Update in Chronic Obstructive Pulmonary Disease 2020

The impact of chronic obstructive pulmonary disease on bone strength

Chronic obstructive pulmonary disease (COPD) is a lifestyle-related disease that develops in middle-aged and older adults, often due to smoking habits, and has been noted to cause bone fragility. COPD is a risk factor for osteoporosis and fragility fracture, and a high prevalence of osteoporosis and incidence of vertebral fractures have been shown in patients with COPD. Findings of lung tissue analysis in patients with COPD are primarily emphysema with a loss of alveolar septal walls, and the severity of pulmonary emphysema is negatively correlated with thoracic spine bone mineral density (BMD). On the other hand, epidemiological studies on COPD and fracture risk have reported a BMD-independent increase in fracture risk; however, verification in animal models and human bone biopsy samples has been slow, and the essential pathogenesis has not been elucidated. The detailed pathological/molecular mechanisms of musculoskeletal complications in patients with COPD are unknown, and basic research is needed to elucidate the mechanisms. This paper discusses the impacts of COPD on bone strength, focusing on findings in animal models in terms of bone microstructure, bone metabolic dynamics, and material properties.

Transcriptomic characterization of the human segmental endotoxin challenge model

Segmental instillation of lipopolysaccharide (LPS) by bronchoscopy safely induces transient airway inflammation in human lungs. This model enables investigation of pulmonary inflammatory mechanisms as well as pharmacodynamic analysis of investigational drugs. The aim of this work was to describe the transcriptomic profile of human segmental LPS challenge with contextualization to major respiratory diseases. Pre-challenge bronchoalveolar lavage (BAL) fluid and biopsies were sampled from 28 smoking, healthy participants, followed by segmental instillation of LPS and saline as control. Twenty-four hours post instillation, BAL and biopsies were collected from challenged lung segments. Total RNA of cells from BAL and biopsy samples were sequenced and analysed for differentially expressed genes (DEGs). After challenge with LPS compared with saline, 6316 DEGs were upregulated and 241 were downregulated in BAL, but only one DEG was downregulated in biopsy samples. Upregulated DEGs in BAL were related to molecular functions such as "Inflammatory response" or "chemokine receptor activity", and upregulated pro-inflammatory pathways such as "Wnt-"/"Ras-"/"JAK-STAT" "-signaling pathway". Furthermore, the segmental LPS challenge model resembled aspects of the five most prevalent respiratory diseases chronic obstructive pulmonary disease (COPD), asthma, pneumonia, tuberculosis and lung cancer and featured similarities with acute exacerbations in COPD (AECOPD) and community-acquired pneumonia. Overall, our study provides extensive information about the transcriptomic profile from BAL cells and mucosal biopsies following LPS challenge in healthy smokers. It expands the knowledge about the LPS challenge model providing potential overlap with respiratory diseases in general and infection-triggered respiratory insults such as AECOPD in particular.

The effect of bradykinin 1 receptor antagonist BI 1026706 on pulmonary inflammation after segmental lipopolysaccharide challenge in healthy smokers

BACKGROUND

Bradykinin 1 receptor (B1R) signalling pathways may be involved in the inflammatory pathophysiology of chronic obstructive pulmonary disease (COPD). B1R signalling is induced by inflammatory stimuli or tissue injury and leads to activation and increased migration of pro-inflammatory cells. Lipopolysaccharide (LPS) lung challenge in man is an experimental method of exploring inflammation in the lung whereby interference in these pathways can help to assess pharmacologic interventions in COPD. BI 1026706, a potent B1R antagonist, was hypothesized to reduce the inflammatory activity after segmental lipopolysaccharide (LPS) challenge in humans due to decreased pulmonary cell influx.

METHODS

In a monocentric, randomized, double-blind, placebo-controlled, parallel-group, phase I trial, 57 healthy, smoking subjects were treated for 28 days with either oral BI 1026706 100 mg bid or placebo. At day 21, turbo-inversion recovery magnitude magnetic resonance imaging (TIRM MRI) was performed. On the last day of treatment, pre-challenge bronchoalveolar lavage fluid (BAL) and biopsies were sampled, followed by segmental LPS challenge (40 endotoxin units/kg body weight) and saline control instillation in different lung lobes. Twenty-four hours later, TIRM MRI was performed, then BAL and biopsies were collected from the challenged segments. In BAL samples, cells were differentiated for neutrophil numbers as the primary endpoint. Other endpoints included assessment of safety, biomarkers in BAL (e.g. interleukin-8 [IL-8], albumin and total protein), B1R expression in lung biopsies and TIRM score by MRI as a measure for the extent of pulmonary oedema.

RESULTS

After LPS, but not after saline, high numbers of inflammatory cells, predominantly neutrophils were observed in the airways. IL-8, albumin and total protein were also increased in BAL samples after LPS challenge as compared with saline control. There were no significant differences in cells or other biomarkers from BAL in volunteers treated with BI 1026706 compared with those treated with placebo. Unexpectedly, neutrophil numbers in BAL were 30% higher and MRI-derived extent of oedema was significantly higher with BI 1026706 treatment compared with placebo, 24 h after LPS challenge. Adverse events were mainly mild to moderate and not different between treatment groups.

