Simvastatin treatment modifies polymorphonuclear leukocyte function in high-risk individuals: a longitudinal study

Effects of Cannabidiol on Innate Immunity: Experimental Evidence and Clinical Relevance

Cannabidiol (CBD) is the main non-psychotropic cannabinoid derived from cannabis (Cannabis sativa L., fam. Cannabaceae). CBD has received approval by the Food and Drug Administration (FDA) and European Medicines Agency (EMA) for the treatment of seizures associated with Lennox-Gastaut syndrome or Dravet syndrome. However, CBD also has prominent anti-inflammatory and immunomodulatory effects; evidence exists that it could be beneficial in chronic inflammation, and even in acute inflammatory conditions, such as those due to SARS-CoV-2 infection. In this work, we review available evidence concerning CBD's effects on the modulation of innate immunity. Despite the lack so far of clinical studies, extensive preclinical evidence in different models, including mice, rats, guinea pigs, and even ex vivo experiments on cells from human healthy subjects, shows that CBD exerts a wide range of inhibitory effects by decreasing cytokine production and tissue infiltration, and acting on a variety of other inflammation-related functions in several innate immune cells. Clinical studies are now warranted to establish the therapeutic role of CBD in diseases with a strong inflammatory component, such as multiple sclerosis and other autoimmune diseases, cancer, asthma, and cardiovascular diseases.

Human Wharton's Jelly Mesenchymal Stem Cell-Mediated Sciatic Nerve Recovery Is Associated with the Upregulation of Regulatory T Cells

The acceleration of peripheral nerve regeneration is crucial for functional nerve recovery. Our previous study demonstrated that human Wharton’s jelly-derived mesenchymal stem cells (hWJ-MSC) promote sciatic nerve recovery and regeneration via the direct upregulation and release of neurotrophic factors. However, the immunomodulatory role of hWJ-MSC in sciatic nerve recovery remains unclear. The effects of hWJ-MSC on innate immunity, represented by macrophages, natural killer cells, and dendritic cells, as well as on adaptive immunity, represented by CD4⁺ T, CD8⁺ T, B, and regulatory T cells (Tregs), were examined using flow cytometry. Interestingly, a significantly increased level of Tregs was detected in blood, lymph nodes (LNs), and nerve-infiltrating cells on POD7, 15, 21, and 35. Anti-inflammatory cytokines, such as IL-4 and IL-10, were significantly upregulated in the LNs and nerves of hWJ-MSC-treated mice. Treg depletion neutralized the improved effects of hWJ-MSC on sciatic nerve recovery. In contrast, Treg administration promoted the functional recovery of five-toe spread and gait stance. hWJ-MSC also expressed high levels of the anti-inflammatory cytokines TGF-β and IL-35. This study indicated that hWJ-MSC induce Treg development to modulate the balance between pro- and anti-inflammation at the injured sciatic nerve by secreting higher levels of anti-inflammatory cytokines.

β2 -Adrenoceptors inhibit neutrophil extracellular traps in human polymorphonuclear leukocytes

This study tests the hypothesis that in isolated human polymorphonuclear leukocytes (PMN) adrenergic ligands can affect neutrophil extracellular trap (NET) formation. We have previously shown that, in PMN, adrenaline (A), through the activation of adrenergic receptors (AR), reduces stimulus-dependent cell activation; we have, therefore, planned to investigate if AR are involved in NET production. PMN were obtained from venous blood of healthy subject. The ability of adrenergic ligands to affect reactive oxygen species (ROS) production, NET production, and cell migration was investigated in cells cultured under resting conditions or after activation with N-formyl-methionyl-leucyl-phenylalanine (fMLP), LPS, or IL-8. Stimuli-induced NET production measured as ROS, microscopic evaluation, and elastase production was reverted by A and this effect was blocked by the selective β₂ -AR antagonist ICI-118,551. The stimulus-induced ROS generation and migration was prevented by A and by isoprenaline (ISO), and these effects were counteracted only by ICI-118,551 and not by the other two selective ligands for the β₁ and β₃ -AR. Finally, the presence of the β-ARs on PMN was confirmed, by means of microscopy and flow cytometry. The data of the present study suggest that adrenergic compounds, through the interaction of mainly β₂ -AR, are able to affect neutrophil functions. These data are suggestive of a possible therapeutic role of β₂ -AR ligands (in addition to their classical use), promoting the possible therapeutic relevance of adrenergic system in the modulation of innate immunity proposing their possible use as anti-inflammatory drugs.

