Cigarette smoke-induced necroptosis and DAMP release trigger neutrophilic airway inflammation in mice

Recent data indicate a role for airway epithelial necroptosis, a regulated form of necrosis, and the associated release of damage-associated molecular patterns (DAMPs) in the development of chronic obstructive pulmonary disease (COPD). DAMPs can activate pattern recognition receptors (PRRs), triggering innate immune responses. We hypothesized that cigarette smoke (CS)-induced epithelial necroptosis and DAMP release initiate airway inflammation in COPD. Human bronchial epithelial BEAS-2B cells were exposed to cigarette smoke extract (CSE), and necrotic cell death (membrane integrity by propidium iodide staining) and DAMP release (i.e., double-stranded DNA, high-mobility group box 1, heat shock protein 70, mitochondrial DNA, ATP) were analyzed. Subsequently, BEAS-2B cells were exposed to DAMP-containing supernatant of CS-induced necrotic cells, and the release of proinflammatory mediators [C-X-C motif ligand 8 (CXCL-8), IL-6] was evaluated. Furthermore, mice were exposed to CS in the presence and absence of the necroptosis inhibitor necrostatin-1, and levels of DAMPs and inflammatory cell numbers were determined in bronchoalveolar lavage fluid. CSE induced a significant increase in the percentage of necrotic cells and DAMP release in BEAS-2B cells. Stimulation of BEAS-2B cells with supernatant of CS-induced necrotic cells induced a significant increase in the release of CXCL8 and IL-6, in a myeloid differentiation primary response gene 88-dependent fashion. In mice, exposure of CS increased the levels of DAMPs and numbers of neutrophils in bronchoalveolar lavage fluid, which was statistically reduced upon treatment with necrostatin-1. Together, we showed that CS exposure induces necrosis of bronchial epithelial cells and subsequent DAMP release in vitro, inducing the production of proinflammatory cytokines. In vivo, CS exposure induces neutrophilic airway inflammation that is sensitive to necroptosis inhibition.

Mitochondria: at the crossroads of regulating lung epithelial cell function in chronic obstructive pulmonary disease

Disturbances in mitochondrial structure and function in lung epithelial cells have been implicated in the pathogenesis of various lung diseases, including chronic obstructive pulmonary disease (COPD). Such disturbances affect not only cellular energy metabolism but also alter a range of indispensable cellular homeostatic functions in which mitochondria are known to be involved. These range from cellular differentiation, cell death pathways, and cellular remodeling to physical barrier function and innate immunity, all of which are known to be impacted by exposure to cigarette smoke and have been linked to COPD pathogenesis. Next to their well-established role as the first physical frontline against external insults, lung epithelial cells are immunologically active. Malfunctioning epithelial cells with defective mitochondria are unable to maintain homeostasis and respond adequately to further stress or injury, which may ultimately shape the phenotype of lung diseases. In this review, we provide a comprehensive overview of the impact of cigarette smoke on the development of mitochondrial dysfunction in the lung epithelium and highlight the consequences for cell function, innate immune responses, epithelial remodeling, and epithelial barrier function in COPD. We also discuss the applicability and potential therapeutic value of recently proposed strategies for the restoration of mitochondrial function in the treatment of COPD.

Use of inhaled and oral glucocorticoids, severity of inflammatory disease and risk of hip/femur fracture: a population-based case-control study

BACKGROUND

Patients using higher dosages of inhaled or oral glucocorticoids (GCs) have an increased risk of hip/femur fractures. The role of the underlying disease in the aetiology of this increased risk has not been widely studied.

OBJECTIVE

To evaluate the contribution of the underlying disease to the risk of hip/femur fracture in patients using inhaled or oral GCs.

DESIGN AND SUBJECTS

A case-control study within the Dutch PHARMO-RLS database was conducted. Cases (n = 6763) were adult patients with a first hip/femur fracture during enrolment. Each case was matched to four controls by age, gender and region.

