Common angiotensin receptor blockers may directly modulate the immune system via VDR, PPAR and CCR2b

A molecular mechanism for angiotensin II receptor blocker-mediated slit membrane protection: Angiotensin II increases nephrin endocytosis via AT1-receptor-dependent ERK 1/2 activation

Albuminuria is characterized by a disruption of the glomerular filtration barrier, which is composed of the fenestrated endothelium, the glomerular basement membrane, and the slit diaphragm. Nephrin is a major component of the slit diaphragm. Apart from hemodynamic effects, Ang II enhances albuminuria by β-Arrestin2-mediated nephrin endocytosis. Blocking the AT1 receptor with candesartan and irbesartan reduces the Ang II-mediated nephrin-β-Arrestin2 interaction. The inhibition of MAPK ERK 1/2 blocks Ang II-enhanced nephrin-β-Arrestin2 binding. ERK 1/2 signaling, which follows AT1 receptor activation, is mediated by G-protein signaling, EGFR transactivation, and β-Arrestin2 recruitment. A mutant AT1 receptor defective in EGFR transactivation and β-Arrestin2 recruitment reduces the Ang II-mediated increase in nephrin β-Arrestin2 binding. The mutation of β-Arrestin2K11,K12, critical for AT1 receptor binding, completely abrogates the interaction with nephrin, independent of Ang II stimulation. β-Arrestin2K11R,K12R does not influence nephrin cell surface expression. The data presented here deepen our molecular understanding of a blood-pressure-independent molecular mechanism of AT-1 receptor blockers (ARBs) in reducing albuminuria.

Effects of telmisartan on metabolic syndrome components: a comprehensive review

Telmisartan is an antagonist of the angiotensin II receptor used in the management of hypertension (alone or in combination with other antihypertensive agents. It belongs to the drug class of angiotensin II receptor blockers (ARBs). Among drugs of this class, telmisartan shows particular pharmacologic properties, including a longer half-life than any other angiotensin II receptor blockers that bring higher and persistent antihypertensive activity. In hypertensive patients, telmisartan has superior efficacy than other antihypertensive drugs (losartan, valsartan, ramipril, atenolol, and perindopril) in controlling blood pressure, especially towards the end of the dosing interval. Telmisartan has a partial PPARγ-agonistic effect whilst does not have the safety concerns of full agonists of PPARγ receptors (thiazolidinediones). Moreover, telmisartan has an agonist activity on PPARα and PPARδ receptors and modulates the adipokine levels. Thus, telmisartan could be considered as a suitable alternative option, with multi-benefit for all components of metabolic syndrome including hypertension, diabetes mellitus, obesity, and hyperlipidemia. This review will highlight the role of telmisartan in metabolic syndrome and the main mechanisms of action of telmisartan are discussed and summarized. Many studies have demonstrated the useful properties of telmisartan in the prevention and improving of metabolic syndrome and this well-tolerated drug can be greatly proposed in the treatment of different components of metabolic syndrome. However, larger and long-duration studies are needed to confirm these findings in long-term observational studies and prospective trials and to determine the optimum dose of telmisartan in metabolic syndrome.

Immunomodulation and immunopharmacology in heart failure

The immune system is intimately involved in the pathophysiology of heart failure. However, it is currently underused as a therapeutic target in the clinical setting. Moreover, the development of novel immunomodulatory therapies and their investigation for the treatment of patients with heart failure are hampered by the fact that currently used, evidence-based treatments for heart failure exert multiple immunomodulatory effects. In this Review, we discuss current knowledge on how evidence-based treatments for heart failure affect the immune system in addition to their primary mechanism of action, both to inform practising physicians about these pleiotropic actions and to create a framework for the development and application of future immunomodulatory therapies. We also delineate which subpopulations of patients with heart failure might benefit from immunomodulatory treatments. Furthermore, we summarize completed and ongoing clinical trials that assess immunomodulatory treatments in heart failure and present several therapeutic targets that could be investigated in the future. Lastly, we provide future directions to leverage the immunomodulatory potential of existing treatments and to foster the investigation of novel immunomodulatory therapeutics.

Mycobacterium tuberculosis grows linearly at the single-cell level with larger variability than model organisms

The ability of bacterial pathogens to regulate growth is crucial to control homeostasis, virulence, and drug response. Yet, we do not understand the growth and cell cycle behaviors of Mycobacterium tuberculosis (Mtb), a slow-growing pathogen, at the single-cell level. Here, we use time-lapse imaging and mathematical modeling to characterize these fundamental properties of Mtb. Whereas most organisms grow exponentially at the single-cell level, we find that Mtb exhibits a unique linear growth mode. Mtb growth characteristics are highly variable from cell-to-cell, notably in their growth speeds, cell cycle timing, and cell sizes. Together, our study demonstrates that growth behavior of Mtb diverges from what we have learned from model bacteria. Instead, Mtb generates a heterogeneous population while growing slowly and linearly. Our study provides a new level of detail into how Mtb grows and creates heterogeneity, and motivates more studies of growth behaviors in bacterial pathogens.

Malnutrition, anaemia and anisocytosis as public health problems among children ≤ 5 years living in malaria perennial transmission areas of Mount Cameroon: a cross sectional study

BACKGROUND

Anaemia, anisocytosis, malnutrition (especially stunting) are common health problems in developing countries with children being the most vulnerable. These conditions have negative impacts on human performance, growth and development, and can further be complicated if comorbidity exists within a holoendemic stratum with strong and perennial malaria parasite transmission such as the Mount Cameroon area. The study aimed at determining the prevalence and severity malnutrition, anaemia and anisocytosis in children ≤ 5 years, living in the conflict hit malaria perennial transmission zone of the Mount Cameroon area.

METHOD

A cross-sectional community-based survey involving 628 children ≤ 5 years was conducted. Malaria parasitaemia was confirmed by Giemsa-stained microscopy and the density was log transformed. Haemoglobin (Hb), mean cell volume and red blood cell distribution width were estimated using an auto-haematology analyser and defined according to WHO standards. Anthropometric indices were analysed and compared with WHO growth reference standards using WHO Anthro software.

RESULTS

Plasmodium infection, anaemia, microcytic anaemia, anisocytosis and stunting were prevalent in 36.0, 72.8, 30.1, 54.1 and 29.0% of the children, respectively. The ≤ 24 months children were more moderately stunted (14.7%), with higher prevalence of microcytic anaemia (38.8%) and anisocytosis (68.8%) (P < 0.002 and P < 0.001, respectively) when compared with the older children. The mean Hb level in the study population was 10.04 g/dL with children ≤ 24 months having the least mean haemoglobin level (9.69 g/dL) when compared with their older counterparts at P < 0.001. The odds of having anisocytosis were highest among children who were malnourished (OR = 4.66, P = 0.005), those infected with malaria parasites (OR = 1.85, P = 0.007), and whose parents had a primary (OR = 3.51, P = 0.002) and secondary levels of education (OR = 2.69, P = 0.017).

CONCLUSION

Malaria, anaemia, anisocytosis and undernutrition still remain severe public health concerns among children ≤ 60 months in the Mount Cameroon area. This therefore emphasizes the need for the implementation of consistent policies, programmes and activities to avoid malaria, anaemia, anisocytosis and stunting in the paediatric age group.

