Pleiotropic effects of angiotensin II receptor blocker in hypertensive patients

Angiotensin-Converting Enzyme (ACE) Inhibitors May Moderate COVID-19 Hyperinflammatory Response: An Observational Study with Deep Immunophenotyping

Background

Angiotensin-converting enzyme inhibitors (ACEi) and angiotensin-II receptor blockers (ARB), the most commonly prescribed antihypertensive medications, counter renin-angiotensin-aldosterone system (RAAS) activation via induction of angiotensin-converting enzyme 2 (ACE2) expression. Considering that ACE2 is the functional receptor for SARS-CoV-2 entry into host cells, the association of ACEi and ARB with COVID-19 outcomes needs thorough evaluation.

Methods

We conducted retrospective analyses using both unmatched and propensity score (PS)-matched cohorts on electronic health records (EHRs) to assess the impact of RAAS inhibitors on the risk of receiving invasive mechanical ventilation (IMV) and 30-day mortality among hospitalized COVID-19 patients. Additionally, we investigated the immune cell gene expression profiles of hospitalized COVID-19 patients with prior use of antihypertensive treatments from an observational prospective cohort.

Results

The retrospective analysis revealed that there was no increased risk associated with either ACEi or ARB use. In fact, the use of ACEi showed decreased risk for mortality. Survival analyses using PS-matched cohorts suggested no significant relationship between RAAS inhibitors with a hospital stay and in-hospital mortality compared to non-RAAS medications and patients not on antihypertensive medications. From the analysis of gene expression profiles, we observed a noticeable up-regulation in the expression of 1L1R2 (an anti-inflammatory receptor) and RETN (an immunosuppressive marker) genes in monocytes among prior users of ACE inhibitors.

Conclusion

Overall, the findings do not support the discontinuation of ACEi or ARB treatment and suggest that ACEi may moderate the COVID-19 hyperinflammatory response.

Monocyte chemoattractant protein-1 and hypertension: An overview

BACKGROUND

The association between hypertension and cardiovascular disease (CVD) has been increasingly studied through early inflammatory biomarkers. The monocyte chemoattractant protein-1 (MCP-1) is the main chemokine implicated in the inflammatory endothelial process, attracting monocytes and macrophages to the atherosclerotic plaque.

METHODS

We reviewed the main observational studies that have analyzed serum MCP-1 in patients with hypertension regardless of CVD, relating them to target organ damage (TOD).

RESULTS

As endothelial dysfunction continues and TOD accumulates, MCP-1 has been perpetuated at higher levels. The relationship between this chemokine and the increase in comorbidities, such as chronic kidney disease, dyslipidaemia, diabetes, and coronary artery disease, became clearer from the observational studies. However, patients with such morbidities use medications with potential anti-inflammatory effects.

CONCLUSION

There is no normal threshold of MCP-1 for the healthy population, nor a uniform curve pattern, due to a balance between genetic factors, age, gender, comorbidities, TOD, and anti-inflammatory effects of drugs. In fact, MCP-1 seems to have a promising role as a tool for further improvement in cardiovascular risk stratification, as prognostic studies have demonstrated an association with fatal and non-fatal cardiovascular outcomes, regardless of other clinical and laboratory predictors.

The Vascular Circadian Clock in Chronic Kidney Disease

Chronic kidney disease is associated with extremely high cardiovascular mortality. The circadian rhythms (CR) have an impact on vascular function. The disruption of CR causes serious health problems and contributes to the development of cardiovascular diseases. Uremia may affect the master pacemaker of CR in the hypothalamus. A molecular circadian clock is also expressed in peripheral tissues, including the vasculature, where it regulates the different aspects of both vascular physiology and pathophysiology. Here, we address the impact of CKD on the intrinsic circadian clock in the vasculature. The expression of the core circadian clock genes in the aorta is disrupted in CKD. We propose a novel concept of the disruption of the circadian clock system in the vasculature of importance for the pathology of the uremic vasculopathy.

The emerging field of non-human leukocyte antigen antibodies in transplant medicine and beyond

The major medical advances in our knowledge of the human leukocyte antigen (HLA) system have allowed us to uncover several gaps in our understanding of alloimmunity. Although the non-HLA system has long sparked the interest of the transplant community, recognition of the role of immunity to non-HLA antigenic targets has only emerged recently. In this review, we will provide a comprehensive summary of the paradigm-changing concept of immunity to the non-HLA angiotensin II type 1 receptor (AT1R), discovered by Duška Dragun et al., that began from careful bedside clinical observations, to validated detection of anti-AT1R antibodies and lead to clinical intervention. This scientific approach has also allowed the recognition of broader pathogenicity of anti-AT1R antibodies across multiple organ transplants and in other human diseases, the integration of both non-HLA and HLA systems to understand their immunologic effects on organ allografts, and the identification of future directions for therapeutic intervention to modulate immunity to AT1R. Rationally designed successful interventions to target AT1R system provide an exemplar for other non-HLA antibodies to cross borders between medical specialties, will generate new avenues in translational research beyond transplantation, and will foster the development of new and reliable tools to improve our understanding of non-HLA immunity and ultimately allow us to improve patient care.

Angiotensin II and leukocyte trafficking: New insights for an old vascular mediator. Role of redox-signaling pathways

Inflammation and activation of the immune system are key molecular and cellular events in the pathogenesis of cardiovascular diseases, including atherosclerosis, hypertension-induced target-organ damage, and abdominal aortic aneurysm. Angiotensin II (Ang-II) is the main effector peptide hormone of the renin-angiotensin system. Beyond its role as a potent vasoconstrictor and regulator of blood pressure and fluid homeostasis, Ang-II is intimately involved in the development of vascular lesions in cardiovascular diseases through the activation of different immune cells. The migration of leukocytes from circulation to the arterial subendothelial space is a crucial immune response in lesion development that is mediated through a sequential and coordinated cascade of leukocyte-endothelial cell adhesive interactions involving an array of cell adhesion molecules present on target leukocytes and endothelial cells and the generation and release of chemoattractants that activate and guide leukocytes to sites of emigration. In this review, we outline the key events of Ang-II participation in the leukocyte recruitment cascade, the underlying mechanisms implicated, and the corresponding redox-signaling pathways. We also address the use of inhibitor drugs targeting the effects of Ang-II in the context of leukocyte infiltration in these cardiovascular pathologies, and examine the clinical data supporting the relevance of blocking Ang-II-induced vascular inflammation.

Effects of Angiotensin-Converting Enzyme Inhibitors and Angiotensin-Receptor Blockers in Heart Failure With Chronic Kidney Disease - Propensity Score Matching Analysis

BACKGROUND

Whether angiotensin-converting enzyme inhibitor (ACEI) or angiotensin-receptor blocker (ARB) exert beneficial effects in patients with concomitant heart failure (HF) and chronic kidney disease (CKD) remains uncertain. In this study, the effects of ACEI and ARB on long-term clinical outcomes in such patients were investigated.Methods and Results:Study data were obtained from a multicenter cohort that included patients hospitalized for HF. A total of 1,601 patients with both HF and CKD were classified according to prescription of ACEI or ARB at discharge. The mortality rate was 19.0% in the ACEI/ARB treatment group (n=943) and 33.6% in the no ACEI/ARB treatment group (n=658) during follow-up. The ACEI/ARB treatment group had a significantly higher cumulative death-free survival rate than the no ACEI/ARB treatment group. Cox regression analysis showed that using ACEI or ARB was independently associated with reduced risk of all-cause death after adjusting for confounding factors. The beneficial effects of ACEI or ARB were retained after propensity score matching.