RESULTS

The risk of hip/femur fracture increased with current use of inhaled GCs (crude OR 1.30, 95% CI:1.16-1.47) and with current use of oral GCs (crude OR 1.66, 95% CI: 1.46-1.90). After adjustment for disease severity, the risk of hip/femur fracture was no longer statistically significantly increased in inhaled GC users (adjusted OR 1.08, 95% CI: 0.91-1.27), whilst it remained elevated in oral GC users (adjusted OR 1.43, 95% CI: 1.22-1.67). Patients using inhaled GCs without any exposure to oral GCs had no increased risk of fracture (adjusted OR 0.98, 95% CI: 0.79-1.22).

CONCLUSION

Inhaled GC users had no increased risk of femur/hip fracture after adjustment for underlying disease severity. Our data suggest that, even at higher dosages, inhaled GC use is not an independent risk factor for fracture. In contrast, oral GC use was associated with an increased risk of fracture, which was not fully explained by the underlying disease severity.

Susceptibility for cigarette smoke-induced DAMP release and DAMP-induced inflammation in COPD

Cigarette smoke (CS) exposure is a major risk factor for chronic obstructive pulmonary disease (COPD). We investigated whether CS-induced damage-associated molecular pattern (DAMP) release or DAMP-mediated inflammation contributes to susceptibility for COPD. Samples, including bronchial brushings, were collected from young and old individuals, susceptible and nonsusceptible for the development of COPD, before and after smoking, and used for gene profiling and airway epithelial cell (AEC) culture. AECs were exposed to CS extract (CSE) or specific DAMPs. BALB/cByJ and DBA/2J mice were intranasally exposed to LL-37 and mitochondrial (mt)DAMPs. Functional gene-set enrichment analysis showed that CS significantly increases the airway epithelial gene expression of DAMPs and DAMP receptors in COPD patients. In cultured AECs, we observed that CSE induces necrosis and DAMP release, with specifically higher galectin-3 release from COPD-derived compared with control-derived cells. Galectin-3, LL-37, and mtDAMPs increased CXCL8 secretion in AECs. LL-37 and mtDAMPs induced neutrophilic airway inflammation, exclusively in mice susceptible for CS-induced airway inflammation. Collectively, we show that in airway epithelium from COPD patients, the CS-induced expression of DAMPs and DAMP receptors in vivo and the release of galectin-3 in vitro is exaggerated. Furthermore, our studies indicate that a predisposition to release DAMPs and subsequent induction of inflammation may contribute to the development of COPD.

Advanced glycation endproducts and their receptor in different body compartments in COPD

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic lung disease characterized by chronic airway inflammation and emphysema, and is caused by exposure to noxious particles or gases, e.g. cigarette smoke. Smoking and oxidative stress lead to accelerated formation and accumulation of advanced glycation end products (AGEs), causing local tissue damage either directly or by binding the receptor for AGEs (RAGE). This study assessed the association of AGEs or RAGE in plasma, sputum, bronchial biopsies and skin with COPD and lung function, and their variance between these body compartments.

METHODS

Healthy smoking and never-smoking controls (n = 191) and COPD patients (n = 97, GOLD stage I-IV) were included. Autofluorescence (SAF) was measured in the skin, AGEs (pentosidine, CML and CEL) and sRAGE in blood and sputum by ELISA, and in bronchial biopsies by immunohistochemistry. eQTL analysis was performed in bronchial biopsies.

RESULTS

COPD patients showed higher SAF values and lower plasma sRAGE levels compared to controls and these values associated with decreased lung function (p <0.001; adjusting for relevant covariates). Lower plasma sRAGE levels significantly and independently predicted higher SAF values (p < 0.001). One SNP (rs2071278) was identified within a region of 50 kB flanking the AGER gene, which was associated with the gene and protein expression levels of AGER and another SNP (rs2071278) which was associated with the accumulation of AGEs in the skin.

CONCLUSION

In COPD, AGEs accumulate differentially in body compartments, i.e. they accumulate in the skin, but not in plasma, sputum and bronchial biopsies. The association between lower sRAGE and higher SAF levels supports the hypothesis that the protective mechanism of sRAGE as a decoy-receptor is impaired in COPD.