The immunomodulatory effects of antihypertensive therapy: A review

Hypertension remains the leading preventable risk factor for stroke and coronary artery disease, significantly contributing to all-cause global mortality and predisposing patients to renal and heart failure, as well as peripheral vascular disease. Due to the widespread usage of antihypertensive drugs, global mean blood pressure has remained unchanged or even slightly decreased over the past four decades. However, considering the broad spectrum of mechanisms involved in the action of antihypertensive drugs and the prevalence of their target receptors on immune cells, possible immunomodulatory effects which may exert beneficial effects of lowering blood pressure but also potentially alter immune function should be considered. In this review, we attempt to assess the consequences to immune system function of administering the five most commonly prescribed groups of antihypertensive drugs and to explain the mechanisms behind those interactions. Finally, we show potential gaps in our understanding of the effects of antihypertensive drugs on patient health. With regard to the widespread use of these drugs in the adult population worldwide, the discussed results may be of vital importance to evidence-based decision-making in daily clinical practice.

Irbesartan, an angiotensin II type 1 receptor blocker, inhibits colitis-associated tumourigenesis by blocking the MCP-1/CCR2 pathway

The introduction of anti-inflammatory therapies has enabled substantial improvement of disease activity in patients with inflammatory bowel diseases (IBD). However, IBD can lead to serious complications such as intestinal fibrosis and colorectal cancer. Therefore, novel therapies reducing the development of these complications are needed. Angiotensin II (Ang II) promotes tissue inflammation by stimulating the production of monocyte chemoattractant protein-1 (MCP-1) or proinflammatory cytokines. It plays a pivotal role in IBD progression. Although blockade of Ang II has been reported to ameliorate experimental colitis and reduce colorectal cancer risk, the cellular and molecular mechanisms remain poorly understood. Our previous work showed that irbesartan, an Ang II type 1 receptor blocker, reduced the number of C-C chemokine receptor 2-positive (CCR2+) monocytic cells in the inflamed pancreas. This study aimed to investigate the possible antifibrotic and antitumour effects of irbesartan using the azoxymethane/dextran sodium sulphate mouse model. Irbesartan suppressed MCP-1 production and the accumulation of Ly6C+CCR2+ monocytes and fibrocytes in the inflamed colon, downregulated the expression of type 1 collagen and matrix metalloproteinase 9 and inhibited the development of intestinal fibrosis and tumours. Our observations suggest that blocking the MCP-1/CCR2 pathway using irbesartan might be beneficial in preventing colitis-associated colon tumours.

The inhibitory mechanisms of losartan and vitamin D on amiodarone-induced lung inflammation in rats: Role of mitogen-activated protein kinases/activator protein-1

Amiodarone (AMD), an antiarrhythmic drug, is used cautiously due to its lung toxicity that is characterized by alveolar inflammation followed by fatal fibrosis. AMD induces lung inflammation via increasing the alveolar macrophages and disturbing the balance of T-helper-1 (Th1) and Th2 cells cytokines. In this study, the role of the mitogen-activated protein kinases (MAPKs)/activator protein-1 (AP-1) pathway in AMD-induced lung inflammation was evaluated. Also, the anti-inflammatory and antifibrotic effects of losartan and/or vitamin D were investigated following 7, 14, and 28 days of AMD administration. AMD resulted in lung injury, inflammatory infiltration, and increased pulmonary levels of inflammatory cytokines starting from Week 1 of exposure. A significant increase in serum levels of interleukin-4 along with a significant reduction of interferon-gamma, in addition to strong expression of CD68, were reported after 14 and 28 days of AMD administration reflecting Th1/Th2 cytokines imbalance and the accumulation of alveolar macrophages, respectively. The phosphorylation of MAPKs (ERK1/2, JNK, p38) and AP-1 was significantly enhanced starting from Week 1 of exposure. Marked expression of transforming growth factor beta-1 and massive deposition of collagen were detected after 28 days reflecting late fibrosis. All these abnormalities were significantly mitigated by vitamin D and its combination with losartan. Losartan alone has less prominent anti-inflammatory effects particularly after 28 days; however, it efficiently prevented late fibrosis. This study concludes that MAPKs/AP-1 pathway is involved in AMD-induced lung inflammation and that vitamin D and/or losartan could be used as a prophylactic agent to prevent AMD-induced lung toxicity.

CoRNeA: A Pipeline to Decrypt the Inter-Protein Interfaces from Amino Acid Sequence Information

Decrypting the interface residues of the protein complexes provides insight into the functions of the proteins and, hence, the overall cellular machinery. Computational methods have been devised in the past to predict the interface residues using amino acid sequence information, but all these methods have been majorly applied to predict for prokaryotic protein complexes. Since the composition and rate of evolution of the primary sequence is different between prokaryotes and eukaryotes, it is important to develop a method specifically for eukaryotic complexes. Here, we report a new hybrid pipeline for predicting the protein-protein interaction interfaces in a pairwise manner from the amino acid sequence information of the interacting proteins. It is based on the framework of Co-evolution, machine learning (Random Forest), and Network Analysis named CoRNeA trained specifically on eukaryotic protein complexes. We use Co-evolution, physicochemical properties, and contact potential as major group of features to train the Random Forest classifier. We also incorporate the intra-contact information of the individual proteins to eliminate false positives from the predictions keeping in mind that the amino acid sequence of a protein also holds information for its own folding and not only the interface propensities. Our prediction on example datasets shows that CoRNeA not only enhances the prediction of true interface residues but also reduces false positive rates significantly.

Telmisartan Protects Auditory Hair Cells from Gentamicin-Induced Toxicity in vitro

BACKGROUND

Telmisartan is an angiotensin II receptor blocker that has pleiotropic effects and protective properties in different cell types. Moreover, telmisartan has also shown partial agonism on the peroxisome proliferator-activated receptor γ (PPAR-γ). Auditory hair cells (HCs) express PPAR-γ, and the protective role of PPAR-γ agonists on HCs has been shown.

OBJECTIVES

The objective of this study was to investigate the effects of telmisartan on gentamicin-induced ototoxicity in vitro.

METHODS

Cochlear explants were exposed to gentamicin with or without telmisartan, and/or GW9662, an irreversible PPAR-γ antagonist.

RESULTS

Telmisartan protected auditory HCs against gentamicin-induced ototoxicity. GW9662 completely blocked this protective effect, suggesting that it was mediated by PPAR-γ signaling. Exposure to GW9662 or telmisartan alone was not toxic to auditory HCs.

CONCLUSIONS

We found that telmisartan, via PPAR-γ signaling, protects auditory HCs from gentamicin-induced ototoxicity. Therefore, telmisartan could potentially be used in the future to prevent or treat sensorineural hearing loss.

Comparative Effects of Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers on Response to a Physical Activity Intervention in Older Adults: Results From the Lifestyle Interventions and Independence for Elders Study

BACKGROUND

Angiotensin-converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) may protect against aging-related decline. This study directly compared ACEis and ARBs on associations with risk of mobility disability in older adults when combined with a physical activity intervention.

