Chronic Obstructive Pulmonary Disease Patients' Experiences of an Enhanced Self-Management Model of Care.

Chronic obstructive pulmonary disease (COPD) is debilitating and costly. Self-management is championed to empower individuals to better manage their condition and also to efficiently utilize health resources. As a multi-disciplinary team, we conducted focus group research with individuals living with COPD who were participating in a longitudinal study to use an electronic "diary" to monitor, record, and transmit their own health status, plus receiving regular nurse visits. The main aims of the focus groups were to investigate how far individuals embraced the electronic diary and experienced it as an aid to the self-management of their condition. We also looked at the importance of the nurse visits to the process. Thematic analysis revealed that patients responded positively to the use of technology (the electronic diary), including psychological benefits of perceived support offered by the remote symptom surveillance. Findings also showed patients' increased awareness and monitoring of personal symptoms together with an improved understanding of disease self-management. Nurse support emerged as an important "human" factor in the process. In addition, a reduction in hospital admission was observed, thus reducing costs to the health service.

Lung Regeneration: Endogenous and Exogenous Stem Cell Mediated Therapeutic Approaches.

The tissue turnover of unperturbed adult lung is remarkably slow. However, after injury or insult, a specialised group of facultative lung progenitors become activated to replenish damaged tissue through a reparative process called regeneration. Disruption in this process results in healing by fibrosis causing aberrant lung remodelling and organ dysfunction. Post-insult failure of regeneration leads to various incurable lung diseases including chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis. Therefore, identification of true endogenous lung progenitors/stem cells, and their regenerative pathway are crucial for next-generation therapeutic development. Recent studies provide exciting and novel insights into postnatal lung development and post-injury lung regeneration by native lung progenitors. Furthermore, exogenous application of bone marrow stem cells, embryonic stem cells and inducible pluripotent stem cells (iPSC) show evidences of their regenerative capacity in the repair of injured and diseased lungs. With the advent of modern tissue engineering techniques, whole lung regeneration in the lab using de-cellularised tissue scaffold and stem cells is now becoming reality. In this review, we will highlight the advancement of our understanding in lung regeneration and development of stem cell mediated therapeutic strategies in combating incurable lung diseases.

Measurement of C-reactive protein, procalcitonin and neutrophil elastase in saliva of COPD patients and healthy controls: correlation to self-reported wellbeing parameters.

BACKGROUND: Saliva is increasingly promoted as an alternative diagnostic bio-sample to blood; however its role in respiratory disease requires elucidation. Our aim was to investigate whether C-reactive protein (CRP), procalcitonin (PCT) and neutrophil elastase (NE) could be measured in unstimulated whole saliva, and to explore differences between COPD patients and controls with normal lung function. We also determined the relationship between these salivary biomarkers and self-reported COPD-relevant metrics. METHODS: Salivary CRP, PCT and NE levels were measured at each of 3 visits over a 14-day period alongside spirometry and a daily self-assessment dairy in 143 subjects: 20 never-smokers and 25 smokers with normal spirometry; 98 COPD patients [GOLD Stage I, 16; Stage II, 32; Stage III, 39; Stage IV, 11]. Twenty-two randomly selected subjects provided simultaneous blood samples. RESULTS: Levels of each salivary biomarker could distinguish between the above cohorts. Significant differences remained for salivary CRP and NE (p < 0.05) following adjustment for age, gender, sampling time, gum disease and total co-morbidities; but not for BMI except for salivary NE, which remained higher in smokers compared to non-smokers and stable COPD subjects (p < 0.001). Patients with acute COPD exacerbations had a median increase in all 3 salivary biomarkers (p < 0.001); CRP: median 5.74 ng/ml, [interquartile range (IQR) 2.86-12.25], PCT 0.38 ng/ml, [IQR 0.22-0.94], and NE 539 ng/ml, [IQR 112.25-1264]. In COPD patients, only salivary CRP and PCT levels correlated with breathing scores (r = 0.14, p < 0.02; r = 0.13, p < 0.03 respectively) and sputum features but not with activities of daily living. Salivary CRP and PCT concentrations strongly correlated with serum counterparts [r = 0.82, (95% CI: 0.72-0.87), p < 0.001 by Spearman's; and r = 0.53, (95% CI: 0.33-0.69), p < 0.006 respectively]; salivary NE did not. CONCLUSIONS: CRP, PCT and NE were reliably and reproducibly measured in saliva, providing clinically-relevant information on health status in COPD; additionally NE distinguished smoking status. All 3 salivary biomarkers increased during COPD exacerbations, with CRP and PCT correlating well with patient-derived clinical metrics. These results provide the conceptual basis for further development of saliva as a viable bio-sample in COPD monitoring and exacerbation management.