The epithelial polarity regulator LGALS9/galectin-9 induces fatal frustrated autophagy in KRAS mutant colon carcinoma that depends on elevated basal autophagic flux

Oncogenic mutation of KRAS (Kirsten rat sarcoma viral oncogene homolog) in colorectal cancer (CRC) confers resistance to both chemotherapy and EGFR (epidermal growth factor receptor)-targeted therapy. We uncovered that KRAS mutant (KRAS^mut) CRC is uniquely sensitive to treatment with recombinant LGALS9/Galectin-9 (rLGALS9), a recently established regulator of epithelial polarity. Upon treatment of CRC cells, rLGALS9 rapidly internalizes via early- and late-endosomes and accumulates in the lysosomal compartment. Treatment with rLGALS9 is accompanied by induction of frustrated autophagy in KRAS^mut CRC, but not in CRC with BRAF (B-Raf proto-oncogene, serine/threonine kinase) mutations (BRAF^mut). In KRAS^mut CRC, rLGALS9 acts as a lysosomal inhibitor that inhibits autophagosome-lysosome fusion, leading to autophagosome accumulation, excessive lysosomal swelling and cell death. This antitumor activity of rLGALS9 directly correlates with elevated basal autophagic flux in KRAS^mut cancer cells. Thus, rLGALS9 has potent antitumor activity toward refractory KRAS^mut CRC cells that may be exploitable for therapeutic use.

Risk of fracture in patients with Parkinson's disease

The aim of the study was to determine fracture risk in incident Parkinson's disease (PD) patients. This study showed that fracture risk assessment may be indicated among patients with PD, in particular when they have recently used selective serotonin re-uptake inhibitors or high-dose antipsychotics, or have a history of fracture, falling, low body mass index (BMI) or renal disease.

INTRODUCTION

PD is a movement disorder associated with falling and detrimental effects on bone. Both are recognized risk factors for fracture. Therefore, the aim was to determine fracture risk in incident PD patients stratified by treatment, severity, duration of disease and related comorbidities.

METHODS

We conducted a retrospective cohort study using the UK General Practice Research Database (1987-2011). Each PD patient was matched by age, sex, calendar time and practice to a control patient without history of PD.

RESULTS

We identified 4,687 incident PD patients. Compared to controls, a statistically significant increased risk was observed for any fracture (adjusted hazard ratio [AHR], 1.89; 95 % confidence interval [CI], 1.67-2.14), osteoporotic fracture (AHR, 1.99; 95 % CI, 1.72-2.30) and hip fracture (AHR 3.08; 95 % CI, 2.43-3.89). Fracture risk further increased with history of fracture, falling, low BMI, renal disease, antidepressant use and use of high-dose antipsychotics.

CONCLUSION

This study showed that incident PD patients have a statistically significant increased risk of fracture. Therefore, fracture risk assessment may be indicated among PD patients, who, besides the general risk factors for fracture, like increasing age and female gender, have recently used selective serotonin re-uptake inhibitors or high-dose antipsychotics or have a history of fracture, falling, low BMI or renal disease.

Soluble receptor for advanced glycation end products (sRAGE) as a biomarker of COPD

BACKGROUND

Soluble receptor for advanced glycation end products (sRAGE) is a proposed emphysema and airflow obstruction biomarker; however, previous publications have shown inconsistent associations and only one study has investigate the association between sRAGE and emphysema. No cohorts have examined the association between sRAGE and progressive decline of lung function. There have also been no evaluation of assay compatibility, receiver operating characteristics, and little examination of the effect of genetic variability in non-white population. This manuscript addresses these deficiencies and introduces novel data from Pittsburgh COPD SCCOR and as well as novel work on airflow obstruction. A meta-analysis is used to quantify sRAGE associations with clinical phenotypes.

METHODS

sRAGE was measured in four independent longitudinal cohorts on different analytic assays: COPDGene (n = 1443); SPIROMICS (n = 1623); ECLIPSE (n = 2349); Pittsburgh COPD SCCOR (n = 399). We constructed adjusted linear mixed models to determine associations of sRAGE with baseline and follow up forced expiratory volume at one second (FEV1) and emphysema by quantitative high-resolution CT lung density at the 15th percentile (adjusted for total lung capacity).

