Impact of the Metalloproteinase-9/Tissue Inhibitor of Metalloproteinase-1 System on Large Arterial Stiffness in Patients with Essential Hypertension

Association between six different types of anthropometric indices and arterial stiffness measured by brachial-ankle pulse wave velocity in hypertensive Chinese adults

Background

The associations of body fat parameters with arterial stiffness measured by brachial-ankle pulse wave velocity in hypertensive patients were scarce.

Methods

This cross-sectional study analyzed 4322 hypertensive adults. The correlations between the anthropometric indexes (body mass index [BMI], waist circumference, waist-tohip ratio [WHR], waist-to-height ratio [WHtR], a body shape index [ABSI], body round index [BRI]) and ba-PWV values were analyzed using multivariable linear regression model.

Results

In both sex categories, linear regression models showed that BMI levels were inversely related to baPWV (adjusted-β per SD increase in male: -0.51, 95% CI -0.66 to -0.36, P < 0.001; female: -0.50, 95% CI -0.63 to -0.37, P < 0.001). Waist circumference positively correlated with baPWV only in male hypertensive individuals. BaPWV positively correlated to WHR or WHtR levels (adjusted-β per SD increase: 0.32, 95% CI 0.21 to 0.43, P < 0.001; 0.64, 95% CI 0.47 to 0.82, P < 0.001; respectively), ABSI (adjusted-β per SD increase for ABSI × 100: 0.27, 95% CI 0.18 to 0.36, P < 0.001) and BRI (adjusted-β per SD increase: 0.64, 95% CI 0.46 to 0.81, P < 0.001) levels. The relationship between anthropometric indices and arterial stiffness based on baPWV values were also consistent. ABSI had the highest predictive power of arterial stiffness (area under the curve, 0.594; P < 0.001).

Conclusion

In Chinese adults with hypertension, BMI was inversely related to baPWV, while WHR, WHtR, ABSI and BRI were positively related. Waist circumference positively correlated with baPWV only in male hypertensive individuals.

Plasma and cerebrospinal fluid proteomic signatures of acutely sleep-deprived humans: an exploratory study

Study Objectives

Acute sleep deprivation affects both central and peripheral biological processes. Prior research has mainly focused on specific proteins or biological pathways that are dysregulated in the setting of sustained wakefulness. This exploratory study aimed to provide a comprehensive view of the biological processes and proteins impacted by acute sleep deprivation in both plasma and cerebrospinal fluid (CSF).

Methods

We collected plasma and CSF from human participants during one night of sleep deprivation and controlled normal sleep conditions. One thousand and three hundred proteins were measured at hour 0 and hour 24 using a high-scale aptamer-based proteomics platform (SOMAscan) and a systematic biological database tool (Metascape) was used to reveal altered biological pathways.

Results

Acute sleep deprivation decreased the number of upregulated and downregulated biological pathways and proteins in plasma but increased upregulated and downregulated biological pathways and proteins in CSF. Predominantly affected proteins and pathways were associated with immune response, inflammation, phosphorylation, membrane signaling, cell-cell adhesion, and extracellular matrix organization.

Conclusions

The identified modifications across biofluids add to evidence that acute sleep deprivation has important impacts on biological pathways and proteins that can negatively affect human health. As a hypothesis-driving study, these findings may help with the exploration of novel mechanisms that mediate sleep loss and associated conditions, drive the discovery of new sleep loss biomarkers, and ultimately aid in the identification of new targets for intervention to human diseases.

Matrix Metalloproteinases and Heart Transplantation-A Pathophysiological and Clinical View

Heart transplantation is undergoing a continuous development, with rates of success increasing substantially due to advances in immunosuppressive therapy and surgical techniques. The most worrying complication occurring after cardiac transplantation is graft rejection, a phenomenon that is much affected by matrix metalloproteinases (MMPs), with the role of these proteases in the cardiac remodeling process being well established in the literature. A detailed investigation of the association between MMPs and cardiac rejection is necessary for the future development of more targeted therapies in transplanted patients, and to discover prognostic serum and immunohistochemical markers that will lead to more organized therapeutic management in these patients. The aim of this review is therefore to highlight the main MMPs relevant to cardiovascular pathology, with particular emphasis on those involved in complications related to heart transplantation, including cardiac graft rejection.

Involvement of Matrix Metalloproteinases in COVID-19: Molecular Targets, Mechanisms, and Insights for Therapeutic Interventions

MMPs are enzymes involved in SARS-CoV-2 pathogenesis. Notably, the proteolytic activation of MMPs can occur through angiotensin II, immune cells, cytokines, and pro-oxidant agents. However, comprehensive information regarding the impact of MMPs in the different physiological systems with disease progression is not fully understood. In the current study, we review the recent biological advances in understanding the function of MMPs and examine time-course changes in MMPs during COVID-19. In addition, we explore the interplay between pre-existing comorbidities, disease severity, and MMPs. The reviewed studies showed increases in different MMP classes in the cerebrospinal fluid, lung, myocardium, peripheral blood cells, serum, and plasma in patients with COVID-19 compared to non-infected individuals. Individuals with arthritis, obesity, diabetes, hypertension, autoimmune diseases, and cancer had higher MMP levels when infected. Furthermore, this up-regulation may be associated with disease severity and the hospitalization period. Clarifying the molecular pathways and specific mechanisms that mediate MMP activity is important in developing optimized interventions to improve health and clinical outcomes during COVID-19. Furthermore, better knowledge of MMPs will likely provide possible pharmacological and non-pharmacological interventions. This relevant topic might add new concepts and implications for public health in the near future.

A functional MMP-9-1562C>T polymorphism, MMP-9 serum levels and nephrolithiasis risk in a southern Chinese population

Background

The role of matrix metalloproteinase 9 (MMP-9) in the pathophysiology of chronic kidney disease (CKD), which is associated with a nearly two-fold greater risk for urinary calculi compared to people without CKD, has been demonstrated. The aim of the research is to evaluate the association between MMP-9-1562C>T polymorphism, MMP-9 serum levels and nephrolithiasis risk.

Methods

A hospital-based case-control study involving 302 kidney stone patients and 408 controls without kidney stone from southern China was conducted. Sanger sequencing was used to genotype the MMP-9-1562C>T polymorphism. The serum MMP-9 was measured in 105 kidney stone patients and 77 controls by enzyme-linked immunosorbent assay.

Results

Compared to the control group, the CT genotype was more frequent in nephrolithiasis patients (adjusted OR = 1.60, 95% CI = 1.09-2.37: the risk of developing nephrolithiasis in individuals with CT genotype compared to CC genotype). Moreover, there was also a higher frequency of CT/TT genotypes among patients with nephrolithiasis (adjusted OR = 1.49, 95% CI = 1.02-2.19: the risk of developing nephrolithiasis in individuals with CT/TT genotypes compared to CC genotype). The risk remained for the subgroups of patients aged >53, smokers with pack-years of smoking >20, non-drinkers, non-diabetic patients, patients with hypertension, recurrent episodes and calcium oxalate stones (OR = 2.26, 95% CI = 1.31-3.91; OR = 5.47, 95% CI = 1.10-27.30; OR = 1.76, 95% CI = 1.14-2.72; OR = 1.54, 95% CI = 1.03-2.30; OR = 1.97, 95% CI = 1.01-3.82; OR = 1.67, 95% CI = 1.06-2.62; OR = 1.54, 95% CI = 1.02-2.32, respectively). Biochemical parameters did not differ between genotypes. Compared to controls (18.57 ± 5.80 ng/mL), nephrolithiasis patients had significantly higher serum MMP-9 levels (30.17 ± 6.78 ng/mL, p < 0.001). The serum MMP-9 levels of patients with CT/TT genotypes of MMP-9-1562C>T were significantly higher than those with CC genotype (32.00 ± 6.33 vs. 29.13 ± 6.85 ng/mL, p = 0.037).

