Allergic asthma accelerates atherosclerosis dependent on Th2 and Th17 in apolipoprotein E deficient mice

Association of asthma with the risk of cardiovascular disease: A Mendelian randomization study

BACKGROUND

Association of asthma with the risk of cardiovascular disease has not been fully elucidated. So, this study tried to explore the genetic effect of asthma on five cardiovascular diseases and 90 peripheral cardiovascular proteins to answer the above topic.

METHODS

Instrumental variables predicting asthma was extracted from its genome-wide association study data. Two-sample and multivariate MR approaches were used to assess the genetic association of exposure factor (i.e., asthma) with outcome factors (i.e., hypertension, atrial fibrillation, angina pectoris, myocardial infarction, heart failure, and 90 peripheral cardiovascular proteins).

RESULTS

First, asthma nominally increased the risk of hypertension and atrial fibrillation (OR = 1.009, 95%CI = 1.003-1.016, P = 0.004; OR = 1.074, 95%CI = 1.024-1.127, P = 0.003). Second, of the 90 cardiovascular proteins, asthma was associated with the increased levels of tumor necrosis factor ligand superfamily member 14 and CC motif chemokine 4 (β = 0.145, 95%CI = 0.077-0.212, P = 2.936e-05; β = 0.128, 95%CI = 0.063-0.193, P = 1.036e-04). Third, CC motif chemokine 4 increased the risk of hypertension (P = 0.043); and after adjusting for this protein, asthma still increased the risk of hypertension, but the strength of its P-value changed from 0.004 to 0.011.

CONCLUSION

Asthma was a risk factor for hypertension and atrial fibrillation at the genetic level, and CC motif chemokine 4 might play a mediating role in the mechanism by which asthma promoted hypertension. Thus, effective control of asthma may help reduce the risk of some cardiovascular diseases in older adults.

Association Between Three Atopic Triad and Retinal Vein Occlusion Risk: A Nationwide Population-Based Study

PURPOSE

To evaluate the association between three allergic diseases (allergic dermatitis, allergic rhinitis, and asthma) and the development of retinal vein occlusion (RVO), a major retinal disease that causes visual impairment.

METHOD

This study used data obtained from the Korean National Health Insurance Claims database between 2009 and 2018. The association between the three atopic triads (allergic dermatitis, allergic rhinitis, and asthma) and the occurrence of sight-threatening RVO, as determined by diagnostic and treatment codes, were analyzed. Multivariate adjusted Cox regression analysis was used to determine the hazard ratios (HRs) and 95% confidence intervals for RVO development in the presence of allergic disease.

RESULTS

In this population-based study, 2,160,195 (54.6%) individuals were male, 1,794,968 (45.4%) were female, and 620,938 (15.7%) were diagnosed with allergic diseases. Patients with either asthma or allergic rhinitis had a greater risk of RVO (adjusted hazard ratio (aHR) = 1.101, 95% confidence interval [CI] = 1.029-1.178 for asthma; aHR = 1.181, 95% CI = 1.147-1.215 for allergic rhinitis) compared to those without asthma or allergic rhinitis; however, patients with atopic dermatitis did not show a significant association with RVO (aHR = 1.071, 95% CI = 0.889-1.290), after adjusting for other risk factors.

CONCLUSION

Our study revealed that allergic rhinitis, asthma, and coexisting multiple allergic conditions were associated with an increased risk of RVO. Thus, it may be advisable to suggest an ophthalmological examination for patients with allergies due to the increased possibility of the occurrence of retinal vascular disease.

Association between asthma and cardiovascular diseases: A longitudinal follow-up study using a national health screening cohort

Background

Asthma has been suggested to be a risk factor for cardiovascular diseases (CVDs), although the evidence supporting this relationship is inconclusive. This study aimed to explore the long-term associations between asthma and asthma exacerbations with the occurrence of cardiovascular diseases (CVDs) such as ischemic heart disease (IHD), heart failure (HF), and cerebral stroke, utilizing data from a nationwide cohort.

Materials and methods

This study utilized data from the Korean National Health Insurance Service-Health Screening Cohort database (2002-2015), including information on 111,316 asthma patients and an equal number of 1:1 matched control participants. A propensity score overlap-weighted Cox proportional hazards regression model was used to analyze the overlap-weighted hazard ratios (HRs) of asthma and exacerbated asthma for cardiovascular diseases (CVDs) within this cohort.

Results

During the follow-up period, the incidence rate (IR) of IHD per 1000 person-years (PYs) was 7.82 in patients with asthma and 5.79 in controls. The IR of HF was 2.53 in asthmatic patients and 1.36 in controls. After adjustment for covariates, asthmatic patients exhibited 1.27-fold and 1.56-fold higher HRs for IHD (95% confidence interval (CI) = 1.23-1.37, P < 0.001) and HF (95% CI = 1.36-1.63, P < 0.001) than the controls, respectively. In addition, there was an increased HR for IHD and HF in the asthma exacerbation group compared with the nonexacerbated asthma group (adjusted HR, 1.29, 95% CI = 1.24-1.34, P < 0.001 for IHD and aHR 1.68, 95% CI = 1.58-1.79, P < 0.001 for HF). However, the occurrence of stroke was decreased in asthmatic patients compared with controls (aHR = 0.96, 95% CI = 0.93-0.99, P = 0.008).

Conclusions

Adults with asthma are more likely to develop CVDs. Additionally, severe asthma exacerbations are significantly associated with an increased occurrence of CVDs.

Mast cells: a novel therapeutic avenue for cardiovascular diseases?