The Pivotal Role of Thymus in Atherosclerosis Mediated by Immune and Inflammatory Response

Atherosclerosis is one kind of chronic inflammatory disease, in which multiple types of immune cells or factors are involved. Data from experimental and clinical studies on atherosclerosis have confirmed the key roles of immune cells and inflammation in such process. The thymus as a key organ in T lymphocyte ontogenesis has an important role in optimizing immune system function throughout the life, and dysfunction of thymus has been proved to be associated with severity of atherosclerosis. Based on previous research, we begin with the hypothesis that low density lipoprotein or cholesterol reduces the expression of the thymus transcription factor Foxn1 via low density lipoprotein receptors on the membrane surface and low density lipoprotein receptor related proteins on the cell surface, which cause the thymus function decline or degradation. The imbalance of T cell subgroups and the decrease of naive T cells due to thymus dysfunction cause the increase or decrease in the secretion of various inflammatory factors, which in turn aggravates or inhibits atherosclerosis progression and cardiovascular events. Hence, thymus may be the pivotal role in coronary heart disease mediated by atherosclerosis and cardiovascular events and it can imply a novel treatment strategy for the clinical management of patients with atherosclerosis in addition to different commercial drugs. Modulation of immune system by inducing thymus function may be a therapeutic approach for the prevention of atherosclerosis. Purpose of this review is to summarize and discuss the recent advances about the impact of thymus function on atherosclerosis by the data from animal or human studies and the potential mechanisms.

Vascular Endothelial Growth Factor Gene Polymorphism (rs2010963) and Its Receptor, Kinase Insert Domain-Containing Receptor Gene Polymorphism (rs2071559), and Markers of Carotid Atherosclerosis in Patients with Type 2 Diabetes Mellitus

Background. The current study was designed to reveal possible associations between the polymorphisms of the vascular endothelial growth factor (VEGF) gene (rs2010963) and its receptor, kinase insert domain-containing receptor (KDR) gene polymorphism (rs2071559), and markers of carotid atherosclerosis in patients with type 2 diabetes mellitus (T2DM). Patients and Methods. 595 T2DM subjects and 200 control subjects were enrolled. The carotid intima-media thickness (CIMT) and plaque characteristics (presence and structure) were assessed ultrasonographically. Biochemical analyses were performed using standard biochemical methods. Genotyping of VEGF/KDR polymorphisms (rs2010963, rs2071559) was performed using KASPar assays. Results. Genotype distributions and allele frequencies of the VEGF/KDR polymorphisms (rs2010963, rs2071559) were not statistically significantly different between diabetic patients and controls. In our study, we demonstrated an association between the rs2071559 of KDR and either CIMT or the sum of plaque thickness in subjects with T2DM. We did not, however, demonstrate any association between the tested polymorphism of VEGF (rs2010963) and either CIMT, the sum of plaque thickness, the number of involved segments, hsCRP, the presence of carotid plaques, or the presence of unstable carotid plaques. Conclusions. In the present study, we demonstrated minor effect of the rs2071559 of KDR on markers of carotid atherosclerosis in subjects with T2DM.

Production of IL-8, VEGF and Elastase by Circulating and Intraplaque Neutrophils in Patients with Carotid Atherosclerosis

Objectives

Polymorphonuclear neutrophils (PMN) in atherosclerotic plaques have been identified only recently, and their contribution to plaque development is not yet fully understood. In this study, production of elastase, interleukin (IL)-8 and vascular endothelial growth factor (VEGF) by PMN was investigated in subjects with carotid stenosis undergoing carotid endarterectomy (CEA).

Methods

The study enrolled 50 patients (Pts) and 10 healthy subjects (HS). Circulating PMN (cPMN) isolated from venous blood (in both Pts and HS) and from plaques (pPMN, in Pts) were cultured, alone or with 0.1 μM fMLP. Elastase, IL-8 and VEGF mRNA were analyzed by real-time PCR. In CEA specimens, PMN were localized by immunohistochemistry.

