Functional consequences for primary human alveolar macrophages following treatment with long, but not short, multiwalled carbon nanotubes

Sinbad Sweeney, Davide Grandolfo, Pakatip Ruenraroengsak, Teresa D TetleyLung Cell Biology, Section of Pharmacology and Toxicology, National Heart and Lung Institute, Imperial College London, London, UKPurpose: Multiwalled carbon nanotubes (MWCNTs) are a potential human health hazard, primarily via inhalation. In the lung, alveolar macrophages (AMs) provide the first line of immune cellular defense against inhaled materials. We hypothesized that, 1 and 5 days after treating AMs with short (0.6 µm in length; MWCNT-0.6 µm) and long (20 µm in length; MWCNT-20 µm) MWCNTs for 24 hours, AMs would exhibit increased markers of adverse bioreactivity (cytokine release and reactive oxygen species generation) while also having a modified functional ability (phagocytosis and migration).Methods: Primary human AMs were treated with short and long MWCNTs for 24 hours, 1 and 5 days after which toxicity end points, including cell death, reactive oxygen species generation, and inflammatory mediator release, were measured. AM functional end points involving phagocytic ability and migratory capacity were also measured.Results: AM viability was significantly decreased at 1 and 5 days after treatment with MWCNT-20 µm, while superoxide levels and inflammatory mediator release were significantly increased. At the same time, there was reduced phagocytosis and migratory capacity alongside increased expression of MARCO; this coincided with frustrated phagocytosis observed by scanning electron microscopy. In contrast, the adverse bioreactivity of the shorter MWCNT-0.6 µm with AMs (and any resulting reduction in AM functional ability) was substantially less marked or absent altogether.Conclusion: This study shows that after 24-hour treatment with long, but not short, MWCNTs, AM function is severely affected up to 5 days after the initial exposure. This has potentially significant pathophysiological consequences for individuals who may be intentionally (via therapeutic applications) or unintentionally exposed to these nanomaterials.Keywords: nanotechnology, MWCNTs, alveolar macrophages, cytokines, phagocytosis, bioreactivit

Pulmonary epithelium, cigarette smoke, and chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a complex chronic inflammatory disease involving a wide variety of cells and inflammatory mediators. The most important etiological factor in the development of this disease is cigarette smoking. Much of the research into the mechanisms of COPD has been concerned with the induction of inflammation and the role of neutrophils and macrophages in the pathophysiology of the disease. The possible contribution of the epithelium to the development of COPD has only recently become apparent and remains unclear. In this article we review research into the effect of cigarette smoke on the pulmonary epithelium with particular emphasis on oxidative stress, proteolytic load, pro-inflammatory cytokine and chemokine profile and epithelial secretions. In addition, we have also reviewed how cigarette smoke may affect epithelial damage and repair processes

Ethical considerations when involving older people in public service participation processes

In the United Kingdom, as in many other countries, New Labour governments have heavily promoted different forms of ‘service-user involvement’ in decision making about public services. The current orthodoxy would appear to be that involvement activities carry with them de facto benefits that are both affirmative and empowering. However, relatively little research has been carried out into considering the real impact (emotional or otherwise) of involving citizens in such processes. In this paper, the findings from a small-scale qualitative study led the authors to reflect that when outcomes of consultation are undesired and that when the precise role of those involved is left unclear in terms of purpose, responsibility and accountability, people can be left with powerful, often uncomfortable, feelings. The ethical dimensions of involving people without adequate, prior preparation or ongoing support are discussed, with suggestions made as to how public organisations can take an ethically sound approach to participation. Drawing on research ethics, and informed by the ethics of care, methods through which the potentially harmful effects of involvement can be mitigated are proposed

The histone deacetylase inhibitor, romidepsin, as a potential treatment for pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive disease that usually affects elderly people. It has a poor prognosis and there are limited therapies. Since epigenetic alterations are associated with IPF, histone deacetylase (HDAC) inhibitors offer a novel therapeutic strategy to address the unmet medical need. This study investigated the potential of romidepsin, an FDA-approved HDAC inhibitor, as an anti-fibrotic treatment and evaluated biomarkers of target engagement that may have utility in future clinical trials. The anti-fibrotic effects of romidepsin were evaluated both in vitro and in vivo together with any harmful effect on alveolar type II cells (ATII). Bronchoalveolar lavage fluid (BALF) from IPF or control donors was analyzed for the presence of lysyl oxidase (LOX). In parallel with an increase in histone acetylation, romidepsin potently inhibited fibroblast proliferation, myofibroblast differentiation and LOX expression. ATII cell numbers and their lamellar bodies were unaffected. In vivo, romidepsin inhibited bleomycin-induced pulmonary fibrosis in association with suppression of LOX expression. LOX was significantly elevated in BALF of IPF patients compared to controls. These data show the anti-fibrotic effects of romidepsin, supporting its potential use as novel treatment for IPF with LOX as a companion biomarker for evaluation of early on-target effects