Mast cells are tissue-resident immune cells strategically located in different compartments of the normal human heart (the myocardium, pericardium, aortic valve, and close to nerves) as well as in atherosclerotic plaques. Cardiac mast cells produce a broad spectrum of vasoactive and proinflammatory mediators, which have potential roles in inflammation, angiogenesis, lymphangiogenesis, tissue remodelling, and fibrosis. Mast cells release preformed mediators (e.g. histamine, tryptase, and chymase) and de novo synthesized mediators (e.g. cysteinyl leukotriene C4 and prostaglandin D2), as well as cytokines and chemokines, which can activate different resident immune cells (e.g. macrophages) and structural cells (e.g. fibroblasts and endothelial cells) in the human heart and aorta. The transcriptional profiles of various mast cell populations highlight their potential heterogeneity and distinct gene and proteome expression. Mast cell plasticity and heterogeneity enable these cells the potential for performing different, even opposite, functions in response to changing tissue contexts. Human cardiac mast cells display significant differences compared with mast cells isolated from other organs. These characteristics make cardiac mast cells intriguing, given their dichotomous potential roles of inducing or protecting against cardiovascular diseases. Identification of cardiac mast cell subpopulations represents a prerequisite for understanding their potential multifaceted roles in health and disease. Several new drugs specifically targeting human mast cell activation are under development or in clinical trials. Mast cells and/or their subpopulations can potentially represent novel therapeutic targets for cardiovascular disorders.

Asthma and cardiovascular disease: A bidirectional association?

See related article

Apolipoprotein E negatively regulates allergic airway inflammation and remodeling in mice with OVA-induced chronic asthma

Apolipoprotein E (ApoE) is a corticosteroid-unresponsive gene that negatively regulates ovalbumin (OVA) -induced allergic airway inflammation in mice with acute asthma. However, whether ApoE negatively regulates airway remodeling in mice with OVA-induced chronic asthma remains unknown. This study aimed to investigate the effects of ApoE on OVA-induced chronic asthma in a murine model. ApoE knockout (ApoE^-/-) and wild-type (WT) mice were sensitized and challenged with OVA for 10 weeks to establish the chronic asthma model. Compared with WT mice, the results demonstrated that ApoE deficiency exacerbated OVA-induced airway inflammation, including elevated numbers of inflammatory cells in the blood and bronchoalveolar lavage fluid (BALF), as well as increased T helper type 2 (Th2) cells in lung tissue, Th2 cytokines in BALF, and total IgE levels in plasma. Importantly, ApoE deficiency aggravated OVA-induced airway remodeling, as evidenced by higher plasma transforming growth factor (TGF)-β1 levels, airway goblet cell hyperplasia, and collagen deposition compared with WT mice. These results revealed that ApoE deficiency aggravates airway remodeling and inflammation in mice with OVA-induced chronic allergic asthma.

The impact of type 2 immunity and allergic diseases in atherosclerosis

Allergic diseases are allergen-induced immunological disorders characterized by the development of type 2 immunity and IgE responses. The prevalence of allergic diseases has been on the rise alike cardiovascular disease (CVD), which affects arteries of different organs such as the heart, the kidney and the brain. The underlying cause of CVD is often atherosclerosis, a disease distinguished by endothelial dysfunction, fibrofatty material accumulation in the intima of the artery wall, smooth muscle cell proliferation, and Th1 inflammation. The opposed T-cell identity of allergy and atherosclerosis implies an atheroprotective role for Th2 cells by counteracting Th1 responses. Yet, the clinical association between allergic disease and CVD argues against it. Within, we review different phases of allergic pathology, basic immunological mechanisms of atherosclerosis and the clinical association between allergic diseases (particularly asthma, atopic dermatitis, allergic rhinitis and food allergy) and CVD. Then, we discuss putative atherogenic mechanisms of type 2 immunity and allergic inflammation including acute allergic reactions (IgE, IgG1, mast cells, macrophages and allergic mediators such as vasoactive components, growth factors and those derived from the complement, contact and coagulation systems) and late phase inflammation (Th2 cells, eosinophils, type 2 innate-like lymphoid cells, alarmins, IL-4, IL-5, IL-9, IL-13 and IL-17).

The role of phosphoinositide 3-kinases in immune-inflammatory responses: potential therapeutic targets for abdominal aortic aneurysm

The pathogenesis of abdominal aortic aneurysm (AAA) includes inflammatory responses, matrix metalloproteinases (MMPs) degradation, VSMC apoptosis, oxidative stress, and angiogenesis, among which the inflammatory response plays a key role. At present, surgery is the only curing treatment, and no effective drug can delay AAA progression in clinical practice. Therefore, searching for a signaling pathway related to the immune-inflammatory response is an essential direction for developing drugs targeting AAA. Recent studies have confirmed that the PI3K family plays an important role in many inflammatory diseases and is involved in regulating various cellular functions, especially in the immune-inflammatory response. This review focuses on the role of each isoform of PI3K in each stage of AAA immune-inflammatory response, making available explorations for a deeper understanding of the mechanism of inflammation and immune response during the formation and development of AAA.

Interleukin 2 receptor subunit beta as a novel hub gene plays a potential role in the immune microenvironment of abdominal aortic aneurysms

BACKGROUND

Abdominal aortic aneurysm (AAA) is potentially life threatening and characterized by immune-inflammatory cell infiltration and extracellular matrix degradation. Currently, pharmacotherapy mainly aims to control risk factors without reversion of the dilated aorta. This study analyzed the immune-inflammatory response and identified the immune-related hub genes of AAA.

METHOD

Gene Expression Omnibus datasets (GSE57691, GSE47472 and GSE7084) were downloaded. After identification of GSE57691 differentially expressed genes (DEGs), weighted gene co-expression network analysis of the DEGs was performed. Through enrichment analysis of each module and screening in Immunology Database and Analysis Portal, immune-related hub genes were identified via protein-protein interaction (PPI) network construction and lasso regression. CIBERSORT was utilized to analyze AAA immune infiltration. The correlations between the immune-related hub genes and infiltrating immune cells were investigated. Receiver operating characteristic (ROC) curve analysis was performed to determine immune-related hub gene cutoff values, which were validated in GSE47472 and GSE7084.