Results

In both Pts cPMN and pPMN, IL-8 mRNA was higher at rest but lower after fMLP (P<0.01 vs HS), and VEGF mRNA was higher both at rest and after fMLP (P<0.01 vs HS), while elastase mRNA was not significantly different. On the contrary, protein production was always higher in cPMN of HS with respect to values measured in cells of Pts. In CEA specimens, CD66b+ cells localized to areas with massive plaque formation close to neovessels. Pts with soft and mix plaques, as defined by computed tomography, did not differ in cPMN or pPMN IL-8, VEGF or elastase mRNA, or in intraplaque CD66b+ cell density. However, Pts with soft plaques had higher white blood cell count due to increased PMN.

Conclusions

In Pts with carotid plaques, both circulating and intraplaque PMN produce IL-8, VEGF and elastase, which are crucial for plaque development and progression. These findings suggest mechanistic explanations to the reported correlation between PMN count and cardiovascular mortality in carotid ATH.

Adrenergic modulation of migration, CD11b and CD18 expression, ROS and interleukin-8 production by human polymorphonuclear leukocytes

OBJECTIVES

Adrenergic modulation of immunity has been extensively characterized, however, few information exist regarding polymorphonuclear leukocytes (PMN), despite their key role in immunity and inflammation. We investigated the effect of adrenergic agents on human PMN migration, CD11b and CD18 expression, reactive oxygen species (ROS) and interleukin (IL)-8 production, and on adrenoceptor (AR) expression.

METHODS

Migration was measured by the Boyden chamber assay, CD11b/CD18 expression was assessed by flow cytometry, intracellular ROS were detected by spectrofluorimetry, and IL-8 was quantitated by standard ELISA assay. AR mRNA levels were measured by real-time PCR and PMN morphology was studied by scanning electron microscopy.

RESULTS

Adrenaline(A), noradrenaline and the β-AR agonist isoprenaline reduced N-formyl-Met-Leu-Phe (fMLP)-induced migration, CD11b/CD18 expression, and ROS production, without affecting IL-8. The effect of A on CD11b was antagonized by yohimbine and propranolol, and increased by prazosin. The effect on ROS production was completely abolished by propranolol. PMN expressed α(1A)-, α(1B)-, α(1D)-, α(2A)-, α(2C)-, β(1)-, β(2)-, and β(3)-AR mRNA. A prevented fMLP-induced morphological changes of PMN.

CONCLUSIONS

Adrenergic agents reduced PMN responses mainly through β-AR, although α-AR may contribute at least to CD11b expression. AR-operated pathways in PMN should be investigated in disease conditions and in the response to therapeutic agents.

Simvastatin down-regulates the production of interleukin-8 by neutrophil leukocytes from dyslipidemic patients

BACKGROUND

Neutrophil (PMN) leukocytes participate to the initial phases of atherosclerosis through the release of Interleukin 8 (CxCL8; IL-8) that contribute to amplification of inflammation. Aim of the study is to investigate the production of IL-8 by PMN leukocytes from dyslipidemic patients treated with simvastatin.

METHODS

In 15 dyslipidemic subjects with moderately increased cardiovascular risk, assessed by Framingham Risk Score, blood samples were obtain to investigate PMNs IL-8 production [at baseline and after N-formyl-Met-Leu-Phe (fMLP) stimulation] before and after long-term (1-year) simvastatin treatment.

RESULTS

The resting release of IL-8 was higher in dyslipidemic patients at baseline when compared with control subjects (p < 0.05). One year of treatment was significantly associated with reduced IL-8 production (p < 0.01). Moreover, the fMLP-induced IL-8 production in dyslipidemic untreated patients was higher than that of controls (p < 0.05) and was reduced after simvastatin treatment (p < 0.01). IL-8 release after 1 year of treatment was reduced to levels which were lower than those observed in control subjects both for resting and stimulated cytokine production (p < 0.01).

CONCLUSIONS

Prolonged treatment with simvastatin is associated with a reduction of IL-8 production, suggesting the possibility of statin to modulate the pro-inflammatory response in PMNs of patients with moderately increased cardiovascular risk.