'How long will I love you?' Sex and intimacy in later life

Valentine’s day is associated with romantic love and relationships, something that most people want in their lives. However, our experiences of love and relationships change across our lifecourse in both positive and negative ways. So as the Waterboys, and more recently Ellie Goulding, have asked ‘How Long Will I Love you?’ (Mike Scott How Long Will I Love You lyrics © Sony/ATV Music Publishing LLC). Goulding ends her version of the song with the words: ‘We're all travelling through time together, every day of our lives, all we can do is do our best, to relish this remarkable ride’. Reflecting on these lyrics what factors then affect our experiences of our intimate relationships as we grow older? As a social scientist and a nurse our worlds have come together to explore relationships and intimacy in later life using data gathered by the English Longitudinal Study of Ageing (ELSA). This report summarises the findings from the Sexual Relations and Activities Questionnaire (SRA-Q) that was used as part of the ELSA study and makes recommendations for practice and policy that can make a difference to the ways in which we can ‘do our best’ to support the sexual and intimate lives of older adults. The people who took part in the study were men and women aged 50 to 90+ living in England

Identification and functional characterisation of CRK12:CYC9, a novel cyclin-dependent kinase (CDK)-cyclin complex in Trypanosoma brucei

The protozoan parasite, Trypanosoma brucei, is spread by the tsetse fly and causes trypanosomiasis in humans and animals. Both the life cycle and cell cycle of the parasite are complex. Trypanosomes have eleven cdc2-related kinases (CRKs) and ten cyclins, an unusually large number for a single celled organism. To date, relatively little is known about the function of many of the CRKs and cyclins, and only CRK3 has previously been shown to be cyclin-dependent in vivo. Here we report the identification of a previously uncharacterised CRK:cyclin complex between CRK12 and the putative transcriptional cyclin, CYC9. CRK12:CYC9 interact to form an active protein kinase complex in procyclic and bloodstream T. brucei. Both CRK12 and CYC9 are essential for the proliferation of bloodstream trypanosomes in vitro, and we show that CRK12 is also essential for survival of T. brucei in a mouse model, providing genetic validation of CRK12:CYC9 as a novel drug target for trypanosomiasis. Further, functional characterisation of CRK12 and CYC9 using RNA interference reveals roles for these proteins in endocytosis and cytokinesis, respectively

Detection of lipocortin 1 in human lung lavage fluid: lipocortin degradation as a possible proteolytic mechanism in the control of inflammatory mediators and inflammation.

Lipocortins are structurally related, glucocorticoid-inducible proteins that inhibit phospholipase A2 (PLA2), thereby reducing the liberation of arachidonic acid from phospholipids and so limiting the synthesis of eicosanoid inflammatory mediators. This study is the first demonstration of one lipocortin, lipocortin 1 (Lc 1; 37 kDa), in human lung lavage supernatants. In lavage fluid from healthy volunteers, a higher percentage (greater than 70%) of the detected Lc 1 was in its native form, compared to that from patients with abnormal lungs. In patients' lavage fluids, Lc 1 was more likely to be partially degraded (34 kDa). In abnormal bronchoalveolar lavage fluid (BALF), the more polymorphonuclear neutrophils (PMN)/lavage, the lower the proportion of Lc 1 in the native (37 kDa) form (n = 7 pairs, rs = -0.8214, p less than 0.05). Furthermore, when BALF cells were cultured and the harvested conditioned media incubated with pure human recombinant Lc 1, degradation of the 37 kDa form increased with the percentage of PMN (n = 10 pairs, s = -0.7200 after 1 hr; n = 6 pairs, rs = -0.9241 after 6 hr). These results suggest that factors released from the PMN are responsible for Lc 1 degradation in man. When recombinant human Lc 1 was incubated with human neutrophil elastase, the enzyme degraded Lc 1 in a dose-dependent way, suggesting that neutrophil elastase may be one such factor. Since PMNs are ubiquitous at sites of inflammation, it is possible that Lc 1 degradation is a permissive mechanism, which ensures that sufficient inflammation occurs to destroy the provocative stimulus. However, it is equally possible that, in some circumstances, the mechanism may be pathological and that the inactivation of Lc 1 leads to chronic, uncontrolled inflammation

Reduction of nitric oxide release from alveolar macrophages by a lipocortin peptide.

Nitric oxide (NO), produced by alveolar macrophages (AM) is used as a marker of respiratory tract inflammation. Lipocortin 1 (Lc-1) is an anti-inflammatory, glucocorticoid-inducible protein. The current aims were to determine whether (a) an Lc-1-derived peptide, Ac2-26, inhibited lipopolysaccharide (LPS)-induced NO release by primary AM in vitro and (b) the inhibitory action of dexamethasone was Lc-1-dependent. LPS treatment stimulated NO release from rat AM. Ac2-26 had little effect on unstimulated release, but suppressed LPS-stimulated release at concentrations > or =320 nM (320 nM, 10 +/- 3%; 3.2 microM, 15 +/- 3%; 32 microM, 27 +/- 4% NO inhibited, mean +/- SEM, n = 6). Inhibition by dexamethasone of NO release was unaffected by neutralizing anti-Lc-1 indicating that this action is Lc-1-independent in primary AM. Nevertheless inhibition of NO release by Ac2-26 (80 microM) was similar to that of 1 microM dexamethasone (Ac2-26, 40 +/- 6%; dexamethasone, 48 +/- 6% NO inhibited, mean +/- SEM, n = 6)