METHODS

This was a secondary analysis of the Lifestyle Interventions and Independence for Elders (LIFE) trial. Participants aged 70-89 years were randomized to a physical activity or health education intervention. Outcomes included incident and persistent major mobility disability, injurious falls, short physical performance battery, and gait speed. For this analysis, only participants who reported ACEi or ARB use at baseline were included. Baseline differences between ACEi and ARB groups were adjusted for using inverse probability of treatment weights. Weighted Cox proportional hazard models and analysis of covariance models were used to evaluate the independent effects of medications and interaction effects with the intervention on each outcome.

RESULTS

Of 1,635 participants in the Lifestyle Interventions and Independence for Elders study, 796 used either an ACEi (496, 62.3%) or ARB (300, 37.7%). Compared with ACEi users, ARB users had 28% lower risk (hazard ratio [HR] = 0.72 [0.60-0.85]) of incident major mobility disability and 35% (HR = 0.65 [0.52-0.82]) lower risk of persistent major mobility disability whereas no interaction between medication use and intervention was observed. Risk of injurious falls and changes in short physical performance battery or gait speed were not different between ARB and ACEi users.

CONCLUSIONS

These results suggest that ARBs may protect from major mobility disability by other mechanisms than improving physical performance.

Infiltrating CCR2+ monocytes and their progenies, fibrocytes, contribute to colon fibrosis by inhibiting collagen degradation through the production of TIMP-1

Intestinal fibrosis is a serious complication in inflammatory bowel disease (IBD). Despite the remarkable success of recent anti-inflammatory therapies for IBD, incidence of intestinal fibrosis and need for bowel resection have not significantly changed. To clarify the contribution of haematopoietic-derived cells in intestinal fibrosis, we prepared bone marrow (BM) chimeric mice (chimeras), which were reconstituted with BM cells derived from enhanced green fluorescent protein (EGFP)-transgenic mice or CC chemokine receptor 2 (CCR2)-deficient mice. After 2 months of transplantation, BM chimeras were treated with azoxymethane/dextran sodium sulphate. During chronic inflammation, CCR2⁺ BM-derived monocyte and fibrocyte infiltration into the colon and CC chemokine ligand 2 production increased, leading to colon fibrosis in EGFP BM chimeras. In CCR2-deficient BM chimeras, monocyte and fibrocyte numbers in the colonic lamina propria significantly decreased, and colon fibrosis was attenuated. In colon tissue, mRNA expression of tissue inhibitor of metalloproteinase (TIMP)-1 but not of collagen I, transforming growth factor-β1 or matrix metalloproteinases was significantly different between the two chimeras. CCR2⁺ monocytes and fibrocytes showed high Timp1 mRNA expression. Our results suggest that infiltrating CCR2⁺ monocytes and their progenies, fibrocytes, promote colon fibrosis by inhibiting collagen degradation through TIMP-1 production.

The Angiotensin Receptor Blocker Losartan Suppresses Growth of Pulmonary Metastases via AT1R-Independent Inhibition of CCR2 Signaling and Monocyte Recruitment

Inflammatory monocytes have been shown to play key roles in cancer metastasis through promotion of tumor cell extravasation, growth, and angiogenesis. Monocyte recruitment to metastases is mediated primarily via the CCL2-CCR2 chemotactic axis. Thus, disruption of this axis represents an attractive therapeutic target for the treatment of metastatic disease. Losartan, a type I angiotensin II receptor (AT1R) antagonist, has been previously shown to have immunomodulatory actions involving monocyte and macrophage activity. However, the exact mechanisms accounting for these effects have not been fully elucidated. Therefore, we investigated the effects of losartan and its primary metabolite on CCL2-mediated monocyte recruitment and CCR2 receptor function using mouse tumor models and in vitro human monocyte cultures. We show, in this study, that losartan and its metabolite potently inhibit monocyte recruitment through the noncompetitive inhibition of CCL2-induced ERK1/2 activation, independent of AT1R activity. Studies in experimental metastasis models demonstrated that losartan treatment significantly reduced the metastatic burden in mice, an effect associated with a significant decrease in CD11b⁺/Ly6C⁺-recruited monocytes in the lungs. Collectively, these results indicate that losartan can exert antimetastatic activity by inhibiting CCR2 signaling and suppressing monocyte recruitment and therefore suggest that losartan (and potentially other AT1R blocker drugs) could be repurposed for use in cancer immunotherapy.

Recent advances in the treatment of pathogenic infections using antibiotics and nano-drug delivery vehicles

The worldwide misuse of antibiotics and the subsequent rise of multidrug-resistant pathogenic bacteria have prompted a paradigm shift in the established view of antibiotic and bacterial-human relations. The clinical failures of conventional antibiotic therapies are associated with lengthy detection methods, poor penetration at infection sites, disruption of indigenous microflora and high potential for mutational resistance. One of the most promising strategies to improve the efficacy of antibiotics is to complex them with micro or nano delivery materials. Such materials/vehicles can shield antibiotics from enzyme deactivation, increasing the therapeutic effectiveness of the drug. Alternatively, drug-free nanomaterials that do not kill the pathogen but target virulent factors such as adhesins, toxins, or secretory systems can be used to minimize resistance and infection severity. The main objective of this review is to examine the potential of the aforementioned materials in the detection and treatment of antibiotic-resistant pathogenic organisms.

Vitamin D Deficiency Is Highly Prevalent in Critically Ill Patients and a Risk Factor for Mortality: A Prospective Observational Study Comparing Noncirrhotic Patients and Patients With Cirrhosis

INTRODUCTION

A 25-hydroxyvitamin D, 25(OH)D, deficiency is common among critically ill patients and correlated with increased mortality. Furthermore, deficiency is associated with advanced liver disease. However, there are no studies available comparing the dimensions and consequences of a 25(OH)D deficiency between patients with and without liver cirrhosis in the setting of intensive care units (ICUs). This study focuses on differences in 25(OH)D status between critically ill noncirrhosis patients and patients with cirrhosis (primary end point), hypothesizing that deficiency and its impact on mortality risk are even more pronounced in patients with cirrhosis.

METHODS

We performed a prospective observational study of 176 patients (noncirrhosis patients, N = 114; patients with cirrhosis, N = 62) with a laboratory assessment of 25(OH)D on ICU admission and survival analyses after 180 days.

RESULTS

On admission, 55% of patients showed a severe deficiency, 25(OH)D <10 ng/mL, and a further 23% moderate deficiency (10-19 ng/mL). The overall median level of 25(OH)D was 8.0 (5.0-18.0) ng/mL (10.5 [6.0-21.3] in noncirrhosis patients vs 7.0 [4.8-10.0] in patients with cirrhosis; P < .001). We found extremely low levels particularly in patients without prior vitamin D supplementation (6.0 [4.0-7.5] in patients with cirrhosis vs 8.0 [5.0-12.0] ng/mL in noncirrhosis patients; P = .004). Vitamin D status correlated inversely with the sequential organ failure assessment, acute and physiology chronic health evaluation, model of end-stage liver disease, and Child-Pugh scores. Survival analyses categorized 25(OH)D levels <10 ng/mL as a high-risk factor for mortality 180 days after admission (hazard ratio [HR]: 2.45, 95% confidence interval [CI] = 1.60-3.70; P < .001). In patients with cirrhosis, a severe deficiency (<10 ng/mL) involved a significantly higher mortality risk than in noncirrhosis patients (HR: 2.30, 95% CI = 1.39-3.82; P = .001). In cases of admission levels ≥10 ng/mL, however, mortality risk was similar between patients with cirrhosis and noncirrhosis patients (HR: 1.08, 95% CI = 0.43-2.73; P = .873).