CONCLUSIONS

Prescription of an ACEI or ARB at discharge was associated with reduction in all-cause mortality in patients with acute HF and CKD. Clinicians need to be aware of the prognostic value and consider prescribing ACEI or ARB to high-risk patients.

Pro-inflammatory Cytokines and Resistant Hypertension: Potential for Novel Treatments?

PURPOSE OF REVIEW

To gather data from studies evaluating the pro-inflammatory profile of individuals with resistant hypertension (RH), and bring a clinical update of new and potential complementary therapies to treat inflammation in RH.

RECENT FINDINGS

Increases in pro-inflammatory cytokines are related to elevated blood pressure and target organ damage in RH patients. Clinical and experimental studies have shown that some biological therapies, especially TNF-α inhibitors, regulated pro- and anti-inflammatory cytokines associated with improvements in clinical outcomes, although they are not yet reported in RH. New emerging therapies to treat inflammation in RH, although promising, are still hypotheses that have not been scientifically confirmed in clinical trials. For this reason, inflammation-target treatments, such as the TNF-α and IL-6 inhibitors, should be encouraged for testing as complementary therapies in RH in order to elucidate their potential benefits.

Inhibition of PAI (Plasminogen Activator Inhibitor)-1 Improves Brain Collateral Perfusion and Injury After Acute Ischemic Stroke in Aged Hypertensive Rats

Background and Purpose- Aging and hypertension, comorbidities prevalent in the stroke population, are associated with poor collateral status and worsened stroke outcome. However, underlying mechanisms by which these conditions affect stroke outcome are not clear. We studied the role of PAI (plasminogen activator inhibitor)-1 that is increased in aging and hypertension on brain and vascular expression of inflammatory factors and perfusion that may contribute to worse stroke outcomes. Methods- Aged (≈50 weeks) and young (≈18 weeks) spontaneously hypertensive rats (SHR) were subjected to ischemia by middle cerebral artery occlusion (2 hours) and reperfusion (2 hours) with or without treatment with the PAI-1 inhibitor TM5441. Changes in middle cerebral artery and collateral perfusion territories were measured by multisite laser Doppler. Reactivity to TM5441 was studied using isolated and pressurized leptomeningeal anastomotic arterioles. Brain injury was determined by 2,3,5-triphenyltetrazolium staining and quantitative immunohistochemistry of amyloid-β-42, PAI-1, and hemoglobin. Circulating inflammatory factors were measured by ELISA. Results- Changes in cerebral blood flow during middle cerebral artery occlusion were similar between groups, with both having poor collateral perfusion and incomplete reperfusion. However, aged SHR had greater brain injury versus young (41±2 versus 23±2%, P<0.05) as well as increased brain deposition of amyloid-β-42 and circulating oxLDL (oxidized low-density lipoprotein). Erythrocyte aggregation and hemorrhage within the injured brain was observed in 50% of aged but no young SHR, with increased circulating PAI-1 in this subgroup of aged SHR (16±3 versus 6±2 ng/mL, P<0.05). PAI-1 inhibition with TM5441 improved brain injury but did not affect hemorrhage. TM5441 increased collateral perfusion by 38±7% and dilated leptomeningeal anastomotic arterioles by 44±10%, which was abolished by nitric oxide synthase inhibition. Conclusions- Increased injury in aged SHR seemed to be related to poor collateral perfusion, hemorrhagic transformation, increased amyloid-β-42, and oxidative stress. PAI-1 inhibition reduced infarction in both groups of SHR that possibly due, in part, to increased collateral perfusion.

Hydration Status and Cardiovascular Function

Hypohydration, defined as a state of low body water, increases thirst sensations, arginine vasopressin release, and elicits renin–angiotensin–aldosterone system activation to replenish intra- and extra-cellular fluid stores. Hypohydration impairs mental and physical performance, but new evidence suggests hypohydration may also have deleterious effects on cardiovascular health. This is alarming because cardiovascular disease is the leading cause of death in the United States. Observational studies have linked habitual low water intake with increased future risk for adverse cardiovascular events. While it is currently unclear how chronic reductions in water intake may predispose individuals to greater future risk for adverse cardiovascular events, there is evidence that acute hypohydration impairs vascular function and blood pressure (BP) regulation. Specifically, acute hypohydration may reduce endothelial function, increase sympathetic nervous system activity, and worsen orthostatic tolerance. Therefore, the purpose of this review is to present the currently available evidence linking acute hypohydration with altered vascular function and BP regulation.

Comparison of the effects of standard vs low-dose prolonged-release tacrolimus with or without ACEi/ARB on the histology and function of renal allografts

Targeting the renin-angiotensin system and optimizing tacrolimus exposure are both postulated to improve outcomes in renal transplant recipients (RTRs) by preventing interstitial fibrosis/tubular atrophy (IF/TA). In this multicenter, prospective, open-label controlled trial, adult de novo RTRs were randomized in a 2 × 2 design to low- vs standard-dose (LOW vs STD) prolonged-release tacrolimus and to angiotensin-converting enzyme inhibitors/angiotensin II receptor 1 blockers (ACEi/ARBs) vs other antihypertensive therapy (OAHT). There were 2 coprimary endpoints: the prevalence of IF/TA at month 6 and at month 24. IF/TA prevalence was similar for LOW vs STD tacrolimus at month 6 (36.8% vs 39.5%; P = .80) and ACEi/ARBs vs OAHT at month 24 (54.8% vs 58.2%; P = .33). IF/TA progression decreased significantly with LOW vs STD tacrolimus at month 24 (mean [SD] change, +0.42 [1.477] vs +1.10 [1.577]; P = .0039). Across the 4 treatment groups, LOW + ACEi/ARB patients exhibited the lowest mean IF/TA change and, compared with LOW + OAHT patients, experienced significantly delayed time to first T cell-mediated rejection. Renal function was stable from month 1 to month 24 in all treatment groups. No unexpected safety findings were detected. Coupled with LOW tacrolimus dosing, ACEi/ARBs appear to reduce IF/TA progression and delay rejection relative to reduced tacrolimus exposure without renin-angiotensin system blockade. ClinicalTrials.gov identifier: NCT00933231.