RESULT

In GSE57691, 1,018 DEGs were identified. Five modules were identified in the co-expression network. The blue and green modules were found to be related to immune-inflammatory responses, and 61 immune-related genes were identified. PPI and lasso regression analyses identified FOS, IL-6 and IL2RB as AAA immune-related hub genes. CIBERSORT analysis indicated significantly increased infiltration of naive B cells, memory activated CD4 T cells, follicular helper T cells, monocytes and M1 macrophages and significantly decreased infiltration of M2 macrophages in AAA compared with normal samples. IL2RB was more strongly associated with immune infiltration in AAA than were FOS and IL6. The IL2RB area under the ROC curve (AUC) value was > 0.9 in both the training and validation set, demonstrating its strong, stable diagnostic value in AAA.

CONCLUSION

AAA and normal samples had different immune infiltration statuses. IL2RB was identified as an immune-related hub gene and a potential hub gene with significant diagnostic value in AAA.

Allergic asthma is a risk factor for human cardiovascular diseases

Asthma is an allergic airway disease in which type 2-mediated inflammation has a pathogenic role. Cardiovascular diseases (CVDs) are type 1-dominant inflammatory diseases in which type 2 cytokines often have a protective role. However, clinical studies demonstrate that allergic asthma and associated allergies are essential risk factors for CVD, including coronary heart diseases, aortic diseases, peripheral arterial diseases, pulmonary embolism, right ventricular dysfunction, atrial fibrillation, cardiac hypertrophy and even hypertension. Mast cells, eosinophils, inflammatory cytokines and immunoglobulin (Ig)E accumulate in asthmatic lungs and in the injured heart and vasculature of patients with CVD. Clinical studies show that many anti-asthmatic therapies affect the risk of CVD. As such, allergic asthma and CVD may share common pathogenic mechanisms. Preclinical investigations indicate that anti-asthmatic drugs have therapeutic potential in certain CVDs. In this Review, we discuss how asthma and allied allergic conditions may contribute to the prevalence, incidence and progression of CVD and vice versa.

Nonrespiratory Comorbidities in Asthma

Asthma is a chronic heterogeneous airway disease. Common comorbid conditions are often disproportionately present in severe asthma. Optimal care of patients with asthma requires the recognition and treatment of these comorbid conditions. This review outlines the pathophysiological mechanisms between nonrespiratory comorbid conditions and asthma and their effect on asthma outcomes. They include: type 2 diabetes mellitus, hypertension, atherosclerotic cardiovascular disease, adrenal and thyroid gland diseases, pregnancy, osteoporosis, adverse effects from medications, and mental health disorders. Studies indicate how poor glycemic control of type 2 diabetes mellitus is associated with not only greater health care utilization but poorer asthma outcomes. Also, a large health care claims database indicates that a substantial proportion of pregnant women have uncontrolled asthma and are prescribed suboptimal controller therapy. Additional data about these nonrespiratory comorbidities and medications known to benefit both nonrespiratory comorbidities and asthma are necessary.

Combining Bioinformatics Techniques to Study the Key Immune-Related Genes in Abdominal Aortic Aneurysm

Approximately 13,000 people die of an abdominal aortic aneurysm (AAA) every year. This study aimed to identify the immune response-related genes that play important roles in AAA using bioinformatics approaches. We downloaded the GSE57691 and GSE98278 datasets related to AAA from the Gene Expression Omnibus database, which included 80 AAA and 10 normal vascular samples. CIBERSORT was used to analyze the samples and detect the infiltration of 22 types of immune cells and their differences and correlations. The principal component analysis showed significant differences in the infiltration of immune cells between normal vascular and AAA samples. High proportions of CD4⁺ T cells, activated mast cells, resting natural killer cells, and 12 other types of immune cells were found in normal vascular tissues, whereas high proportions of macrophages, CD8⁺ T cells, resting mast cells, and six other types of immune cells were found in AAA tissues. In the selected samples, we identified 39 upregulated (involved in growth factor activity, hormone receptor binding, and cytokine receptor activity) and 133 downregulated genes (involved in T cell activation, cell chemotaxis, and regulation of immune response mediators). The key differentially expressed immune response-related genes were screened using the STRING database and Cytoscape software. Two downregulated genes, PI3 and MAP2K1, and three upregulated genes, SSTR1, GPER1, and CCR10, were identified by constructing a protein-protein interaction network. Functional enrichment of the differentially expressed genes was analyzed, and the expression of the five key genes in AAA samples was verified using quantitative polymerase chain reaction, which revealed that MAP2K1 was downregulated in AAA, whereas SSTR1, GEPR1, and CCR10 were upregulated; there was no significant difference in PI3 expression. Our study shows that normal vascular and AAA samples can be distinguished via the infiltration of immune cells. Five genes, PI3, MAP2K1, SSTR1, GPER1, and CCR10, may play important roles in the development, diagnosis, and treatment of AAA.

Cytokines at the Interplay Between Asthma and Atherosclerosis?

Cardiovascular disease (CVD) is an important comorbidity in a number of chronic inflammatory diseases. However, evidence in highly prevalent respiratory disease such as asthma are still limited. Epidemiological and clinical data are not univocal in supporting the hypothesis that asthma and CVD are linked and the mechanisms of this relationship remain poorly defined. In this review, we explore the relationship between asthma and cardiovascular disease, with a specific focus on cytokine contribution to vascular dysfunction and atherosclerosis. This is important in the context of recent evidence linking broad inflammatory signaling to cardiovascular events. However inflammatory regulation in asthma is different to the one typically observed in atherosclerosis. We focus on the contribution of cytokine networks encompassing IL-4, IL-6, IL-9, IL-17A, IL-33 but also IFN-γ and TNF-α to vascular dysfunction in atherosclerosis. In doing so we highlight areas of unmet need and possible therapeutic implications.