Club cells inhibit alveolar epithelial wound repair via TRAIL-dependent apoptosis.

Club cells (Clara cells) participate in bronchiolar wound repair and regeneration. Located in the bronchioles, they become activated during alveolar injury in idiopathic pulmonary fibrosis (IPF) and migrate into the affected alveoli, a process called alveolar bronchiolisation. The purpose of this migration and the role of club cells in alveolar wound repair is controversial. This study was undertaken to investigate the role of club cells in alveolar epithelial wound repair and pulmonary fibrosis. A direct-contact co-culture in vitro model was used to evaluate the role of club cells (H441 cell line) on alveolar epithelial cell (A549 cell line) and small airway epithelial cell (SAEC) wound repair. Immunohistochemistry was conducted on lung tissue samples from patients with IPF to replicate the in vitro findings ex vivo. Our study demonstrated that club cells induce apoptosis in alveolar epithelial cells and SAECs through a tumour necrosis factor-related apoptosis-inducing ligand (TRAIL)-dependent mechanism resulting in significant inhibition of wound repair. Furthermore, in IPF lungs, TRAIL-expressing club cells were detected within the affected alveolar epithelia in areas of established fibrosis, together with widespread alveolar epithelial cell apoptosis. From these findings, we hypothesise that the extensive pro-fibrotic remodelling associated with IPF could be driven by TRAIL-expressing club cells inducing apoptosis in alveolar epithelial cells through a TRAIL-dependent mechanism.

Mesenchymal stem cells promote alveolar epithelial cell wound repair in vitro through distinct migratory and paracrine mechanisms.

BACKGROUND: Mesenchymal stem cells (MSC) are in clinical trials for widespread indications including musculoskeletal, neurological, cardiac and haematological disorders. Furthermore, MSC can ameliorate pulmonary fibrosis in animal models although mechanisms of action remain unclear. One emerging concept is that MSCs may have paracrine, rather than a functional, roles in lung injury repair and regeneration. METHODS: To investigate the paracrine role of human MSC (hMSC) on pulmonary epithelial repair, hMSC-conditioned media (CM) and a selected cohort of hMSC-secretory proteins (identified by LC-MS/MS mass spectrometry) were tested on human type II alveolar epithelial cell line A549 cells (AEC) and primary human small airway epithelial cells (SAEC) using an in vitro scratch wound repair model. A 3D direct-contact wound repair model was further developed to assess the migratory properties of hMSC. RESULTS: We demonstrate that MSC-CM facilitates AEC and SAEC wound repair in serum-dependent and -independent manners respectively via stimulation of cell migration. We also show that the hMSC secretome contains an array of proteins including Fibronectin, Lumican, Periostin, and IGFBP-7; each capable of influencing AEC and SAEC migration and wound repair stimulation. In addition, hMSC also show a strong migratory response to AEC injury as, supported by the observation of rapid and effective AEC wound gap closure by hMSC in the 3D model. CONCLUSION: These findings support the notion for clinical application of hMSCs and/or their secretory factors as a pharmacoregenerative modality for the treatment of idiopathic pulmonary fibrosis (IPF) and other fibrotic lung disorders.

Phase III, two arm, multi-centre, open label, parallel-group randomised designed clinical investigation of the use of a personalised early warning decision support system to predict and prevent acute exacerbations of chronic obstructive pulmonary disease: 'Predict & Prevent AECOPD' - study protocol.