RESULTS

Lower plasma or serum sRAGE values were associated with a COPD diagnosis (P < 0.001), reduced FEV1 (P < 0.001), and emphysema severity (P < 0.001). In an inverse-variance weighted meta-analysis, one SD lower log10-transformed sRAGE was associated with 105 ± 22 mL lower FEV1 and 4.14 ± 0.55 g/L lower adjusted lung density. After adjusting for covariates, lower sRAGE at baseline was associated with greater FEV1 decline and emphysema progression only in the ECLIPSE cohort. Non-Hispanic white subjects carrying the rs2070600 minor allele (A) and non-Hispanic African Americans carrying the rs2071288 minor allele (A) had lower sRAGE measurements compare to those with the major allele, but their emphysema-sRAGE regression slopes were similar.

CONCLUSIONS

Lower blood sRAGE is associated with more severe airflow obstruction and emphysema, but associations with progression are inconsistent in the cohorts analyzed. In these cohorts, genotype influenced sRAGE measurements and strengthened variance modelling. Thus, genotype should be included in sRAGE evaluations.

Effect of long-term corticosteroid treatment on microRNA and gene-expression profiles in COPD

The aim was to investigate whether microRNA (miRNA) expression is modulated by inhaled corticosteroid (ICS) treatmentWe performed genome-wide miRNA analysis on bronchial biopsies of 69 moderate/severe chronic obstructive pulmonary disease (COPD) patients at baseline and after 6- and 30-month treatment with the ICS fluticasone propionate or placebo. The effect of ICS on miRNA expression was validated in differentiated primary bronchial epithelial cultures, and functional studies were conducted in BEAS-2B cells. MiRNAs affected by ICS and their predicted targets were compared to an independent miRNA dataset of bronchial brushings from COPD patients and healthy controls.Treatment with ICS for both 6 and 30 months significantly altered the expression of four miRNAs, including miR-320d, which was increased during ICS treatment compared with placebo. The ICS-induced increase of miR-320d was confirmed in primary airway epithelial cells. MiR-320d negatively correlated targets were enriched for pro-inflammatory genes and were increased in the bronchial brushes of patients with lower lung function in the independent dataset. Overexpression of miR-320d in BEAS-2B cells dampened cigarette smoke extract-induced pro-inflammatory activity via inhibition of nuclear factor-κB.Collectively, we identified miR-320d as a novel mediator of ICS, regulating the pro-inflammatory response of the airway epithelium.

A fully validated liquid chromatography-mass spectrometry method for the quantification of the soluble receptor of advanced glycation end-products (sRAGE) in serum using immunopurification in a 96-well plate format

The study of proteins is central to unraveling (patho)physiological processes and has contributed greatly to our understanding of biological systems. Corresponding studies often employ procedures to enrich proteins from their biological matrix using antibodies or other affinity binders coupled to beads with a large surface area and a correspondingly high binding capacity. Striving for maximal binding capacity may, however, not always be required or desirable, for example for proteins of low abundance. Here we describe a simplified immunoprecipitation in 96-well ELISA format (IPE) approach for fast and easy enrichment of proteins. The applicability of this approach for enriching low-abundant proteins was demonstrated by an IPE-based quantitative workflow using liquid chromatography-mass spectrometry (LC-MS) for the soluble Receptor of Advanced Glycation End-products (sRAGE), a promising biomarker in chronic obstructive pulmonary disease (COPD). The method was validated according to U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) guidelines and enabled accurate quantitation of sRAGE between 0.1 and 10 ng/mL in 50 µL serum. The assay showed substantial correlation with the two most commonly-used sRAGE immunoassays (ELISAs) (R²-values between 0.7 and 0.8). However, the LC-MS method reported 2-4 times higher sRAGE levels compared to the ELISAs, which is largely due to a suboptimal amount of capturing antibody and/or calibration strategy used by the immunoassays. In conclusion, our simplified IPE approach proved to be an efficient strategy for enriching the low-abundant protein sRAGE from serum and may provide an easy to use platform for enriching other (low-abundant) proteins from complex, biological matrices.