Soluble RAGE plasma levels in patients with coronary artery disease and peripheral artery disease

The objective of the present study was define in a relatively large patient population with coronary artery disease (CAD) whether the concomitant presence of peripheral artery disease (PAD), which is known to convey additional cardiovascular risk, was associated with different circulating levels of sRAGE with respect to CAD alone and control subjects. Clinical and laboratory parameters including the ankle brachial index (ABI) and sRAGE (enzyme-linked immunosorbent assay kit) were investigated in 544 patients with angiographically documented CAD and 328 control subjects. 213/554 CAD patients (39%) showed an ABI <0.9 associated with typical symptoms (group CAD + PAD), whereas 331 patients were free from PAD. The concentration of plasma sRAGE was significantly lower (P < 0.0001) in CAD population, with and without PAD, than in control subjects. Among CAD patients, those with PAD showed lower levels of sRAGE. The distribution of the three groups (CAD, CAD + PAD, and controls) according to sRAGE tertiles showed that lower levels were more frequent in patients with CAD and CAD + PAD, whereas higher levels were more frequently found in controls. CAD patients presenting with PAD have lower sRAGE levels than CAD patients without peripheral atherosclerosis showing that stable atherosclerotic lesions in different vascular districts are inversely related to soluble decoy receptor sRAGE.

Clinical review: Statins and trauma--a systematic review

Statins, in addition to their lipid-lowering properties, have anti-inflammatory actions. The aim of this review is to evaluate the effect of pre-injury statin use, and statin treatment following injury. MEDLINE, EMBASE, and CENTRAL databases were searched to January 2012 for randomised and observational studies of statins in trauma patients in general, and in patients who have suffered traumatic brain injury, burns, and fractures. Of 985 identified citations, 7 (4 observational studies and 3 randomised controlled trials (RCTs)) met the inclusion criteria. Two studies (both observational) were concerned with trauma patients in general, two with patients who had suffered traumatic brain injury (one observational, one RCT), two with burns patients (one observational, one RCT), and one with fracture healing (RCT). Two of the RCTs relied on surrogate outcome measures. The observational studies were deemed to be at high risk of confounding, and the RCTs at high risk of bias. Three of the observational studies suggested improvements in a number of clinical outcomes in patients taking statins prior to injury (mortality, infection, and septic shock in burns patients; mortality in trauma patients in general; mortality in brain injured patients) whereas one, also of trauma patients in general, showed no difference in mortality or infection, and an increased risk of multi-organ failure. Two of three RCTs on statin treatment in burns patients and brain injured patients showed improvements in E-selectin levels and cognitive function. The third, of patients with radial fractures, showed no acceleration in fracture union. In conclusion, there is some evidence that pre-injury statin use and post-injury statin treatment may have a beneficial effect in patients who have suffered general trauma, traumatic brain injury, and burns. However, these studies are at high risk of confounding and bias, and should be regarded as 'hypothesisgenerating'. A well-designed RCT is required to determine the therapeutic efficacy in improving outcomes in this patient population.

Angiotensin II type 1 and type 2 receptor expression in circulating monocytes of diabetic and hypercholesterolemic patients over 3-month rosuvastatin treatment

Background

In diabetes, a variety of pro-inflammatory cellular changes has been found in various cell types, including monocytes which are known to be involved in all the phases of atherogenesis. Angiotensin II (Ang II) type 1 receptor (AT₁R) mediates the pro-atherogenic effects of Ang II whereas the type 2 receptor (AT₂R) seems associated with atheroprotection. We sought to investigate the potential changes of AT₁R-AT₂R expression in human monocytes of type 2 diabetic- hypercholesterolemic patients and in hypercholesterolemic subjects, upon clinical treatment with rosuvastatin.

Methods

The AT₁R membrane protein and mRNA AT₁R and AT₂R expression in monocytes were investigated in 10 type 2 diabetic-hypercholesterolemic patients and in 10 hypercholesterolemic subjects, before and after 3-month rosuvastatin treatment. Moreover, the serum cytokine levels of interferon-γ (IFN-γ) and interleukin-4 (IL-4) were detected.