Conclusion

The MMP-9-1562C>T polymorphism in association with its soluble protein increased the risk of kidney stone, thus suggesting it could be used as a susceptibility biomarker for nephrolithiasis. Further functional studies and larger studies that include environmental exposure data are needed to confirm the findings.

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.

Cardiovascular Biomarkers: Lessons of the Past and Prospects for the Future

Cardiovascular diseases (CVDs) are a major healthcare burden on the population worldwide. Early detection of this disease is important in prevention and treatment to minimise morbidity and mortality. Biomarkers are a critical tool to either diagnose, screen, or provide prognostic information for pathological conditions. This review discusses the historical cardiac biomarkers used to detect these conditions, discussing their application and their limitations. Identification of new biomarkers have since replaced these and are now in use in routine clinical practice, but still do not detect all disease. Future cardiac biomarkers are showing promise in early studies, but further studies are required to show their value in improving detection of CVD above the current biomarkers. Additionally, the analytical platforms that would allow them to be adopted in healthcare are yet to be established. There is also the need to identify whether these biomarkers can be used for diagnostic, prognostic, or screening purposes, which will impact their implementation in routine clinical practice.

Pathophysiology of Circulating Biomarkers and Relationship With Vascular Aging: A Review of the Literature From VascAgeNet Group on Circulating Biomarkers, European Cooperation in Science and Technology Action 18216

Impairment of the arteries is a product of sustained exposure to various deleterious factors and progresses with time; a phenomenon inherent to vascular aging. Oxidative stress, inflammation, the accumulation of harmful agents in high cardiovascular risk conditions, changes to the extracellular matrix, and/or alterations of the epigenetic modification of molecules, are all vital pathophysiological processes proven to contribute to vascular aging, and also lead to changes in levels of associated circulating molecules. Many of these molecules are consequently recognized as markers of vascular impairment and accelerated vascular aging in clinical and research settings, however, for these molecules to be classified as biomarkers of vascular aging, further criteria must be met. In this paper, we conducted a scoping literature review identifying thirty of the most important, and eight less important, biomarkers of vascular aging. Herein, we overview a selection of the most important molecules connected with the above-mentioned pathological conditions and study their usefulness as circulating biomarkers of vascular aging.

Does body mass index or waist-hip ratio correlate with arterial stiffness based on brachial-ankle pulse wave velocity in Chinese rural adults with hypertension?

BACKGROUND

The relationship between obesity indices and arterial stiffness (AS) has not been fully discovered nor has it been studied in depth in large hypertensive patient populations. The aim of this study was to explore the association between body mass index (BMI) and waist-hip ratio (WHR) levels and AS based on brachial-ankle pulse wave velocity (baPWV) in Chinese rural adults with hypertension.

METHODS

This cross-sectional study analyzed 5049 Chinese rural adults with essential hypertension. BMI was calculated as the body weight in kilograms divided by the square of the height in meters (kg/m2). Central obesity was defined as WHR ≥ 0.9 for males and ≥ 0.85 for females. Measurement of arterial stiffness was carried out via brachial-ankle pulse wave velocity (baPWV).

RESULTS

The prevalence of overweight, general obesity, central obesity and increased AS were 26.88%, 3.39%, 63.85% and 44.01%, respectively. Multivariate logistic regression analysis indicated that BMI levels were negatively associated with the prevalence of increased AS (adjusted-OR per SD increase: 0.74, 95% CI 0.67-0.81, P < 0.001). When BMI was instead treated as a categorical variable divided into tertiles, the same relationship was observed (P for trend < 0.001). Inversely, WHR levels were positively associated with the prevalence of increased AS (adjusted-OR per SD increase: 1.25, 95% CI 1.14-1.36, P < 0.001). Compared to subjects without central obesity, those with central obesity had a higher prevalence of increased AS (adjusted-OR: 1.52, 95% CI 1.28-1.81, P < 0.001). Linear regression models indicated similar results in the correlation between BMI or WHR levels and baPWV levels (adjusted-β per SD increase: - 0.57, 95% CI - 0.68 to - 0.46, P < 0.001; adjusted-β per SD increase: 4.46, 95% CI 3.04-5.88, P < 0.001). There were no interactions in terms of age and blood pressure on the relationship between BMI or WHR levels and the prevalence of increased AS or baPWV levels.

CONCLUSION

There was an inverse relationship between BMI levels and increased AS or baPWV levels, whereas WHR levels and central obesity were positively associated with increased AS or baPWV levels in Chinese rural adults with hypertension.

Association of Circulating Extracellular Matrix Components with Central Hemodynamics and Arterial Distensibility of Peripheral Arteries

BACKGROUND

In addition to neuronal and endothelial regulators of vascular tone, the passive mechanical properties of arteries, determined by the molecular structure of extracellular matrices, are the principle modulators of vascular distensibility. Specifically, the association between collagen type IV (Col IV), a constituent of basement membrane, and arterial compliance remains unclear.

METHODS

In 31 healthy adult men, radial applanation tonometry and pulse wave analysis were used to assess aortic augmentation index (AIx), aortic-to-radial pulse pressure amplification (PPAmpl), and time to reflection wave.

RESULTS

Plasma Col IV and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) concentrations were correlated with AIx (r = 0.51, p = 0.021 and r = -0.45, p = 0.042, respectively) after adjustment for age and heart rate (HR). Greater matrix metalloproteinase-9 (MMP-9) and TIMP-1 levels were associated with high PPAmpl (r = 0.45 and r = 0.64, respectively) and hence with compliant arteries. Multiple regression analyses revealed that 99% of the variation in PPAmpl was attributable to age, HR, Col IV, TIMP-1, and Col × TIMP-1 interaction (p < 0.001). No relations between tonometric variables and levels of MMP-1, -2, and -3; TIMP-2 and -4; fibronectin; glycosaminoglycans; and hydroxyproline were found.

CONCLUSION

High circulating Col IV level indexes were associated with stiffer peripheral arteries whereas increased MMP-9 and TIMP-1 concentrations were associated with more compliant ones.

Matrix metalloproteinase-9 as a messenger in the cross talk between obstructive sleep apnea and comorbid systemic hypertension, cardiac remodeling, and ischemic stroke: a literature review

STUDY OBJECTIVES

OSA is a common sleep disorder. There is a strong link between sleep-related breathing disorders and cardiovascular and cerebrovascular diseases. Matrix metalloproteinase-9 (MMP-9) is a biological marker for extracellular matrix degradation, which plays a significant role in systemic hypertension, myocardial infarction and postmyocardial infarction heart failure, and ischemic stroke. This article reviews MMP-9 as an inflammatory mediator and a potential messenger between OSA and OSA-induced comorbidities.

METHODS

We reviewed the MEDLINE database (PubMed) for publications on MMP-9, OSA, and cardiovascular disease, identifying 1,592 studies and including and reviewing 50 articles for this work.

RESULTS

There is strong evidence that MMP-9 and tissue inhibitor of metalloproteinase-1 levels are elevated in patients with OSA (mainly MMP-9), systemic hypertension, myocardial infarction, and postmyocardial infarction heart failure. Our study showed variable results that could be related to the sample size or to laboratory methodology.

CONCLUSIONS

MMP-9 and its endogenous inhibitor, tissue inhibitor of metalloproteinase-1, are a common denominator in OSA, systemic hypertension, myocardial infarction, and heart failure. This characterization makes MMP-9 a target for developing novel selective inhibitors that can serve as adjuvant therapy in patients with OSA, which may ameliorate the cardiovascular and cerebrovascular mortality associated with OSA.

