Differential gene expression of bradykinin receptors 1 and 2 in peripheral monocytes from patients with essential hypertension.

Bradykinin participates in various hypertensive processes, exerted via its type 1 and type 2 receptors (BKR1 and BKR2). The aim of the study was to investigate BKR1 and BK2R gene expression in peripheral monocytes in patients with essential hypertension compared with healthy individuals. Seventeen hypertensive patients (9 males, age 56 ± 7 years) and 12 healthy individuals (7 males, age 55 ± 6) participated. Mononuclear cells isolated using anti-CD14+ antibodies and mRNAs of BKR1 and BKR2 were estimated by real-time quantitative reverse transcription-PCR. Both BKR1 and BKR2 showed significantly upregulated gene expression in the group of hypertensive patients. Specifically, BKR1 gene expression was 142.1 ± 42.2 in hypertensives versus 20.2 ± 8 in controls (P = 0.024) and BKR2 was 1222.2 ± 361.6 in hypertensives versus 259.5 ± 99.1 in controls (P = 0.038). Antihypertensive treatment resulted in a decrease in BKR1 (from 142.1 ± 42.2 to 55.2 ± 17.1, P = 0.065) and in BKR2 (from 1222.2 ± 361.6 to 256.8 ± 81.8, P = 0.014) gene expression. BKR1 and BKR2 gene expression on peripheral monocytes is upregulated in essential hypertension. This may lead to functional changes in monocytes and contribute to the development of target organ damage in hypertensive patients.

Differential expression of vascular smooth muscle-modulating microRNAs in human peripheral blood mononuclear cells: novel targets in essential hypertension.

Vascular smooth muscle cell (VSMC) phenotypic plasticity has a critical role in the pathophysiology of arterial remodeling in essential hypertension. MicroRNAs are emerging as potential biomarkers and therapeutic targets in cardiovascular disease. We assessed the expression levels of the microRNAs miR-143, miR-145, miR-21, miR-133 and miR-1, which are implicated in VSMC phenotypic modulation, in 60 patients with essential hypertension and 29 healthy individuals. All patients underwent 24-h ambulatory blood pressure (BP) monitoring. MicroRNA levels in peripheral blood mononuclear cells were quantified by real-time reverse transcription polymerase chain reaction. Hypertensive patients showed lower miR-143 (2.20±0.25 versus 4.19±0.57, P<0.001), miR-145 (13.51±1.73 versus 22.38±3.31, P=0.010) and miR-133 (8.15±1.32 versus 37.03±8.18, P<0.001) and higher miR-21 (3.08±0.32 versus 2.06±0.31, P=0.048) and miR-1 (33.94±5.19 versus 12.35±2.13 P=0.006) expression levels compared with controls. In hypertensive patients, we observed correlations of miR-143 (r = -0.380, P=0.003), miR-145 (r=-0.405, P=0.001), miR-21 (r=-0.486, P<0.001) and miR-133 (r=0.479, P<0.001) expression levels with 24-h diastolic BP. Furthermore, we observed correlations of miR-21 (r=-0.291, P=0.024), miR-1 (r=-0.312, P=0.015) and miR-133 (r=0.310, P=0.016) levels with the dipping status. Associations of miR-143 (r=-0.292, P=0.025), miR-145 (r=-0.399, P=0.002), miR-21 (r=-0.343, P=0.008) and miR-133 (r=0.370, P=0.004) levels with 24-h mean pulse pressure were also found. Our data provide important evidence that VSMC-modulating microRNAs are closely related to essential hypertension in humans and they may represent potential therapeutic targets in essential hypertension.

Arterial stiffness in hypertensives in relation to expression of angiopoietin-1 and 2 genes in peripheral monocytes.