Substrate stiffness engineered to replicate disease conditions influence senescence and fibrotic responses in primary lung fibroblasts

In fibrosis remodelling of ECM leads to changes in composition and stiffness. Such changes can have a major impact on cell functions including proliferation, secretory profile and differentiation. Several studies have reported that fibrosis is characterised by increased senescence and accumulating evidence suggests that changes to the ECM including altered composition and increased stiffness may contribute to premature cellular senescence. This study investigated if increased stiffness could modulate markers of senescence and/or fibrosis in primary human lung fibroblasts. Using hydrogels representing stiffnesses that fall within healthy and fibrotic ranges, we cultured primary fibroblasts from non-diseased lung tissue on top of these hydrogels for up to 7 days before assessing senescence and fibrosis markers. Fibroblasts cultured on stiffer (±15 kPa) hydrogels showed higher Yes-associated protein-1 (YAP) nuclear translocation compared to soft hydrogels. When looking at senescence-associated proteins we also found higher secretion of receptor activator of nuclear factor kappa-B ligand (RANKL) but no change in transforming growth factor-β1 (TGF-β1) or connective tissue growth factor (CTGF) expression and higher decorin protein deposition on stiffer matrices. With respect to genes associated with fibrosis, fibroblasts on stiffer hydrogels compared to soft had higher expression of smooth muscle alpha (α)-2 actin (ACTA2), collagen (COL) 1A1 and fibulin-1 (Fbln1) and higher Fbln1 protein deposition after 7 days. Our results show that exposure of lung fibroblasts to fibrotic stiffness activates genes and secreted factors that are part of fibrotic responses and part of the Senescence-associated secretory phenotype (SASP). This overlap may contribute to the creation of a feedback loop whereby fibroblasts create a perpetuating cycle reinforcing progression of a fibrotic response.

Lipoedema in patients after bariatric surgery: report of two cases and review of literature

Lipoedema is a disorder of adipose tissue that is characterized by abnormal subcutaneous fat deposition, leading to swelling and enlargement of the lower limbs as well as the trunk. This entity is often misdiagnosed as lymphoedema or obesity and, therefore, may be overlooked and missed in patients scheduled for bariatric surgery. Patients with lipoedema who undergo bariatric surgery may have to continue to have extensive lower extremity and trunk adiposity despite adequate weight loss. In this report, we present two patients who had extensive trunk and lower extremity adiposity, one of them before and the other after the bariatric surgery.

AGER expression and alternative splicing in bronchial biopsies of smokers and never smokers

Cigarette smoking is one of the major risk factors for the development of chronic obstructive pulmonary disease (COPD). Evidence is accumulating that Receptor for Advanced Glycation-End products (RAGE)-signaling is a key pathway in the pathophysiology of COPD. To date, it is unknown how smoking affects RAGE expression. In the current study, we investigated the effect of smoking on AGER, the gene encoding RAGE, expression and on alternative splicing of AGER. To this end, we conducted RNA-Seq on bronchial biopsies for asymptomatic smokers (n = 36) and never smokers (n = 40). Total AGER gene expression was accessed using DESeq2, while alternative splicing was investigated by measuring the number of specific split reads spanning exon-exon junctions and the total split reads. One of the major isoforms of RAGE is endogenous soluble (es) RAGE, an anti-inflammatory decoy receptor, making up for approximately 10% of the total amount of soluble (s)RAGE. We found that smokers show decreased total gene expression of AGER in bronchial biopsies, while the relative abundance of the esRAGE isoform is increased. Furthermore, no difference in the serum levels of total sRAGE were observed between smokers and non-smokers. Our data indicates that smoking initiates a protective anti-inflammatory mechanism with decreased expression of the pro-inflammatory gene AGER and increased relative abundance of the anti-inflammatory isoform esRAGE.

Cardiac structure and function before and after bariatric surgery: a clinical overview

Obesity, defined as a body mass index of ≥30 kg/m² , is the most common chronic metabolic disease worldwide and its prevalence has been strongly increasing. Obesity has deleterious effects on cardiac function. The purpose of this review is to evaluate the effects of obesity and excessive weight loss due to bariatric surgery on cardiac function, structural changes and haemodynamic responses of both the left and right ventricle.

RAGE and TLR4 differentially regulate airway hyperresponsiveness: Implications for COPD

BACKGROUND

The receptor for advanced glycation end products (RAGE) and Toll-like receptor 4 (TLR4) is implicated in COPD. Although these receptors share common ligands and signalling pathways, it is not known whether they act in concert to drive pathological processes in COPD. We examined the impact of RAGE and/or TLR4 gene deficiency in a mouse model of COPD and also determined whether expression of these receptors correlates with airway neutrophilia and airway hyperresponsiveness (AHR) in COPD patients.