Angiotensin II deteriorates advanced atherosclerosis by promoting MerTK cleavage and impairing efferocytosis through the AT1R/ROS/p38 MAPK/ADAM17 pathway

Vulnerable plaques in advanced atherosclerosis have defective efferocytosis. The role of ANG II in the progression of atherosclerosis is not fully understood. Herein, we investigated the effects and the underlying mechanisms of ANG II on macrophage efferocytosis in advanced atherosclerosis. ANG II decreased the surface expression of Mer tyrosine kinase (MerTK) in macrophages through a disintegrin and metalloproteinase17 (ADAM17)-mediated shedding of the soluble form of MerTK (sMer) in the medium, which led to efferocytosis suppression. ANG II-activated ADAM17 required reactive oxygen species (ROS) and p38 MAPK phosphorylation. Selective angiotensin II type 1 receptor (AT1R) blocker losartan suppressed ROS production, and ROS scavenger N-acetyl-l-cysteine (NAC) prevented p38 MAPK phosphorylation. In addition, mutant MERTKΔ483-488was resistant to ANG II-induced MerTK shedding and efferocytosis suppression. The advanced atherosclerosis model that is characterized by larger necrotic cores, and less collagen content was established by feeding apolipoprotein E knockout (ApoE−/−) mice with a high-fat diet for 16 wk. NAC and losartan oral administration prevented atherosclerotic lesion progression. Meanwhile, the inefficient efferocytosis represented by decreased macrophage-associated apoptotic cells and decreased MerTK+CD68+double-positive macrophages in advanced atherosclerosis were prevented by losartan and NAC. Additionally, the serum levels of sMer were increased and positively correlated with the upregulated levels of ANG II in acute coronary syndrome (ACS) patients. In conclusion, ANG II promotes MerTK shedding via AT1R/ROS/p38 MAPK/ADAM17 pathway in macrophages, which led to defective efferocytosis and atherosclerosis progression. Defining the molecular mechanisms of defective efferocytosis may provide a promising prognosis and therapy for ACS patients.

Allergic asthma aggravated atherosclerosis increases cholesterol biosynthesis and foam cell formation in apolipoprotein E-deficient mice

Several studies have demonstrated that allergic asthma can induce atherosclerosis formation in mice. Moreover, allergic asthma and atherosclerosis have been shown to be strongly associated with dyslipidemia. In this study, we investigated the underlying mechanism of allergic asthma-aggravated atherosclerosis-induced cholesterol metabolism disorder in asthmatic apoE^-/- mice. We found that allergic asthma increased the expression of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) in the liver and CD36 in the aorta during the acute and advanced stages of atherosclerosis, respectively. These results indicate that cholesterol biosynthesis is increased during acute atherosclerosis and cholesterol uptake and foam cell formation is increased during advanced atherosclerosis. Simvastatin administration significantly ameliorated the aortic root lesion size of asthmatic mice and significantly decreased HMGCR and CD36 expression. However, the expression of the low-density lipoprotein receptor and ATP-binding cassette transporter A1 was markedly increased, indicating that the beneficial effect of statins in allergic asthma and coronary artery disease was mediated, at least in part, by decreasing cholesterol biosynthesis and foam cell formation. In conclusion, allergic asthma aggravates atherosclerosis by regulating cholesterol metabolism in apoE^-/- mice. Allergic asthma selectively promotes cholesterol biosynthesis in acute atherosclerosis and increases foam cell formation in advanced atherosclerosis.

Eosinophils count in peripheral circulation is associated with coronary artery disease

BACKGROUND AND AIMS

Allergic asthma can accelerate atherosclerosis, a disease in which plaque is deposited onto arterial walls and that may lead to coronary artery disease (CAD). Eosinophils are the most important effector cells in allergic asthma and are likely to become novel biomarkers for risk stratification of patients with CAD, but the relationship between eosinophil count and CAD remains unclear. We aimed to evaluate this relationship and the use of eosinophils in predicting CAD.

METHODS

A total of 5287 patients who underwent coronary angiography were recruited. Their biochemical parameters, including eosinophil count, were measured and their correlation with the severity of coronary artery stenosis, as quantified by the Gensini score system, was evaluated.

RESULTS

The percentages of eosinophils in leukocytes (PELs) were lower in CAD patients (p < 0.001), and had a significant negative correlation with Gensini scores (r = -0.112, p < 0.001). PELs were also significantly lower in acute myocardial infarction patients (p < 0.001). After adjusting for baseline differences, low PELs remained strongly associated with severe CAD and acute coronary arterial thrombotic event. Receiver-operating characteristic curve analysis showed that combining PELs with traditional risk factors in predictive models for CAD severity (z = 4.470, p < 0.001) or acute coronary arterial thrombotic event (z = 9.435, p < 0.001) improved the predictive capabilities of those models.

CONCLUSIONS

PELs, at least in patients undergoing coronary angiography, may be strongly related to the subtype and severity of CAD and, therefore, eosinophil count may be an accurate and independent biomarker to predict CAD severity and acute coronary arterial thrombotic events.