Matrix Metalloproteinases and Arterial Hypertension: Role of Oxidative Stress and Nitric Oxide in Vascular Functional and Structural Alterations

Various pathophysiological mechanisms have been implicated in hypertension, but those resulting in vascular dysfunction and remodeling are critical and may help to identify critical pharmacological targets. This mini-review article focuses on central mechanisms contributing to the vascular dysfunction and remodeling of hypertension, increased oxidative stress and impaired nitric oxide (NO) bioavailability, which enhance vascular matrix metalloproteinase (MMP) activity. The relationship between NO, MMP and oxidative stress culminating in the vascular alterations of hypertension is examined. While the alterations of hypertension are not fully attributable to these pathophysiological mechanisms, there is strong evidence that such mechanisms play critical roles in increasing vascular MMP expression and activity, thus resulting in abnormal degradation of extracellular matrix components, receptors, peptides, and intracellular proteins involved in the regulation of vascular function and structure. Imbalanced vascular MMP activity promotes vasoconstriction and impairs vasodilation, stimulating vascular smooth muscle cells (VSMC) to switch from contractile to synthetic phenotypes, thus facilitating cell growth or migration, which is associated with the deposition of extracellular matrix components. Finally, the protective effects of MMP inhibitors, antioxidants and drugs that enhance vascular NO activity are briefly discussed. Newly emerging therapies that address these essential mechanisms may offer significant advantages to prevent vascular remodeling in hypertensive patients.

The Roles of Matrix Metalloproteinases and Their Inhibitors in Human Diseases

Matrix metalloproteinases (MMPs) are a family of zinc-dependent extracellular matrix (ECM) remodeling endopeptidases that have the capacity to degrade almost every component of the ECM. The degradation of the ECM is of great importance, since it is related to embryonic development and angiogenesis. It is also involved in cell repair and the remodeling of tissues. When the expression of MMPs is altered, it can generate the abnormal degradation of the ECM. This is the initial cause of the development of chronic degenerative diseases and vascular complications generated by diabetes. In addition, this process has an association with neurodegeneration and cancer progression. Within the ECM, the tissue inhibitors of MMPs (TIMPs) inhibit the proteolytic activity of MMPs. TIMPs are important regulators of ECM turnover, tissue remodeling, and cellular behavior. Therefore, TIMPs (similar to MMPs) modulate angiogenesis, cell proliferation, and apoptosis. An interruption in the balance between MMPs and TIMPs has been implicated in the pathophysiology and progression of several diseases. This review focuses on the participation of both MMPs (e.g., MMP-2 and MMP-9) and TIMPs (e.g., TIMP-1 and TIMP-3) in physiological processes and on how their abnormal regulation is associated with human diseases. The inclusion of current strategies and mechanisms of MMP inhibition in the development of new therapies targeting MMPs was also considered.

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.

RNA-sequencing analysis of differential gene expression associated with arterial stiffness

OBJECTIVES

Arterial stiffness is recognized as an important predictor of cardiovascular disease morbidity and mortality, independent of traditional cardiovascular disease risk factors. Given that arterial tissue is not easily accessible, most gene expression studies on arterial stiffness have been conducted on animals or on patients who have undergone by-pass surgeries. In order to obtain a deeper understanding of early changes of arterial stiffness, this study compared transcriptome profiles between healthy adults with higher and lower arterial stiffness.

METHODS

The sample included 20 healthy female adults without cardiovascular disease. Arterial stiffness was measured by carotid-femoral pulse wave velocity, the "gold-standard" measure of central arterial stiffness. Peripheral blood samples collected to PAXgene™ RNA tubes were used for RNA sequencing (RNA-seq). The potential confounding effects of age, body mass index, and mean arterial pressure were controlled for in RNA-seq analysis. To validate RNA-seq results, quantitative real-time PCR (qRT-PCR) was performed for six selected genes.

RESULTS

The findings demonstrated that genes including CAPN9, IL32, ERAP2, RAB6B, MYBPH, and miRNA626 were down-regulated, and that MOCS1 gene was up-regulated among the people with higher arterial stiffness. Real-time PCR showed that the changes of CAPN9, IL32, ERAP2, and RAB6B were in concordance with RNA-seq data, and confirmed the validity of the gene expression profiles obtained by RNA-seq analysis.

CONCLUSIONS

Previous studies have suggested the potential roles of CAPN9, IL32, and ERAP2 in structural changes of the arterial wall through up-regulation of metalloproteinases. However, the current study showed that CAPN9, IL32, and ERAP2 were down-regulated in the individuals with higher arterial stiffness, compared with those with lower arterial stiffness. The unexpected directions of expression of these genes may indicate an effort to maintain vascular homeostasis during increased arterial stiffness among healthy individuals. Further studies are guaranteed to investigate the roles of CAPN9, IL32, and ERAP2 in regulating arterial stiffness in people with and without cardiovascular disease.

Enhanced Antioxidative Defense by Vitamins C and E Consumption Prevents 7-Day High-Salt Diet-Induced Microvascular Endothelial Function Impairment in Young Healthy Individuals

This study aimed to examine whether the oral supplementation of vitamins C and E during a seven-day high salt diet (HS; ~14 g salt/day) prevents microvascular endothelial function impairment and changes oxidative status caused by HS diet in 51 (26 women and 25 men) young healthy individuals. Laser Doppler flowmetry measurements demonstrated that skin post-occlusive reactive hyperemia (PORH), and acetylcholine-induced dilation (AChID) were significantly impaired in the HS group, but not in HS+C+E group, while sodium nitroprusside-induced dilation remained unaffected by treatments. Serum oxidative stress markers: Thiobarbituric acid reactive substances (TBARS), 8-iso prostaglandin-F2α, and leukocytes’ intracellular hydrogen peroxide (H₂O₂) production were significantly increased, while ferric-reducing ability of plasma (FRAP) and catalase concentrations were decreased in the HS group. All these parameters remained unaffected by vitamins supplementation. Matrix metalloproteinase 9, antioxidant enzymes Cu/Zn SOD and glutathione peroxidase 1, and leukocytes’ intracellular superoxide production remained unchanged after the protocols in both HS and HS+C+E groups. Importantly, multiple regression analysis revealed that FRAP was the most powerful predictor of AChID, while PORH was strongly predicted by both FRAP and renin-angiotensin system activity. Hereby, we demonstrated that oxidative dis-balance has the pivotal role in HS diet-induced impairment of endothelial and microvascular function in healthy individuals which could be prevented by antioxidative vitamins consumption.