Potential Protective Role of Blood Pressure-Lowering Drugs on the Balance between Hemostasis and Fibrinolysis in Hypertensive Patients at Rest and During Exercise

In patients with hypertension, the triad represented by endothelial dysfunction, platelet hyperactivity, and altered fibrinolytic function disturbs the equilibrium between hemostasis and fibrinolysis and translates into a hypercoagulable state, which underlies the risk of thrombotic complications. This article reviews the scientific evidence regarding some biological effects of antihypertensive drugs, which can protect patients from the adverse consequences of hypertensive disease, improving endothelial function, enhancing antioxidant activity, and restoring equilibrium between hemostatic and fibrinolytic factors. These protective effects appear not to be mediated through blood pressure reduction and are not shared by all molecules of the same pharmacological class.

A Proposed Inflammatory Score of Circulating Cytokines/Adipokines Associated with Resistant Hypertension, but Dependent on Obesity Parameters

Background

There is evidence that subclinical systemic inflammation is present in resistant hypertension (RHTN).

Objective

The aim of the study was to develop an integrated measure of circulating cytokines/adipokines involved in the pathophysiology of RHTN.

Methods

RHTN (n = 112) and mild to moderate hypertensive (HTN) subjects (n=112) were studied in a cross-sectional design. Plasma cytokines/adipokines (TNF-alpha, interleukins [IL]-6, -8, -10, leptin and adiponectin) values were divided into tertiles, to which a score ranging from 1 (lowest tertile) to 3 (highest tertile) was assigned. The inflammatory score (IS) of each subject was the sum of each pro-inflammatory cytokine scores from which anti-inflammatory cytokines (adiponectin and IL-10) scores were subtracted. The level of significance accepted was alpha = 0.05.

Results

IS was higher in RHTN subjects compared with HTN subjects [4 (2-6) vs. 3 (2-5); p = 0.02, respectively]. IS positively correlated with body fat parameters, such as body mass index (r = 0.40; p < 0.001), waist circumference (r = 0.30; p < 0.001) and fat mass assessed by bioelectrical impedance analysis (r = 0.31; p < 0.001) in all hypertensive subjects. Logistic regression analyses revealed that IS was an independent predictor of RHTN (OR = 1.20; p = 0.02), independent of age, gender and race, although it did not remain significant after adjustment for body fat parameters.

Conclusion

A state of subclinical inflammation defined by an IS including TNF-alpha, IL-6, IL-8, IL-10, leptin and adiponectin is associated with obese RHTN. In addition, this score correlates with obesity parameters, independently of hypertensive status. The IS may be used for the evaluation of conditions involving low-grade inflammation, such as obesity-related RHTN. Indeed, it also highlights the strong relationship between obesity and inflammatory process.

Comparison of fimasartan and amlodipine therapy on carotid atherosclerotic plaque inflammation

Background

The renin‐angiotensin system plays an important role in promoting atherosclerotic plaque inflammation, which may be inhibited by angiotension‐II receptor blockers.

Hypothesis

We investigated the effects of fimasartan and amlodipine therapy on carotid atherosclerotic plaque inflammation using ¹⁸F‐fluorodeoxyglucose (¹⁸FDG) positron emission tomography (PET) imaging.

Methods

Fifty patients with acute coronary syndrome (ACS) and at least one lesion with ¹⁸FDG uptake in the carotid artery (target‐to‐background ratio [TBR] ≥ 1.6) were randomly assigned to receive either fimasartan (60 mg once a day) or amlodipine (5 mg once a day). ¹⁸FDG PET examinations were performed in all patients at baseline and 6 months. The primary endpoint was the percent change in the index vessel TBR for the most diseased segment (MDS TBR).

Results

The two groups had similar baseline characteristics. At the 6‐month follow‐up, index vessel and aorta MDS TBR significantly decreased in both groups. However, the percent change in index vessel MDS TBR was similar between the two groups (−9.33 ± 14.2% vs −7.73 ± 19.1%, respectively, P = 0.9). No significant difference was found for the percent change in the whole vessel TBR for the index vessel between the two groups, with similar findings for changes in MDS TBR or whole vessel TBR for the aorta. Total cholesterol, low‐density lipoprotein cholesterol levels, and blood pressure improved to a similar degree in both groups.

Conclusions

Fimasartan and amlodipine reduce carotid atherosclerotic plaque inflammation similarly in patients with ACS, offering the same level of effectiveness.

Nanomedical studies of the restoration of nitric oxide/peroxynitrite balance in dysfunctional endothelium by 1,25-dihydroxy vitamin D3 - clinical implications for cardiovascular diseases

Background

Clinical studies indicate that vitamin D₃ improves circulation and may have beneficial effects in hypertension. This study uses nanomedical systems to investigate the role of 1,25-dihydroxy vitamin D₃ in the preservation/restoration of endothelial function in an angiotensin II (Ang II) cellular model of hypertension.

Methods

1,25-dihydroxy vitamin D₃-stimulated nitric oxide (NO) and peroxynitrite (ONOO⁻) concentrations were measured in situ with nanosensors (200–300 mm diameter with a detection limit of 1 nM) in human umbilical vein endothelial cells of African American (AA) and Caucasian American (CA) donors exposed to Ang II. The balance/imbalance between NO and ONOO⁻ concentrations ([NO]/[ONOO⁻]) was simultaneously monitored and used as an indicator of endothelial nitric oxide synthase (eNOS) uncoupling and endothelial dysfunction.

Results

[NO]/[ONOO⁻] imbalance in Ang II-stimulated dysfunctional endothelium was 0.20±0.16 for CAs and 0.11±0.09 for AAs. Uncoupled eNOS and overexpression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase contributed to high production of ONOO⁻. Vitamin D₃ treatment reversed [NO]/[ONOO⁻] to 3.0±0.1 in CAs and 2.1±0.1 in AAs – exceeding that observed in normal endothelium. Vitamin D₃ restored uncoupled eNOS and endothelial function by increasing cytoprotective NO and decreasing the cytotoxic ONOO⁻. The beneficial effect of vitamin D₃ is associated with a favorable rate of NO and ONOO⁻ release, restoration of the [NO]/[ONOO⁻] and the overall decrease in the overexpression of eNOS, inducible nitric oxide synthase and NADPH oxidase. This effect of vitamin D₃ may prove to be beneficial in the treatment of hypertension and other cardiovascular diseases, including heart failure, myocardial infarction, vasculopathy, stroke and diabetes.

Combining Potent Statin Therapy with Other Drugs to Optimize Simultaneous Cardiovascular and Metabolic Benefits while Minimizing Adverse Events

Hypercholesterolemia and hypertension are among the most important risk factors for cardiovascular (CV) disease. They are also important contributors to metabolic diseases including diabetes that further increase CV risk. Updated guidelines emphasize targeted reduction of overall CV risks but do not explicitly incorporate potential adverse metabolic outcomes that also influence CV health. Hypercholesterolemia and hypertension have synergistic deleterious effects on interrelated insulin resistance and endothelial dysfunction. Dysregulation of the renin-angiotensin system is an important pathophysiological mechanism linking insulin resistance and endothelial dysfunction to atherogenesis. Statins are the reference standard treatment to prevent CV disease in patients with hypercholesterolemia. Statins work best for secondary CV prevention. Unfortunately, most statin therapies dose-dependently cause insulin resistance, increase new onset diabetes risk and exacerbate existing type 2 diabetes mellitus. Pravastatin is often too weak to achieve target low-density lipoprotein cholesterol levels despite having beneficial metabolic actions. Renin-angiotensin system inhibitors improve both endothelial dysfunction and insulin resistance in addition to controlling blood pressure. In this regard, combined statin-based and renin-angiotensin system (RAS) inhibitor therapies demonstrate additive/synergistic beneficial effects on endothelial dysfunction, insulin resistance, and other metabolic parameters in addition to lowering both cholesterol levels and blood pressure. This combined therapy simultaneously reduces CV events when compared to either drug type used as monotherapy. This is mediated by both separate and interrelated mechanisms. Therefore, statin-based therapy combined with RAS inhibitors is important for developing optimal management strategies in patients with hypertension, hypercholesterolemia, diabetes, metabolic syndrome, or obesity. This combined therapy can help prevent or treat CV disease while minimizing adverse metabolic consequences.