CONCLUSIONS

Hypovitaminosis D is a highly frequent disorder in critically ill patients admitted to ICU. A severe deficiency with levels <10 ng/mL is a high risk factor for increased mortality, especially in patients with cirrhosis.

System pharmacogenomics application in infectious diseases

The new era in systems pharmacology has revolutionized the human biology. Its applicability, precise treatment, adequate response and safety measures fit into all the paradigm of medical/clinical practice. The importance of mathematical models in understanding the disease pathology and epideomology is now being realized. The advent of high-throughput technologies and the emergence of systems biology have resulted in the creation of systems pharmacogenomics and the focus is now on personalized medicine. However, there are some regulatory issues that need to be addresssed; are we ready for this universal adoption? This article details some of the infectious disease pharmacogenomics to the developments in this area.

Inhibitory Effects of Angiotensin II Receptor Blockade on Human Tenon Fibroblast Migration and Reactive Oxygen Species Production in Cell Culture

Purpose

We investigate the effect of angiotensin receptor blockade on the migration of human Tenon fibroblasts (HTF), using irbesartan, an angiotensin II receptor type 1 (AT1R) blocker (ARB) as a potential antifibrotic agent in glaucoma filtration surgery.

Methods

Confluent HTF cultures were scratched with a 1 mL pipette tip and treated with either irbesartan (10, 50, and 100 μg/mL) or angiotensin II (2 μg/mL). The extent of HTF migration up to 30 hours, and cell number and morphology at 72 hours was evaluated. To assess the effect on reactive oxygen species (ROS) level, HTF were treated with either irbesartan (10 μg/mL) or angiotensin II (2 μg/mL) for 24 hours after scratching, and then stained with dihydroethidium (DHE) before evaluation by confocal microscopy.

Results

Irbesartan inhibited HTF migration by 50% to 70% compared to controls (P < 0.05). Levels of ROS were almost completely attenuated by irbesartan (DHE fluorescence intensity of 5.68E-09) (P < 0.05). Irbesartan reduced cell numbers by 50% and induced morphologic changes with loss of pseudopods (P < 0.05). Conversely, angiotensin II increased cell numbers up to 4-fold while retaining cell viability.

Conclusions

Irbesartan inhibited HTF migration and ROS production. It also reduced cell numbers and altered HTF morphology. Angiotensin II increased cell number without altering morphology. This initial study warrants future investigations for further potential antifibrotic effects of this drug.

Translational Relevance

This in vitro study focused on investigations of irbesartan's effects on HTF migration, ROS production, as well as HTF cell numbers and morphology. It suggests a potential therapeutic strategy worth further exploration with a view towards postoperative wound healing modulation in glaucoma filtration surgery.

A Meta-analysis of antihypertensive effect of telmisartan versus candesartan in patients with essential hypertension

OBJECTIVE

The comparison of antihypertensive effects between telmisartan and candesartan in patients with essential hypertension has been investigated in several small studies. The results were not consistent. We performed this meta-analysis determining the antihypertensive effect of telmisartan versus candesartan in these patients.

METHODS

We searched Pubmed, Web of Science, and Cochrane Central for all published studies comparing the antihypertensive effects between telmisartan and candesartan in patients with essential hypertension.

RESULTS

The antihypertensive effects were assessed in 302 patients included in 4 trials with a mean follow-up of 10 ± 4 weeks. There were no significant differences between telmisartan and candesartan in reduction of systolic blood pressure (SBP) and diastolic BP (DBP) in patients with essential hypertension (weighted mean differences (WMD) for SBP 1.98 mm Hg (95% confidence interval (CI), -0.53, 4.49), p > 0.05; WMD for DBP 0.26 mm Hg (95% CI, -1.65, 2.16), p > 0.05), respectively. In a sub-analysis including 2 randomized studies, there was not a significant difference for the reduction of SBP (WMD 0.90 (95% CI, -2.88, 4.68) mm Hg, p > 0.05) or DBP (WMD -0.80 (95% CI, -3.40, 1.81) mm Hg, p > 0.05) treated with telmisartan or candesartan.

CONCLUSIONS

This meta-analysis provides the evidence that the antihypertensive effects of telmisartan and candesartan are similar on SBP and DBP reduction in patients with essential hypertension, suggesting that strict designed randomized controlled trial would be helpful to compare antihypertensive effects of angiotensin II receptor blockers (ARBs) and improve the choice of ARBs in antihypertensive therapy.

Use of olmesartan and enteropathy outcomes: a multi-database study

BACKGROUND

Multiple case reports suggest that olmesartan may be linked to sprue-like enteropathy; however, few epidemiological studies have examined this association and results have been mixed.

AIM

To assess whether olmesartan is associated with a higher rate of enteropathy vs other angiotensin II receptor blockers (ARBs).

METHODS

We conducted a cohort study among ARB initiators in 5 US claims databases representing different health insurance programmes. Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for enteropathy-related outcomes, including coeliac disease, malabsorption, concomitant diagnoses of diarrhoea and weight loss, and non-infectious enteropathy, comparing olmesartan initiators to initiators of other ARBs after propensity score (PS) matching.

RESULTS

We identified 1 928 469 eligible patients. The unadjusted incidence rates were 0.82, 1.41, 1.66 and 29.20 per 1000 person-years for coeliac disease, malabsorption, concomitant diagnoses of diarrhoea and weight loss, and non-infectious enteropathy respectively. HRs after PS matching comparing olmesartan to other ARBs were 1.21 (95% CI, 1.05-1.40), 1.00 (95% CI, 0.88-1.13), 1.22 (95% CI, 1.10-1.36) and 1.04 (95% CI, 1.01-1.07) for each outcome. HRs were larger for patients aged 65 years and older (eg for coeliac disease, 1.57 [95% CI, 1.20-2.05]), for patients receiving treatment for more than 1 year (1.62 [95% CI, 1.24-2.12]), and for patients receiving higher cumulative olmesartan doses (1.78 [95% CI, 1.33-2.37]).

CONCLUSIONS

This large-scale, multi-database study found a higher rate of enteropathy in olmesartan initiators as compared to initiators of other ARBs, although the absolute incidence rate was low in both groups.

Antimicrobial peptides as an alternative to anti-tuberculosis drugs

Tuberculosis (TB) presently accounts for high global mortality and morbidity rates, despite the introduction four decades ago of the affordable and efficient four-drugs (isoniazid, rifampicin, pyrazinamide and ethambutol). Thus, a strong need exists for new drugs with special structures and uncommon modes of action to effectively overcome M. tuberculosis. Within this scope, antimicrobial peptides (AMPs), which are small, cationic and amphipathic peptides that comprise a section of the innate immune system, are currently the leading potential agents for the treatment of TB. Many studies have recently illustrated the capability of anti-mycobacterial peptides to disrupt the normal mycobacterial cell wall function through various modes, thereby interacting with the intracellular targets, as well as encompassing nucleic acids, enzymes and organelles. This review presents a wide array of antimicrobial activities, alongside the associated properties of the AMPs that could be utilized as potential agents in therapeutic tactics for TB treatment.