[Vasoprotective Effects of Prolonged Therapy With Perindopril A in Patients with Hypertension Including Concomitant Type 2 Diabetes Mellitus]

Objective Investigate the dynamics of morphological and functional markers of vascular remodeling in patients with arterial hypertension (AH), including those with concomitant type 2 diabetes mellitus (DM2), during 12-month administration of perindopril A.Material and Methods The study included patients with grade I-II AH, with and without DM2 (30 and 32 patients, respectively), who underwent outpatient correction of initially ineffective antihypertensive therapy and administration of perindopril A, 10 mg/day. Morphological and functional parameters of vascular remodeling were evaluated in all patients at baseline and at 12 months using photoplethysmography. Stiffness index (SI) and phase shift (PS) were measured in large vessels. Reflection index (RI) and occlusion index (OI) were measured in microvessels. Computed nailfold videocapillaroscopy was used to determine capillary density (CD) at rest (CDr), CD during venous occlusion test (CDvo), and CD during reactive hyperemia test (CDrh). Data are medians [interquartile range].Results After 12-month administration of perindopril A, the morphological and functional parameters of vascular remodeling in AH patients without DM2 significantly improved at all vascular levels. SI decreased to 9.25 [7.8; 10.93 ] m/s and PS increased to 7.4 [5.6; 9.05] ms. In microvasculature, a statistically significant reduction was observed in RI, 31 [27; 36.5]%, and an increase was observed in OI, which characterizes endothelium function, 1.75 [1.68; 1.9]. Capillary CDr significantly increased to 40.5 [34.93; 46] cap/mm2, as did CDvo and CDrh. At the same time, in the group of patients with AH and DM2, a significant improvement was observed for the large vessels. SI decreased to 9.8 [9.08; 10.58] m/s, and PS increased to 6.95 [5.13; 10.08]. The RI index, reflecting the structural condition of arterioles, significantly decreased to 34 [25.9; 45.53]%, and the OI index, characterizing endothelial function, did not change significantly, 1.4 [1.3; 1.6]. Capillary CDr significantly increased to 31.55 [27.68; 34.7 ] cap/mm2; however, CDvo and CDrh did not change significantly. Renal function improved in both groups.Conclusion Both groups demonstrated improvement of morphological parameters at all levels of the arterial bed. However, patients with AH and concomitant DM2 showed no improvement of the endothelial function of arterioles and capillaries compared to improvement in AH patients without DM2. This reflected the more severe endothelial dysfunction present in AH patients with DM2.

microRNA-451a prevents activation of matrix metalloproteinases 2 and 9 in human cardiomyocytes during pathological stress stimulation

Matrix metalloproteinases (MMP) are important for cardiac remodeling. Recently, microRNA (miR)-451a has been found to inhibit the expression of both MMP-2 and MMP-9 in human malignancies, but its role in cardiomyocytes has not been explored. We hypothesized that miR-451a modulates MMP-2 and MMP-9 levels in human cardiomyocytes. The role of miR-451a on regulation of MMP-2 and MMP-9 was evaluated in two separate pathological models using Cor.4U human inducible pluripotent stem cell-derived cardiomyocytes (hiPS-CMs): 1) endothelin-1 (ET-1), and 2) 48-h hypoxia (1% O₂). Both models were transfected with synthetic miR-451a mimics or scramble control. Expression of both mRNA and miR was determined by quantitative real-time polymerase chain reaction and protein activity by (MMP-2/9) activity assay. Bioinformatic analyses were performed using Targetscan 7.1 and STRING 10.5. hiPS-CMs stimulated by hypoxia increased both MMP-2 and MMP-9 expression levels compared with normoxia (P < 0.05), whereas ET-1 stimulation only increased the MMP-9 level compared with vehicle controls (P < 0.05). miR-451a mimics prevented the increase of MMP-2 and MMP-9 expression in both models. Protein activity of MMP-2 and MMP-9 was confirmed to be lower following treatment with miR-451a mimic compared with scramble-controls. Six of 28 predicted gene transcripts of miR-451a were linked to MMP-2 and MMP-9; Macrophage migration inhibitory factor (MIF) was the only predicted target of miR-451a that was increased by ET-1 and hypoxia and reduced following miR-451a mimic transfection. miR-451a prevent the increase of MMP-2 and MMP-9 in human cardiomyocytes during pathological stress. The modulation by miR-451a on MMP-2 and MMP-9 is caused by MIF.

Plasma levels of matrix metalloproteinase-9: A possible marker for cold-induced stroke risk in hypertensive rats

The cold weather is associated with an increased occurrence of acute stroke events. However, the underlying mechanisms have not yet been fully elucidated. In the present study, we investigated whether plasma matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels as well as the MMP-9/TIMP-1 ratio could be used as predictor for cold-induced stroke risk in hypertensive rats. A total of 50 male rats were subjected to either control group or 2-kidney, 2-clip (2K - 2C) group (N = 25, each), After blood pressure was stabilized, rats were placed in an intelligent artificial climate chamber and maintained on a 12-h light (22 °C)/dark (4 °C) cycle for 3 days. Plasma levels of MMP-9 and TIMP-1 were measured before and after cold exposure from 50 rats by ELISA. Pretreatment plasma MMP-9 levels were significantly higher in 2K-2C rats than in the controls (P <  0.05), TIMP-1 levels were significantly lower in 2K-2C rats than in the controls (P <  0.05), pretreatment plasma MMP-9 levels were significantly higher in those with cold-induced stroke compared to those without (P <  0.05). Logistic regression analysis showed that only plasma MMP-9 levels remained independently associated with cold-induced stroke after adjusting for potential confounders (OR, 1.17; 95% CI, 1.08 to 1.32; P < 0.007). In contrast, no correlation was observed between systolic blood pressure (SBP), TIMP-1 or MMP-9/TIMP-1 ratio and the cold-induced stroke. Higher plasma MMP-9 levels are significantly correlated with cold-induced stroke in hypertensive rats treated with intermittent cold stress. Plasma MMP-9 may be as a promising biomarker to predict the risk of cold-induced stroke events in hypertensive rats.

Association Between Body Mass Index (BMI) and Brachial-Ankle Pulse Wave Velocity (baPWV) in Males with Hypertension: A Community-Based Cross-Section Study in North China

BACKGROUND The aim of this study was to investigate the association between body mass index (BMI) and brachial-ankle pulse wave velocity (baPWV) in hypertensive males. MATERIAL AND METHODS Altogether, 14 866 male hypertensive participants were included in the analysis. Participants were divided into 3 groups: low BMI group (BMI <24 kg/m²), moderate BMI group (24 kg/m² ≤BMI <28 kg/m²), and high BMI group (BMI ≥28 kg/m²). According to baPWV values, arteriosclerosis (AS) was set as 3 degrees: mild AS (baPWV ≥1400 cm/s), moderate AS (baPWV ≥1700 cm/s) and severe AS (baPWV ≥2000 cm/s). Multivariate logistic regression analysis was used to explore the effect of different BMI groups on different degrees of AS. The multivariate linear regression analysis was used to explore the relationship between BMI and baPWV. RESULTS Among low BMI, moderate BMI, and high BMI groups, the average baPWV values were 1824±401 cm/s, 1758±363 cm/s, and 1686±341 cm/s, respectively. Prevalence in the mild, moderate and high BMI groups were 91.0%, 87.8%, 81.5%, respectively for mild AS; 55.3%, 48.8%, and 40.0% respectively for moderate AS; and 25.9%, 20.2%, and 14.9% respectively for severe AS. Compared to the low BMI group, multivariate logistic regression analysis showed that odds ratio (OR) and 95% confidence intervals (95%CI) in the moderate BMI group and the high BMI were 0.71 (95%Cl, 0.62-0.80), 0.43 (95%Cl, 0.38-0.50) for mild AS; and similar trends were shown for moderate AS and severe AS. Based on age-stratification, a negative relationship remained for 35-55 years old participants for different degrees of AS among the moderate BMI group and the high BMI group. A negative relationship was detected between BMI and baPWV in total and different age-stages. CONCLUSIONS Among male hypertension participants in this study, there was a negative relationship between BMI and baPWV. High BMI was found to be a protective factor for AS especially in the age range of 35-55 years.