Results

As expected, rosuvastatin was associated with a change in the lipid profile in the two groups. Both the membrane protein (P = 0.008) and the AT₁R mRNA expression (P = 0.038) were significantly reduced during treatment in the absence of AT₂R expression change in diabetic-hypercholesterolemic patients whereas no significant difference was observed in hypercholesterolemic subjects. The serum IL-4 levels were increased during treatment whereas no change was observed in IFN-γ in diabetic-hypercholesterolemic patients. No cytokine change was observed in hypercholesterolemic subjects.

Conclusions

Our study on monocytes of diabetic-hypercholesterolemic patients, showing a reduced AT₁R but not AT₂R expression during rosuvastatin treatment, suggests that statin therapy may modulate favorably the AT₁-AT₂ receptor balance in subjects with coexistent type 2 diabetes.

Myeloid-specific Krüppel-like factor 2 inactivation increases macrophage and neutrophil adhesion and promotes atherosclerosis

RATIONALE

Hemizygous deficiency of the transcription factor Krüppel-like factor 2 (KLF2) has been shown previously to augment atherosclerosis in hypercholesterolemic mice. However, the cell type responsible for the increased atherosclerosis due to KLF2 deficiency has not been identified. This study examined the consequence of myeloid cell-specific KLF2 inactivation in atherosclerosis.

METHODS AND RESULTS

Cell-specific knockout mice were generated by Cre/loxP recombination. Macrophages isolated from myeloid-specific Klf2 knockout (myeKlf2(-/-)) mice were similar to myeKlf2(+/+) macrophages in response to activation, polarization, and lipid accumulation. However, in comparison to myeKlf2(+/+) macrophages, myeKlf2(-/-) macrophages adhered more robustly to endothelial cells. Neutrophils from myeKlf2(-/-) mice also adhered more robustly to endothelial cells, and fewer myeKlf2(-/-) neutrophils survived in culture over a 24-hour period in comparison with myeKlf2(+/+) neutrophils. When myeKlf2(-/-) mice were mated to Ldlr(-/-) mice and then fed a high fat and high cholesterol diet, significant increase in atherosclerosis was observed in the myeKlf2(-/-)Ldlr(-/-) mice compared with myeKlf2(+/+)Ldlr(-/-) littermates. The increased atherosclerosis in myeKlf2(-/-)Ldlr(-/-) mice was associated with elevated presence of neutrophils and macrophages, with corresponding increase of myeloperoxidase as well as chlorinated and nitrosylated tyrosine epitopes in their lesion areas compared with myeKlf2(+/+)Ldlr(-/-) mice.

CONCLUSIONS

This study documents a role for myeloid KLF2 expression in modulating atherosclerosis. The increased neutrophil accumulation and atherosclerosis progression with myeloid-specific KLF2 deficiency also underscores the importance of neutrophils in promoting vascular oxidative stress and atherosclerosis. Collectively, these results suggest that elevating KLF2 expression may be a novel strategy for prevention and treatment of atherosclerosis.

Simvastatin improves morphological and functional recovery of sciatic nerve injury in Wistar rats

AIM

The purpose of this work is to investigate the effects of simvastatin on sciatic nerve regeneration in male Wistar Rats.

MATERIALS AND METHODS

Forty animals were allocated into four groups: (1) control (C); (2) control+simvastatin (CS); (3) lesioned animals+sterile PBS (LC) and (4) lesioned animals+simvastatin (LS). Lesioned animals were submitted to crushing lesion of right sciatic nerve. Simvastatin (20mg/kg/day, i.p.) was administered for five days. Footprints were obtained weekly for evaluation of functional locomotor recovery by means of the Sciatic Function Index (SFI). Blood samples were obtained weekly for quantifying circulating leukocytes. Animals were sacrificed after 21 days for histological analyses of sciatic nerve and spleen.

RESULTS

LS Animals presented increased SFI scores, decreased areas of oedema and mononuclear cell infiltration during Wallerian degeneration and nerve regeneration (7,14 and 21 days; P<0.05). Spleen weight and white pulp areas was increased in LC animals after 21 days. Increased numbers of circulating neutrophils were observed in simvastatin treated animals (CS e LS) at seven, 14 and 21 days, compared to non-treated groups (C and LC).

CONCLUSION

The study suggests that simvastatin accelerates the morphological and functional recovery process of the peripheral nervous system interfering with innate and acquired immunity.

