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Aims: To evaluate the safety and efficacy of the balloon-based bipolar Vessix Renal Denervation System in treating patients with resistant hypertension., Methods and Results: In this prospective, multicentre, single-arm study, 146 patients (age 58.6±10.5 years; 61% men) with office systolic blood pressure (BP) ≥160 mmHg despite ≥3 antihypertensive medications at maximally tolerated doses were treated with the Vessix System. Efficacy endpoints were reductions in office and 24-hour ambulatory systolic and diastolic BPs at six months. Acute and long-term safety, with a focus on the renal artery and estimated glomerular filtration rate (eGFR), were assessed. Baseline office and ambulatory BPs were 182.4±18.4/100.2±14.0 mmHg and 153.0±15.1/87.5±13.2 mmHg, respectively. No acute renal artery injury requiring intervention or serious periprocedural cardiovascular events occurred. At six months, office BP was reduced by 24.7±22.1/10.3±12.7 mmHg (p<0.0001) and ambulatory BP was reduced by 8.4±14.4/5.9±9.1 mmHg (N=69; p<0.0001). Twenty-six patients (18%) achieved an office systolic BP <140 mmHg. One patient had renal artery stenosis which required stenting. Mean eGFR remained stable., Conclusions: Renal artery denervation with the Vessix System reduced both office and ambulatory BP at six months in patients with resistant hypertension. Renal artery safety and renal function results are favourable.

Heparin is known to have anti-inflammatory effects, yet the mechanisms are not completely understood. In this study, we tested the hypothesis that heparin has a direct effect on activated polymorphonuclear leukocytes (PMNLs), changing their activation state, and can explain its anti-inflammatory effect. To test our hypothesis, we designed both in vitro and ex vivo studies to elucidate the mechanism by which heparin modulates PMNL functions and therefore the inflammatory response. We specifically tested the hypothesis that priming of PMNLs renders them more susceptible to heparin. Amplified levels of CD11b and increased rate of superoxide release manifested PMNL priming. Increase in cell priming resulted in a dose-dependent increase in heparin binding to PMNLs followed by augmented apoptosis. Blocking antibodies to CD11b inhibited heparin binding and abolished the apoptotic response. Moreover, heparin caused a significant dose-dependent decrease in the rate of superoxide release from PMNLs, which was blunted by blocking antibodies to CD11b. Altogether, this study shows that the interaction of heparin with the PMNL CD11b results in cell apoptosis and explains heparin's anti-inflammatory effects.

Objective: To evaluate the safety and effectiveness of different bipolar radiofrequency system algorithms in interrupting the renal sympathetic nerves and reducing renal norepinephrine in a healthy porcine model., Methods: A porcine model (N = 46) was used to investigate renal norepinephrine levels and changes to renal artery tissues and nerves following percutaneous renal denervation with radiofrequency bipolar electrodes mounted on a balloon catheter. Parameters of the radiofrequency system (i.e. electrode length and energy delivery algorithm), and the effects of single and longitudinal treatments along the artery were studied with a 7-day model in which swine received unilateral radiofrequency treatments. Additional sets of animals were used to examine norepinephrine and histological changes 28 days following bilateral percutaneous radiofrequency treatment or surgical denervation; untreated swine were used for comparison of renal norepinephrine levels., Results: Seven days postprocedure, norepinephrine concentrations decreased proportionally to electrode length, with 81, 60 and 38% reductions (vs. contralateral control) using 16, 4 and 2-mm electrodes, respectively. Applying a temperature-control algorithm with the 4-mm electrodes increased efficacy, with a mean 89.5% norepinephrine reduction following a 30-s treatment at 68°C. Applying this treatment along the entire artery length affected more nerves vs. a single treatment, resulting in superior norepinephrine reduction 28 days following bilateral treatment., Conclusion: Percutaneous renal artery application of bipolar radiofrequency energy demonstrated safety and resulted in a significant renal norepinephrine content reduction and renal nerve injury compared with untreated controls in porcine models.

Aims: To test the hypothesis that primed PMNLs in blood of chronic kidney disease patients release the active form of elastase and cathepsin G causing degradation of vital proteins and promote tissue damage., Methods: RT-PCR, immunocytochemical staining, immunoblotting, and FACS analyses were used to study these enzymes in hemodialysis patients (HD) versus healthy normal controls (NC). Using PMNLs and endothelial cells cocultivation system we measure the effect of HD PMNLs on the endothelial VE-cadherin, an essential protein for maintaining endothelial integrity., Results: Levels of elastase and cathepsin G were reduced in PMNLs of HD patients, while mRNA enzymes levels were not different. Elevated levels of the active form of these enzymes were found in blood of HD patients compared to NC.HD plasma had higher levels of soluble VE-cadherin present in three molecular forms: whole 140 kDa molecule and two fragments of 100 and 40 kDa. Cocultivation studies showed that primed PMNLs cleave the endothelial cadherin, resulting in a 100 kDa fragment., Conclusions: Elastase and cathepsin G are elevated in the plasma of HD patients, originating from primed PMNLs. In these patients, chronic elevation of these enzymes contributes to cleavage of VE-cadherin and possible disruption of endothelial integrity.