Effects of captopril, telmisartan and bardoxolone methyl (CDDO-Me) in ischemia-reperfusion-induced acute kidney injury in rats: an experimental comparative study

Renal ischemia-reperfusion (IR) injury is one of the most common causes of acute kidney injury. This study investigated the effects of captopril (CAP), telmisartan (TEL) and bardoxolone methyl (BM) in animals with renal IR injury. Adult male Wistar-Albino rats were divided into six groups: control, vehicle, IR, IR with CAP, IR with TEL and IR with BM. Before IR was induced, drugs were administered by oral gavage. After a 60-min ischemia and a 120-min reperfusion period, bilateral nephrectomies were performed. Serum urea, creatinine, neutrophil gelatinase-associated lipocalin (NGAL) levels, tissue total oxidant status (TOS), total antioxidant status (TAS), total thiol (TT), asymmetric dimethylarginine (ADMA) levels, superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-Px) activity were measured. Tissue mRNA expression levels of peroxisome proliferator-activated receptor-ɣ (PPAR-ɣ), nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) were analyzed. In addition, renal tissues were evaluated histopathologically and immunohistochemically. All tested drugs reduced renal damage, apoptosis, urea, creatinine, NGAL, TOS, nitric oxide (NO) and ADMA levels, NF-κB, inducible nitric oxide synthase (iNOS) and endothelin-1 (ET-1) expressions (P < 0.001). All tested drugs increased SOD activity, GSH-Px activity, TAS levels, TT levels, endothelial nitric oxide synthase (eNOS) expression, dimethylarginine dimethylaminohydrolases (DDAHs) expression, Nrf2 expression and PPAR-ɣ expression (P < 0.001, P < 0.003). These results suggest that CAP, TEL and BM pretreatment could reduce renal IR injury via anti-inflammatory, antioxidant and anti-apoptotic effects.

Ribosome biogenesis in replicating cells: Integration of experiment and theory

Ribosomes-the primary macromolecular machines responsible for translating the genetic code into proteins-are complexes of precisely folded RNA and proteins. The ways in which their production and assembly are managed by the living cell is of deep biological importance. Here we extend a recent spatially resolved whole-cell model of ribosome biogenesis in a fixed volume [Earnest et al., Biophys J 2015, 109, 1117-1135] to include the effects of growth, DNA replication, and cell division. All biological processes are described in terms of reaction-diffusion master equations and solved stochastically using the Lattice Microbes simulation software. In order to determine the replication parameters, we construct and analyze a series of Escherichia coli strains with fluorescently labeled genes distributed evenly throughout their chromosomes. By measuring these cells' lengths and number of gene copies at the single-cell level, we could fit a statistical model of the initiation and duration of chromosome replication. We found that for our slow-growing (120 min doubling time) E. coli cells, replication was initiated 42 min into the cell cycle and completed after an additional 42 min. While simulations of the biogenesis model produce the correct ribosome and mRNA counts over the cell cycle, the kinetic parameters for transcription and degradation are lower than anticipated from a recent analytical time dependent model of in vivo mRNA production. Describing expression in terms of a simple chemical master equation, we show that the discrepancies are due to the lack of nonribosomal genes in the extended biogenesis model which effects the competition of mRNA for ribosome binding, and suggest corrections to parameters to be used in the whole-cell model when modeling expression of the entire transcriptome. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 735-751, 2016.

Angiotensin II type 1 receptor antagonists in animal models of vascular, cardiac, metabolic and renal disease

We have reviewed the effects of angiotensin II type 1 receptor antagonists (ARBs) in various animal models of hypertension, atherosclerosis, cardiac function, hypertrophy and fibrosis, glucose and lipid metabolism, and renal function and morphology. Those of azilsartan and telmisartan have been included comprehensively whereas those of other ARBs have been included systematically but without intention of completeness. ARBs as a class lower blood pressure in established hypertension and prevent hypertension development in all applicable animal models except those with a markedly suppressed renin-angiotensin system; blood pressure lowering even persists for a considerable time after discontinuation of treatment. This translates into a reduced mortality, particularly in models exhibiting marked hypertension. The retrieved data on vascular, cardiac and renal function and morphology as well as on glucose and lipid metabolism are discussed to address three main questions: 1. Can ARB effects on blood vessels, heart, kidney and metabolic function be explained by blood pressure lowering alone or are they additionally directly related to blockade of the renin-angiotensin system? 2. Are they shared by other inhibitors of the renin-angiotensin system, e.g. angiotensin converting enzyme inhibitors? 3. Are some effects specific for one or more compounds within the ARB class? Taken together these data profile ARBs as a drug class with unique properties that have beneficial effects far beyond those on blood pressure reduction and, in some cases distinct from those of angiotensin converting enzyme inhibitors. The clinical relevance of angiotensin receptor-independent effects of some ARBs remains to be determined.

Potential coeliac disease markers and autoimmunity in olmesartan induced enteropathy: A population-based study

AIMS

(1) Assess the population-based incidence of severe olmesartan-associated enteropathy. (2) To describe patients of the Spanish registry. (3) Evaluate markers of potential coeliac disease and associated autoimmunity.

METHODS

Crude incidence rates in the area of Terrassa (Catalonia) were calculated. Clinical characteristics of patients in the Spanish registry were collected. Duodenal lymphocyte subpopulations and anti-TG2 IgA deposits were assessed in a subset of patients.

RESULTS

Annual incidence rates (2011-2014) ranged from 0 to 22 cases per 10(4) treated patients. Twenty patients were included in the Spanish registry. Nineteen (95%) exhibited villous atrophy and 16 (80%) had severe enteropathy. Lupus-like disease occurred during olmesartan treatment in 3 patients. HLA-DQ2/DQ8 was positive in 64%. Markers of potential coeliac disease were present in 4 out of 8 patients (positive anti-TG2 deposits and/or increased CD3+gammadelta+ intraepithelial lymphocytes and reduced CD3-). Histopathological changes and clinical manifestations including autoimmune disorders improved after olmesartan discontinuation but not after gluten-free diet, irrespective of the presence or absence of coeliac markers.

CONCLUSIONS

Incidence of severe olmesartan-associated enteropathy was low. Autoimmune phenomena were present in a subset of cases and reversed after olmesartan removal. A genetic coeliac disease background and the presence of potential coeliac markers might uncover predisposing factors.