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) preserves gut barrier function by blocking neutrophil-endothelial cell adhesion after hemorrhagic shock and resuscitation in mice

BACKGROUND

We have shown that heparin-binding epidermal growth factor-like growth factor (HB-EGF) protects the intestines from injury in several different animal models, including hemorrhagic shock and resuscitation (HS/R). The current study was designed to explore the mechanisms underlying the anti-inflammatory role of HB-EGF in preservation of gut barrier function after injury.

METHODS

In vivo, HS/R was induced in wild-type and neutropenic mice, with or without administration of HB-EGF, and intestinal permeability determined by use of the everted gut sac method. In vitro, cultured human umbilical vein endothelial cells (HUVECs) and freshly isolated human peripheral blood mononuclear cells (PMNs) were used to determine the effects of HB-EGF on HUVEC-PMN adhesion, reactive oxygen species production in PMN, adhesion molecule expression in HUVEC and PMN, and the signaling pathways involved.

RESULTS

We found that administration of HB-EGF to healthy mice led to preservation of gut barrier function after HS/R. Likewise, induction of neutropenia in mice also led to preservation of gut barrier function after HS/R. Administration of HB-EGF to neutropenic mice did not lead to further improvement in gut barrier function. In vitro studies showed that HB-EGF decreased neutrophil-endothelial cell (PMN-EC) adherence by down-regulating adhesion molecule expression in EC via the phosphoinositide 3-kinase-Akt pathway, and by inhibiting adhesion molecule surface mobilization and reactive oxygen species production in PMN.

CONCLUSION

These results indicate that HB-EGF preserves gut barrier function by inhibiting PMN and EC activation, thereby blocking PMN-EC adherence after HS/R in mice, and support the future use of HB-EGF in disease states manifested by hypoperfusion injury.

Immunomodulatory activity of the lignan 7-hydroxymatairesinol potassium acetate (HMR/lignan) extracted from the heartwood of Norway spruce (Picea abies)

The pharmacological profile of the lignan 7-hydroxymatairesinol (HMR/lignan, HMR) includes chemopreventive effects, antioxidant properties, and mild proestrogenic activity. The present study was devised to investigate the effects of HMR on THP-1 cells, an established model of human monocytes, and on human polymorphonuclear leukocytes (PMNs). In THP-1 cells, HMR concentration-dependently reduced LPS-stimulated tumor necrosis factor (TNF)-alpha secretion in the supernatant. HMR at low, sub-muM concentrations also reduced TNF-alpha mRNA, which was however enhanced by supra-muM concentrations of HMR. In human PMNs, HMR concentration-dependently reduced ROS production induced by either N-formyl-Met-Leu-Phe, phorbol myristate acetate or angiotensin II, as well as interleukin-8 production induced by either N-formyl-Met-Leu-Phe or angiotensin II. Results indicate that HMR is an effective inhibitor of both monocytic THP-1 cells and of human PMNs and warrant further studies to assess their relevance for the prevention and treatment of several conditions characterized by chronic systemic inflammation.

Cytokine production from peripheral blood mononuclear cells and polymorphonuclear leukocytes in patients studied for suspected obstructive sleep apnea

PURPOSE

The relationship between obstructive sleep apnea (OSA) and atherosclerosis-related inflammation has been poorly investigated, particularly focusing on functional responses of immune cells playing a key role in atherogenesis and in comparison with control groups with similar cardiovascular risk factors which are known to be themselves associated with inflammation. We sought to determine cellular tumor necrosis factor-alpha (TNF-α) production from peripheral blood mononuclear cells (PBMCs) and interleukin (IL)-8 release from neutrophils (PMNs) in patients studied for suspected OSA.

METHODS

Thirty-six consecutive patients who underwent a nocturnal complete cardiorespiratory evaluation for suspected OSA were initially evaluated. Serum, PBMCs, and PMNs were isolated (at baseline and after 12 weeks) from patients with apnea-ipopnea index (AHI) >20 (OSA group, n = 16) and from control patients with AHI <5 (nonOSA group, n = 11). All patients continued the same pharmacological therapy for 12 weeks; the OSA group was additionally treated with nocturnal continuous positive-airway-pressure ventilation (cPAP).