Angiotensin receptor blockers & endothelial dysfunction: Possible correlation & therapeutic implications

The endothelium is one of the most important constituents of vascular homeostasis, which is achieved through continual and balanced production of different relaxing and contractile factors. When there is a pathological disturbance in release of these products, endothelial dysfunction (ED) will probably occur. ED is considered to be the initial step in the development of atherosclerosis. This pathological activation and inadequate functioning of endothelial cells was shown to be to some extent a reversible process, which all together resulted in increased interest in investigation of different beneficial treatment options. To this point, the pharmacological approach, including for example, the use of angiotensin-converting enzyme inhibitors or statins, was clearly shown to be effective in the improvement of ED. One of many critical issues underlying ED represents instability in the balance between nitric oxide and angiotensin II (Ang II) production. Considering that Ang II was confirmed to be important for the development of ED, the aim of this review article was to summarize the findings of up to date clinical studies associated with therapeutic application of angiotensin receptor blockers and improvement in ED. In addition, it was of interest to review the pleiotropic actions of angiotensin receptor blockers linked to the improvement of ED. The prospective, randomized, double-blind, placebo or active-controlled clinical trials were identified and selected for the final evaluation.

Evidence that remodeling of insular cortex neurovascular unit contributes to hypertension-related sympathoexcitation

The intermediate region of the posterior insular cortex (intermediate IC) mediates sympathoexcitatory responses to the heart and kidneys. Previous studies support hypertension-evoked changes to the structure and function of neurons, blood vessels, astrocytes and microglia, disrupting the organization of the neurovascular unit (NVU). In this study, we evaluated the functional and anatomical integrity of the NVU at the intermediate IC in the spontaneously hypertensive rat (SHR) and its control the Wistar-Kyoto (WKY). Under urethane anesthesia, NMDA microinjection (0.2 mmol/L/100 nL) was performed at the intermediate IC with simultaneous recording of renal sympathetic nerve activity (RSNA), heart rate (HR) and mean arterial pressure (MAP). Alterations in NVU structure were investigated by immunofluorescence for NMDA receptors (NR1), blood vessels (70 kDa FITC-dextran), astrocytes (GFAP), and microglia (Iba1). Injections of NMDA into intermediate IC of SHR evoked higher amplitude responses of RSNA, MAP, and HR On the other hand, NMDA receptor blockade decreased baseline RSNA, MAP and HR in SHR, with no changes in WKY Immunofluorescence data from SHR intermediate IC showed increased NMDA receptor density, contributing to the SHR enhanced sympathetic responses, and increased in vascular density (increased number of branches and endpoints, reduced average branch length), suggesting angiogenesis. Additionally, IC from SHR presented increased GFAP immunoreactivity and contact between astrocyte processes and blood vessels. In SHR, IC microglia skeleton analysis supports their activation (reduced number of branches, junctions, endpoints and process length), suggesting an inflammatory process in this region. These findings indicate that neurogenic hypertension in SHR is accompanied by marked alterations to the NVU within the IC and enhanced NMDA-mediated sympathoexcitatory responses likely contributors of the maintenance of hypertension.

The effect of candesartan on pentraxin-3 plasma levels as marker of endothelial dysfunction in patients with essential arterial hypertension

BACKGROUND

In the last decades, the studies performed on the field of endothelial dysfunction confirmed the fact that the starting point of this pathology is the inflammation. Several inflammatory biomarkers had been discovered and studied, ones showing systemic inflammation, and others being more specific biomarkers and showing the local inflammation. Pentraxin-3 (PTX3) is a new inflammatory biomarker, from the same family as high-selectivity C-reactive protein (hs-CRP), but it is a more specific biomarker, due to its local production: the endothelial cells and not the liver like in the case of hs-CRP.

AIMS

Several antihypertensive classes of drugs seem to have a positive impact on reducing the local endothelial inflammation, beyond their effect of lowering the blood pressure, so this study aims to analyze the effect of candesartan on the two inflammatory biomarkers: PTX3 and CRP, compared with other antihypertensive drugs, in hypertensive patients with endothelial dysfunction.

METHODS

A total of 365 patients were included in the study: 127 hypertensive patients were under treatment with candesartan, 134 patients were under treatment with other hypotensive medication (beta blockers, calcium channel blockers, and diuretics), both groups with controlled values of blood pressure, and 104 were normotensive persons. Classical methods of assessing the endothelial function were correlated with these biochemical markers.

RESULTS

The patients treated with candesartan had a significant lower value of PTX3 and hs-CRP, compared with those under treatment with other antihypertensive medication as follows: PTX3: 0.61 ± 0.49 vs 0.95 ± 1.04 ng/ml, P = 0.006 and hs-CRP: 0.19 ± 0.20 vs 0.20 ± 0.22 mg/dl, P = 0.54.

CONCLUSIONS

Candesartan decreases PTX3 and hs-CRP plasma levels more powerful than other classes of antihypertensive drugs (beta blockers, calcium channel blockers, and diuretics), so we may assume that candesartan has a more potent action in reversing endothelial dysfunction and that it offers a higher vascular protection than other classes of antihypertensive drugs. We are suggesting that this new biochemical marker, PTX3, might be better and more specific marker for endothelial dysfunction, than hs-CRP.

Immunologic Effects of the Renin-Angiotensin System

Inappropriate activation of the renin-angiotensin system (RAS) exacerbates renal and vascular injury. Accordingly, treatment with global RAS antagonists attenuates cardiovascular risk and slows the progression of proteinuric kidney disease. By reducing BP, RAS inhibitors limit secondary immune activation responding to hemodynamic injury in the target organ. However, RAS activation in hematopoietic cells has immunologic effects that diverge from those of RAS stimulation in the kidney and vasculature. In preclinical studies, activating type 1 angiotensin (AT₁) receptors in T lymphocytes and myeloid cells blunts the polarization of these cells toward proinflammatory phenotypes, protecting the kidney from hypertensive injury and fibrosis. These endogenous functions of immune AT₁ receptors temper the pathogenic actions of renal and vascular AT₁ receptors during hypertension. By counteracting the effects of AT₁ receptor stimulation in the target organ, exogenous administration of AT₂ receptor agonists or angiotensin 1-7 analogs may similarly limit inflammatory injury to the heart and kidney. Moreover, although angiotensin II is the classic effector molecule of the RAS, several RAS enzymes affect immune homeostasis independently of canonic angiotensin II generation. Thus, as reviewed here, multiple components of the RAS signaling cascade influence inflammatory cell phenotype and function with unpredictable and context-specific effects on innate and adaptive immunity.