A Dormant Microbial Component in the Development of Preeclampsia

Preeclampsia (PE) is a complex, multisystem disorder that remains a leading cause of morbidity and mortality in pregnancy. Four main classes of dysregulation accompany PE and are widely considered to contribute to its severity. These are abnormal trophoblast invasion of the placenta, anti-angiogenic responses, oxidative stress, and inflammation. What is lacking, however, is an explanation of how these themselves are caused. We here develop the unifying idea, and the considerable evidence for it, that the originating cause of PE (and of the four classes of dysregulation) is, in fact, microbial infection, that most such microbes are dormant and hence resist detection by conventional (replication-dependent) microbiology, and that by occasional resuscitation and growth it is they that are responsible for all the observable sequelae, including the continuing, chronic inflammation. In particular, bacterial products such as lipopolysaccharide (LPS), also known as endotoxin, are well known as highly inflammagenic and stimulate an innate (and possibly trained) immune response that exacerbates the inflammation further. The known need of microbes for free iron can explain the iron dysregulation that accompanies PE. We describe the main routes of infection (gut, oral, and urinary tract infection) and the regularly observed presence of microbes in placental and other tissues in PE. Every known proteomic biomarker of "preeclampsia" that we assessed has, in fact, also been shown to be raised in response to infection. An infectious component to PE fulfills the Bradford Hill criteria for ascribing a disease to an environmental cause and suggests a number of treatments, some of which have, in fact, been shown to be successful. PE was classically referred to as endotoxemia or toxemia of pregnancy, and it is ironic that it seems that LPS and other microbial endotoxins really are involved. Overall, the recognition of an infectious component in the etiology of PE mirrors that for ulcers and other diseases that were previously considered to lack one.

AT1R blockade in adverse milieus: role of SMRT and corepressor complexes

ANG II type 1 receptor blockade (AT1R-BLK) is used extensively to slow down the progression of proteinuric kidney diseases. We hypothesized that AT1R-BLK provides podocyte protection through regulation of silencing mediator of retinoic acid and thyroid hormone receptor (SMRT) and vitamin D receptor (VDR) expression under adverse milieus such as high glucose and human immunodeficiency virus infection. Both AT1R-BLK and VDR agonists (VDAs) stimulated VDR complex formation that differed not only in their composition but also in their functionality. AT1R-BLK-induced VDR complexes contained predominantly unliganded VDR, SMRT, and phosphorylated histone deacetylase 3, whereas VDA-VDR complexes were constituted by liganded VDR and CREB-binding protein/p300. AT1R-BLK-induced complexes attenuated podocyte acetyl-histone 3 levels as well as cytochrome P-450 family 24A1 expression, thus indicating their deacetylating and repressive properties. On the other hand, VDA-VDR complexes not only increased podocyte acetyl-histone 3 levels but also enhanced cytochrome P-450 family 24A1 expression, thus suggesting their acetylating and gene activation properties. AT1R-BLK- induced podocyte SMRT inhibited expression of the proapoptotic gene BAX through downregulation of Wip1 and phosphorylation of checkpoint kinase 2 in high-glucose milieu. Since SMRT-depleted podocytes lacked AT1R-BLK-mediated protection against DNA damage, it appears that SMRT is necessary for DNA repairs during AT1R-BLK. We conclude that AT1R-BLK provides podocyte protection in adverse milieus predominantly through SMRT expression and partly through unliganded VDR expression in 1,25(OH)2D-deficient states; on the other hand, AT1R-BLK contributes to liganded VDR expression in 1,25(OH)2D-sufficient states.

Inflammation and vitamin D: the infection connection

INTRODUCTION

Inflammation is believed to be a contributing factor to many chronic diseases. The influence of vitamin D deficiency on inflammation is being explored but studies have not demonstrated a causative effect.

METHODS

Low serum 25(OH)D is also found in healthy persons exposed to adequate sunlight. Despite increased vitamin D supplementation inflammatory diseases are increasing. The current method of determining vitamin D status may be at fault. The level of 25(OH)D does not always reflect the level of 1,25(OH)2D. Assessment of both metabolites often reveals elevated 1,25(OH)2D, indicating abnormal vitamin D endocrine function.

FINDINGS

This article reviews vitamin D's influence on the immune system, examines the myths regarding vitamin D photosynthesis, discusses ways to accurately assess vitamin D status, describes the risks of supplementation, explains the effect of persistent infection on vitamin D metabolism and presents a novel immunotherapy which provides evidence of an infection connection to inflammation.

CONCLUSION

Some authorities now believe that low 25(OH)D is a consequence of chronic inflammation rather than the cause. Research points to a bacterial etiology pathogenesis for an inflammatory disease process which results in high 1,25(OH)2D and low 25(OH)D. Immunotherapy, directed at eradicating persistent intracellular pathogens, corrects dysregulated vitamin D metabolism and resolves inflammatory symptoms.

Investigation of the effect of telmisartan on experimentally induced peripheral nerve injury in rats

AIM

The aim of this study was to investigate the effects of telmisartan on nerve healing in a rat peripheral nerve injury model.

MATERIAL AND METHOD

Thirty adult male Wistar albino rats were divided into five groups: healthy, axonotmesis, anastomosis, axonotmesis+10 mg/kg telmisartan and anastomosis+10 mg/kg telmisartan. Walking track analyses were performed 4 weeks after the surgery. The right sciatic nerves of all the animals were examined histopathologically, stereologically and molecularly.

RESULTS

Many badly damaged axons were detected in the axonotmesis group, in addition to enlarged spaces between the axons. In the anastomosis group, both ir- regular and degenerated axons at different severities were observed. The sections of the telmisartan group after the axonotmesis were similar to those of the healthy group. The sections of the telmisartan group after the anastomosis were similar to those of the healthy group and the telmisartan group after the axonotmesis. Interleukin-1 beta (IL-1β) gene expression increased in both the axonotmesis and the anastomosis groups when compared with the healthy group. Telmisartan had a significant down-regulatory effect on IL-1β expression. Caspase-3 mRNA expression was significantly increased in the anastomosis group, and the administration of telmisartan in this group significantly decreased this rise in caspase-3 mRNA expression. As a functional outcome, telmisartan also increased the walking distance of the rats after axonotmesis and anastomosis.

CONCLUSION

The histopathological, stereological, functional and molecular data suggest that telmisartan improves nerve regeneration in peripheral nerve injuries by inhibiting inflammatory cytokine IL-1β and apoptotic caspase-3.

PENDISC: a simple method for constructing a mathematical model from time-series data of metabolite concentrations

The availability of large-scale datasets has led to more effort being made to understand characteristics of metabolic reaction networks. However, because the large-scale data are semi-quantitative, and may contain biological variations and/or analytical errors, it remains a challenge to construct a mathematical model with precise parameters using only these data. The present work proposes a simple method, referred to as PENDISC (arameter stimation in a on-mensionalized -system with onstraints), to assist the complex process of parameter estimation in the construction of a mathematical model for a given metabolic reaction system. The PENDISC method was evaluated using two simple mathematical models: a linear metabolic pathway model with inhibition and a branched metabolic pathway model with inhibition and activation. The results indicate that a smaller number of data points and rate constant parameters enhances the agreement between calculated values and time-series data of metabolite concentrations, and leads to faster convergence when the same initial estimates are used for the fitting. This method is also shown to be applicable to noisy time-series data and to unmeasurable metabolite concentrations in a network, and to have a potential to handle metabolome data of a relatively large-scale metabolic reaction system. Furthermore, it was applied to aspartate-derived amino acid biosynthesis in Arabidopsis thaliana plant. The result provides confirmation that the mathematical model constructed satisfactorily agrees with the time-series datasets of seven metabolite concentrations.

Effect of candesartan on the expression of sclera-choroidal intercellular adhesion molecule-1 in hypercholesterolemic models

OBJECTIVE

To evaluate the effect of blocking the angiotensin II AT-1 receptor by the systemic administration of candesartan on the expression of intercellular adhesion molecule-1 in the sclera and choroid of hypercholesterolemic rabbits.