INTRODUCTION: With 65 million cases globally, chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death and imposes a heavy burden on patients' lives and healthcare resources worldwide. Around half of all patients with COPD have frequent (≥2 per year) acute exacerbations of COPD (AECOPD). Rapid readmissions are also common. Exacerbations impact significantly on COPD outcomes, causing significant lung function decline. Prompt exacerbation management optimises recovery and delays the time to the next acute episode. METHODS/ANALYSIS: The Predict & Prevent AECOPD trial is a phase III, two arm, multi-centre, open label, parallel-group individually randomised clinical trial investigating the use of a personalised early warning decision support system (COPDPredict) to predict and prevent AECOPD. We aim to recruit 384 participants and randomise each individual in a 1:1 ratio to either standard self-management plans with rescue medication (RM) (control arm) or COPDPredict with RM (intervention arm).The trial will inform the future standard of care regarding management of exacerbations in COPD patients. The main outcome measure is to provide further validation, as compared with usual care, for the clinical effectiveness of COPDPredict to help guide and support COPD patients and their respective clinical teams in identifying exacerbations early, with an aim to reduce the total number of AECOPD-induced hospital admissions in the 12 months following each patient's randomisation. ETHICS AND DISSEMINATION: This study protocol is reported in accordance with the guidance set out in the Standard Protocol Items: Recommendations for Interventional Trials statement. Predict & Prevent AECOPD has obtained ethical approval in England (19/LO/1939). On completion of the trial and publication of results a lay findings summary will be disseminated to trial participants. TRIAL REGISTRATION NUMBER: NCT04136418.

Idiopathic pulmonary fibrosis in the UK: analysis of the British Thoracic Society electronic registry between 2013 and 2019.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and terminal interstitial lung disease (ILD) with a median survival of 3-5 years. The British Thoracic Society (BTS) established the UK IPF Registry in 2013 as a platform to collect data on clinical characteristics, treatments and outcomes for this cohort in the UK. Between 1 January 2013 and 31 October 2019, 2474 cases were registered. Most patients were male (79%) with a mean±sd age of 74±8.3 years and 66% were ex-smokers. Over time we observed an increase in the number of patients aged over 70 years. However, we have not seen a trend towards earlier presentation as symptoms of breathless and/or cough were present for >12 months in 63% of the cohort. At presentation, mean±sd % predicted forced vital capacity (FVC) was 78.2±18.3%, median 76.2% (interquartile range (IQR) 22.4%) and transfer factor of the lung for carbon monoxide (T LCO) 48.4±16.0, median 47.5 (IQR 20.1). Most cases were discussed at an ILD multidisciplinary meeting, with an increase over this time in the number of cases reported as having possible usual interstitial pneumonia (UIP) pattern on high-resolution computed tomography (HRCT) thorax. We noted a reduction in the number of patients undergoing surgical lung biopsy or bronchoalveolar lavage. Although more patients were prescribed anti-fibrotic therapies from 2013 to 2019, 43% were ineligible for treatment based upon National Institute for Health and Care Excellence (NICE) prescribing criteria. Hypertension, ischaemic heart disease, diabetes mellitus and gastro-oesophageal reflux were the most common comorbidities. In conclusion, we have presented baseline demographics as well as diagnostic and treatment strategies from the largest single-country IPF registry, reflecting changes in UK practices over this period.

Validation of COPDPredict™: Unique Combination of Remote Monitoring and Exacerbation Prediction to Support Preventative Management of COPD Exacerbations.

Background: COPDPredict™ is a novel digital application dedicated to providing early warning of imminent COPD (chronic obstructive pulmonary disease) exacerbations for prompt intervention. Exacerbation prediction algorithms are based on a decision tree model constructed from percentage thresholds for disease state changes in patient-reported wellbeing, forced expiratory volume in one second (FEV1) and C-reactive protein (CRP) levels. Our study determined the validity of COPDPredict™ to identify exacerbations and provide timely notifications to patients and clinicians compared to clinician-defined episodes. Methods: In a 6-month prospective observational study, 90 patients with COPD and frequent exacerbations registered wellbeing self-assessments daily using COPDPredict™ App and measured FEV1 using connected spirometers. CRP was measured using finger-prick testing. Results: Wellbeing self-assessment submissions showed 98% compliance. Ten patients did not experience exacerbations and treatment was unchanged. A total of 112 clinician-defined exacerbations were identified in the remaining 80 patients: 52 experienced 1 exacerbation; 28 had 2.2±0.4 episodes. Sixty-two patients self-managed using prescribed rescue medication. In 14 patients, exacerbations were more severe but responded to timely escalated treatment at home. Four patients attended the emergency room; with 2 hospitalised for <72 hours. Compared to the 6 months pre-COPDPredict™, hospitalisations were reduced by 98% (90 vs 2, p<0.001). COPDPredict™ identified COPD-related exacerbations at 7, 3 days (median, IQR) prior to clinician-defined episodes, sending appropriate alerts to patients and clinicians. Cross-tabulation demonstrated sensitivity of 97.9% (95% CI 95.7-99.2), specificity of 84.0% (95% CI 82.6-85.3), positive and negative predictive value of 38.4% (95% CI 36.4-40.4) and 99.8% (95% CI 99.5-99.9), respectively. Conclusion: High sensitivity indicates that if there is an exacerbation, COPDPredict™ informs patients and clinicians accurately. The high negative predictive value implies that when an exacerbation is not indicated by COPDPredict™, risk of an exacerbation is low. Thus, COPDPredict™ provides safe, personalised, preventative care for patients with COPD.

