The role of lipoxin A4 in regulating ion transport and airway surface liquid dynamics in cystic fibrosis bronchial epithelium

The thesis reports novel findings on the role of LXA4 in inodulating the airway surface liquid (ASL) layer height and in particular expanding the deficient ASL observed in CF as a novel means to augmenting existing therapy. Lipoxin A4 (LXA4) is produced at inflammatory sites, and exerts antiinflammatoiy effects and has been reported to be reduced in cystic fibrosis (CF) airways. The altered Cl- secretion and Na+ hyperabsorption in CF affects the ASL height and leads to a defective mucociliary clearance, chronic infection, inflammation and progressive lung destruction. The role of LXA4 in modulating ion transport and ASL height in CF and non-CF airway epithelia was investigated. CF (CuFi-1) and non-CF (NuLi-1) bronchial epithelial cell lines were grown into well-differentiated epithelia. LXA4 effects were explored using laser confocal inicroscopy to measure ASL height, short-circuit current to investigate ion transporters activity, and ATP assay to measure ATP release at the apical side of CF epithelia. LXA4 (1 nM) treatment for 15 minutes, increased ASL height in Nuli-1 and CuFi-1 epithelia. The stimulatory effect of LXA4 on ASL height was inhibited by the LXA4 receptor FPR2/ALX inhibitor, boc-2; in addition to bumetanide, reactive blue and extracellular hexolinase, while amiloride was showed an additive effect to LXA4. LXA4 was activated Cl- secretion and inhibited Na+ absorption in the CF epithelia. In addition, LXA4 stimulated an apical Boc-2 sensitive release of ATP in CF epithelia. This thesis provides evidence for a novel effect of LXA4 involving the FPR2/ALX receptor, apical ATP release and purinoreceptor activation, inhibition of Na+ absorption and stimulation of Cl+ secretion in CF and non-CF epithelia to finally increase ASL height. These effects open up a new therapeutic avenue in the treatment of CF

Physiological levels of lipoxin A4 inhibit ENaC and restore airway surface liquid height in cystic fibrosis bronchial epithelium.

In cystic fibrosis (CF), the airway surface liquid (ASL) is depleted. We previously demonstrated that lipoxin A4 (LXA4) can modulate ASL height (ASLh) through actions on Cl(-) transport. Here, we report novel effects of lipoxin on the epithelial Na(+) channel ENaC in this response. ASL dynamics and ion transport were studied using live-cell confocal microscopy and short-circuit current measurements in CF (CuFi-1) and non-CF (NuLi-1) cell cultures. Low physiological concentrations of LXA4 in the picomolar range produced an increase in ASLh which was dependent on inhibition of an amiloride-sensitive Na(+) current and stimulation of a bumetanide-sensitive Cl(-) current. These ion transport and ASLh responses to LXA4 were blocked by Boc-2 an inhibitor of the specific LXA4 receptor ALX/FPR2. LXA4 affected the subcellular localization of its receptor and enhanced the localization of ALX/FPR2 at the apical membrane of CF cells. Our results provide evidence for a novel effect of low physiological concentrations of LXA4 to inhibit airway epithelial Na(+) absorption that results in an ASL height increase in CF airway epithelia

Sustained Expression of Steroid Receptor Coactivator SRC-2/TIF-2 is Associated with Better Prognosis in Malignant Pleural Mesothelioma.

INTRODUCTION:: Estrogen receptor beta (ERβ) overexpression by malignant pleural mesothelioma (MPM) tumor cells correlates with enhanced patient survival. ER-regulated transcription is mediated by the p160 family of steroid receptor coactivators (SRCs), and SRC isoform overexpression is associated with worse prognosis in many steroid-related malignancies. The aim of this study was to establish whether SRC isoform expression varied between individual MPM tumors with positive or negative prognostic significance. METHODS:: Immunohistochemical analysis of tumor biopsies from 89 subjects with confirmed histological diagnosis of MPM and biopsies from 3 normal control subjects was performed to detect the expression of SRC-1, SRC-2 (TIF-2), SRC-3 (AIB-1), and ERβ. Allred scores for expression of ERβ and each of the SRCs were determined, and Kaplan-Meier survival curves were calculated to correlate biomarker expression, gender, and histology type with postdiagnosis survival. RESULTS:: ERβ and all the SRCs were expressed at high levels in normal pleural mesothelium, and expression of each biomarker was reduced or lost in a subset of the MPM subjects; however, postdiagnosis survival only significantly correlated with TIF-2 expression. Low or intermediate expression of TIF-2 correlated with reduced median postdiagnosis survival (9 months) compared with those subjects whose tumors highly expressed TIF-2 (20 months) (p = 0.036, log-rank test). CONCLUSIONS:: Maintained high expression of TIF-2 in tumor cells is a positive prognostic indicator for postdiagnosis survival in patients with confirmed MPM. This is the first clinical study to correlate high TIF-2 expression with improved patient prognosis in any malignancy