Flow Cytometry-Based Characterization of Mast Cells in Human Atherosclerosis

The presence of mast cells in human atherosclerotic plaques has been associated with adverse cardiovascular events. Mast cell activation, through the classical antigen sensitized-IgE binding to their characteristic Fcε-receptor, causes the release of their cytoplasmic granules. These granules are filled with neutral proteases such as tryptase, but also with histamine and pro-inflammatory mediators. Mast cells accumulate in high numbers within human atherosclerotic tissue, particularly in the shoulder region of the plaque. These findings are largely based on immunohistochemistry, which does not allow for the extensive characterization of these mast cells and of the local mast cell activation mechanisms. In this study, we thus aimed to develop a new flow-cytometry based methodology in order to analyze mast cells in human atherosclerosis. We enzymatically digested 22 human plaque samples, collected after femoral and carotid endarterectomy surgery, after which we prepared a single cell suspension for flow cytometry. We were able to identify a specific mast cell population expressing both CD117 and the FcεR, and observed that most of the intraplaque mast cells were activated based on their CD63 protein expression. Furthermore, most of the activated mast cells had IgE fragments bound on their surface, while another fraction showed IgE-independent activation. In conclusion, we are able to distinguish a clear mast cell population in human atherosclerotic plaques, and this study establishes a strong relationship between the presence of IgE and the activation of mast cells in advanced atherosclerosis. Our data pave the way for potential therapeutic intervention through targeting IgE-mediated actions in human atherosclerosis.

Curcumin ameliorates atherosclerosis in apolipoprotein E deficient asthmatic mice by regulating the balance of Th2/Treg cells

BACKGROUND

Allergic asthma and atherosclerosis represent different directions of inflammatory responses of CD4⁺ T cells, and allergic asthma accelerates atherosclerosis formation. Curcumin could ameliorate the progression of both atherosclerosis and allergic asthma.

PURPOSE

We aimed to investigate the roles of curcumin in asthma-accelerated atherosclerosis plaque formation, and the change of CD4⁺ T-cell subsets in this process.

METHODS

Six to eight-week-old apolipoprotein E^-/- (apoE^-/-) mice were sensitized and challenged by ovalbumin (OVA) to establish an allergic asthma model, and then received curcumin or vehicle treatment for 8 weeks.

RESULTS

The accelerated atherosclerosis was induced by allergic asthma accompanied by increased T helper cell (Th)2 and Th17 cells and decreased regulatory T cells (Tregs) in the spleen. After the 8-week treatment with curcumin, the lesion areas in the aortic root in asthmatic mice significantly improved, and the elevated Th2 and Th17 cells significantly decreased, but Tregs markedly increased. Although curcumin treatment markedly reduced the interleukin (IL)-4 and IL-13 in serum and spleen, the elevated IL-17A did not decrease. Moreover, Th1 cells showed no significant change between different groups. The mRNA expression levels of M1 macrophage-related inflammatory factors IL-6, iNOS and IL-1β were markedly elevated in the spleens of asthmatic mice, but significantly decreased after the 8-week treatment with curcumin.

CONCLUSION

Curcumin ameliorated the aggravation of atherosclerotic lesions and stabilised plaque by modulating the balance of Th2/Tregs in asthmatic apoE^-/- mice.

The role of infiltrating immune cells in dysfunctional adipose tissue

Adipose tissue (AT) dysfunction, characterized by loss of its homeostatic functions, is a hallmark of non-communicable diseases. It is characterized by chronic low-grade inflammation and is observed in obesity, metabolic disorders such as insulin resistance and diabetes. While classically it has been identified by increased cytokine or chemokine expression, such as increased MCP-1, RANTES, IL-6, interferon (IFN) gamma or TNFα, mechanistically, immune cell infiltration is a prominent feature of the dysfunctional AT. These immune cells include M1 and M2 macrophages, effector and memory T cells, IL-10 producing FoxP3+ T regulatory cells, natural killer and NKT cells and granulocytes. Immune composition varies, depending on the stage and the type of pathology. Infiltrating immune cells not only produce cytokines but also metalloproteinases, reactive oxygen species, and chemokines that participate in tissue remodelling, cell signalling, and regulation of immunity. The presence of inflammatory cells in AT affects adjacent tissues and organs. In blood vessels, perivascular AT inflammation leads to vascular remodelling, superoxide production, endothelial dysfunction with loss of nitric oxide (NO) bioavailability, contributing to vascular disease, atherosclerosis, and plaque instability. Dysfunctional AT also releases adipokines such as leptin, resistin, and visfatin that promote metabolic dysfunction, alter systemic homeostasis, sympathetic outflow, glucose handling, and insulin sensitivity. Anti-inflammatory and protective adiponectin is reduced. AT may also serve as an important reservoir and possible site of activation in autoimmune-mediated and inflammatory diseases. Thus, reciprocal regulation between immune cell infiltration and AT dysfunction is a promising future therapeutic target.

Modulation of Immune-Inflammatory Responses in Abdominal Aortic Aneurysm: Emerging Molecular Targets

Abdominal aortic aneurysm (AAA), a deadly vascular disease in human, is a chronic degenerative process of the abdominal aorta. In this process, inflammatory responses and immune system work efficiently by inflammatory cell attraction, proinflammatory factor secretion and subsequently MMP upregulation. Previous studies have demonstrated various inflammatory cell types in AAA of human and animals. The majority of cells, such as macrophages, CD4+ T cells, and B cells, play an important role in the diseased aortic wall through phenotypic modulation. Furthermore, immunoglobulins also greatly affect the functions and differentiation of immune cells in AAA. Recent evidence suggests that innate immune system, especially Toll-like receptors, chemokine receptors, and complements are involved in the progression of AAAs. We discussed the innate immune system, inflammatory cells, immunoglobulins, immune-mediated mechanisms, and key cytokines in the pathogenesis of AAA and particularly emphasis on a further trend and application of these interventions. This current understanding may offer new insights into the role of inflammation and immune response in AAA.