Vascular Remodeling Markers in Patients with Essential Arterial Hypertension Depending on Presence of Type 2 Diabetes Mellitus

Aim. To study some vascular remodeling markers in hypertensive patients depending on the presence of type 2 diabetes mellitus.Material and methods. The study included patients with essential hypertension 1-2 degrees of increase in blood pressure with/without type 2 diabetes (30 and 32 patients respectively). Using photoplethysmography in combination with reactive hyperemia test structural and functional markers of vascular remodeling were determined: in large vessels – stiffness index and phase shift; in microvessels – reflection index and the occlusion index. Using the computer video capillaroscopy of the nail bed the density of the capillary network at rest, after venous occlusion and after the test with reactive hyperemia was determined. ELISA was used for determining the level of humoral markers of endothelium dysfunction and vascular bed remodeling: metalloproteinase 9, metalloproteinase 9 inhibitor, E-selectin, endothelin, transforming growth factor (TGF-β1), endothelial growthfactor A.Results. In compare with hypertensive patients in hypertensive patients with type 2 diabetes significantly higher stiffness index values (11.15 [10.05; 12.35] vs 10.15 [8.83; 11.83] m/s; p=0.04) were found as well as significantly lower (p=0.00) capillary network density at rest (26.4 [24.2; 27.6] vs 35.1 [33.0; 45.0] cap/mm2; p=0.00) after the tests with reactive hyperemia (29 [24; 33.3] vs 40.0 [35.0;43.3] cap/mm2; p=0.00) and venous occlusion (32.5 [27.8; 34.5] vs 40.0 [33.0; 45.0] cap/mm2). In hypertensive patients with type 2 diabetes significantly higher levels of TFG-β1 (11648 [4117.8; 37933.8] vs 3938.5 [1808.8; 7694] pg/ml; p=0.00) and significantly lower levels of endothelin-1 (0,46 [0,29;1,3] vs 1.73 [0.63; 2.30] ng/ml; p=0.01) was detected in compare with hypertensive patients without type 2 diabetes.Conclusion. In both groups some signs of vascular remodeling were found at the level of both large arteries and microvessels (arterioles and capillaries). However, the group of hypertension + type 2 diabetes mellitus had statistically significantly more pronounced changes in arterial stiffness, capillary network density, as well as humoral markers levels of fibrosis and endothelial dysfunction. 

In healthy normotensive subjects age and blood pressure better predict subclinical vascular and cardiac organ damage than atherosclerosis biomarkers

PURPOSE

Only few studies evaluated biomarkers useful for defining the cardiovascular risk of a subject in a pre-clinical condition (i.e. healthy subjects). In this context we sought to determine the relationships of Plasminogen activator inhibitor type 1 (PAI-1), P-Selectin, Tissue Inhibitors Metalloproteinases type 1 (TIMP-1) and Cystatin-C with subclinical Target Organ Damage (TOD) in normotensive and normoglycemic subjects without known cardiovascular and kidney diseases.

MATERIALS AND METHODS

480 blood donors participated at the present analysis. TOD was evaluated as Pulse Wave Velocity (PWV), Left Ventricular Hypertrophy (LVH) and Intima Media Thickness (IMT) and carotid plaque presence) grouped together under carotid TOD.

RESULTS

3.1% of the subjects showed a PWV higher than 10 m/sec with those subjects exerting significantly lower values of P-Selectine (0.068 ± 0.015 vs 0.08 ± 0.036 mg/L, p = .014). 8.8% of the subjects showed carotid TOD that was associated with higher Cystatin-C values (0.67 ± 0.17 vs 0.63 ± 0.14 mg/L, p = .045). Finally 23.8% of the subjects showed LVH with no significant differences regarding biomarkers. Despite some significant correlations between biomarkers and TOD, at the multivariate analysis none came out to be as significant predictor of the assessed TOD.

CONCLUSIONS

in normotensive and normoglycemic healthy subjects, the evaluated biomarkers of atherosclerotic process didn't show any significant association with cardiac, carotid and vascular TOD while age and BP are its principal predictors.

Role of Thioredoxin in Age-Related Hypertension

PURPOSE OF REVIEW

Although the roles of oxidant stress and redox perturbations in hypertension have been the subject of several reviews, role of thioredoxin (Trx), a major cellular redox protein in age-related hypertension remains inadequately reviewed. The purpose of this review is to bring readers up-to-date with current understanding of the role of thioredoxin in age-related hypertension.

RECENT FINDINGS

Age-related hypertension is a major underlying cause of several cardiovascular disorders, and therefore, intensive management of blood pressure is indicated in most patients with cardiovascular complications. Recent studies have shown that age-related hypertension was reversed and remained lowered for a prolonged period in mice with higher levels of human Trx (Trx-Tg). Additionally, injection of human recombinant Trx (rhTrx) decreased hypertension in aged wild-type mice that lasted for several days. Both Trx-Tg and aged wild-type mice injected with rhTrx were normotensive, showed increased NO production, decreased arterial stiffness, and increased vascular relaxation. These studies suggest that rhTrx could potentially be a therapeutic molecule to reverse age-related hypertension in humans. The reversal of age-related hypertension by restoring proteins that have undergone age-related modification is conceptually novel in the treatment of hypertension. Trx reverses age-related hypertension via maintaining vascular redox homeostasis, regenerating critical vasoregulatory proteins oxidized due to advancing age, and restoring native function of proteins that have undergone age-related modifications with loss-of function. Recent studies demonstrate that Trx is a promising molecule that may ameliorate or reverse age-related hypertension in older adults.

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.

Xuezhikang reduced arterial stiffness in patients with essential hypertension: a preliminary study

This study aimed to test the effects of xuezhikang, a cholestin extract that contains statin-like components, on arterial stiffness in patients with essential hypertension. One hundred hypertensive patients from the Chinese PLA General Hospital were randomly allocated to receive xuezhikang (1200 mg/day, orally) or placebo (same capsules containing only pharmaceutical excipients). Physical examination outcomes, lipid profile, high sensitivity C-reactive protein (hs-CRP) levels, matrix metalloproteinases-9 (MMP-9) levels, and arterial outcomes, including stiffness parameter (β), pressure-strain elasticity modulus (Ep), arterial compliance (AC), augmentation index (AI), and one-point pulse wave velocity (PWVβ) were obtained at baseline and after 6 months of the intervention. Xuezhikang significantly reduced β (8.4±3.1 vs 6.8±2.1, P=0.007), Ep (122.8±43.9 vs 100.7±33.2, P=0.009), PWVβ (6.7±1.2 vs 6.1±1.0, P=0.013), low-density lipoprotein cholesterol (3.4±0.6 vs 2.9±0.5, P=0.001), hs-CRP [2.1 (0.4-10.0) vs 1.4 (0.3-4.1), P=0.020], and MMP-9 (17.2±2.4 vs 12.7±3.8, P <0.001) compared to baseline. The placebo had no effect on these parameters. The changes of PWVβ in the xuezhikang group was significantly associated with the changes of hs-CRP and MMP-9 (r=0.144, P=0.043; r=0.278, P=0.030, respectively) but not with lipid profile changes. Our research showed xuezhikang can improve the parameters of arterial stiffness in hypertensive patients, and its effect was independent of lipid lowering.

High serum adipocyte fatty acid binding protein level as a potential biomarker of aortic arterial stiffness in hypertensive patients with metabolic syndrome

BACKGROUND

The adipocyte-fatty-acid-binding protein (A-FABP) has been implicated in arterial stiffness, metabolic syndrome (MetS), and cardiovascular disease. We aimed to determine the relationship among serum A-FABP concentration, cardiometabolic risk factors, and central arterial stiffness in a hypertensive population.

METHODS

Fasting blood samples and baseline characteristics were obtained from 110 hypertensive patients. Serum A-FABP concentrations were determined by enzyme immunoassay kit. High arterial stiffness was defined as carotid-femoral pulse wave velocity values >10m/s via the SphygmoCor system.