Candesartan ameliorates arsenic-induced hypertensive vascular remodeling by regularizing angiotensin II and TGF-beta signaling in rats

Arsenic exposure can cause several cardiovascular diseases, including hypertension, atherosclerosis and microvascular disease. Earlier, we reported that arsenic-mediated enhancement of angiotensin II (AngII) signaling can impair vascular physiology. Here, we investigated whether the AT₁ receptor (AT₁R) blocker candesartan can ameliorate the arsenic-induced hypertensive vascular remodeling in rats and whether the amelioration could relate to attenuation in vascular AngII and TGF-β signaling. Rats were exposed to sodium arsenite (50ppm) through drinking water for 90 consecutive days. Candesartan (1mg/kg bw, orally) was administered once daily during the last 30days of arsenic exposure. Non-invasive blood pressure was recorded weekly in conscious rats, while AngII-induced change in mean arterial pressure in anaesthetized rats was measured by invasive method on the 91st day. On this day, blood was collected from other animals for measuring AngII level. Western blot of AT₁, AT₂ and TβRII receptors; ELISA of PTK, RasGAP, ERK-1/2, TGF-β and CTGF; immunohistochemistry of phosphorylated Smad3, Smad4 and collagen III, hydroxyproline/total collagen estimation, collagen deposition by Masson's trichrome staining and histomorphometry were carried out in thoracic aorta. Arsenic increased non-invasive systolic, diastolic and mean arterial pressure. Further, AngII caused concentration-dependent incremental change in mean arterial pressure in the arsenic-exposed rats. Arsenic upregulated AT₁ and TβRII receptor proteins; elevated the levels of PTK, ERK-1/2, TGF-β and CTGF, decreased RasGAP level and augmented the immunoreactivities of Smad3, Smad4 and collagen III. Arsenic also increased hydroxyproline/total collagen level, proliferation of collagen fibres and thickness of aortic wall and collagenous adventitia. Candesartan normalized blood pressure, regularized receptor expressions, MAP kinase and TGF-β signaling, restored collagen deposition and regressed aortic thickness. Our results demonstrate that candesartan can ameliorate the arsenic-mediated systemic hypertension and vascular remodeling in rats by regularizing the signaling pathways of AngII and TGF-β.

Angiotensin receptor blockers are not associated with reduced inflammatory markers in the general population

OBJECTIVE

Angiotensin receptor blockers (ARBs) have been suggested to reduce inflammation in randomized controlled trials. We assessed the association between ARBs and inflammatory markers in a general population setting.

METHODS

This is a population-based prospective study conducted in Lausanne, Switzerland. Baseline data from 933 participants on antihypertensive drugs (424 on ARBs) was collected in 2003-2006. Follow-up data from 1120 participants (572 on ARBs) was collected in 2009-2012. C-reactive protein (CRP), interleukins 1β and 6 and tumor necrosis factor alpha (TNF-α) were assessed and categorized in quartiles.

RESULTS

At baseline, no differences were found between participants taking or not taking ARBs for all inflammatory markers studied, and this association persisted after multivariate adjustment: odds ratios (ORs) and (95% confidence interval) for being in the highest quartile of interleukin-1β, interleukin-6, TNF-α and CRP for participants on ARB compared to participants not on ARB were 1.23 (0.89-1.70), 1.26 (0.93-1.70), 1.14 (0.85-1.53) and 1.27 (0.96-1.69) respectively (P > 0.05). These findings were further replicated in the follow-up study: OR and (95% CI) of 1.10 (0.78-1.55), 0.87 (0.64-1.19), 0.83 (0.61-1.14) and 0.91 (0.68-1.22) for interleukin-1β, interleukin-6, TNF-α and CRP respectively (P > 0.05). Finally, no effect of ARBs was found when comparing participants who received ARBs throughout the 5.4-year follow-up with participants on other antihypertensive drugs: OR and (95% CI) of 0.93 (0.61-1.42), 0.80 (0.54-1.17), 0.86 (0.59-1.25) and 0.95 (0.67-1.35) for interleukin-1β, interleukin-6, TNF-α and CRP respectively (P > 0.05).

CONCLUSION

ARBs are not associated with reduced levels of inflammatory markers in the general population.

Hypercholesterolemia and Hypertension: Two Sides of the Same Coin

The aim of this review article is to summarize the current knowledge about mechanisms that connect blood pressure regulation and hypercholesterolemia, the mutual interaction between hypertension and hypercholesterolemia, and their influence on atherosclerosis development. Our research shows that at least one-third of the population of Western Europe has hypertension and hypercholesterolemia. Several biohumoral mechanisms could explain the relationship between hypertension and hypercholesterolemia and the association between these risk factors and accelerated atherosclerosis. The most investigated mechanisms are the renin-angiotensin-aldosterone system, oxidative stress, endothelial dysfunction, and increased production of endothelin-1. Arterial hypertension is frequently observed in combination with hypercholesterolemia, and this is related to accelerated atherosclerosis. Understanding the mechanisms behind this relationship could help explain the benefits of therapy that simultaneously reduce blood pressure and cholesterol levels.

Pathophysiology and Medical Treatment of Carotid Artery Stenosis

Stroke is the third leading cause of mortality. Approximately 80 to 85% strokes are ischemic due to carotid artery stenosis (CAS). The prevalence of significant CAS is 7% in women and 9% in men. Severe asymptomatic CAS varies from 0 to 3.1%. Prevalence of symptomatic CAS is high in patients with peripheral arterial disease. CAS is due to atherosclerosis, the major risk factors for which include dyslipidemia, hypertension, diabetes, obesity, cigarette smoking, advanced glycation end products (AGEs) and its receptors (RAGE, soluble RAGE [sRAGE]), lack of exercise and C-reactive protein (CRP). This article discusses the basic mechanism of atherosclerosis and the mechanisms by which these risk factors induce atherosclerosis. The role of AGEs and its receptors in the development and progression of CAS has been discussed in detail. Lifestyle changes and medical treatment of CAS such as lifestyle changes, lipid-lowering agents, antihypertensive agents, antidiabetic drugs, anti-AGE therapy, measures to elevate soluble receptors of AGE (sRAGE, esRAGE). CRP-lowering agents have been discussed in detail. The drugs especially lipid-lowering agents, and antihypertensive and antidiabetic drugs suppress, regress, and slow the progression of CAS. The possible role of lowering the levels of AGEs and raising the levels of sRAGE in the treatment of CAS has been proposed. Lifestyle changes besides medical treatment have been stressed. Lifestyle changes and medical treatment not only would slow the progression of CAS but would also regress the CAS.