Sarcoidosis in the UK: insights from British Thoracic Society registry data.

Introduction: The British Thoracic Society Sarcoidosis Registry allows physicians to record clinical data after gaining written consent from patients. The registry's aim is to phenotype sarcoidosis in the UK. Methods: Between February 2013 and July 2017, demographic details for 308 patients (with complete clinical data for 205 patients) presenting to 24 UK hospitals were recorded. This data was analysed to detail methods of presentation, diagnosis and management. Results: Fatigue was a significant complaint, affecting 30% of all patients. The most prevalent CT findings were nodules (in 77% of cases) with traction bronchiectasis (11%), distortion (9%) and ground glass (5%) less prominent. Of 205 patients with complete clinical data, only 64% had a diagnostic tissue biopsy. 35% of all patients underwent endobronchial ultrasound-guided transbronchial needle aspirate (EBUS-TBNA) with 15% having a transbronchial biopsy. Use of EBUS-TBNA showed an overall increase over time, from 28% of all patients in 2013 to 43% in 2016. The most common steroid sparing treatment was methotrexate, but 42% of patients were not initiated on any pharmacological treatment at the time of inclusion. Discussion: Fatigue was common and has shown association with poor quality of life. We therefore suggest using a fatigue questionnaire as part of all new patient assessments. It may be that EBUS-TBNA should be reserved for cases of stage I or II disease where there is a reported higher yield than using transbronchial biopsy alone. Bronchoalveolar lavage was not widely used in our data, but it is generally a safe and useful adjunct and should be used more widely.

Optical coherence tomography: real-time imaging of bronchial airways microstructure and detection of inflammatory/neoplastic morphologic changes.

PURPOSE: Current diagnostic imaging modalities for human bronchial airways do not possess sufficient resolution and tissue penetration depth to detect early morphologic changes and to differentiate in real-time neoplastic pathology from nonspecific aberrations. Optical coherence tomography (OCT) possesses the requisite high spatial resolution for reproducible delineation of endobronchial wall profiling. EXPERIMENTAL DESIGN: To establish whether OCT could differentiate between the composite microstructural layers of the human airways and simultaneously determine in situ morphologic changes, using a bench-top OCT system, we obtained cross-sectional images of bronchi from 15 patients undergoing lung resections for cancer. All scanned sections underwent subsequent detailed histologic analysis, allowing direct comparisons to be made. RESULTS: OCT imaging enables characterization of the multilayered microstructural anatomy of the airways, with a maximum penetration depth up to 2 to 3 mm and 10-microm spatial resolution. The epithelium, subepithelial components, and cartilage are individually defined. The acquired OCT images closely match histologically defined patterns in terms of structural profiles. Furthermore, OCT identifies in situ morphologic changes associated with inflammatory infiltrates, squamous metaplasia, and tumor presence. CONCLUSIONS: Our results confirm that OCT is a highly feasible optical tool for real-time near-histologic imaging of endobronchial pathology, with potential for lung cancer surveillance applications in diagnosis and treatment.

BMP2 repression and optimized culture conditions promote human bone marrow-derived mesenchymal stem cell isolation.

AIM: Human mesenchymal stem cells (hMSC) are multipotent progenitor cells. We propose the optimization of hMSC isolation and recovery using the application of a controlled hypoxic environment. MATERIALS & METHODS: We evaluated oxygen, glucose and serum in the recovery of hMSC from bone marrow (BMhMSC). Colony forming units-fibroblastic, cell numbers, tri-lineage differentiation, immunofluorescence and microarray were used to confirm and characterize BMhMSC. RESULTS: In an optimized (2% O(2), 4.5 g/l glucose and 5% serum) environment both colony forming units-fibroblastic (p = 0.01) and cell numbers (p = 0.0001) were enhanced over standard conditions. Transcriptional analysis identified differential expression of bone morphogenetic protein 2 (BMP2) and, putatively, chemokine (C-X-C motif) receptor 2 (CXCR2) signaling pathways. CONCLUSION: We have detailed a potential milestone in the process of refinement of the BMhMSC isolation process.