RESULTS

Patients with MetS and high arterial stiffness accounted for 67.3% and 42.7% of the study population, respectively. Serum A-FABP was positively associated with MetS and high arterial stiffness (P=0.006 and P<0.001, respectively). Multivariable stepwise linear regression analysis of the significant variables of arterial stiffness revealed that logarithmically transformed A-FABP (log-A-FABP, β=0.278, P=0.002) was positively correlated arterial stiffness in hypertensive patients. Subgroup analysis revealed that log-A-FABP (β=0.327, P=0.003), age (β=0229, P=0.032), and triglyceride (β=0.307, P=0.004) were significantly positively correlated with arterial stiffness in hypertensive patients with MetS.

CONCLUSIONS

Elevated A-FABP concentration could be a predictor for MetS and arterial stiffness in hypertensive patients.

The effect of antihypertensive treatment on arterial stiffness and serum concentration of selected matrix metalloproteinases

INTRODUCTION

The aim of the study was to assess the arterial stiffness and serum levels of selected metalloproteinases (MMPs) in hypertensive patients and their changes following antihypertensive therapy.

MATERIAL AND METHODS

The study group consisted of 95 patients with essential arterial hypertension (HT) stage 1 or 2 (mean age: 53.1 ±13.0 years). The control group consisted of 31 normotensives of the same age range. Hypertension patients were randomized to one of the following monotherapies for 6 months: quinapril, losartan, amlodipine, hydrochlorothiazide or bisoprolol. Carotid-femoral pulse wave velocity (PWV) was measured using a Complior device. Serum concentrations of MMPs (proMMP-1, MMP-2, MMP-3, MMP-9) and plasma concentration of tissue inhibitor of MMPs (TIMP-1) were measured using ELISA.

RESULTS

Pulse wave velocity and serum concentrations of MMP-2 and MMP-9 were higher in HT patients than in the control group. In HT patients PWV was significantly associated (R² = 0.41) with age (B = 0.408, p = 0.00027), systolic blood pressure (SBP) (B = 0.441, p = 0.0011), and MMP-3 (B = 0.204, p = 0.0459). After 6 months of treatment, regardless of the agent used, we observed a significant decrease of PWV, SBP, MMP-2 and MMP-3 and an increase of TIMP-1 plasma concentration. The decrease of PWV was significantly associated with a decrease of SBP (R² = 0.07, B = 0.260, p = 0.015) only.

CONCLUSIONS

In patients with arterial hypertension, beside age and systolic blood pressure, the determinants of arterial stiffness include serum MMP-3 concentration. For drugs compared in the study with the same hypotensive effect obtained, the arterial stiffness reduction effect is not dependent on the drug used. Systolic blood pressure is one of the independent factors responsible for the reduction of arterial stiffness in the course of antihypertensive treatment.

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.

Low serum adiponectin level is associated with metabolic syndrome and is an independent marker of peripheral arterial stiffness in hypertensive patients

BACKGROUND

Adiponectin has been implicated in metabolic syndrome (MetS) and arterial stiffness (AS). We aim to determine the relationship between serum adiponectin concentration as well as peripheral AS in hypertensive patients.

METHODS

Fasting blood samples were obtained from 101 hypertensive patients. Brachial-ankle pulse wave velocity (baPWV) was measured with an automatic pulse wave analyzer. Serum adiponectin concentrations were determined by using an enzyme immunoassay kit. A baPWV >14.0 m/s was defined as high AS.

RESULTS

MetS and high AS were present in 62.4 and 71.3% of the study population. Adiponectin was inversely associated with MetS and high AS (both P < 0.001). Serum higher high-density lipoprotein cholesterol (HDL-C) (P = 0.012), triglycerides (P = 0.001), C-reactive protein (P < 0.001), insulin (P = 0.027), body weight (P = 0.002), waist circumference (WC, P < 0.001), body mass index (P = 0.001) bilateral-baPWV (P < 0.001), systolic blood pressure (SBP, P < 0.001), diastolic blood pressure (DBP, P = 0.012), pulse pressure (P = 0.019), homeostasis model assessment of insulin resistance (HOMA1-IR (P = 0.026) and HOMA2-IR (P = 0.020)) and lower glomerular filtration rate (GFR, P = 0.029) were significantly associated with high AS. Multivariate logistic regression analysis of the factors significantly associated with AS revealed that adiponectin [odds ratio: 0.932, 95% confidence interval (CI) 0.881-0.985, P = 0.012], and SBP (odds ratio: 1.059, 95% CI 1.008-1.113, P = 0.022) were the independent predictors of arterial stiffness in hypertensive patients. Subgroup analysis revealed that SBP (odds ratio: 1.126, 95% CI 1.024-1.237, P = 0.014) and GFR (odds ratio: 0.858, 95% CI 0.739-0.996, P = 0.043) were the independent predictors of arterial stiffness in hypertensive patients without MetS; adiponectin (odds ratio: 0.909, 95% CI 0.931-0.996, P = 0.040) was the independent predictor of arterial stiffness in hypertensive patients with MetS.

CONCLUSIONS

Hypoadiponectinemia has positive association with MetS and peripheral AS in hypertensive patients.

Differential hypertensive protease expression in the thoracic versus abdominal aorta

BACKGROUND

Hypertension (HTN), which is a major risk factor for cardiovascular morbidity and mortality, can drive pathologic remodeling of the macro- and microcirculation. Patterns of aortic pathology differ, however, suggesting regional heterogeneity of the pressure-sensitive protease systems triggering extracellular matrix remodeling in the thoracic (TA) and abdominal aortas (AA). This study tested the hypothesis that the expression of two major protease systems (matrix metalloproteinases [MMPs] and cathepsins) in the TA and AA would be differentially affected with HTN.

METHODS

Normotensive (BPN3) mice at 14-16 weeks of age underwent implantation of osmotic infusion pumps for 28-day angiotensin II (AngII) delivery (1.46 mg/kg/day; BPN3+AngII; n = 8) to induce HTN. The TA and AA were harvested to determine levels of MMP-2, MMP-9, and membrane type 1-MMP, and cathepsins S, K, and L were evaluated in age-matched BPN3 (n = 8) control and BPH2 spontaneously hypertensive mice (non-AngII pathway; n = 7). Blood pressure was monitored via CODA tail cuff plethysmography (Kent Scientific Corporation, Torrington, Conn). Quantitative real-time polymerase chain reaction and immunoblotting/zymography were used to measure MMP and cathepsin messenger RNA expression and protein abundance, respectively. Target protease values were compared within each aortic region via analysis of variance.

RESULTS

Following 28 days infusion, the BPN3+AngII mice had a 17% increase in systolic blood pressure, matching that of the BPH2 spontaneously hypertensive mice (both P < .05 vs BPN3). MMP-2 gene expression demonstrated an AngII-dependent increase in the TA (P < .05), but MMP-9 was not altered with HTN. Expression of tissue inhibitor of metalloproteinases-1 was markedly increased in TA of BPN3+AngII mice, but tissue inhibitor of metalloproteinases-2 demonstrated decreased expression in the AA of both hypertensive groups (P < .05). Only cathepsin K responded to AngII-induced HTN with significant elevation in the TA of those mice, but expression of cathepsin L and cystatin C was inhibited in AA of both hypertensive groups (P < .05). Apoptotic markers were not significantly elevated in any experimental group.

CONCLUSIONS

By using two different models of HTN, this study has identified pressure-dependent as well as AngII-dependent regional alterations in aortic gene expression of MMPs and cathepsins that may lead to differential remodeling responses in each of the aortic regions. Further studies will delineate mechanisms and may provide targeted therapies to attenuate down-stream aortic pathology based on demonstrated regional heterogeneity.

