Neutrophil Extracellular Traps and NLRP3 Inflammasome: A Disturbing Duo in Atherosclerosis, Inflammation and Atherothrombosis.

Atherosclerosis is the formation of plaque within arteries due to overt assemblage of fats, cholesterol and fibrous material causing a blockage of the free flow of blood leading to ischemia. It is harshly impinging on health statistics worldwide because of being principal cause of high morbidity and mortality for several diseases including rheumatological, heart and brain disorders. Atherosclerosis is perpetuated by pro-inflammatory and exacerbated by pro-coagulatory mediators.

A susceptibility putative haplotype within NLRP3 inflammasome gene influences ischaemic stroke risk in the population of Punjab, India.

Despite strong genetic implications of NLRP3 inflammasome, its examination as genetic determinant of ischaemic stroke (IS) remains to be done in Punjab, which has been investigated in this study. In this case control study, 400 subjects (200 IS patients, 200 stroke free controls) were included. Contributions of 5 single nucleotide polymorphisms (SNPs) including a functional SNP within NLRP3 gene (rs10754558, rs4612666, rs2027432, rs3738488 and rs1539019) for the risk of IS were investigated through genetic models after correcting the effect of significant variables.

Anti-inflammatory effects of the phosphodiesterase type 4 inhibitor CHF6001 on bronchoalveolar lavage lymphocytes from asthma patients.

Background: Lymphocytes play a key role in asthma pathophysiology, secreting various cytokines involved in chronic inflammation. CHF6001 is a highly potent and selective phosphodiesterase type 4 (PDE4) inhibitor designed for inhaled administration and has been shown to reduce the late asthmatic response. However, the effect of PDE4 inhibition on the different cytokines produced by lung lymphocytes from asthma patients has not been examined.

The effects of repeated Toll-like receptors 2 and 4 stimulation in COPD alveolar macrophages.

Background: COPD is a progressive inflammatory airway disease characterized by increased numbers of alveolar macrophages in the lungs. Bacterial colonization of the lungs is a common feature in COPD and can promote inflammation through continual and repeated Toll-like receptor (TLR) stimulation. We have studied the response of COPD alveolar macrophages to repetitive stimulation with TLR2 and TLR4 ligands.

Morvan's syndrome with anti contactin associated protein like 2 - voltage gated potassium channel antibody presenting with syndrome of inappropriate antidiuretic hormone secretion.

Morvan's syndrome is a rare autoimmune disorder characterized by triad of peripheral nerve hyperexcitability, autonomic dysfunction, and central nervous system symptoms. Antibodies against contactin-associated protein-like 2 (CASPR2), a subtype of voltage-gated potassium channel (VGKC) complex, are found in a significant proportion of patients with Morvan's syndrome and are thought to play a key role in peripheral as well as central clinical manifestations. We report a patient of Morvan's syndrome with positive CASPR2-anti-VGKC antibody having syndrome of inappropriate antidiuretic hormone as a cause of persistent hyponatremia.

Additive anti-inflammatory effects of corticosteroids and phosphodiesterase-4 inhibitors in COPD CD8 cells.

Background: CD8 lymphocytes play an important role in the pathogenesis of COPD. Corticosteroids and phosphodiesterase 4 (PDE4) inhibitors are anti-inflammatory drugs used for COPD treatment. Little is known of the combined effect of these drugs on COPD CD8 cells.

The role of CRAC channel in asthma.

Asthma is increasing globally and current treatments only manage a proportion of patients. There is an urgent need to develop new therapies. Lymphocytes are thought to play a central role in the pathophysiology of asthma through the production of inflammatory mediators.

Macrophage adaptation in airway inflammatory resolution.

Bacterial and viral infections (exacerbations) are particularly problematic in those with underlying respiratory disease, including post-viral infection, asthma, chronic obstructive pulmonary disease and pulmonary fibrosis. Patients experiencing exacerbations tend to be at the more severe end of the disease spectrum and are often difficult to treat. Most of the unmet medical need remains in this patient group.

The Axl receptor tyrosine kinase is a discriminator of macrophage function in the inflamed lung.

Much of the biology surrounding macrophage functional specificity has arisen through examining inflammation-induced polarizing signals, but this also occurs in homeostasis, requiring tissue-specific environmental triggers that influence macrophage phenotype and function. The TAM receptor family of receptor tyrosine kinases (Tyro3, Axl and MerTK) mediates the non-inflammatory removal of apoptotic cells by phagocytes through the bridging phosphatidylserine-binding molecules growth arrest-specific 6 (Gas6) or Protein S. We show that one such TAM receptor (Axl) is exclusively expressed on mouse airway macrophages, but not interstitial macrophages and other lung leukocytes, under homeostatic conditions and is constitutively ligated to Gas6.