Angiopoietins (Angs) are important angiogenic and endothelial cell growth factors with many functions, including influence on the vascular wall. Pulse-wave velocity (pwv) is an independent marker of cardiovascular adverse outcome in hypertensives, although all the pathophysiological mechanisms that affect it have not yet been determined. We investigated the relationship between arterial stiffness and Ang-1 and Ang-2 gene expression in the peripheral blood monocytes of hypertensive patients. We studied 53 patients who had untreated grade-1 or grade-2 essential hypertension and no indications of other organic heart disease. Carotid-femoral (c-f) and carotid-radial (c-r) artery waveforms were measured and pwv was determined. The monocytes were isolated using anti-CD14(+) antibodies and mRNAs were estimated by real-time quantitative reverse transcription-PCR. Ang-1 gene expression was strongly correlated with both c-f-pwv (r=0.952, P<0.001) and c-r-pwv (r=0.898, P<0.001). Similarly, Ang-2 gene expression was significantly correlated with both c-f-pwv (r=0.471, P=0.002) and c-r-pwv (r=0.437, P=0.003). Our data provide important evidence that Ang-1 and Ang-2 gene expression levels in peripheral monocytes are closely related with pwv in patients with essential hypertension. This positive correlation may suggest a link between angiogenesis and arterial stiffness in those patients.

Effect of angiotensin-converting enzyme inhibitors on systemic inflammation and myocardial sympathetic innervation in normotensive patients with type 2 diabetes mellitus.

Diabetes mellitus (DM) may cause an increase in the inflammatory status and oxidative stress as well as sympathetic nervous system overactivity, even in the absence of any other organic heart disease. We investigated the effect of perindopril, an angiotensin-converting enzyme inhibitor (ACE-i), on indexes of systemic inflammation and oxidative stress in normotensive patients with type 2 DM. We also examined the effect of the drug on the disturbances of left ventricular myocardial adrenergic innervation that may be seen in these patients. We studied 62 normotensive patients with type 2 DM, who were randomized to receive perindopril (n=32) or placebo (n=30). At the start of the study and after 6 months' therapy blood samples were taken to evaluate total peroxides (TP), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha), and the patients underwent a (123)I-metaiodobenzylguanidine myocardial scintigraphy study. ACE-i caused a significant reduction in levels of cytokines and TP (P<0.001 for IL-6 and TNF-alpha, P=0.001 for TP). There was also a reduction in total defect score (P<0.001) and the heart to mediastinum ratio at 10 min and 4 h was improved (P<0.001 for both). No significant alterations were observed in the placebo group. Our data indicate that the addition of ACE-i to the medication of normotensive diabetic type 2 patients may improve the disturbed myocardial adrenergic innervation, the systemic inflammatory status and oxidative stress. Our findings indicate the cardioprotective action of ACE-i and suggest that earlier treatment might be appropriate in those patients.

Segmental pattern of myocardial sympathetic denervation in idiopathic dilated cardiomyopathy: relationship to regional wall motion and myocardial perfusion abnormalities.

BACKGROUND: Iodine 123-labeled metaiodobenzylguanidine (MIBG) has been used to study cardiac adrenergic nerve activity. Cardiac MIBG uptake is diminished in patients with heart failure. However, it is not known how this reduction is related to regional abnormalities of myocardial wall motion or perfusion. METHODS AND RESULTS: We studied 24 patients with idiopathic dilated cardiomyopathy (ejection fraction <45%) and 15 healthy control subjects using I-123 MIBG cardiac imaging, echocardiographic assessment of wall motion abnormalities, technetium 99m sestamibi perfusion scintigraphy, and hemodynamic assessment. Cardiac MIBG was significantly correlated with ejection fraction (r = 0.67), cardiac index (r = 0.57), left ventricular wall motion score index (r = -0.68), and systolic wall stress (r = -0.61). MIBG was lower in patients than in control subjects (1.43 +/- 0.19 vs 2.05 +/- 0.02; P <.01), whereas the washout rate was higher (P <.01). Moreover, a significant correlation was found between the reduction in MIBG uptake and the severity of echocardiographic wall motion abnormalities in the anterior wall (r = 0.543), apex (r = 0.530), and septum (r = 0.675), as well as with the severity of decrease in resting myocardial perfusion in the anterior wall (r = 0.480) and septum (r = 0.580). CONCLUSIONS: Patients with idiopathic dilated cardiomyopathy show not only global but also regional abnormalities of cardiac sympathetic innervation. The severity of these changes is partially correlated with abnormalities of regional wall motion and myocardial perfusion.

Pulmonary tumor embolism from primary cardiac B-cell lymphoma.