Asthma is associated with atherosclerotic artery changes

Asthma is a chronic airway inflammation with a potential systemic impact. Atherosclerosis is a chronic inflammatory artery disease. The aim of our study was to prove if there is a correlation between the occurrence of asthma and increased atherosclerotic vessel disorders. Vessel status was compared between mild-to-moderate, severe allergic asthma and matched controls. Measurements of artery stiffness were calculated by central pulse wave velocity, ultrasonographic strain imaging and ankle-brachial index. Atherosclerotic plaque burden was assessed by colour-coded duplex sonography. Additionally, analysis of cardiovascular and asthma blood markers was conducted. Arterial stiffness expressed as an increased central pulse wave velocity and decreased circumferential and radial strains as well as the prevalence of media sclerosis were significantly higher among asthma patients compared to controls. Atherosclerotic plaque burden was relevantly increased in asthma groups vs. controls (severe asthma: 43.1%, mild-to-moderate asthma: 25.0%, control: 14.3% of study participants). Except for the elevated IgE and fibrinogen concentrations as well as leukocyte number there were no relevant differences in the blood parameters between the groups. Allergic asthma is associated with distinct atherosclerotic artery changes compared to the respectively matched control collective. The severity of asthma correlates with more pronounced pathological vessel alternations.

IgE induces hypotension in asthma mice by down-regulating vascular NCX1 expression through activating MiR-212-5p

Immunoglobulin E (IgE) has been suggested as a risk factor for allergy-induced low blood pressure, which has not been well explained in molecular details. Our current study shows a novel mechanism involving IgE, FcɛR1, miRNA-212-5p (miR-212-5p), and sodium/calcium exchanger protein 1(NCX1) for asthma to induce hypotension. In arterial smooth muscle cells, IgE up-regulated miR212-5p via its receptor FcɛR1, which resulted in down-regulation of NCX1 that is a regulating factor for blood pressure. In mice, asthma induced hypotension by interfering vasoconstrictive function; knockout of FcɛR1 kept the asthmatic mice from developing hypotension; knock-down of miR-212-5p in asthmatic mice resulted in a significant restoration of blood pressure. In human, asthma and IgE were positively correlated with hypotension in cohort study on NIH epidemiological data. This study suggests a novel therapeutic target (miR-212-5p) for treatment of asthma-induced hypotension.

Interleukin 17A in atherosclerosis - Regulation and pathophysiologic effector function

This review summarizes the current data on the interleukin (IL)-17A pathway in experimental atherosclerosis and clinical data. IL-17A is a prominent cytokine for early T cell response produced by both innate and adaptive leukocytes. In atherosclerosis, increased total IL-17A levels and expression in CD4⁺ T helper and γδ T cells have been demonstrated. Cytokines including IL-6 and TGFβ that increase IL-17A expression are elevated. Many other factors such as lipids, glucose and sodium chloride concentrations as well as vitamins and arylhydrocarbon receptor agonists that promote IL-17A expression are closely associated with cardiovascular risk in the human population. In acute inflammation models, IL-17A mediates innate leukocyte recruitment of both neutrophils and monocytes. In atherosclerosis, IL-17A increased aortic macrophage and T cell infiltration in most models. Secondary recruitment effects via the endothelium and according to recent data also pericytes have been demonstrated. IL-17 receptor A is highly expressed on monocytes and direct effects have been reported as well. Beyond leukocyte accumulation, IL-17A may affect other factors of plaque formation such as endothelial function, and according to some reports, fibrous cap formation and vascular relaxation with an increase in blood pressure. Anti-IL-17A agents are now available for clinical use. Cardiovascular side effect profiles are benign at this point. IL-17A appears to be a differential regulator of atherosclerosis and its effects in mouse models suggest that its modulation may have contradictory effects on plaque size and possibly stability in different patient populations.

Asthma and risk of cardiovascular disease or all-cause mortality: a meta-analysis

BACKGROUND

Previous studies have demonstrated that asthma might be associated with an increase in cardiovascular disease (CVD) and death. However, this relationship differs by gender.

OBJECTIVES

To systematically evaluate the association of asthma on the incidence of CVD and death in cohort studies.

DESIGN

Fixed and random effects models were used to calculate risk estimates in a meta-analysis. Potential publication bias was calculated using a funnel plot, Begg's rank correlation test, and Egger's linear regression test.

SEARCH STRATEGY

We searched the PubMed and Embase databases for studies that examined the relationship between asthma and CVD or all-cause mortality.

SELECTION CRITERIA

Prospective and retrospective cohort studies.

RESULTS

Ten studies containing 406 426 participants were included. The summary relative risk (95% confi-dence interval, CI) for patients with asthma was 1.33 (95% CI: 1.15-1.53), for CVD in women, it was 1.55 (95% CI: 1.20-2.00), for CVD in men it was 1.20 (95% CI: 0.92-1.56), and for all-cause mortality in both genders it was 1.36 (95% CI: 1.01-1.83). These findings remained consistent after sensitivity analysis.

CONCLUSION

The results indicate that asthma was associated with an increased risk of CVD and all-cause mortality.

SYSTEMATIC REVIEW REGISTRATION NUMBER

Systematic review was not registered.