Growth factors in idiopathic pulmonary fibrosis: relative roles.

Treatment of idiopathic pulmonary fibrosis patients has evolved very slowly; the fundamental approach of corticosteroids alone or in combination with other immunosuppressive agents has had little impact on long-term survival. The continued use of corticosteroids is justified because of the lack of a more effective alternative. Current research indicates that the mechanisms driving idiopathic pulmonary fibrosis reflect abnormal, dysregulated wound healing within the lung, involving increased activity and possibly exaggerated responses by a spectrum of profibrogenic growth factors. An understanding of the roles of these growth factors, and the way in which they modulate events at cellular level, could lead to more targeted therapeutic strategies, improving patients' quality of life and survival.

Use of optical coherence tomography in delineating airways microstructure: comparison of OCT images to histopathological sections.

An ideal diagnostic system for the human airways should be able to detect and define early development of premalignant pathological lesions, to facilitate optimal curative treatment and prevent irreversible and/or invasive lung disease. There is great need for exploration of safe, repeatable imaging techniques which can run at real-time and with high spatial resolution. In this study, optical coherence tomography (OCT) was utilized to acquire cross-sectional images of upper and lower airways using fresh pig lung resections as a model system. Obtained OCT images were compared with parallel tissue characterization by conventional histological analysis. Our objective was to determine whether OCT differentiates the composite structural layers and inherent anatomical variations along different airway locations. The data show that OCT can clearly display the multilayered structure of the airways. The subtle architectural differences in three separate anatomical locations including trachea, main bronchus and tertiary bronchus were clearly delineated. Images of the appropriate anatomical profiles, with depth of up to 2 mm and 10 microm spatial resolution were obtained by our current OCT system, which was sufficient for recognition of the epithelium, subepithelial tissues and cartilage. In addition, the relative thickness of individual structural components was accurately reflected and comparable to histological sections. These data support OCT as a highly feasible, optical biopsy tool, which merits further exploration for early diagnosis of human airway epithelial pathology.

Alveolar epithelial cells in idiopathic pulmonary fibrosis display upregulation of TRAIL, DR4 and DR5 expression with simultaneous preferential over-expression of pro-apoptotic marker p53.

Idiopathic pulmonary fibrosis (IPF) is a progressive, debilitating, and fatal lung disease of unknown aetiology with no current cure. The pathogenesis of IPF remains unclear but repeated alveolar epithelial cell (AEC) injuries and subsequent apoptosis are believed to be among the initiating/ongoing triggers. However, the precise mechanism of apoptotic induction is hitherto elusive. In this study, we investigated expression of a panel of pro-apoptotic and cell cycle regulatory proteins in 21 IPF and 19 control lung tissue samples. We reveal significant upregulation of the apoptosis-inducing ligand TRAIL and its cognate receptors DR4 and DR5 in AEC within active lesions of IPF lungs. This upregulation was accompanied by pro-apoptotic protein p53 overexpression. In contrast, myofibroblasts within the fibroblastic foci of IPF lungs exhibited high TRAIL, DR4 and DR5 expression but negligible p53 expression. Similarly, p53 expression was absent or negligible in IPF and control alveolar macrophages and lymphocytes. No significant differences in TRAIL expression were noted in these cell types between IPF and control lungs. However, DR4 and DR5 upregulation was detected in IPF alveolar macrophages and lymphocytes. The marker of cellular senescence p21(WAF1) was upregulated within affected AEC in IPF lungs. Cell cycle regulatory proteins Cyclin D1 and SOCS3 were significantly enhanced in AEC within the remodelled fibrotic areas of IPF lungs but expression was negligible in myofibroblasts. Taken together these findings suggest that, within the remodelled fibrotic areas of IPF, AEC can display markers associated with proliferation, senescence, and apoptotosis, where TRAIL could drive the apoptotic response. Clear understanding of disease processes and identification of therapeutic targets will direct us to develop effective therapies for IPF.

Mesenchymal stem cell therapy and lung diseases.