RESULTS

The two groups had similar clinical characteristics (prevalence of hypertension, dyslipidemia, diabetes, and cardio-metabolic therapies) except for obesity. Resting and stimulated TNF-α production from PBMCs and IL-8 release from PMNs were similar in the two groups. Serum cytokines resulted within the normal range. In the OSA group, cPAP was not associated with changes in cellular responses.

CONCLUSIONS

In patients showing similar prevalence of major cardiovascular risk factors and cardio-metabolic therapies, differing for the presence or absence of OSA, cytokine productions from PBMC and PMN were similar and were not modified during cPAP therapy. Studies designed to investigate OSA-associated inflammation should carefully match the control group subjects.

Role of polymorphonuclear neutrophils in atherosclerosis: current state and future perspectives

Contrary to the long-standing and widely accepted belief that polymorphonuclear neutrophils (PMN) are of marginal relevance in atherosclerosis, evidence revealing a previously unappreciated role of PMN in the process of atherosclerosis is being accumulating. Systemic inflammation involving activated PMN is clearly associated with unstable conditions of coronary artery disease and an increased number of circulating neutrophils is a well-known risk indicator of future cardiovascular outcomes. Furthermore, PMN are activated in a number of clinical conditions associated with high risk of developing atherosclerosis and are detectable into culprit lesions of patients with coronary artery disease. At present, pharmacological interventions aimed at blocking neutrophil emigration from the blood into the arterial wall and/or inhibiting neutrophil-mediated inflammatory functions are not an option for treating atherosclerosis. Nevertheless, several lines of evidence suggest that part of the atheroprotective effects of statins as well as HDL and HDL apolipoproteins may be related to their ability to modulate neutrophilic inflammation in the arterial wall. These hypotheses are not definitely established and warrant for further study. This Review describes the evidence suggesting that PMN may have a causative role in atherogenesis and atheroprogression and discusses the potential importance of modulating neutrophilic inflammation as part of a novel, improved strategy for preventing and treating atherosclerosis.

Epithelial neutrophil-activating peptide (ENA-78), acute coronary syndrome prognosis, and modulatory effect of statins

Endothelial inflammation with chemokine involvement contributes to acute coronary syndromes (ACS). We tested the hypothesis that variation in the chemokine gene CXCL5, which encodes epithelial neutrophil-activating peptide (ENA-78), is associated with ACS prognosis. We also investigated whether statin use, a potent modulator of inflammation, modifies CXCL5's association with outcomes and characterized the in vitro effect of atorvastatin on endothelial ENA-78 production. Using a prospective cohort of ACS patients (n = 704) the association of the CXCL5 −156 G>C polymorphism (rs352046) with 3-year all-cause mortality was estimated with hazard ratios (HR). Models were stratified by genotype and race. To characterize the influence of statins on this association, a statin*genotype interaction was tested. To validate ENA-78 as a statin target in inflammation typical of ACS, endothelial cells (HUVECs) were treated with IL-1β and atorvastatin with subsequent quantification of CXCL5 expression and ENA-78 protein concentrations. C/C genotype was associated with a 2.7-fold increase in 3-year all-cause mortality compared to G/G+G/C (95%CI 1.19–5.87; p = 0.017). Statins significantly reduced mortality in G/G individuals only (58% relative risk reduction; p = 0.0009). In HUVECs, atorvastatin dose-dependently decreased IL-1β-stimulated ENA-78 concentrations (p<0.0001). Drug effects persisted over 48 hours (p<0.01). CXCL5 genotype is associated with outcomes after ACS with potential statin modification of this effect. Atorvastatin lowered endothelial ENA-78 production during inflammation typical of ACS. These findings implicate CXCL5/ENA-78 in ACS and the statin response.

Simvastatin treatment in subjects at high cardiovascular risk modulates AT1R expression on circulating monocytes and T lymphocytes

OBJECTIVE

Angiotensin II, through the activation of angiotensin II type 1 receptors, plays a crucial role in atherosclerosis. Statins may interfere with the effects of angiotensin II.

METHODS

We have investigated the expression of angiotensin II type 1 receptor, angiotensin II type 2 receptor and angiotensinogen on circulating monocytes and T-lymphocytes from subjects at high risk for vascular events before and during simvastatin treatment, and healthy controls. In-vitro experiments were also performed to assess the ability of simvastatin to interfere with angiotensin II signalling.