METHODS

We measured airway inflammation and AHR in wild-type, RAGE^-/- , TLR4^-/- and TLR4^-/- RAGE^-/- mice following acute exposure to cigarette smoke (CS). We also examined the impact of smoking status on AGER (encodes RAGE) and TLR4 bronchial gene expression in patients with and without COPD. Finally, we determined whether expression of these receptors correlates with airway neutrophilia and AHR in COPD patients.

RESULTS

RAGE^-/- mice were protected against CS-induced neutrophilia and AHR. In contrast, TLR4^-/- mice were not protected against CS-induced neutrophilia and had more severe CS-induced AHR. TLR4^-/- RAGE^-/- mice were not protected against CS-induced neutrophilia but were partially protected against CS-induced mediator release and AHR. Current smoking was associated with significantly lower AGER and TLR4 expression irrespective of COPD status, possibly reflecting negative feedback regulation. However, consistent with preclinical findings, AGER expression correlated with higher sputum neutrophil counts and more severe AHR in COPD patients. TLR4 expression did not correlate with neutrophilic inflammation or AHR.

CONCLUSIONS

Inhibition of RAGE but not TLR4 signalling may protect against airway neutrophilia and AHR in COPD.

Genetic variation associates with susceptibility for cigarette smoke-induced neutrophilia in mice

Neutrophilic airway inflammation is one of the major hallmarks of chronic obstructive pulmonary disease and is also seen in steroid resistant asthma. Neutrophilic airway inflammation can be induced by different stimuli including cigarette smoke (CS). Short-term exposure to CS induces neutrophilic airway inflammation in both mice and humans. Since not all individuals develop extensive neutrophilic airway inflammation upon smoking, we hypothesized that this CS-induced innate inflammation has a genetic component. This hypothesis was addressed by exposing 30 different inbred mouse strains to CS or control air for 5 consecutive days, followed by analysis of neutrophilic lung inflammation. By genomewide haplotype association mapping, we identified four susceptibility genes with a significant association to lung tissue levels of the neutrophil marker myeloperoxidase under basal conditions and an additional five genes specifically associated with CS-induced tissue MPO levels. Analysis of the expression levels of the susceptibility genes by quantitative RT-PCR revealed that three of the four genes associated with CS-induced tissue MPO levels had CS-induced changes in gene expression levels that correlate with CS-induced airway inflammation. Most notably, CS exposure induces an increased expression of the coiled-coil domain containing gene, Ccdc93, in mouse strains susceptible for CS-induced airway inflammation whereas Ccdc93 expression was decreased upon CS exposure in nonsusceptible mouse strains. In conclusion, this study shows that CS-induced neutrophilic airway inflammation has a genetic component and that several genes contribute to the susceptibility for this response.

Risk of fracture in patients with muscular dystrophies

The aim of the study was to determine fracture risk in incident muscular dystrophy (MD) patients. Patients with MD are at a 1.4-fold increased risk of fracture as compared with population-based control patients. Risk further increased among elderly and female patients and among patients exposed to oral glucocorticoids.

INTRODUCTION

Muscular dystrophies (MDs) are inherited diseases causing muscle weakness and thereby increase the risk of falling and detrimental effects on bone. Both are recognised risk factors for fracture. Therefore, the aim of this study was to determine the hazard ratio of fracture in patients with MD.

METHODS

We conducted a retrospective cohort study using the UK General Practice Research Database (1987-2012). Each patient with MD was matched by year of birth, sex and practice to up to six patients without a history of MD. Outcome measure was all fractures.

RESULTS

As compared with control patients, risk of any fracture was statistically significantly increased in MD patients (adjusted hazard ratio [AHR], 1.40; 95 % confidence interval [CI], 1.14-1.71). An increased risk of fracture was observed among MD patients with female gender (AHR, 1.78; 95 % CI, 1.33-2.40) and an increasing age as compared with control patients. Stratification to Duchenne MD showed no association with fracture, whereas risk of fracture was increased twofold among patients with myotonic dystrophy (AHR, 2.34; 95 % CI, 1.56-3.51). MD patients had an almost tripled risk of fracture when they used oral glucocorticoids in the previous 6 months as compared to non-users with MD.