Resting Heart Rate and Aortic Stiffness in Normotensive Adults

Background and Objectives

Large-artery stiffness is an independent predictor of cardiovascular disease (CVD), and carotid-femoral pulse wave velocity (cfPWV) is considered the gold standard measure of arterial stiffness. A resting heart rate is an easily measured vital sign that is also associated with CVD morbidity and mortality. Previous studies have reported the significant relationship of a resting heart rate with arterial stiffness as measured by cfPWV only in hypertensive subjects; their relationship in nonhypertensive subjects remains unknown. The present study, therefore, examined their relationship in normotensive subjects.

Subjects and Methods

In 102 healthy Korean Americans between ages 20 and 60 years, their resting heart rate was measured by an automated blood pressure measuring device after a 10 minute rest in the supine position. Arterial stiffness was measured by cfPWV using the SphygmoCor device.

Results

The mean resting heart rate of participants (mean age, 39.64 years; 59% women) was 61.91 bpm (standard deviation [SD], 9.62 bpm) and mean the cfPWV was 6.99 (SD, 1.14) m/s. A multiple regression analysis showed that a resting heart rate is a significant predictor of cfPWV after controlling for age, body mass index, and mean arterial pressure. For one bpm increase of resting heart rate, cfPWV increased approximately 0.02 m/s.

Conclusion

Our results suggest that a higher resting heart rate is independently associated with increased arterial stiffness as measured by cfPWV in normotensive adults. Arterial stiffness may explain the prognostic role of an individual's heart rate in cardiovascular morbidity and mortality.

Rice bran protein hydrolysates reduce arterial stiffening, vascular remodeling and oxidative stress in rats fed a high-carbohydrate and high-fat diet

PURPOSE

Rice bran protein hydrolysates (RBPH) contain highly nutritional proteins and antioxidant compounds which show benefits against metabolic syndrome (MetS). Increased arterial stiffness and the components of MetS have been shown to be associated with an increased risk of cardiovascular disease. This study aimed to investigate whether RBPH could alleviate the metabolic disorders, arterial stiffening, vascular remodeling, and oxidative stress in rats fed a high-carbohydrate and high-fat (HCHF) diet.

METHODS

Male Sprague-Dawley rats were fed either a standard chow and tap water or a HCHF diet and 15 % fructose solution for 16 weeks. HCHF rats were treated orally with RBPH (250 or 500 mg/kg/day) for the final 6 weeks of the experimental period.

RESULTS

Rats fed with HCHF diet had hyperglycemia, insulin resistance, dyslipidemia, hypertension, increased aortic pulse wave velocity, aortic wall hypertrophy and vascular remodeling with increased MMP-2 and MMP-9 expression. RBPH supplementation significantly alleviated these alterations (P < 0.05). Moreover, RBPH reduced the levels of angiotensin-converting enzyme (ACE) and tumor necrosis factor-alpha in plasma. Oxidative stress was also alleviated after RBPH treatment by decreasing plasma malondialdehyde, reducing superoxide production and suppressing p47^phox NADPH oxidase expression in the vascular tissues of HCHF rats. RBPH increased plasma nitrate/nitrite level and up-regulated eNOS expression in the aortas of HCHF-diet-fed rats, indicating that RBPH increased NO production.

CONCLUSION

RBPH mitigate the deleterious effects of HCHF through potential mechanisms involving enhanced NO bioavailability, anti-ACE, anti-inflammatory and antioxidant properties. RBPH could be used as dietary supplements to minimize oxidative stress and vascular alterations triggered by MetS.

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.

Computational model of collagen turnover in carotid arteries during hypertension

It is well known that biological tissues adapt their properties because of different mechanical and chemical stimuli. The goal of this work is to study the collagen turnover in the arterial tissue of hypertensive patients through a coupled computational mechano-chemical model. Although it has been widely studied experimentally, computational models dealing with the mechano-chemical approach are not. The present approach can be extended easily to study other aspects of bone remodeling or collagen degradation in heart diseases. The model can be divided into three different stages. First, we study the smooth muscle cell synthesis of different biological substances due to over-stretching during hypertension. Next, we study the mass-transport of these substances along the arterial wall. The last step is to compute the turnover of collagen based on the amount of these substances in the arterial wall which interact with each other to modify the turnover rate of collagen. We simulate this process in a finite element model of a real human carotid artery. The final results show the well-known stiffening of the arterial wall due to the increase in the collagen content.

C-Reactive protein and soluble intracellular adhesion molecule-1 are related to pulse wave reflection in type 1 diabetes 1C-1

BACKGROUND

The association of inflammation with cardiovascular (CV) complications in diabetes remains a matter of considerable debate. Arterial stiffness and enhanced wave reflection play an important role in CV complications. Therefore, in the present study we investigated whether markers of inflammation are correlated with parameters of wave reflection in type 1 diabetes (T1D).

METHODS

In all, 145 T1D patients were included in the study (median age 32 years, disease duration 10 years, HbA1c 8.2%). Serum concentrations of high-sensitivity C-reactive protein (hs-CRP), matrix metalloproteinase (MMP)-9, soluble intracellular adhesion molecule-1 (sICAM-1), and myeloperoxidase (MPO) were estimated as markers of inflammation. Parameters of pulse wave reflection (central augmentation index [cAIx] and peripheral augmentation index [pAIx]) were assessed using pulse wave analysis.

RESULTS

Multivariate linear regression analysis revealed that, after adjustment for age, mean blood pressure, HbA1c, low-density lipoprotein-cholesterol, and the presence of at least one microangiopathic complication of diabetes, cAIx and pAIx were associated with serum concentration of hs-CRP (β = 1.838, 95% confidence interval [CI] 0.336-3.339 [P = 0.017]; and β = 2.041, 95% CI 0.683-3.400 [P = 0.004], respectively) and sICAM-1 (β = 0.073, 95% CI 0.015-0.131 [P = 0.014]; and β = 0.066, 95% CI 0.013-0.119 [P = 0.016], respectively) in the study group.

CONCLUSIONS

In T1D parameters of wave reflection are related to markers of inflammation.

Matrix metalloproteinase-9: Many shades of function in cardiovascular disease

Matrix metalloproteinase (MMP)-9, one of the most widely investigated MMPs, regulates pathological remodeling processes that involve inflammation and fibrosis in cardiovascular disease. MMP-9 directly degrades extracellular matrix (ECM) proteins and activates cytokines and chemokines to regulate tissue remodeling. MMP-9 deletion or inhibition has proven overall beneficial in multiple animal models of cardiovascular disease. As such, MMP-9 expression and activity is a common end point measured. MMP-9 cell-specific overexpression, however, has also proven beneficial and highlights the fact that little information is available on the underlying mechanisms of MMP-9 function. In this review, we summarize our current understanding of MMP-9 physiology, including structure, regulation, activation, and downstream effects of increased MMP-9. We discuss MMP-9 roles during inflammation and fibrosis in cardiovascular disease. By concentrating on the substrates of MMP-9 and their roles in cardiovascular disease, we explore the overall function and discuss future directions on the translational potential of MMP-9 based therapies.