Interaction between allergic asthma and atherosclerosis

Prior studies have established an essential role of mast cells in allergic asthma and atherosclerosis. Mast cell deficiency or inactivation protects mice from allergen-induced airway hyper-responsiveness and diet-induced atherosclerosis, suggesting that mast cells share pathologic activities in both diseases. Allergic asthma and atherosclerosis are inflammatory diseases that contain similar sets of elevated numbers of inflammatory cells in addition to mast cells in the airway and arterial wall, such as macrophages, monocytes, T cells, eosinophils, and smooth muscle cells. Emerging evidence from experimental models and human studies points to a potential interaction between the 2 seemingly unrelated diseases. Patients or mice with allergic asthma have a high risk of developing atherosclerosis or vice versa, despite the fact that asthma is a T-helper (Th)2-oriented disease, whereas Th1 immunity promotes atherosclerosis. In addition to the preferred Th1/Th2 responses that may differentiate the 2 diseases, mast cells and many other inflammatory cells also contribute to their pathogenesis by more than just T cell immunity. Here, we summarize the different roles of airway and arterial wall inflammatory cells and vascular cells in asthma and atherosclerosis and propose an interaction between the 2 diseases, although limited investigations are available to delineate the molecular and cellular mechanisms by which 1 disease increases the risk of the other. Results from mouse allergic asthma and atherosclerosis models and from human population studies lead to the hypothesis that patients with atherosclerosis may benefit from antiasthmatic medications or that the therapeutic regimens targeting atherosclerosis may also alleviate allergic asthma.

Higher circulating levels of chemokines CXCL10, CCL20 and CCL22 in patients with ischemic heart disease

Recruitment of leukocytes is one of the earliest events in the pathogenesis of ischemic heart disease (IHD) and chemokines play an important role in the migration of these cells into the inflammation sites. The aim of this study was to evaluate the CXCL10, CCL20 and CCL22 levels and the single nucleotide polymorphisms (SNPs) rs4508917, rs6749704 and rs4359426 in chemokine genes in patients with IHD to clarify any association. A total of 300 patients with IHD as having acute myocardial infarction (AMI; n=100), stable angina (SA; n=100) or unstable angina (UA; n=100) and 100 healthy subjects as a control group were enrolled to study. Serum samples from all participants were tested for the CXCL10, CCL20 and CCL22 levels by using ELISA. The SNPs were determined by polymerase chain reaction-restriction length polymorphism (PCR-RFLP) method. The mean serum concentrations of CXCL10, CCL20 and CCL22 in AMI patients (395.97±21.20Pg/mL, 108.38±10.31Pg/mL and 1852.58±205.77Pg/mL), SA patients (405.48±27.36Pg/mL, 90.20±7.69Pg/mL and 2322.04±231.23Pg/mL) and UA patients (396.69±22.79Pg/mL, 141.87±18.10Pg/mL and 2754.89±211.70Pg/mL) were significantly higher than in the healthy group (179.38±8.85Pg/mL, 51.92±4.62Pg/mL and 451.82±23.76Pg/mL, respectively; P<0.001). Similarly, the serum levels of CXCL10, CCL20 and CCL22 in total IHD patients (399.38±13.77Pg/mL, 113.49±7.48Pg/mL and 2309.84±126.39Pg/mL, respectively) were also significantly higher as compared with healthy subjects (P<0.001). The serum levels of CCL20 and CCL22 in UA patients were significantly higher than those in SA and AMI patients, respectively (P<0.01 and P<0.003, respectively). The serum levels of CXCL10 and CCL20 in diabetic patients were significantly higher in comparison to non-diabetic patients (P<0.05 and P<0.02, respectively). The serum levels of CCL22 in dyslipidemic- and obese patients were also significantly higher in comparison with non-dyslipidemic- and non-obese patients, correspondingly (P<0.05 and P<0.01, respectively). There were no significant differences between men and women or between patients who treated with statin, aspirin, β-blockers or angiotensin converting enzyme (ACE) inhibitors and patients without mentioned treatment regarding the levels of chemokines. The frequency of the GG genotype at SNP rs4508917 in CXCL10 gene was higher, whereas the frequency of the AA genotype at SNP rs4359426 in CCL22 gene was lower in total patients with IHD as compared with healthy subjects (P<0.04 and P<0.002, respectively). These results showed that the higher levels of CXCL10, CCL20 and CCL22 were associated with IHD. The serum levels of chemokines may influence by the certain traditional risk factors of IHD and some studied SNPs, but did not influence by treatment and gender of patients.

Allergic lung inflammation promotes atherosclerosis in apolipoprotein E-deficient mice

Inflammation drives asthma and atherosclerosis. Clinical studies suggest that asthmatic patients have a high risk of atherosclerosis. Yet this hypothesis remains uncertain, given that Th2 imbalance causes asthma whereas Th1 immunity promotes atherosclerosis. In this study, chronic allergic lung inflammation (ALI) was induced in mice by ovalbumin sensitization and challenge. Acute ALI was induced in mice by ovalbumin and aluminum sensitization and ovalbumin challenge. Atherosclerosis was produced in apolipoprotein E-deficient (Apoe(-/-)) mice with a Western diet. When chronic ALI and atherosclerosis were produced simultaneously, ALI increased atherosclerotic lesion size, lesion inflammatory cell content, elastin fragmentation, smooth muscle cell (SMC) loss, lesion cell proliferation, and apoptosis. Production of acute ALI before atherogenesis did not affect lesion size, but increased atherosclerotic lesion CD4(+) T cells, lesion SMC loss, angiogenesis, and apoptosis. Production of acute ALI after atherogenesis also did not change atherosclerotic lesion area, but increased lesion elastin fragmentation, cell proliferation, and apoptosis. In mice with chronic ALI and diet-induced atherosclerosis, daily inhalation of a mast cell inhibitor or corticosteroid significantly reduced atherosclerotic lesion T-cell and mast cell contents, SMC loss, angiogenesis, and cell proliferation and apoptosis, although these drugs did not affect lesion area, compared with those that received vehicle treatment. In conclusion, both chronic and acute ALI promote atherogenesis or aortic lesion pathology, regardless whether ALI occurred before, after, or at the same time as atherogenesis. Antiasthmatic medication can efficiently mitigate atherosclerotic lesion pathology.