CONCLUSION

Patients with MD are at a 1.4-fold increased risk of fracture as compared with population-based control patients. Especially in older age groups and female gender, the fracture risk of MD versus non-MD patients is increased, whereas exposure to glucocorticoids further increased fracture risk among MD patients.

Airway granulation response to lung-implantable medical devices: a concise overview

Increasing numbers of endoscopically implantable devices are implanted in the airways, such as airway stents, one-way valves and coils, to treat both malignant and benign diseases. They significantly improve patient outcomes, but their long-term effectiveness and sustainability is hampered by the reaction of the formation of granulation tissue. Factors including procedural-related tissue injury; micro-organism presence; device-related factors, such as the material, design and sizing in relation to the airway; and patient-related factors, including genetic susceptibility, comorbidities and medication use, might all effect the severity of the tissue response and the subsequent degree of granulation tissue formation. However, research into the underlying mechanism and risk factors is scarce and therefore our knowledge is limited. Joint efforts from the scientific community, both pre-clinical and clinical, are needed to gain a deeper understanding and eventually improve the long-term treatment effectiveness of lung-implantable devices.

BJS commission on surgery and perioperative care post-COVID-19

BACKGROUND

Coronavirus disease 2019 (COVID-19) was declared a pandemic by the WHO on 11 March 2020 and global surgical practice was compromised. This Commission aimed to document and reflect on the changes seen in the surgical environment during the pandemic, by reviewing colleagues' experiences and published evidence.

METHODS

In late 2020, BJS contacted colleagues across the global surgical community and asked them to describe how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had affected their practice. In addition to this, the Commission undertook a literature review on the impact of COVID-19 on surgery and perioperative care. A thematic analysis was performed to identify the issues most frequently encountered by the correspondents, as well as the solutions and ideas suggested to address them.

RESULTS

BJS received communications for this Commission from leading clinicians and academics across a variety of surgical specialties in every inhabited continent. The responses from all over the world provided insights into multiple facets of surgical practice from a governmental level to individual clinical practice and training.

CONCLUSION

The COVID-19 pandemic has uncovered a variety of problems in healthcare systems, including negative impacts on surgical practice. Global surgical multidisciplinary teams are working collaboratively to address research questions about the future of surgery in the post-COVID-19 era. The COVID-19 pandemic is severely damaging surgical training. The establishment of a multidisciplinary ethics committee should be encouraged at all surgical oncology centres. Innovative leadership and collaboration is vital in the post-COVID-19 era.

Genetic variance is associated with susceptibility for cigarette smoke-induced DAMP release in mice

Chronic obstructive pulmonary disease (COPD) is characterized by unresolved neutrophilic airway inflammation and is caused by chronic exposure to toxic gases, such as cigarette smoke (CS), in genetically susceptible individuals. Recent data indicate a role for damage-associated molecular patterns (DAMPs) in COPD. Here, we investigated the genetics of CS-induced DAMP release in 28 inbred mouse strains. Subsequently, in lung tissue from a subset of strains, the expression of the identified candidate genes was analyzed. We tested whether small interfering RNA-dependent knockdown of candidate genes altered the susceptibility of the human A549 cell line to CS-induced cell death and DAMP release. Furthermore, we tested whether these genes were differentially regulated by CS exposure in bronchial brushings obtained from individuals with a family history indicative of either the presence or absence of susceptibility for COPD. We observed that, of the four DAMPs tested, double-stranded DNA (dsDNA) showed the highest correlation with neutrophilic airway inflammation. Genetic analyses identified 11 candidate genes governing either CS-induced or basal dsDNA release in mice. Two candidate genes ( Elac2 and Ppt1) showed differential expression in lung tissue on CS exposure between susceptible and nonsusceptible mouse strains. Knockdown of ELAC2 and PPT1 in A549 cells altered susceptibility to CS extract-induced cell death and DAMP release. In bronchial brushings, CS-induced expression of ENOX1 and ARGHGEF11 was significantly different between individuals susceptible or nonsusceptible for COPD. Our study shows that genetic variance in a mouse model is associated with CS-induced DAMP release, and that this might contribute to susceptibility for COPD.