The association of serum inflammatory biomarkers with chronic kidney disease in hypertensive patients

A positive association between inflammation and chronic kidney disease (CKD) has been reported but the impact of hypertension on this relation remains unclear. The aim of this study is to investigate the association of various inflammation markers with risk of CKD in hypertensive patients. 387 hypertensive patients (mean age 55.5 years) were recruited. Serum matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1(TIMP-1), high-sensitivity C-reactive protein (hsCRP) and osteopontin (OPN) were measured by ELISA. CKD was diagnosed either as evidence of kidney damage, including microalbuminuria, or by low glomerular filtration rate (GFR) (<60 mL/min/1.73 m(2)), which was estimated using the Modification of Diet in Renal Disease (MDRD) abbreviated equation. Compared with the reference groups (eGFR ≥ 60 mL/min/1.73 m(2)), the serum levels of TIMP-1, OPN, hsCRP were significantly higher, and the MMP-9/TIMP-1 ratio was lower in the risk group (eGFR < 60 mL/min/1.73 m(2)). Multiple logistic regression analysis showed that TIMP-1, MMP-9/TIMP-1 ratio, OPN and hsCRP were associated with low GFR separately after adjustment, whereas MMP-9/TIMP-1 ratio, OPN and hsCRP were associated with microalbuminuria. The significant association of MMP-9/TIMP-1 ratio and OPN with low GFR and microalbuminuria persisted after additional adjustment for other studied inflammatory biomarkers. Our data suggest that inflammation is strongly and independently associated with renal damage in hypertensive patients. MMP-9/TIMP-1 ratio and OPN may serve as novel risk factors and therapeutic targets for the treatment of CKD in hypertensive patients.

Associations of MMP1, 3, 9 and TIMP3 genes polymorphism with isolated systolic hypertension in Chinese Han population

BACKGROUND AND AIMS

Large artery stiffness and endothelial dysfunction are the predominant characteristic of isolated systolic hypertension. Recently studies have revealed MMP1, 3, 9 and TIMP3 Genes polymorphism were associated with arterial stiffness, but the relationship with isolated systolic hypertension were not further studied. This study was to investigate the associations of MMP1,3,9 and TIMP3 Genes polymorphism with isolated systolic hypertension.

METHODS

We identified the genotype of the genes in 503 patients with isolated systolic hypertension, 481 essential hypertension patients with elevated diastolic blood pressure and 244 age-matched normotensive controls for 5 SNPs and detected the brachial-ankle pulse wave velocity, flow-mediated dilatation, endothelin-1 and nitric oxide among the participants.

RESULTS

Multinomial logistic analyses showed that the 5A allele of rs3025058(5A/6A) in MMP3 and the T allele of rs3918242(C-1562T) in MMP9 were significantly associated with isolated systolic hypertension after adjusted by age, triglyceride, low-density lipoprotein (P<0.001, Pcorr<0.003; P=0.009, Pcorr=0.027). The 5A/G/C and 6A/A/T haplotypes were significantly associated with isolated systolic hypertension (Permutation p=0.0258; Permutation p=0.000002). In addition, the brachial-ankle pulse wave velocity of different genotypes for the 5A/6A and C-1562T polymorphisms was significantly highest in 5A or T homozygotes (P<0.01), however, the flow-mediated dilatation and nitric oxide were markedly lowest in 5A or T homozygotes (P<0.01).

CONCLUSION

MMP3 and MMP9 genes variant seem to contribute to the development of isolated systolic hypertension by affecting arterial stiffness and endothelial function.

17ß-estradiol antagonizes the down-regulation of ERα/NOS-3 signaling in vascular endothelial dysfunction of female diabetic rats

Previous studies indicated that estrogen could improve endothelial function. However, whether estrogen protects vascular complications of diabetes has yet to be clarified. The study was designed to investigate the action of 17ß-estradiol on vascular endothelium in streptozotocin (STZ)-induced diabetic rats. Ovariectomized female Sprague-Dawley rats were administered with streptozotocin to produce an ovariectomized-diabetic (OVS) model which manifested as dysfunction of aortic dilation and contraction ability. Meanwhile, OVS animals with 17ß-estradiol supplementation significantly improved aortic function. Accordingly, nitric oxide synthase-3 (NOS-3), Akt, PI3K and estrogen receptor α (ERα) protein expression in aorta declined in the OVS group. Such effects were partially restored by estrogen replacement. The presence of 17ß-estradiol similarly counteracted the reduction of cyclic guanosine monophosphate (cGMP), the enhanced expression of inducible NOS (NOS-2) and NO metabolites (nitrite and nitrate), as well as the increase of matrix metalloproteinase-9/tissue inhibitor of metalloproteinase-1 (MMP-9/TIMP-1), which is an index of arterial compliance. 17ß-estradiol could also decrease ROS production in vascular endothelium. In EA hy 926 cells we found that ER antagonist, wortmannin and Akt inhibitor could block improvement effects of 17ß-estradiol. These results strongly suggest that functional impairment of the ERα/NOS-3 signaling network in OVS animals was partially restored by 17ß-estradiol administration, which provides experimental support for estrogen recruitment to improve vascular outcomes in female diabetes after endogenous hormone depletion.

Arterial stiffness is associated with increased monocyte expression of adiponectin receptor mRNA and protein in patients with coronary artery disease

BACKGROUND

Arterial stiffness and carotid intima-media thickness (IMT) constitute validated cardiovascular prognostic markers. Adiponectin and its receptors 1 (AdipoR1) and 2 (AdipoR2) are involved in coronary artery disease (CAD). We investigated whether AdipoR1 and R2 mRNA and protein expression are associated with arterial stiffness, IMT and extent of coronary atherosclerosis.

METHODS

We studied 71 patients (61 men, 10 women) with angiographically proven CAD. We measured: (i) monocyte expression of AdipoR1 and AdipoR2 mRNA (quantitative real-time PCR) and protein expression (flow cytometry) (iii) adiponectin, metalloproteinase-9 (MMP-9) and C-reactive protein (CRP) blood levels, (iv) carotid-femoral artery pulse wave velocity (PWV) and carotid IMT.

RESULTS

Patients with multi-vessel CAD had higher AdipoR1 and AdipoR2 mRNA than those with single-vessel (P < 0.05). PWV was associated with AdipoR1 mRNA (r = 0.474), AdipoR1 protein (r = 0.228), AdipoR2 mRNA (r = 0.716), AdipoR2-protein (r = 0.261), adiponectin (r = 0.236), and MMP-9 (r = 0.350) (P < 0.05, for all correlations). After adjustment for age, sex, waist-hip ratio, and mean blood pressure both AdipoR1 and AdipoR2 mRNA remained independent determinants of PWV (R(2) = 0.35 and R(2) = 0.57, P < 0.05). IMT was also associated with AdipoR2 mRNA, AdipoR2 protein, and MMP-9 (P < 0.05). Increased expression of ADR2 mRNA significantly related to MMP-9 (r = 0.210), and CRP (r = 0.531) (P < 0.05).

CONCLUSION

Increased mRNA and protein expression of adiponectin receptors is related with increased aortic stiffness, coronary and peripheral atherosclerosis in patients with CAD. The interrelation of AdipoR2 with inflammatory markers, PWV and IMT suggests a compensatory increase of these receptors to counteract the excess inflammatory and atherogenic process in CAD. Thus, adiponectin receptors may provide a potential therapeutic target of agents activating their beneficial action.American Journal of Hypertension 2012; doi:10.1038/ajh.2012.42.

An emerging role of degrading proteinases in hypertension and the metabolic syndrome: autodigestion and receptor cleavage

One of the major challenges for hypertension research is to identify the mechanisms that cause the comorbidities encountered in many hypertensive patients, as seen in the metabolic syndrome. An emerging body of evidence suggests that human and experimental hypertensives may exhibit uncontrolled activity of proteinases, including the family of matrix metalloproteinases, recognized for their ability to restructure the extracellular matrix proteins and to play a role in hypertrophy. We propose a new hypothesis that provides a molecular framework for the comorbidities of hypertension, diabetes, capillary rarefaction, immune suppression, and other cell and organ dysfunctions due to early and uncontrolled extracellular receptor cleavage by active proteinases. The proteinase and signaling activity in hypertensives requires further detailed analysis of the proteinase expression, the mechanisms causing proenzyme activation, and identification of the proteinase substrate. This work may open the opportunity for reassessment of old interventions and development of new interventions to manage hypertension and its comorbidities.