Pharmacological modulation of fibrinolytic response - In vivo and in vitro studies

Fibrinolysis is an action of converting plasminogen by its activators, like tissue- or urokinase-type plasminogen activators (t-PA, u-PA), to plasmin, which in turn cleaves fibrin, thereby causing clot dissolution and restoration of blood flow. Endothelial cells release t-PA, prostacyclin (PGI2) and nitric oxide (NO), the potent factors playing a crucial role in regulation of the fibrinolytic system. Since blood platelets can release not only prothrombotic, but also antifibrinolytic factors, like plasminogen activator inhibitor type-1 (PAI-1), they are involved in fibrynolysis regulation. Therefore agents enhancing fibrinolysis can be preferred pharmacologicals in many cardiovascular diseases. This review describes mechanisms by which major cardiovascular drugs (renin-angiotensin-aldosterone system inhibitors, statins, adrenergic receptors and calcium channel blockers, aspirin and 1-methylnicotinamide) influence fibrinolysis. The presented data indicate, that the influence of these drugs on endothelium-blood platelets interactions via NO/PGI2 pathway is fundamental for its antithrombotic and profibrinolytic action. We also described new approaches for intravital confocal real-time imaging as a tool useful to investigate mechanisms of thrombus formation and the effects of drugs affecting haemostasis and mechanisms of their action in the circulation.

Olmesartan protects endothelial cells against oxidative stress-mediated cellular injury

BACKGROUND

The primary cause of death of hemodialysis (HD) patients is cardiovascular disease, and increased oxidative stress has been proposed to be involved in the disease pathogenesis. In this study, we examined the effect of olmesartan on oxidative stress induced by angiotensin II, lipopolysaccharide, indoxyl sulfate, advanced oxidation protein products (AOPP) or hydrogen peroxide (H2O2), which are known to be present at higher concentrations in the blood of HD patients, using human umbilical vein endothelial cells (HUVECs).

METHODS

Oxidative stress was evaluated by measuring the mean fluorescence intensity of CM-H2DCFCA, an ROS-sensitive fluorescent dye, in HUVECs. HUVECs were incubated with each of the above compounds in the presence or absence of olmesartan. Moreover, these oxidant-stimulated cells were also treated with the reactive oxygen species (ROS) inhibitor N-acetyl-cysteine (NAC), NADPH oxidase inhibitor diphenylene iodonium (DPI) or PKC inhibitor calphostin C. In addition, we investigated the effects of olmesartan on cytotoxicity and vascular endothelial growth factor (VEGF) secretion, which is involved in vascular inflammation in HUVECs induced by AOPP or H2O2.

RESULTS

The treatment of these oxidant-stimulated cells with olmesartan resulted in a significant reduction in intracellular ROS production to an extent that was nearly equivalent to that of NAC, DPI or calphostin C. Furthermore, olmesartan reduced the cytotoxicity and VEGF secretion induced by AOPP or H2O2.

CONCLUSIONS

These results demonstrated that the antioxidant activity of olmesartan might contribute to both its vasculoprotective and anti-hypertensive effects.

Effect of Angiotensin Receptor Blockers on Flow-Mediated Vasodilation: A Meta-Analysis of Randomized Controlled Trials

Background: In a meta-analysis, we investigated the effects of angiotensin receptor blockers (ARBs) in comparison to placebo or other classes of antihypertensive drugs on endothelial function, which was measured by brachial flow-mediated vasodilation (FMD). Methods: We searched for randomized controlled trials that compared ARBs with placebo or other classes of antihypertensive drugs in improving FMD. A random-effect model was used to compute pooled estimates. Results: In 13 trials (n = 529), ARBs were more efficacious in improving brachial FMD than placebo [pooled weighted mean change difference (WMD) 1.34%, 95% CI, 0.93-1.75%, p < 0.001]. In 15 trials (n = 918), treatment with ARBs had a significant effect on brachial FMD when compared with other antihypertensive drugs (pooled WMD 0.59%, 95% CI, 0.20-0.98%, p = 0.003 with significant heterogeneity). ARBs were also more efficacious in improving brachial FMD than calcium channel blockers (CCBs; pooled WMD 1.61%, 95% CI, 0.72-2.49%, p < 0.001) but not the other classes of drugs (p ≥ 0.072). Conclusions: This meta-analysis shows that ARBs improve brachial FMD, a marker of endothelial function, and that they are superior to placebo and CCBs. There was no significant difference in the effect on brachial FMD between ARBs and the other antihypertensive drugs.

Endocan, a novel marker of endothelial dysfunction in patients with essential hypertension: comparative effects of amlodipine and valsartan

Vascular inflammation plays an important role in the pathophysiology of hypertension and high levels of endocan may reflect ongoing vascular inflammation in hypertensive patients. In the present hypothesis-generating study, we aimed at investigating the comparative effects of amlodipine and valsartan on endocan levels in newly diagnosed hypertensive patients. The study population consisted of 37 untreated hypertensive patients who were randomized to the two treatment arms. After baseline assessment, each patient was randomly allocated to either 10 mg daily of amlodipine (n = 18, 7 males) or 160 mg daily of valsartan (n = 19, 3 males) and treated for a 3-month period. Sphygmomanometric blood pressure (BP) and serum endocan were measured before and every 2 weeks during drug treatment. There was no statistically significant difference between the two treatment arms as far as baseline socio-demographic and clinical characteristics are concerned. After a 3-month treatment period, systolic and diastolic BP values significantly reduced by antihypertensive treatment (p < 0.001). Furthermore, endocan levels were significantly decreased in both treatment arms (p < 0.05). However, amlodipine caused a greater percent decrease in circulating endocan levels compared with valsartan at the end of the treatment period. Both drugs reduced high sensitivity C-reactive protein values. However, the statistical significant difference vs baseline was achieved only in the group treated with amlodipine. No correlation was found between endocan plasma levels and BP reduction. The results of this hypothesis-generating study suggest that amlodipine and valsartan decrease endocan levels in newly diagnosed hypertensive patients. The effects, which are more evident with amlodipine, may contribute to the anti-inflammatory effects exerted by the two drugs on the vascular target.

Losartan improved antioxidant defense, renal function and structure of postischemic hypertensive kidney

Ischemic acute renal failure (ARF) is a highly complex disorder involving renal vasoconstriction, filtration failure, tubular obstruction, tubular backleak and generation of reactive oxygen species. Due to this complexity, the aim of our study was to explore effects of Angiotensin II type 1 receptor (AT1R) blockade on kidney structure and function, as well as oxidative stress in spontaneously hypertensive rats (SHR) after renal ischemia reperfusion injury. Experiments were performed on anaesthetized adult male SHR in the model of ARF with 40 minutes clamping the left renal artery. The right kidney was removed and 40 minutes renal ischemia was performed. Experimental groups received AT1R antagonist (Losartan) or vehicle (saline) in the femoral vein 5 minutes before, during and 175 minutes after the period of ischemia. Biochemical parameters were measured and kidney specimens were collected 24h after reperfusion. ARF significantly decreased creatinine and urea clearance, increased LDL and lipid peroxidation in plasma. Treatment with losartan induced a significant increase of creatinine and urea clearance, as well as HDL. Lipid peroxidation in plasma was decreased and catalase enzyme activity in erythrocytes was increased after losartan treatment. Losartan reduced cortico-medullary necrosis and tubular dilatation in the kidney. High expression of pro-apoptotic Bax protein in the injured kidney was downregulated after losartan treatment. Our results reveal that angiotensin II (via AT1R) mediates the most postischemic injuries in hypertensive kidney through oxidative stress enhancement. Therefore, blockade of AT1R may have beneficial effects in hypertensive patients who have developed ARF.