Mesenchymal stem cells (MSCs), a distinct population of adult stem cells, have amassed significant interest from both medical and scientific communities. An inherent multipotent differentiation potential offers a cell therapy option for various diseases, including those of the musculoskeletal, neuronal, cardiovascular and pulmonary systems. MSCs also secrete an array of paracrine factors implicated in the mitigation of pathological conditions through anti-inflammatory, anti-apoptotic and immunomodulatory mechanisms. The safety and efficacy of MSCs in human application have been confirmed through small- and large-scale clinical trials. However, achieving the optimal clinical benefit from MSC-mediated regenerative therapy approaches is entirely dependent upon adequate understanding of their healing/regeneration mechanisms and selection of appropriate clinical conditions. MSC-mediated acute alveolar injury repair. A cartoon depiction of an injured alveolus with associated inflammation and AEC apoptosis. Proposed routes of MSC delivery into injured alveoli could be by either intratracheal or intravenous routes, for instance. Following delivery a proposed mechanism of MSC action is to inhibit/reduce alveolar inflammation by abrogation of IL-1_-depenedent Tlymphocyte proliferation and suppression of TNF-_ secretion via macrophage activation following on from stimulation by MSC-secreted IL-1 receptor antagonist (IL-1RN). The inflammatory environment also stimulates MSC to secrete prostaglandin-E2 (PGE2) which can stimulate activated macrophages to secrete the anti-inflammatory cytokine IL-10. Inhibition of AEC apoptosis following injury can also be promoted via MSC stimulated up-regulation of the anti-apoptotic Bcl-2 gene. MSC-secreted KGF can stimulate AECII proliferation and migration propagating alveolar epithelial restitution. Alveolar structural engraftment of MSC is a rare event.

Idiopathic pulmonary fibrosis: immunohistochemical analysis provides fresh insights into lung tissue remodelling with implications for novel prognostic markers.

AIM: This study explored the cellular and biological interrelationships involved in Idiopathic Pulmonary Fibrosis (IPF) lung tissue remodelling using immunohistochemical analysis. METHODS AND RESULTS: IPF and control lung tissues were examined for localisation of Epithelial Mesenchymal Transition (EMT), proliferation and growth factor markers assessing their relationship to key histological aberrations. E-cadherin was expressed in IPF and control (Alveolar type II) ATII cells (>75%). In IPF, mean expression of N-cadherin was scanty (<10%): however 4 cases demonstrated augmented expression in ATII cells correlating to histological disease status (Pearson correlation score 0.557). Twist was expressed within fibroblastic foci but not in ATII cells. Transforming Growth Factor- ß (TGF-ß) protein expression was significantly increased in IPF ATII cells with variable expression within fibroblastic foci. Antigen Ki-67 was observed within hyperplastic ATII cells but not in cells overlying foci. Collagen I and α-smooth muscle actin (α-SMA) were strongly expressed within fibroblastic foci (>75%); cytoplasmic collagen I in ATII cells was present in 3 IPF cases. IPF ATII cells demonstrated variable Surfactant Protein-C (SP-C). CONCLUSIONS: The pathogenesis of IPF is complex and involves multiple factors, possibly including EMT. Histological analysis suggests TGF-ß-stimulated myofib rob lasts initiate a contractile response within established fibroblastic foci while proliferating ATII cells attempt to instigate alveolar epithelium repair. Marker expression (N-cadherin and Ki-67) correlation with histological disease activity (as reflected by fibroblastic foci extent) may emerge as future prognostic indicators for IPF.

IFN-gamma regulation of ICAM-1 receptors in bronchial epithelial cells: soluble ICAM-1 release inhibits human rhinovirus infection.

BACKGROUND: Intercellular adhesion molecule-1 (ICAM-1) is a critical target-docking molecule on epithelial cells for 90% of human rhinovirus (HRV) serotypes. Two forms of ICAM-1 exist, membranous (mICAM-1) and soluble (sICAM-1), both expressed by bronchial epithelial cells. Interferon-gamma (IFN-gamma), a crucial Th-1 immuno-regulatory mediator, can modulate mICAM-1 expression; however its simultaneous effects on mICAM-1: sICAM-1 levels and their consequent outcome on cell infectivity have not been previously explored. METHODS: Primary normal human bronchial epithelial cells were pre-stimulated with IFN-gamma (1 ng/ml for 24 h) and subsequently inoculated with HRV-14 or HRV-1b (TCID50 10 2.5). Epithelial surface ICAM-1 expression and soluble ICAM-1 release were measured at the protein and gene level by immunofluorescence and ELISA respectively; mRNA levels were semi-quantified using RT-PCR. Molecular mechanisms regulating ICAM-1 isoform expression and effects on epithelial cell infectivity were explored. RESULTS: In IFN-gamma-biased cells infected with HRV-14, but not HRV-1b, mICAM-1 expression is down-regulated, with simultaneous induction of sICAM-1 release. This differential effect on HRV-14 receptor isoforms appears to be related to a combination of decreased IFN-gamma-induced JAK-STAT signalling and proteolytic receptor cleavage of the membranous form in IFN-gamma-biased HRV-14 infected cells. The observed changes in relative mICAM-1: sICAM-1 expression levels are associated with reduced HRV-14 viral titres. CONCLUSION: These findings support the hypothesis that in epithelial cells conditioned to IFN-gamma and subsequently exposed to HRV-14 infection, differential modulation in the ratio of ICAM-1 receptors prevails in favour of an anti-viral milieu, appearing to limit further target cell viral attachment and propagation.