In the Sabra rat, oxidative stress (OS) and inflammation precede the development of hypertension. Inhibition of the phagocytic NADPH oxidase attenuates the rise in blood pressure. The present study was set to identify possible priming agents for this enzyme and to test the hypothesis that the phagocytic NADPH oxidase contributes to OS and inflammation. Sabra salt-sensitive and Sabra salt-resistant rats were salt loaded or provided regular chow for 60 days with or without apocynin to inhibit NADPH oxidase. Levels of interleukin 6, tumor necrosis factor-alpha, and interferon-gamma served as indices of inflammation. Extracellular and intracellular levels of the polymorphonuclear leukocyte tumor necrosis factor-alpha receptors (p55 and p75) were assessed by flow cytometry in young and adult rats. NADPH oxidase activity and expression of p47phox were measured in polymorphonuclear leukocytes and aortic rings. Malondialdehyde and carbonylated fibrinogen served as indices of OS. Inflammatory and OS indices excluding interferon-gamma were higher in the hypertensive state and reduced by apocynin. Levels of malondialdehyde and tumor necrosis factor-alpha were elevated already in the prehypertensive state. No differences were found in the levels of p75. The extracellular expression of p55 was higher in adult Sabra salt-resistant compared with Sabra salt-sensitive rats (7.46+/-2.2% versus 2.1+/-0.5%; P<0.05), whereas levels of the intracellular p55 were higher in adult Sabra salt-sensitive rats (3.2+/-2% versus 1.1+/-0.5%; P<0.05). In young normotensive rats, the extracellular levels of p55 were higher in Sabra salt-sensitive compared with Sabra salt-resistant rats (10.6+/-5.2% versus 2.9+/-1.5%; P<0.01). Tumor necrosis factor-alpha plays a role in activation of the polymorphonuclear leukocyte NADPH oxidase, thereby contributing to systemic OS, inflammation, and the development of hypertension in this model.

Background: Oxidative stress (OS) and chronic inflammation are involved and contribute to the development of atherosclerosis. Primed polymorphonuclear leukocytes (PMNLs) are a possible source for superoxide radicals and inflammatory mediators, hence can promote OS and inflammation. The involvement of primed PMNLs in clinical states associated with high risk for developing cardiovascular disease and atherosclerosis, such as hypertension, renal failure and diabetes has been described, however, little is known about PMNLs characteristics in hyperlipidemic patients., Methods: Hyperlipidemic patients and healthy control (HC) subjects were enrolled in this cross-sectional study. PMNL priming was estimated by measuring the rate of superoxide release and by levels of membrane CD11b. PMNL priming and myeloperoxidase (MPO) levels served as OS indices. Inflammation was linked to peripheral white blood cells and PMNL counts and to apoptosis. Systemic inflammation was estimated by blood levels of fibrinogen, C-reactive protein (CRP), transferrin and albumin. PMNL priming and inflammation parameters were related to the severity of hyperlipidemia., Results: PMNLs from hyperlipidemic patients are primed compared to HC. A decrease in PMNL-MPO levels with increased levels of serum MPO were found in hyperlipidemic patients. Leukocyte counts tended to be higher in hyperlipidemic patients with increased PMNL apoptosis. PMNL priming and fibrinogen levels correlated positively with the severity of hyperlipidemia (r=0.32, P=0.02 for CD11b vs. cholesterol and r=0.38, P=0.009 for CD11b vs. LDL-c; r=0.35, P=0.01 for fibrinogen vs. cholesterol and r=0.3, P=0.03 for superoxide release vs. LDL-c)., Conclusion: PMNLs are primed in hyperlipidemic patients contributing to OS and inflammation in these patients. This study highlights primed PMNLs as an additional risk factor for promoting atherosclerosis in hyperlipidemic patients.

Background: Polymorphonuclear leukocyte priming and low grade inflammation are related to severity of kidney disease. Erythropoietin-receptor is present on PMNLs. OBJECTIVESxi: To evaluate the effect of 20 weeks of epoetin-alpha treatment on PMNL characteristics in relation to the rate of kidney function deterioration in patients with chronic kidney disease., Methods: Forty anemic chronic kidney disease patients, stage 4-5, were assigned to EPO and non-EPO treatment for 20 weeks. A group of 20 healthy controls was also studied. PMNL priming and PMNL-derived low grade inflammation were estimated, in vivo and ex vivo, before and after EPO treatment: The rate of superoxide release, white blood cells and PMNL counts, serum alkaline phosphatase and PMNL viability were measured. EPO-receptor on PMNLs was assayed by flow cytometry. The effect of 20 weeks of EPO treatment on kidney function was related to the estimated glomerular filtration rate. esults: EPO treatment attenuated superoxide release ex vivo and in vivo and promoted PMNL survival ex vivo. Decreased low grade inflammation was reflected by reduced WBC and PMNL counts and ALP activity following treatment. EPO retarded the deterioration in GFR. The percent of PMNLs expressing EPO-R was higher before EPO treatment and correlated positively with the rate of superoxide release. After 20 weeks of EPO treatment the percent of PMNLs expressing EPO-R was down-regulated., Conclusions: These non-erythropoietic properties of EPO are mediated by EPO-R on PMNLs, not related to the anemia correction. A new renal protection effect of EPO via attenuation of PMNL priming that decreases systemic low grade inflammation and oxidative stress is suggested.