The effects of corticosteroids on cytokine production from asthma lung lymphocytes.

Background: Lymphocytes play a central role in the pathophysiology of asthma. Corticosteroids have a limited effect in severe asthma and we hypothesise that lymphocytes play a central role in corticosteroid insensitivity. We investigated the effects of corticosteroids on cytokine production from lung lymphocytes obtained from patients with moderate severe asthma (MSA) compared to mild asthma (MA) and healthy non-smokers (HNS).

Induction of regulator of G-protein signaling 2 expression by long-acting β2-adrenoceptor agonists and glucocorticoids in human airway epithelial cells.

In asthma and chronic obstructive pulmonary disease (COPD) multiple mediators act on Gαq-linked G-protein-coupled receptors (GPCRs) to cause bronchoconstriction. However, acting on the airway epithelium, such mediators may also elicit inflammatory responses. In human bronchial epithelial BEAS-2B cells (bronchial epithelium + adenovirus 12-SV40 hybrid), regulator of G-protein signaling (RGS) 2 mRNA and protein were synergistically induced in response to combinations of long-acting β2-adrenoceptor agonist (LABA) (salmeterol, formoterol) plus glucocorticoid (dexamethasone, fluticasone propionate, budesonide).

Down regulation of T cell receptor expression in COPD pulmonary CD8 cells.

CD8 cells may contribute towards an autoimmune process in COPD. Down regulation of T cell receptor (TCR) signalling molecules occurs in autoimmune diseases with consequent T cell dysfunction. We hypothesise that TCR signalling is abnormal in COPD pulmonary CD8 cells.

Neutrophil chemotaxis caused by chronic obstructive pulmonary disease alveolar macrophages: the role of CXCL8 and the receptors CXCR1/CXCR2.

Alveolar macrophages produce neutrophil chemoattractants; this cellular cross-talk contributes to neutrophilic airway inflammation in chronic obstructive pulmonary disease (COPD). We have investigated the chemotaxis cross-talk mechanisms between these cells using COPD alveolar macrophages. Using conditioned media from stimulated COPD alveolar macrophages, we investigated the relative contributions of growth-related oncogene (CXCL1), interleukin-8 (CXCL8), and regulated on activation normal T cell expressed and secreted (CCL5) to neutrophil chemotaxis and evaluated the effect of blocking the chemokine receptors CXCR1 and CXCR2 on chemotaxis caused by macrophage-conditioned media.

CRAC channel inhibition produces greater anti-inflammatory effects than glucocorticoids in CD8 cells from COPD patients.

There are increased numbers of pulmonary CD8 lymphocytes in COPD (chronic obstructive pulmonary disease). CRAC (calcium release-activation calcium) channels play a central role in lymphocyte activation though the regulation of the transcription factor NFAT (nuclear factor of activated T-cells). We studied the expression of NFAT in lungs from COPD patients compared with controls, and evaluated the effects of CRAC channel inhibition compared with corticosteroids on NFAT activation and cytokine production in CD8 cells from COPD patients.

Increased phosphorylated p38 mitogen-activated protein kinase in COPD lungs.

The p38 mitogen-activated protein kinase (MAPK) pathway is upregulated in chronic obstructive pulmonary disease (COPD). To date, dual labelling to identify cell-type-specific presence of phosphorylated (phospho-)p38 MAPK has not been carried out. Phospho-p38 MAPK was quantified in a variety of cell types in the lung tissue of 20 COPD patients, 12 smokers and 12 nonsmokers using immunohistochemistry.

Cigarette smoke and its component acrolein augment IL-8/CXCL8 mRNA stability via p38 MAPK/MK2 signaling in human pulmonary cells.

Interleukin-8 (IL-8/CXCL8) is an important neutrophil chemoattractant known to be elevated in the airways of cigarette smokers and in patients with chronic obstructive pulmonary disease (COPD). We examined the acute effect of aqueous cigarette smoke extract (CSE) on IL-8 expression in primary human pulmonary cells, in particular in normal human bronchial smooth muscle cells (HBSMCs). IL-8 mRNA levels increased upon CSE exposure in a concentration- and time-dependent manner, and such an effect was accompanied by IL-8 secretion.

T lymphocyte insensitivity to corticosteroids in chronic obstructive pulmonary disease.

Background: There are increased numbers of activated lymphocytes in the lungs of chronic obstructive pulmonary disease (COPD) patients. The clinical benefits of corticosteroids in COPD patients are limited. Our hypothesis is that lymphocytes play a role in this corticosteroid insensitivity.