METHODS

New Zealand rabbits were divided into 3 groups, as follows: GI, which was fed a rabbit standard diet; GII, which was fed a hypercholesterolemic diet; and GIII, which received hypercholesterolemic diet plus candesartan. Samples of the rabbits' sclera and choroid were then studied by hematoxylin-eosin staining and histomorphometric and immunohistochemical analyses for intercellular adhesion molecule-1 expression.

RESULTS

Histological analysis of hematoxylin- and eosin-stained sclera and choroid revealed that macrophages were rarely present in GI, and GII had significantly increased macrophage numbers compared to GIII. Moreover, in GII, the sclera and choroid morphometry showed a significant increase in thickness in comparison to GI and GIII. GIII presented a significant increase in thickness in relation to GI. Sclera and choroid immunohistochemical analysis for intercellular adhesion molecule-1 expression revealed a significant increase in immunoreactivity in GII in relation to GI and GIII. GIII showed a significant increase in immunoreactivity in relation to GI.

CONCLUSION

Candesartan reduced the expression of intercellular adhesion molecule-1 and consequently macrophage accumulation in the sclera and choroid of hypercholesterolemic rabbits.

Monocytes infiltrate the pancreas via the MCP-1/CCR2 pathway and differentiate into stellate cells

Recent studies have shown that monocytes possess pluripotent plasticity. We previously reported that monocytes could differentiate into hepatic stellate cells. Although stellate cells are also present in the pancreas, their origin remains unclear. An accumulation of enhanced green fluorescent protein (EGFP)⁺CD45^– cells was observed in the pancreases and livers of chimeric mice, which were transplanted with a single hematopoietic stem cell isolated from EGFP-transgenic mice and treated with carbon tetrachloride (CCl₄). Because the vast majority of EGFP⁺CD45^– cells in the pancreas expressed stellate cell-associated antigens such as vimentin, desmin, glial fibrillary acidic protein, procollagen-I, and α-smooth muscle actin, they were characterized as pancreatic stellate cells (PaSCs). EGFP⁺ PaSCs were also observed in CCl₄-treated mice adoptively transferred with monocytes but not with other cell lineages isolated from EGFP-transgenic mice. The expression of monocyte chemoattractant protein-1 (MCP-1) and angiotensin II (Ang II) increased in the pancreas of CCl₄-treated mice and their respective receptors, C-C chemokine receptor 2 (CCR2) and Ang II type 1 receptor (AT1R), were expressed on Ly6C^high monocytes isolated from EGFP-transgenic mice. We examined the effect of an AT1R antagonist, irbesartan, which is also a CCR2 antagonist, on the migration of monocytes into the pancreas. Monocytes migrated toward MCP-1 but not Ang II in vitro. Irbesartan inhibited not only their in vitro chemotaxis but also in vivo migration of adoptively transferred monocytes from peripheral blood into the pancreas. Irbesartan treatment significantly reduced the numbers of EGFP⁺F4/80⁺CCR2⁺ monocytic cells and EGFP⁺ PaSCs in the pancreas of CCl₄-treated chimeric mice receiving EGFP⁺ bone marrow cells. A specific CCR2 antagonist RS504393 inhibited the occurrence of EGFP⁺ PaSCs in injured mice. We propose that CCR2⁺ monocytes migrate into the pancreas possibly via the MCP-1/CCR2 pathway and give rise to PaSCs.

Preventive effect of irbesartan on bleomycin-induced lung injury in mice

BACKGROUND

Idiopathic pulmonary fibrosis is a specific form of chronic fibrosing interstitial pneumonia that is limited to the lung. Angiotensin receptor blockers (ARBs) and peroxisome proliferator-activated receptor (PPAR) γ ligands have anti-inflammatory and anti-fibrotic effects. We investigated the effects of irbesartan-an ARB with PPAR γ activity-on the development of bleomycin-induced pulmonary fibrosis in mice.

METHODS

Lung injury was induced in imprinting control region (ICR) mice by intratracheal instillation of 2mg/kg of bleomycin. The treatment group orally received 20mg/kg of irbesartan for 5 consecutive days before instillation. The mice were sacrificed and were evaluated 14 days after bleomycin instillation.

RESULTS

Irbesartan reduced the fluid content and hydroxyproline level in the lung and improved the pathological findings as indicated by the Ashcroft score. Total cell counts, the numbers of macrophages, neutrophils, and lymphocytes, and the levels of transforming growth factor (TGF) β1 and monocyte chemotactic protein (MCP) 1 in the bronchoalveolar lavage fluid (BALF) were decreased. Treatment with a PPARγ antagonist GW9662 reversed some of the effects of irbesartan.

CONCLUSIONS

The results of this study indicated that irbesartan attenuated the development of bleomycin-induced pulmonary fibrosis in mice by decreasing TGF-β1 and MCP-1 via blocking of ATI, by binding to CCR2b, and by PPARγ-mediated inhibition of inflammation.

Identification of a metabolic reaction network from time-series data of metabolite concentrations

Recent development of high-throughput analytical techniques has made it possible to qualitatively identify a number of metabolites simultaneously. Correlation and multivariate analyses such as principal component analysis have been widely used to analyse those data and evaluate correlations among the metabolic profiles. However, these analyses cannot simultaneously carry out identification of metabolic reaction networks and prediction of dynamic behaviour of metabolites in the networks. The present study, therefore, proposes a new approach consisting of a combination of statistical technique and mathematical modelling approach to identify and predict a probable metabolic reaction network from time-series data of metabolite concentrations and simultaneously construct its mathematical model. Firstly, regression functions are fitted to experimental data by the locally estimated scatter plot smoothing method. Secondly, the fitted result is analysed by the bivariate Granger causality test to determine which metabolites cause the change in other metabolite concentrations and remove less related metabolites. Thirdly, S-system equations are formed by using the remaining metabolites within the framework of biochemical systems theory. Finally, parameters including rate constants and kinetic orders are estimated by the Levenberg–Marquardt algorithm. The estimation is iterated by setting insignificant kinetic orders at zero, i.e., removing insignificant metabolites. Consequently, a reaction network structure is identified and its mathematical model is obtained. Our approach is validated using a generic inhibition and activation model and its practical application is tested using a simplified model of the glycolysis of Lactococcus lactis MG1363, for which actual time-series data of metabolite concentrations are available. The results indicate the usefulness of our approach and suggest a probable pathway for the production of lactate and acetate. The results also indicate that the approach pinpoints a probable strong inhibition of lactate on the glycolysis pathway.