Divorce and Severity of Coronary Artery Disease: A Multicenter Study

The association between marital status and coronary artery disease (CAD) is supported by numerous epidemiological studies. While divorce may have an adverse effect on cardiac outcomes, the relationship between divorce and severe CAD is unclear. We conducted a multicenter, observational study of consecutive patients undergoing coronary angiography during the period between April 1, 2013, and March 30, 2014. Of 1,068 patients, 124 (12%) were divorced. Divorce was more frequent among women (27%) compared to men (6%). Most divorced patients had been divorced only once (49%), but a subset had been divorced 2 (38%) or ≥3 (12%) times. After adjusting for baseline differences, there was no significant association between divorce and severe CAD in men. In women, there was a significant adjusted association between divorce and severe MVD (OR 2.31 [1.16, 4.59]) or LMD (OR 5.91 [2.19, 15.99]). The modification of the association between divorce and severe CAD by gender was statistically significant for severe LMD (Pinteraction 0.0008) and marginally significant for CAD (Pinteraction 0.05). Among women, there was a significant adjusted association between number of divorces and severe CAD (OR 2.4 [95% CI 1.2, 4.5]), MVD (OR 2.0 [95% CI 1.4, 3.0]), and LMD (OR 3.4 [95% CI 1.9, 5.9]). In conclusion, divorce, particularly multiple divorces, is associated with severe CAD, MVD, and LMD in women but not in men

Lipoxin A4 Stimulates Calcium-Activated Chloride Currents and Increases Airway Surface Liquid Height in Normal and Cystic Fibrosis Airway Epithelia

Cystic Fibrosis (CF) is a genetic disease characterised by a deficit in epithelial Cl− secretion which in the lung leads to airway dehydration and a reduced Airway Surface Liquid (ASL) height. The endogenous lipoxin LXA4 is a member of the newly identified eicosanoids playing a key role in ending the inflammatory process. Levels of LXA4 are reported to be decreased in the airways of patients with CF. We have previously shown that in normal human bronchial epithelial cells, LXA4 produced a rapid and transient increase in intracellular Ca2+. We have investigated, the effect of LXA4 on Cl− secretion and the functional consequences on ASL generation in bronchial epithelial cells obtained from CF and non-CF patient biopsies and in bronchial epithelial cell lines. We found that LXA4 stimulated a rapid intracellular Ca2+ increase in all of the different CF bronchial epithelial cells tested. In non-CF and CF bronchial epithelia, LXA4 stimulated whole-cell Cl− currents which were inhibited by NPPB (calcium-activated Cl− channel inhibitor), BAPTA-AM (chelator of intracellular Ca2+) but not by CFTRinh-172 (CFTR inhibitor). We found, using confocal imaging, that LXA4 increased the ASL height in non-CF and in CF airway bronchial epithelia. The LXA4 effect on ASL height was sensitive to bumetanide, an inhibitor of transepithelial Cl− secretion. The LXA4 stimulation of intracellular Ca2+, whole-cell Cl− currents, conductances and ASL height were inhibited by Boc-2, a specific antagonist of the ALX/FPR2 receptor. Our results provide, for the first time, evidence for a novel role of LXA4 in the stimulation of intracellular Ca2+ signalling leading to Ca2+-activated Cl− secretion and enhanced ASL height in non-CF and CF bronchial epithelia

The IRIS rapid prototyping system selector for educational and manufacturing users

The development of a number of rapid prototyping (RP) technologies with wide-ranging capabilities, features and applications has created a problem of selecting an appropriate RP system for engineering engineering educational institutions as well as manufacturing organisations intending to adopt this new technology. This paper presents an IRIS Rapid Prototyping System Selector (IRPS) for selection of a rapid prototyping system from among a wide range of RP systems commercially available from the RP manufacturers worldwide. The search routines give access to a large database built on entity relationship techniques to enable fast retrieval of information. The system is designed to be user-friendly, flexible and expandable, and can also he used as an educational tool for RP systems education due to its large information base on each specific RP machine