We report the case of a 54-year-old man with pulmonary embolism during convalescence from "idiopathic" pericarditis. A transthoracic echocardiographic examination indicated a large mass within the right atrium. Subsequently, he died from refractory hypotension. On autopsy, two large whitish nodules were found in the right atrium; there was also nodular epicardial infiltration. Both lungs showed multiple, grossly visible tumor emboli with pulmonary infarction and no evidence of conventional thromboembolism. This is the first report of pulmonary tumor embolism due to large cell B-cell primary cardiac lymphoma. Refractory unexplained pericardial effusion, pulmonary embolism without risk factors for venous thrombosis, and/or the existence of a mass in the right heart should arouse clinical suspicion for this rare malignancy.

Assessment of left ventricular ejection dynamics in patients with coronary artery disease during dipyridamole-stress Doppler echocardiography.

OBJECTIVES: To investigate the contribution of Doppler-echocardiographically derived aortic indexes of left ventricular systolic function during dipyridamole-stress to the diagnosis of coronary artery disease (CAD). DESIGN: This was a clinical study. METHODS: Echocardiographic studies under baseline and peak dipyridamole stresses were performed on 15 normal subjects and 32 patients with angiographically confirmed CAD. Peak Doppler velocity, acceleration, and acceleration time of the ascending aorta, as well as segmental left ventricular wall motion, were analyzed. RESULTS: The sensitivity, specificity and overall accuracy of wall-motion abnormalities induced by dipyridamole for the detection of CAD were 62.5, 100, and 74.5%, respectively. When wall-motion abnormalities were combined with the percentage changes in peak aortic velocity and acceleration, the overall sensitivities were 84.38 and 78.15%, respectively, the specificities were 66.7 and 80.00%, respectively, and the accuracy was 78.72% for both models. When all three parameters were combined, the sensitivity, specificity and overall accuracy of the method were 87.5, 86.7, and 87.2%, respectively. CONCLUSIONS: Doppler-echocardiographically derived aortic indexes of left ventricular systolic function during dipyridamole stress could be a useful adjunct to two-dimensional echocardiography by improving its sensitivity in the diagnosis of CAD.

Volatile buffers can override the "pH memory" of subtilisin catalysis in organic media.

The protonation state and activity of enzymes in low-water media are affected by the aqueous pH before drying ("pH memory"). However, both protonation and activity will change if buffer ions can be removed as volatile or organic-extractable weak acids or bases. With NH4OOCH buffers, in which both ions can be removed, pH memory disappears completely for subtilisin-catalyzed transesterification in hexane. Only weak pH memory is found with buffers having one volatile component, NH4-phosphate and NaOOCH. The changes in ionization state result from proton exchanges like Protein-COO-NH4+ --> Protein-COOH + NH3 (g) and Protein-NH3+HCOO- --> Protein-NH2 + HOOCH (g). An equivalent, complementary picture is that net charges on the protein and buffer ions must remain equal and opposite. With NaOOCH buffers, loss of some HCOO- ions gives a more negative net charge on the protein, balanced by the excess Na+. With NH4-phosphate buffers, loss of NH3 gives protein with a more positive net charge. The resulting catalytic activities were high and low, respectively, similar to those after drying from Na-phosphate buffers of optimal (8.5) and acid pH. All of the above effects have been demonstrated for both covalently immobilized subtilisin and the lyophilized free enzyme. Subtilisin lyophilized from NH4OOCH buffers gave pH approximately 4 after redissolution in water, probably because removal of HCOO- counterions remains incomplete. The resulting catalytic activity was low. The effects are discussed in relation to the possible locations, in low-dielectric media, of the positive charge that balances the net negative catalytic triad in active subtilisin.

Selection of salt hydrate pairs for use in water control in enzyme catalysis in organic solvents.

The water activities (a(w)) of 13 salt hydrate pairs were determined from vapor pressure measurements; a(w) values for a subset were also estimated from a study of water transfer to isopropylether. The application of salt hydrates as water buffers was investigated in two models: (i) effect of hydration on the initial rate of subtilisincatalyzed transesterification of the nitrophenol ester of CBZ-alanine with butanol; and (ii) effect of hydrates on the equilibrium concentrations of reactants in the esterification of dodecanol and decanoic acid, catalyzed by lipase. Transfer of ions from salt to enzyme particles was also demonstrated. The implications of the results for the successful use of salt hydrates as water buffers are discussed. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 55: 367-374, 1997.