Angiotensin II AT(1) receptor blockers as treatments for inflammatory brain disorders

The effects of brain AngII (angiotensin II) depend on AT(1) receptor (AngII type 1 receptor) stimulation and include regulation of cerebrovascular flow, autonomic and hormonal systems, stress, innate immune response and behaviour. Excessive brain AT(1) receptor activity associates with hypertension and heart failure, brain ischaemia, abnormal stress responses, blood-brain barrier breakdown and inflammation. These are risk factors leading to neuronal injury, the incidence and progression of neurodegerative, mood and traumatic brain disorders, and cognitive decline. In rodents, ARBs (AT(1) receptor blockers) ameliorate stress-induced disorders, anxiety and depression, protect cerebral blood flow during stroke, decrease brain inflammation and amyloid-β neurotoxicity and reduce traumatic brain injury. Direct anti-inflammatory protective effects, demonstrated in cultured microglia, cerebrovascular endothelial cells, neurons and human circulating monocytes, may result not only in AT(1) receptor blockade, but also from PPARγ (peroxisome-proliferator-activated receptor γ) stimulation. Controlled clinical studies indicate that ARBs protect cognition after stroke and during aging, and cohort analyses reveal that these compounds significantly reduce the incidence and progression of Alzheimer's disease. ARBs are commonly used for the therapy of hypertension, diabetes and stroke, but have not been studied in the context of neurodegenerative, mood or traumatic brain disorders, conditions lacking effective therapy. These compounds are well-tolerated pleiotropic neuroprotective agents with additional beneficial cardiovascular and metabolic profiles, and their use in central nervous system disorders offers a novel therapeutic approach of immediate translational value. ARBs should be tested for the prevention and therapy of neurodegenerative disorders, in particular Alzheimer's disease, affective disorders, such as co-morbid cardiovascular disease and depression, and traumatic brain injury.

Inhibition of MCP-1/CCR2 signaling pathway is involved in synergistic inhibitory effects of irbesartan with rosuvastatin on vascular remodeling

Additional beneficial effects of angiotensin II type 1 (AT(1)) receptor blockers beyond AT(1) receptor blockade have been highlighted. Irbesartan is reported to act as an antagonist of the monocyte chemoattractant protein-1 (MCP-1) receptor, C-C chemokine receptor 2 (CCR2). We examined the possible synergistic effects of the combination of irbesartan with rosuvastatin on preventing vascular remodeling focusing on the MCP-1/CCR2 pathway. We observed that administration of irbesartan and CCR2 antagonist, propagermanium, at noneffective doses, decreased the neointima with a decrease in PCNA labeling index in the injured mouse femoral artery induced by cuff placement. We also observed that administration of a noneffective dose of rosuvastatin with propagermanium decreased the neointima area, suggesting that the inhibitory effect of rosuvastatin on neointima formation is at least partly attributable to blockade of the MCP-1/CCR2 pathway. Moreover, we demonstrated that the combination of irbesartan with rosuvastatin decreased neointima formation. MCP-1 mRNA level was significantly increased in injured femoral arteries, and administration of irbesartan with rosuvastatin decreased the mRNA levels of MCP-1, TNFα, and IL-1β, and increased PPARγ mRNA expression. These results suggest that the synergistic inhibitory effects of irbesartan with rosuvastatin on neointima formation may involve attenuation of MCP-1/CCR2 signaling.

Comparative effect of angiotensin II type I receptor blockers and calcium channel blockers on laboratory parameters in hypertensive patients with type 2 diabetes

BACKGROUND

Both angiotensin II type I receptor blockers (ARBs) and calcium channel blockers (CCBs) are widely used antihypertensive drugs. Many clinical studies have demonstrated and compared the organ-protection effects and adverse events of these drugs. However, few large-scale studies have focused on the effect of these drugs as monotherapy on laboratory parameters. We evaluated and compared the effects of ARB and CCB monotherapy on clinical laboratory parameters in patients with concomitant hypertension and type 2 diabetes mellitus.

METHODS

We used data from the Clinical Data Warehouse of Nihon University School of Medicine obtained between Nov 1, 2004 and July 31, 2011, to identify cohorts of new ARB users (n = 601) and propensity-score matched new CCB users (n = 601), with concomitant mild to moderate hypertension and type 2 diabetes mellitus. We used a multivariate-adjusted regression model to adjust for differences between ARB and CCB users, and compared laboratory parameters including serum levels of triglyceride (TG), total cholesterol (TC), non-fasting blood glucose, hemoglobin A1c (HbA1c), sodium, potassium, creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), hemoglobin and hematocrit, and white blood cell (WBC), red blood cell (RBC) and platelet (PLT) counts up to 12 months after the start of ARB or CCB monotherapy.

RESULTS

We found a significant reduction of serum TC, HbA1c, hemoglobin and hematocrit and RBC count and a significant increase of serum potassium in ARB users, and a reduction of serum TC and hemoglobin in CCB users, from the baseline period to the exposure period. The reductions of RBC count, hemoglobin and hematocrit in ARB users were significantly greater than those in CCB users. The increase of serum potassium in ARB users was significantly greater than that in CCB users.

CONCLUSIONS

Our study suggested that hematological adverse effects and electrolyte imbalance are greater with ARB monotherapy than with CCB monotherapy.

Binding site characterization of G protein-coupled receptor by alanine-scanning mutagenesis using molecular dynamics and binding free energy approach: application to C-C chemokine receptor-2 (CCR2)

The C-C chemokine receptor 2 (CCR2) was proved as a multidrug target in many diseases like diabetes, inflammation and AIDS, but rational drug design on this target is still lagging behind as the information on the exact binding site and the crystal structure is not yet available. Therefore, for a successful structure-based drug design, an accurate receptor model in ligand-bound state is necessary. In this study, binding-site residues of CCR2 was determined using in silico alanine scanning mutagenesis and the interactions between TAK-779 and the developed homology model of CCR2. Molecular dynamic simulation and Molecular Mechanics-Generalized Born Solvent Area method was applied to calculate binding free energy difference between the template and mutated protein. Upon mutating 29 amino acids of template protein and comparison of binding free energy with wild type, six residues were identified as putative hot spots of CCR2.

Improved insulin sensitivity after long-term treatment with AT1 blockers is not associated with PPARγ target gene regulation

In both cell culture experiments and in vivo studies, a number of angiotensin II type 1 (AT(1)) receptor antagonists activated the peroxisome proliferator-activated receptor-γ (PPARγ). This mechanism has been discussed to be, at least in part, responsible for the improvement in glucose metabolism observed in animal studies and clinical trials. To investigate whether the PPARγ-dependent mechanism may represent a valid target for chronic therapy, spontaneously hypertensive rats (SHR) were fed either with a cafeteria diet (CD) or standard chow. CD-fed SHR were simultaneously treated with either telmisartan (TEL; 8 mg/kg(body weight)· d) or candesartan (CAND; 10 mg/kg(body weight)· d) for 3 months because TEL, but not CAND, has been demonstrated to be a strong activator of PPARγ. After 3 months, chow- and CD-fed controls were hypertensive, whereas TEL and CAND treatment resulted in normalized blood pressures in SHR. Body weight and the amount of abdominal fat (determined by magnetic resonance imaging) were higher in CD- than in chow-fed SHR. After TEL or CAND, body weight, abdominal fat quantity, and adipocyte size returned to normal. In glucose tolerance tests, the glucose responses were comparable in the TEL- and CAND-treated SHR and obese controls, whereas the insulin response was almost halved by AT(1) blockade. Expression of PPARγ target genes aP2, FAT CD36, FASn, and PEPCK remained unaltered at the protein level in visceral fat after TEL and CAND compared with the CD-fed controls. Because the expression of examined PPARγ target genes was not affected, we concluded that improved insulin sensitivity after long-term treatment with AT(1) blockers was not related to a PPARγ-dependent mechanism.