductions induced by lercanidipine were markedly and significantly greater than those caused by hydrochlorothiazide (-46.1% and -40.9% vs -22.5% and -19.9%, p < 0.01 for both). FVR(min), and CVR(min), however, remained higher than those found in 10 age-matched normotensive individuals.

CONCLUSIONS

These data provide evidence that, compared to hydrochlorothiazide, lercanidipine favours a greater regression of the vascular structural changes associated with hypertension, probably through its "ancillary" properties. Lercanidipine, however, does not allow restoration of a "normal" vascular structure, thereby suggesting that vascular hypertrophy is only in part a reversible phenomenon.

Rapid separation of serum does not avoid artificially higher matrix metalloproteinase (MMP)-9 levels in serum versus plasma

OBJECTIVES

To examine whether the time between blood drawing and centrifugation (TBDC) affects the levels of matrix metalloproteinase (MMP)-9 and MMP-2 levels in serum and in plasma samples, and to assess whether there is correlation between MMP-9 and MMP-2 levels in serum and plasma samples.

DESIGN AND METHODS

Serum and plasma samples (N=8) were separated from venous blood collected into citrate, heparin, and EDTA tubes, which were either centrifuged immediately or after 5, 10, 20, or 30 min after blood drawing. We assessed the correlation between MMP-9/MMP-2 in serum and citrate, heparin, and plasma samples (N=20), which were assayed for gelatine zymography of MMP-2 and MMP-9.

RESULTS

MMPs are released by platelets or leukocytes during platelet activation or sampling process, thus leading to artificially higher MMP-9 levels in serum compared with citrate, heparin, or EDTA plasma samples, independently of TBDC. Citrate and heparin plasma samples had the lowest Pro-MMP-9 and MMP-9 levels, which correlated with each other. Pro-MMP-9 levels in serum correlated with Pro-MMP-9 levels in EDTA or citrate plasma, but not with heparin plasma. While no significant correlations were found between MMP-9 levels in serum and those found in plasma samples, the total MMP-9 levels (Pro-MMP-9+MMP-9) in serum and in plasma samples correlated with each other. No significant differences were found in pro-MMP-2 levels.

CONCLUSIONS

These results suggest that the circulating levels of MMP-9 should be assessed in citrate or heparin plasma samples, but not in serum samples because of artificially higher MMP-9 levels in serum, independently of TBDC, and because they do not correlate with the MMP-9 levels in plasma samples.

eNOS gene T-786C polymorphism modulates atorvastatin-induced increase in blood nitrite

Statins inhibit cholesterol synthesis and produce pleiotropic, cholesterol-independent effects including endothelial NO synthase (eNOS) stimulation and increased expression. However, a functional polymorphism in the promoter of the eNOS gene (T-786C) reduces its activity and could modulate the response to statins. Here, we examined whether this polymorphism modulates the effects of atorvastatin on the plasma levels of markers of NO formation and oxidative stress. We genotyped 200 healthy subjects for this polymorphism, and 15 subjects with the TT genotype and 15 with the CC genotype were selected to receive placebo or atorvastatin 10 mg/day po for 14 days. To assess NO bioavailability, the plasma concentrations of nitrate, nitrite, and cGMP and the whole blood nitrite concentrations were determined after placebo or atorvastatin using an ozone-based chemiluminescence assay and an enzyme immunoassay. Thiobarbituric acid-reactive species (TBA-RS) were measured in the plasma to assess oxidative stress. Atorvastatin decreased cholesterol concentrations independent of genotype. Whereas atorvastatin produced no significant changes in plasma nitrite, nitrate, or cGMP concentrations in both genotype groups, atorvastatin increased whole blood nitrite concentrations and decreased plasma TBA-RS concentrations in the CC (but not in the TT) genotype group. These findings suggest that the T-786C polymorphism modulates the effects of atorvastatin on NO bioavailability and oxidative stress.

Anti-inflammatory effects of atorvastatin: modulation by the T-786C polymorphism in the endothelial nitric oxide synthase gene

Statins produce cholesterol-independent, anti-inflammatory effects, which result at least in part from increased endothelial nitric oxide production. These effects may be modulated by polymorphisms in the endothelial nitric oxide synthase (eNOS) gene. Here, we examined whether the T-786C polymorphism of eNOS gene affects the concentrations of markers of atherosclerosis and inflammation (sCD40L, sVCAM-1, sICAM-1, sP-selectin, MCP-1, high sensitivity (hs)-CRP, MMP-2, MMP-9, and TIMP-1). We also studied whether atorvastatin-induced anti-inflammatory effects are modulated by this polymorphism. Healthy male volunteers (N=200), Caucasians, non-smokers, were genotyped for the T-786C polymorphism by restriction fragment length polymorphism. Subjects with TT or CC genotype received placebo for 14 days followed by 14 days of treatment with atorvastatin, 10mg/day p.o. The concentrations of inflammatory markers were measured with ELISA kits or by gelatin zymography. Serum cholesterol and LDL-cholesterol were significantly reduced after atorvastatin treatment in both genotype groups (P<0.05). No significant differences between genotype groups were found in the concentrations of the inflammatory markers after placebo. However, atorvastatin significantly reduced the concentrations of sCD40L, sVCAM-1, sP-selectin and MMP-9 in subjects with CC (but not TT) genotype (P<0.05). While atorvastatin decreased hs-CRP levels in both genotype groups (P<0.05), no significant effects were found on the concentrations of sICAM-1, MCP-1, pro-MMP-9, pro-MMP-2 and TIMP-1. These results suggest no effects for the T-786C polymorphism on the concentrations of inflammatory markers. However, this polymorphism modulates the anti-inflammatory effects of atorvastatin. These findings may be relevant for the primary prevention of cardiovascular events in subjects with CC genotype, who may be at increased cardiovascular risk and could benefit from treatment with statins.