Asthma Associates With Human Abdominal Aortic Aneurysm and Rupture

OBJECTIVE

Both asthma and abdominal aortic aneurysms (AAA) involve inflammation. It remains unknown whether these diseases interact.

APPROACH AND RESULTS

Databases analyzed included Danish National Registry of Patients, a population-based nationwide case-control study included all patients with ruptured AAA and age- and sex-matched AAA controls without rupture in Denmark from 1996 to 2012; Viborg vascular trial, subgroup study of participants from the population-based randomized Viborg vascular screening trial. Patients with asthma were categorized by hospital diagnosis, bronchodilator use, and the recorded use of other anti-asthma prescription medications. Logistic regression models were fitted to determine whether asthma associated with the risk of ruptured AAA in Danish National Registry of Patients and an independent risk of having an AAA at screening in the Viborg vascular trial. From the Danish National Registry of Patients study, asthma diagnosed <1 year or 6 months before the index date increased the risk of AAA rupture before (odds ratio [OR]=1.60-2.12) and after (OR=1.51-2.06) adjusting for AAA comorbidities. Use of bronchodilators elevated the risk of AAA rupture from ever use to within 90 days from the index date, before (OR=1.10-1.37) and after (OR=1.10-1.31) adjustment. Patients prescribed anti-asthma drugs also showed an increased risk of rupture before (OR=1.12-1.79) and after (OR=1.09-1.48) the same adjustment. In Viborg vascular trial, anti-asthmatic medication use associated with increased risk of AAA before (OR=1.45) or after adjustment for smoking (OR=1.45) or other risk factors (OR=1.46).

CONCLUSIONS

Recent active asthma increased risk of AAA and ruptured AAA. These findings document and furnish novel links between airway disease and AAA, 2 common diseases that share inflammatory aspects.

ORMDL3 contributes to the risk of atherosclerosis in Chinese Han population and mediates oxidized low-density lipoprotein-induced autophagy in endothelial cells

ORMDL sphingolipid biosynthesis regulator 3 (ORMDL3) is a universally confirmed susceptibility gene for asthma and has recently emerged as a crucial modulator in lipid metabolism, inflammation and endoplasmic reticulum (ER) stress-the mechanisms also closely involved in atherosclerosis (AS). Here we first presented the evidence of two single nucleotide polymorphisms regulating ORMDL3 expression (rs7216389 and rs9303277) significantly associated with AS risk and the evidence of increased ORMDL3 expression in AS cases compared to controls, in Chinese Han population. Following the detection of its statistical correlation with AS, we further explored the functional relevance of ORMDL3 and hypothesized a potential role mediating autophagy as autophagy is activated upon modified lipid, inflammation and ER stress. Our results demonstrated that in endothelial cells oxidized low-density lipoprotein (ox-LDL) up-regulated ORMDL3 expression and knockdown of ORMDL3 alleviated not only ox-LDL-induced but also basal autophagy. BECN1 is essential for autophagy initiation and silencing of ORMDL3 suppressed ox-LDL-induced as well as basal BECN1 expression. In addition, deletion of ORMDL3 resulted in greater sensitivity to ox-LDL-induced cell death. Taken together, ORMDL3 might represent a causal gene mediating autophagy in endothelial cells in the pathogenesis of AS.

Inhibitory effects of kaempferol-3-O-rhamnoside on ovalbumin-induced lung inflammation in a mouse model of allergic asthma

The modification of natural flavonoid by glycosylation alters their physicochemical and pharmacokinetic properties, such as increased water solubility and stability, reduced toxicity, and sometimes enhanced or even new pharmacological activities. Kaempferol (KF), a plant flavonoid, and its glycosylated derivative, kaempferol-3-O-rhamnoside (K-3-rh), were evaluated and compared for their anti-inflammatory, anti-oxidant, and anti-asthmatic effects in an asthma model mouse. The results showed that K-3-rh fully maintained its anti-inflammatory and anti-asthmatic effects compared with KF in an asthma model mouse. Both KF and K-3-rh significantly reduced the elevated inflammatory cell numbers in the bronchoalveolar lavage fluid (BALF). KF and K-3-rh also significantly inhibited the increase in Th2 cytokines (IL-4, IL-5, and IL-13) and TNF-α protein levels through inhibition of the phosphorylation Akt and effectively suppressed eosinophilia in a mouse model of allergic asthma. The total immunoglobulin (Ig) E levels in the serum and BALF were also blocked by KF and K-3-rh to similar extents. K-3-rh exerts similar or even slightly higher inhibitory effects on Th2 cytokines and IgE production compared with KF, whereas K-3-rh was less effective at DPPH radical scavenging and the inhibition of ROS generation in inflammatory cells compared with KF. These results suggested that the K-3-rh, as well as KF, may also be a promising candidate for the development of health beneficial foods or therapeutic agents that can prevent or treat allergic asthma.

I-L-C-2 it: type 2 immunity and group 2 innate lymphoid cells in homeostasis

Innate type 2 immune cells are activated in response to helminths, allergens, and certain types of proteases and particulates. Recently, innate type 2 immune pathways have also been implicated in protective host responses to homeostatic perturbations, such as metabolic dysfunction, atherosclerosis, and tissue injury. In this context, innate type 2 cytokines stimulate local tissues, recruit eosinophils, and alternatively activate macrophages to restore homeostasis. As the major source of innate interleukin (IL)-5 and IL-13, group 2 innate lymphoid cells are positioned to initiate and maintain homeostatic type 2 responses. The absence of exogenous stimuli in these processes implicates endogenous pathways in the activation of type 2 immunity and suggests an alternative evolutionary trajectory for type 2 immunity, apart from its role in response to helminths and allergens.