RESULTS

In comparison with controls, high-risk subjects had similar angiotensin II type 1 receptor expression on the cell membranes but significantly higher angiotensin II type 1 receptor mRNA levels at least in monocyte subsets whereas their expression on T cells was similar. Angiotensin II type 2 receptor mRNA expression was higher than controls in both monocytes and T lymphocytes. No differences were observed in angiotensinogen expression on monocytes while T lymphocytes of high-risk subjects show higher expression. One-month treatment of high-risk subjects with simvastatin resulted in a reduction of angiotensin II type 1 receptor mRNA without affecting angiotensin II type 2 receptor whereas angiotensinogen mRNA expression was reduced at least in monocytes. Incubation in vitro with simvastatin reduces the expression of angiotensin II type 1 receptor mRNA levels on monocytes from untreated subjects.

CONCLUSION

Simvastatin induces down-regulation of the angiotensin II type 1 receptor, interferes with angiotensin II activity in immune cells and contributes to the anti-inflammatory profile of statins that can explain the therapeutic effects of these drugs.

Angiotensin II type 1 receptor expression in polymorphonuclear leukocytes from high-risk subjects: changes after treatment with simvastatin

Statins may directly interfere with the effects of angiotensin (Ang) II, which is a key player in the pathogenesis of atherosclerosis (ATH). Ang II promotes a wide array of detrimental processes including a prominent proinflammatory effect, increasingly regarded as a target for therapeutic intervention. Because the proinflammatory effects of Ang II are exerted mainly through the activation of Ang II type 1 receptors (AT1Rs) the present study was devised to investigate by means of real-time polymerase chain reaction (PCR) and flow cytometry techniques the expression of such receptors on circulating polymorphonuclear leukocytes (PMNs) from subjects at high risk for vascular events before and during treatment with simvastatin and in sex- and age-matched healthy controls. In vitro experiments were also performed to assess the ability of simvastatin to interfere with Ang II signaling in human PMNs. In comparison to controls, high-risk subjects had similar AT1R expression on the cell membranes but significantly higher AT1R messenger ribonucleic acid (mRNA) levels. Treatment of high-risk subjects with simvastatin for 30 days resulted in a reduction of AT1R mRNA down to the levels of cells from healthy subjects. In vitro, Ang II-induced activation of the guanosine triphosphate (GTP)-binding protein Rac 1 in human PMNs was inhibited by simvastatin. In conclusion, simvastatin induces downregulation of AT1R expression, interferes with Ang II activity in PMNs, and contributes to the antiinflammatory profile of statins that can explain the therapeutic effects of these drugs.

Neutrophil activation status in stable coronary artery disease

Background

During the last years, neutrophils have emerged as important players in atherogenesis. They are highly activated in peripheral blood of patients with unstable angina. Moreover, a primed state of circulating neutrophils has been proposed in patients with stable angina. Our aim was to investigate the neutrophil activation status in patients with stable coronary artery disease (CAD) at conventional drug treatment.

Methodology and Principal Findings

Thirty patients with stable CAD and 30 healthy controls were included using a paired design. The neutrophil expression of CD18 and high-affinity state of CD11b was analysed by flow cytometry before and after stimulation with chemoattractants. Also, the production of reactive oxygen species (ROS) was determined by chemiluminescence. During basal conditions, the neutrophil expression of CD18 or high-affinity state of CD11b did not differ between patients and controls. Chemoattractants (Interleukin-8 and Leukotriene B₄) did not increase either the expression or the amount of high-affinity CD11b/CD18-integrins in CAD patients compared to controls, and had no effect on the production of ROS. On the other hand, the ROS production in response to C3bi-opsonised yeast particles and the neutrophils' inherent capacity to produce ROS were both significantly decreased in patients.

Conclusion/Significance

We could not find any evidence that neutrophils in patients with stable CAD were primed, i.e. more prone to activation, compared to cells from healthy controls. According to our data, the circulating neutrophils in CAD patients rather showed an impaired activation status. It remains to be elucidated whether the neutrophil dysfunction in CAD is mainly a marker of chronic disease, an atherogenic factor or a consequence of the drug treatment.