Alpha-1 proteinase inhibitors for the treatment of alpha-1 antitrypsin deficiency: safety, tolerability, and patient outcomes

Alpha-1 antitrypsin (AAT) deficiency remains an underrecognized genetic disease with predominantly pulmonary and hepatic manifestations. AAT is derived primarily from hepatocytes; however, macrophages and neutrophils are secondary sources. As the natural physiological inhibitor of several proteases, most importantly neutrophil elastase (NE), it plays a key role in maintaining pulmonary protease–antiprotease balance. In deficient states, unrestrained NE activity promotes damage to the lung matrix, causing structural defects and impairing host defenses. The commonest form of AAT deficiency results in a mutated Z AAT that is abnormally folded, polymerized, and aggregated in the liver. Consequently, systemic levels are lower, resulting in diminished pulmonary concentrations. Hepatic disease occurs due to liver aggregation of the protein, while lung destruction ensues from unopposed protease-mediated damage. In this review, we will discuss AAT deficiency, its clinical manifestations, and augmentation therapy. We will address the safety and tolerability profiles of AAT replacement in the context of patient outcomes and cost-effectiveness and outline future directions for work in this field.Published versio

Aspergillus-Associated Airway Disease, Inflammation, and the Innate Immune Response

Aspergillus moulds exist ubiquitously as spores that are inhaled in large numbers daily. Whilst most are removed by anatomical barriers, disease may occur in certain circumstances. Depending on the underlying state of the human immune system, clinical consequences can ensue ranging from an excessive immune response during allergic bronchopulmonary aspergillosis to the formation of an aspergilloma in the immunocompetent state. The severest infections occur in those who are immunocompromised where invasive pulmonary aspergillosis results in high mortality rates. The diagnosis of Aspergillus-associated pulmonary disease is based on clinical, radiological, and immunological testing. An understanding of the innate and inflammatory consequences of exposure to Aspergillus species is critical in accounting for disease manifestations and preventing sequelae. The major components of the innate immune system involved in recognition and removal of the fungus include phagocytosis, antimicrobial peptide production, and recognition by pattern recognition receptors. The cytokine response is also critical facilitating cell-to-cell communication and promoting the initiation, maintenance, and resolution of the host response. In the following review, we discuss the above areas with a focus on the innate and inflammatory response to airway Aspergillus exposure and how these responses may be modulated for therapeutic benefit

Activation of P2RY11 and ATP Release by LXA 4 Restores the Airway Surface Liquid Layer and Epithelial Repair in Cystic Fibrosis

International audienc

Lipoxin A4 stimulates calcium-activated chloride secretion and increases airway surface liquid height in normal and cystic fibrosis airway epithelia

Cystic Fibrosis (CF) is a genetic disease characterised by a deficit in epithelial Cl- secretion leading to airway dehydration and a reduced Airway Surface Liquid (ASL) height. The endogenous lipoxin LXA4 is a member of the newly identified eicosanoids playing a key role in ending the inflammatory process. Levels of LXA4 are decreased in the airways of patients with CF. We have previously shown that in normal human bronchial epithelial cells, LXA4 produced a rapid and transient intracellular Ca2+ increase. We have investigated here, the effect of LXA4 on Cl- secretion and the functional consequences on ASL height in bronchial epithelial cells obtained from CF and non-CF patient biopsies and in bronchial epithelial cell lines. We found that LXA4 stimulated a rapid intracellular Ca2+ increase in all of the different CF bronchial epithelial cells tested. In non-CF and CF bronchial epithelia, LXA4 stimulated whole-cell Cl- currents which were inhibited by NPPB (calcium-activated Cl- channel inhibitor), BAPTA-AM (chelator of intracellular Ca2+) but not by CFTRinh-172 (CFTR inhibitor). We found, using confocal imaging, that LXA4 increased the ASL height in non-CF and in CF airway bronchial epithelia. The LXA4 effect on ASL height was sensitive to bumetanide an inhibitor of transepithelial Cl- secretion. The effects of LXA4 on intracellular Ca2+, whole-cell Cl- currents, conductances and ASL height were inhibited by Boc-2 the antagonist of the ALX/FPR2 receptor. Our results provide, for the first time, evidence for a novel role of LXA4 in the stimulation of Ca2+ signalling, Ca2+-activated Cl- secretion and ASL height in non-CF and CF bronchial epithelia.</p