Regulation of tristetraprolin expression by interleukin-1 beta and dexamethasone in human pulmonary epithelial cells: roles for nuclear factor-kappa B and p38 mitogen-activated protein kinase.

The mRNA-destabilizing protein tristetraprolin (TTP) negatively regulates adenine- and uridine-rich element (ARE)-containing mRNAs. In A549 pulmonary cells, TTP mRNA and both a approximately 40- and a approximately 45-kDa phosphorylated version of TTP protein were rapidly induced in response to interleukin (IL)-1beta. Analysis with IkappaBalphaDeltaN, a dominant version of inhibitor of kappaBalpha (IkappaBalpha), as well as dominant-negative and small-molecule IkappaB kinase (IKK) inhibitors demonstrated that IL-1beta-induced TTP is nuclear factor-kappaB (NF-kappaB)-dependent.

The effect of asthma therapeutics on signalling and transcriptional regulation of airway smooth muscle function.

Our knowledge of the multifunctional nature of airway smooth muscle (ASM) has expanded rapidly in the last decade, but the underlying molecular mechanisms and how current therapies for obstructive airway diseases, such as asthma and chronic obstructive pulmonary disease (COPD), affect these are still being elucidated. Our current knowledge has built on the pharmacology of human ASM contraction and relaxation established prior to that and which is reviewed in detail elsewhere in this issue. The advent of methods to isolate and culture ASM cells, especially human ASM cells, has made it possible to study how they may contribute to airway remodelling through their synthetic, proliferative, and migratory capacities.

Effect of beta2-adrenoceptor agonists and other cAMP-elevating agents on inflammatory gene expression in human ASM cells: a role for protein kinase A.

In diseases such as asthma, airway smooth muscle (ASM) cells play a synthetic role by secreting inflammatory mediators such as granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6, or IL-8 and by expressing surface adhesion molecules, including ICAM-1. In the present study, PGE(2), forskolin, and short-acting (salbutamol) and long-acting (salmeterol and formoterol) beta(2)-adrenoceptor agonists reduced the expression of ICAM-1 and the release of GM-CSF evoked by IL-1beta in ASM cells. IL-1beta-induced IL-8 release was also repressed by PGE(2) and forskolin, whereas the beta(2)-adrenoceptor agonists were ineffective.

Phorbol ester-stimulated NF-kappaB-dependent transcription: roles for isoforms of novel protein kinase C.

Since protein kinase C (PKC) isoforms are variously implicated in the activation of NF-kappaB, we have investigated the role of PKC in the activation of NF-kappaB-dependent transcription by the diacyl glycerol (DAG) mimetic, phorbol 12-myristate 13-acetate (PMA), and by tumour necrosis factor (TNF) alpha in pulmonary A549 cells. The PKC selective inhibitors, Ro31-8220, Gö6976, GF109203X and Gö6983, revealed no effect on TNFalpha-induced NF-kappaB DNA binding and a similar lack of effect on serine 32/36 phosphorylated IkappaBalpha and the loss of total IkappaBalpha indicates that activation of the core IKK-IkappaBalpha-NF-kappaB cascade by TNFalpha does not involve PKC. In contrast, differential sensitivity of an NF-kappaB-dependent reporter to Ro31-8220, Gö6976, GF109203X and Gö6983 (EC(50)s 0.

Long-acting beta2-adrenoceptor agonists synergistically enhance glucocorticoid-dependent transcription in human airway epithelial and smooth muscle cells.

Addition of an inhaled long-acting beta(2)-adrenoceptor agonist (LABA) to an inhaled corticosteroid (ICS) is more effective at improving asthma control and reducing exacerbations than increasing the dose of ICS. Given that LABA monotherapy is not anti-inflammatory, pathways may exist by which LABAs enhance ICS actions. In the current study, the glucocorticoid dexamethasone had no effect on beta(2)-adrenoceptor agonist-induced cAMP-response element-dependent transcription in the human bronchial epithelial cell line BEAS-2B.

MTSEA prevents ligand binding to the human melanocortin-4 receptor by modification of cysteine 130 in transmembrane helix 3.

We have investigated the effect of the sulfhydryl-reactive reagent, methyl thiosulfonate ethylammonium (MTSEA), on ligand binding to the human melanocortin-4 (MC4) receptor stably expressed in HEK-293 cells. MTSEA inhibited binding of the agonist, 125I-NDPalpha-MSH, and the antagonist, 125I-SHU9119, in a concentration-dependent manner. Pre-incubation of cells with either the agonist or antagonist protected from subsequent MTSEA inhibition of radioligand binding.