Patients on chronic hemodialysis (HD) are at high risk for developing atherosclerosis and cardiovascular complications. Heparanase, an endoglycosidase that cleaves heparan sulfate (HS) side chains of proteoglycans, is involved in extracellular matrix degradation and, as such, may be involved in the atherosclerotic lesion progression. We hypothesize that heparanase is elevated in HD patients, partly due to its release from primed circulating polymorphonuclear leukocytes (PMNLs), undergoing degranulation. Priming of PMNLs was assessed by levels of CD11b and the rate of superoxide release. Heparanase mRNA expression in PMNLs was determined by RT-PCR. PMNL and plasma levels of heparanase were determined by immunoblotting, immunofluorescence, and flow cytometry analyses. The levels of soluble HS in plasma were measured by a competition ELISA. This study shows that PMNLs isolated from HD patients have higher mRNA and protein levels of heparanase compared with normal control (NC) subjects and that heparanase levels correlate positively with PMNL priming. Plasma levels of heparanase were higher in HD patients than in NC subjects and were further elevated after the dialysis session. In addition, heparanase expression inversely correlates with plasma HS levels. A pronounced expression of heparanase was found in human atherosclerotic lesions. The increased heparanase activity in the blood of HD patients results at least in part from the degranulation of primed PMNLs and may contribute to the acceleration of the atherosclerotic process. Our findings highlight primed PMNLs as a possible source for the increased heparanase in HD patients, posing heparanase as a new risk factor for cardiovascular complications and atherosclerosis.

Background: We previously showed that priming of the polymorphonuclear leukocyte (PMNL), inflammation and oxidative stress antecede the development of hypertension in the Sabra rat model of hypertension. The actual role of PMNLs and PMNL-mediated oxidative stress and inflammation in the development of hypertension in this model has remained, however, unresolved., Objective: The aim of our study was to test the hypothesis that PMNLs and that the PMNL-associated NADPH oxidase contribute to the development of hypertension in the Sabra rat model., Methods: To determine the contribution of the PMNL to the development of hypertension, we depleted Sabra hypertension-prone (SBH/y) animals from PMNLs with an anti-PMNL antibody, salt-loaded them and monitored their blood pressure over a period of 30 days. To determine the contribution of the NADPH oxidase on the development of hypertension, we inhibited the activity of this enzyme with phenylarsine oxide or apocynin in SBH/y rats while salt-loading the animals and followed the course of their blood pressure over 60 days., Results: PMNL depletion attenuated significantly the development of hypertension in SBH/y rats. Inhibition of NADPH oxidase with phenylarsine oxide and apocynin markedly inhibited the development of hypertension in SBH/y rats, as well as decreased the rate of superoxide release, the level of PMNL CD11b and the PMNL count., Conclusion: These data are consistent with a significant contribution of PMNLs to the development of hypertension, and suggest that the mechanism may be related, at least in part, to PMNL-mediated oxidative stress and inflammation.

This study characterizes the causal relationship between peripheral polymorphonuclear leukocyte (PMNL) priming, systemic oxidative stress (OS), and inflammation in patients with varying degrees of renal insufficiency (chronic kidney disease [CKD] not on renal replacement therapy [RRT]: continuous ambulatory peritoneal dialysis or hemodialysis [HD]) and healthy control subjects. Rate of superoxide release was measured after stimulation of PMNL with phorbol 12-myristate 13-acetate or zymosan. Priming was estimated by the rate of superoxide release after phorbol 12-myristate 13-acetate stimulation. Systemic OS was related to PMNL priming and intracellular myeloperoxidase activity. Inflammation was linked to peripheral white blood cells and PMNL counts, PMNL apoptosis, and PMNL ex vivo survival in autologous and heterologous sera. PMNL priming and counts were related to the severity of renal failure in CKD not on RRT. Compared with control subjects, PMNL from all CKD patients showed increased priming, highest in HD, with a significant decrease in their response to zymosan. PMNL myeloperoxidase activity and apoptosis were increased in all renal failure patients. Decreased ex vivo cell survival and elevated leukocyte counts were found in all patients, highest in HD. Both PMNL priming and counts correlated negatively with the GFR. A positive significant correlation was shown between PMNL counts and their priming in all groups, suggesting that the increased PMNL count in peripheral blood is an adaptive response to PMNL priming. Hence, PMNL priming is a key mediator of low-grade inflammation and OS associated with renal failure, occurring before the onset of RRT and further augmented in chronic HD.