Interrelationship between brachial artery function and renal small artery sclerosis in chronic kidney disease

Chronic kidney disease (CKD), characterized by senile inflammation, is a risk factor for cardiovascular disease. Conduit artery function and small artery structure relate to cardiovascular disease. We examined the correlations, determinants and interrelationships of arterial indices in association with CKD in a cross-sectional study of 139 patients (60% male; mean age 44 years) with CKD (stages 3-5, 39%) who underwent a renal biopsy. Conduit artery function and small artery sclerosis were assessed by brachial artery flow-mediated dilatation (FMD) and semiquantitative evaluation of small artery intimal thickening (SA-IT), respectively. The estimated glomerular filtration rate correlated with FMD (r=0.31, P=0.0002) and inversely correlated with SA-IT (r=-0.54, P<0.0001). Multiple regression analysis showed that FMD was inversely correlated with SA-IT and vice versa. In addition, high-sensitivity C-reactive protein (hs-CRP) was significantly correlated with SA-IT, but not FMD. Multiple logistic analysis revealed that higher hs-CRP concomitant with decreased FMD was further associated with the risk of severe SA-IT compared with their individual effects. These findings suggest that both conduit artery and small artery disease develop with mutual interaction in parallel with decreased kidney function. Coexistence of inflammation and conduit artery dysfunction may be closely related to renal small artery sclerosis in patients with CKD.

Suppressive effects of irbesartan on inflammation and apoptosis in atherosclerotic plaques of apoE-/- mice: molecular imaging with 14C-FDG and 99mTc-annexin A5

OBJECTIVES

To investigate the effects of irbesartan on inflammation and apoptosis in atherosclerotic plaques by histochemical examination and molecular imaging using (14)C-FDG and (99m)Tc-annexin A5.

BACKGROUND

Irbesartan has a peroxisome proliferator-activated receptor gamma (PPARγ) activation property in addition to its ability to block the AT1 receptor. Accordingly, irbesartan may exert further anti-inflammatory and anti-apoptotic effects in atherosclerotic plaques. However, such effects of irbesartan have not been fully investigated. Molecular imaging using (18)F-FDG and (99m)Tc-annexin A5 is useful for evaluating inflammation and apoptosis in atherosclerotic plaques.

METHODS

Female apoE(-/-) mice were treated with irbesartan-mixed (50 mg/kg/day) or irbesartan-free (control) diet for 12 weeks (n = 11/group). One week after the treatment, the mice were co-injected with (14)C-FDG and (99m)Tc-annexin A5, and cryostat sections of the aortic root were prepared. Histochemical examination with Movat's pentachrome (plaque size), Oil Red O (lipid deposition), Mac-2 (macrophage infiltration), and TUNEL (apoptosis) stainings were performed. Dual-tracer autoradiography was carried out to evaluate the levels of (14)C-FDG and (99m)Tc-annexin A5 in plaques (%ID×kg). In vitro experiments were performed to investigate the mechanism underlying the effects.

RESULTS

Histological examination indicated that irbesartan treatment significantly reduced plaque size (to 56.4%±11.1% of control), intra-plaque lipid deposition (53.6%±20.2%) and macrophage infiltration (61.9%±20.8%) levels, and the number of apoptotic cells (14.5%±16.6%). (14)C-FDG (43.0%±18.6%) and (99m)Tc-annexin A5 levels (45.9%±16.8%) were also significantly reduced by irbesartan treatment. Irbesartan significantly suppressed MCP-1 mRNA expression in TNF-α stimulated THP-1 monocytes (64.8%±8.4% of un-treated cells). PPARγ activation was observed in cells treated with irbesartan (134%±36% at 3 µM to 3329%±218% at 81 µM) by a PPARγ reporter assay system.

CONCLUSIONS

Remissions of inflammation and apoptosis as potential therapeutic effects of irbesartan on atherosclerosis were observed. The usefulness of molecular imaging using (18)F-FDG and (99m)Tc-annexin A5 for evaluating the therapeutic effects of irbesartan on atherosclerosis was also suggested.

Statins and renin-angiotensin system inhibitor combination treatment to prevent cardiovascular disease

Hypercholesterolemia and hypertension are common risk factors for cardiovascular disease (CVD). Updated guidelines emphasize target reductions of overall cardiovascular risks. Experimental studies have shown reciprocal relationships between insulin resistance (IR) and endothelial dysfunction. Hypercholesterolemia and hypertension have a synergistic deleterious effect on IR and endothelial dysfunction. Unregulated renin-angiotensin system (RAS) is important in the pathogenesis of atherosclerosis and hypertension. Various strategies with different classes of antihypertensive medications to reach target goals have failed to reduce residual CVD risk further. Of interest, treating moderate cholesterol elevations with low-dose statins in hypertensive patients reduced CVD risk by 35-40% further. Therefore, statins are important in reducing CVD risk. Unfortunately, statin therapy causes IR and increases the risk of type 2 diabetes mellitus. RAS inhibitors improve both endothelial dysfunction and IR. Further, cross-talk between hypercholesterolemia and RAS exists at multiple steps of IR and endothelial dysfunction. In this regard, combined therapy with statins and RAS inhibitors demonstrates additive/synergistic effects on endothelial dysfunction and IR in addition to lowering cholesterol levels and blood pressure when compared with either monotherapy in patients. This is mediated by both distinct and interrelated mechanisms. Therefore, combined therapy with statins and RAS inhibitors may be important in developing optimal management strategies in patients with hypertension, hypercholesterolemia, diabetes, metabolic syndrome, or obesity to prevent CVD.  

Evaluation of adverse effects of lisinopril and rosuvastatin on hematological and biochemical analytes in wistar rats

Objective:

Combination therapy of lisinopril and rosuvastatin may be an important concept in developing more effective strategies to treat and prevent atherosclerosis, coronary heart disease, and co-morbid metabolic disorders. The present study was designed to evaluate toxic effects of lisinopril and rosuvastatin alone or its combination therapy on hematological and biochemical analytes in Wistar rats.

Materials and Methods:

Forty-two rats were divided into seven groups, with each group comprising six rats. Rats were administered with lisinopril, rosuvastatin alone, or in-combination at two different doses. The blood samples were collected from rats after 21 days of oral administration of the drug/s and analyzed for various hematological and biochemical analytes.