Simvastatin inhibits growth factor expression and modulates profibrogenic markers in lung fibroblasts.

Simvastatin is best known for its antilipidemic action and use in cardiovascular disease due to its inhibition of 3-hydroxy-3-methylglutaryl CoenzymeA (HMG CoA) reductase, a key enzyme in the cholesterol synthesis pathway. Inhibition of biological precursors in this pathway also enables pleiotrophic immunomodulatory and anti-inflammatory capabilities, including modulation of growth factor expression. Connective tissue growth factor (CTGF) and persistent myofibroblast formation are major determinants of the aggressive fibrotic disease, idiopathic pulmonary fibrosis (IPF). In this study we used human lung fibroblasts derived from healthy and IPF lungs to examine Simvastatin effects on CTGF gene and protein expression, analyzed by RT-PCR and ELISA, respectively. Simvastatin significantly inhibited (P < 0.05) CTGF gene and protein expression, overriding the induction by transforming growth factor-beta1, a known potent inducer of CTGF. Such Simvastatin suppressor action on growth factor interaction was reflected functionally on recognized phenotypes of fibrosis. alpha-smooth muscle actin expression was downregulated and collagen gel contraction reduced by 4.94- and 7.58-fold in IMR90 and HIPF lung fibroblasts, respectively, when preconditioned with 10 microM Simvastatin compared with transforming growth factor-beta1 treatment alone after 24 h. Our data suggest that Simvastatin can modify critical determinants of the profibrogenic machinery responsible for the aggressive clinical profile of IPF, and potentially prevents adverse lung parenchymal remodeling associated with persistent myofibroblast formation.

Connective tissue growth factor expression and induction by transforming growth factor-beta is abrogated by simvastatin via a Rho signaling mechanism.

Connective tissue growth factor (CTGF), a potent profibrotic mediator, acts downstream and in concert with transforming growth factor (TGF)-beta to drive fibrogenesis. Significant upregulation of CTGF has been reported in fibrogenic diseases, including idiopathic pulmonary fibrosis (IPF), and is partly responsible for associated excessive fibroblast proliferation and extracellular matrix deposition, but no effective therapy exists for averting such fibrogeneic events. Simvastatin has reported putative antifibrotic actions in renal fibroblasts; this study explores such actions on human IPF-derived and normal lung fibroblasts and examines associated driving mechanisms. Simvastatin reduces basal CTGF gene and protein expression in all fibroblast lines, overriding TGF-beta induction through inhibition of the cholesterol synthesis pathway. Signaling pathways driving simvastatin's effects on CTGF/TGF-beta interaction were evaluated using transient reporter transfection of a CTGF promoter construct. Inhibition of CTGF promoter activity by simvastatin was most marked at 10 muM concentration, reducing activity by 76.2 and 51.8% over TGF-beta-stimulated cultures in IPF and normal fibroblasts, respectively. We also show that geranylgeranylpyrophosphate (GGPP), but not farnesylpyrophosphate, induces CTGF promoter activity following simvastatin inhibition by 55.3 and 31.1% over GGPP-negative cultures in IMR90 and IPF-derived fibroblasts, respectively, implicating small GTPase Rho involvement rather than Ras in these effects. Indeed, the specific Rho inhibitor C3 exotoxin significantly (P < 0.05) suppressed TGF-beta-induced CTGF promoter activity in transfected lung fibroblasts, a finding further supported by transfection of dominant-negative and constitutively active RhoA constructs, thus demonstrating that simvastatin through a Rho signaling mechanism in lung fibroblasts can modulate CTGF expression and interaction with TGF-beta.