Results:

Lisinopril alone and its combination treatment with rosuvastatin at high doses decreased hemoglobin and hematocrit. Rosuvastatin alone at high dose and its concomitant administration with lisinopril at two different doses showed increase in total white blood cells and absolute lymphocyte count and neutrophil count. Serum levels of aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total bilirubin were significantly increased in rosuvastatin alone and its combination with lisinopril at both the doses. Besides this, lisinopril treatment decreased serum levels of sodium and increased the levels of potassium. Serum creatine kinase (CK) levels were increased in the animals treated with rosuvastatin at both the doses. However, increased serum CK level because of rosuvastatin became normal with co-administration of lisinopril at low doses.

Conclusion:

Our results indicate that administration of lisinopril with rosuvastatin does not ameliorate hepatotoxicity caused by rosuvastatin. However, combination treatment reduces serum CK levels elevated due to rosuvastatin, implicating protective effect of combination treatment on myopathy at low doses.

Opposite effect of angiotensin receptor blockade on CXCL8 production and CXCR1/2 expression of angiotensin II-treated THP-1 monocytes

Interleukin-8 (IL-8) or CXCL8 is a potent chemotactic factor that is involved in atherogenesis. IL-8 mediates its pre-inflammatory effects through interaction with CXCR1 and CXCR2. In the present study, we investigated the effects of angiotensin II (Ang II) on IL-8 synthesis and CXCR1/CXCR2 expression of THP-1 monocytes. IL-8 was measured in the culture medium using ELISA. Expression of chemokine receptors CXCR1 and CXCR2 was evaluated by flow cytometry. Results demonstrated that the addition of Ang II increased IL-8 production in the THP-1 monocytes. The Ang II type 1 receptor blocker (ARB) losartan significantly blocked Ang II-induced IL-8 production. Notably, losartan blocked LPS-induced IL-8 production by THP-1 monocytes and produced a small but statistically significant reduction of baseline IL-8 production of naïve THP-1 cells. Losartan also produced a statistically significant increase of fluorescence intensity of naïve CXCR1- and CXCR2-positive THP-1 monocytes, probably as a negative feedback effect secondary to IL-8 downregulation. In conclusion, we demonstrated that Ang II increased IL-8 production by THP-1 monocytes. Losartan significantly suppressed the latter effect, suggesting an AT-1 mediated pathway. Moreover, losartan suppressed the IL-8 production of naïve THP-1 monocytes and LPS-treated THP-1 monocytes, suggesting a broader spectrum of pleiotropic effects. Extrapolating this in vitro observation to in vivo pathways, we propose Ang II-induced IL-8 production by monocytes as another pre-atherogenic potential of Ang II that can be effectively blocked by the AT1 receptor blockade.

Combination therapy with an angiotensin-converting-enzyme inhibitor and an angiotensin II receptor antagonist ameliorates microinflammation and oxidative stress in patients with diabetic nephropathy

Aims/Introduction

Recent studies have pointed to the effectiveness of combination therapy with an angiotensin‐converting‐enzyme inhibitor (ACEI) and an angiotensin receptor blocker (ARB) for diabetic nephropathy. However, some controversy over this combination treatment remains and the mechanisms underlying its renoprotective effects have not been fully clarified. Therefore, we compared the renoprotective effects of imidapril (ACEI) and losartan (ARB) combination therapy with losartan monotherapy in patients with diabetic nephropathy. We also compared the anti‐inflammatory and anti‐oxidative stress effects of these two treatments.

Materials and Methods

A total of 32 Japanese patients with type 2 diabetes and nephropathy were enrolled. Patients were randomized to either 100 mg/day losartan (n = 16) or 50 mg/day losartan plus 5 mg/day imidapril (n = 16). We evaluated clinical parameters, serum concentrations of high‐sensitivity C‐reactive protein (hs‐CRP), soluble intercellular adhesion molecule‐1 (sICAM‐1), interleukin‐18 (IL‐18) and monocyte chemotactic protein‐1 (MCP‐1), and the urinary concentrations of IL‐18, MCP‐1 and 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) at 24 and 48 weeks after starting treatment.

Results

Blood pressure was not significantly different between the two groups. The serum levels of hs‐CRP, sICAM‐1 and IL‐18, as well as urinary excretion of albumin, IL‐18 and 8‐OHdG decreased significantly in the combination therapy group at 48 weeks. The percent decreases in serum IL‐18 concentrations and urinary IL‐18 and 8‐OHdG were significantly greater in the combination therapy group than in the monotherapy group.

Conclusions

Combination therapy with an ACEI and an ARB could be beneficial for treating diabetic nephropathy through its anti‐inflammatory and anti‐oxidative stress effects.

Increased inflammatory biomarkers in hypertensive type 2 diabetic patients: improvement after angiotensin II type 1 receptor blockade

Diabetes and hypertension increasingly are recognized as pro-inflammatory conditions. We tested the hypothesis that in patients with hypertension and type 2 diabetes, blood pressure (BP) reduction with an angiotensin receptor blocker (ARB), valsartan, or with a beta blocker, atenolol, is associated with a decreased inflammatory response. Normotensive subjects and hypertensive patients with type 2 diabetes (40 to 70 years of age) participated in the study. Patients (n = 28) were randomized to double-blind treatment for 1 year with valsartan (80-160 mg) or atenolol (50-100 mg) daily, added to previous therapy. Age-matched controls (n = 12) were also studied. Serum levels of cytokines (IL-6, IL-18), chemokines (MCP-1), and adhesion molecules (sICAM, sE-selectin) were measured by enzyme-linked immunosorbent assay (ELISA) as indices of systemic and vascular inflammation, before and 1 year after treatment. BP was similarly reduced by valsartan and atenolol. Glycemic control and lipid profiles were comparable in the two groups and did not change significantly with antihypertensive therapy. Serum levels of all inflammatory markers were increased in patients before treatment (by two- to four-fold vs. controls, P < .05). IL-6, IL-18, sICAM, and MCP-1 levels were reduced by valsartan (three-fold, P < .05). Only IL-18 was reduced by atenolol compared with pretreatment levels (P < .05). These data indicate that proinflammatory mediators are significantly increased in hypertensive type 2 diabetic patients and that despite similar BP lowering by valsartan and atenolol and similar glucose levels in both treated groups, global inflammatory status was improved only in the valsartan group. Our findings suggest that antihypertensive treatment, particularly with an ARB, ameliorates inflammatory processes in diabetic hypertensive patients. Such effects, which are independent of BP and glycemic control, may contribute to cardiovascular protection.

Telmisartan: from lowering blood pressure to end-organ protection

The principal aim in the treatment of patients with high blood pressure is to ensure a maximum reduction in the total risk of cardiovascular morbidity and mortality. The renin-angiotensin system plays an important role in volume homeostasis and blood pressure regulation. The angiotensin receptor blockers control high blood pressure by preventing the binding of angiotensin II to the subtype 1 receptor, which is believed to mediate most of the physiologic actions of angiotensin II relevant to the regulation of blood pressure. Telmisartan is a widely used angiotensin receptor blocker with distinct pharmacokinetic and pharmacodynamic properties. Due to its long duration of action, it compares favorably with other angiotensin receptor blockers. Latest data from clinical trials and newest research regarding telmisartan will be reviewed in this article.