CONCLUSIONS

Treatment with BI 1026706 for four weeks was safe and well-tolerated in healthy smoking subjects. BI 1026706 100 mg bid did not provide evidence for anti-inflammatory effects in the human bronchial LPS challenge model.

TRIAL REGISTRATION

The study was registered on January 14, 2016 at ClinicalTrials.gov (NCT02657408).

Oxidative stress causes muscle structural alterations via p38 MAPK signaling in COPD mouse model

INTRODUCTION

Sarcopenia is a complication of Chronic Obstructive Pulmonary Disease (COPD) that negatively affects physical activity and quality of life. However, the underlying mechanism by which COPD affects skeletal muscles remains to be elucidated. Therefore, we investigated the association between oxidative stress and structural alterations in muscles in elastase-induced emphysema mouse models.

MATERIALS AND METHODS

Twelve-week-old male C57BL/6J mice were treated with either intratracheal porcine pancreatic elastase (PPE) dissolved in saline, or saline alone. The mice were euthanized 12 weeks after treatment, and the lungs and limb muscles were used for protein analysis of oxidative stress, p38 mitogen-activated protein kinase (p38 MAPK) signaling pathway and muscle atrophy signaling pathway related with oxidative stress. Furthermore, C57BL/6J mice treated with PPE or saline were analyzed for the effects of oral administration of astaxanthin or p38 inhibitor.

RESULTS

The weight of the soleus muscle, proportion of type I muscle fibers, and cross-sectional areas of muscle fibers in the PPE group were lower than those in the control group. Oxidative stress marker levels in the PPE group were elevated in skeletal muscles. The p38 MAPK signaling pathway was activated in the soleus muscles, leading to the activation of the ubiquitin-proteasome system and autophagy. Astaxanthin and p38 inhibitors attenuated alterations in muscle structure through the deactivation of the p38 MAPK signaling pathway.

CONCLUSIONS

This study provides first evidence in COPD mouse model that oxidative stress trigger a series of muscle structural changes. Our findings suggest a novel target for sarcopenia in COPD.

MAFLD associated with COPD via systemic inflammation independent of aging and smoking in men

BACKGROUND AND AIM

Metabolic dysfunction and associated systemic inflammation are risk factors for chronic obstructive pulmonary disease (COPD) and COPD is highly prevalent in men. We investigated the impact of metabolic-associated fatty liver disease (MAFLD) and MAFLD-related systemic inflammation on COPD in men.

METHODS

We enrolled 2,041 men with fatty liver. Patients were classified into the COPD (n = 420/2041) and non-COPD (n = 1621/2041) groups. COPD and its high-risk group were diagnosed using the Japanese Respiratory Society Disease statement. Systemic inflammation was evaluated using the C-reactive protein (CRP)/albumin ratio. Independent factors for COPD were investigated by multivariate analysis and decision-tree analysis.

RESULTS

The prevalence of MAFLD was significantly higher in the COPD group than in the non-COPD group. In multivariable analysis, in addition to heavy smoking and aging, MAFLD was identified as an independent factor for COPD (OR 1.46, 95% CI 1.020-2.101, P = 0.0385). Decision-tree analysis showed that MAFLD, rather than heavy smoking, was the most influential classifier for COPD in non-elderly men (14% in MAFLD vs 6% in non-MAFLD groups). MAFLD was also the second most influential factor in elderly men who were not heavy smokers. In both groups, the CRP/albumin ratio was the first classifier for COPD (16% in the high CRP/albumin ratio group vs 3% in the low CRP/albumin ratio group of non-elderly men).

CONCLUSIONS

MAFLD is an independent predictor of COPD in men. MAFLD had a significant impact on COPD through systemic inflammation in men of all ages who were not heavy smokers. MAFLD may be useful to broadly identify COPD in men.

Molecular mechanism of betulin palliative therapy for chronic obstructive pulmonary disease (COPD) based on P2X7 receptor target of gated ion channel

Background

The aim of this study was to discover the molecular mechanism of betulin palliative therapy for chronic obstructive pulmonary disease (COPD) based on the P2X7 receptor target of gated ion channel.

Methods

A COPD mouse model was developed. Changes in pulmonary ventilation function, pulmonary airway and vascular remodeling indicators, inflammatory cells, and inflammatory factors were determined after betulin intervention, and the pathological alterations of lung tissues were detected. An in vitro experimental model was constructed to observe the influence of betulin at varying concentrations on the proliferation of human bronchial epidermal cell line (16-HBE) cells and changes in inflammatory factors in cell supernatant. The expression levels of key proteins in 16-HBE cells transfected with overexpressed or silenced P2X7 genes were determined through quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blot.

Results

After betulin intervention, pulmonary ventilation function in the 20 mg/kg betulin and 40 mg/kg betulin groups was improved. Levels of white blood cells (WBCs), neutrophils (Ns), tumor necrosis factor (TNF), TNF-ɑ, interleukin (IL)-1β, and IL-6 in the 2 groups also decreased significantly (all P<0.05). The pathological changes in COPD mice were detected. After betulin intervention, the pathological injury of the lung was reduced, the pathological score decreased significantly, and the remodeling indicators of pulmonary airway and pulmonary vessels diminished remarkably (all P<0.05). Betulin had no effect on the proliferation of 16-HBE cells in vitro. After cigarette smoke extract (CSE) stimulation, the rate of survival for 16-HBE cells decreased significantly. After betulin treatment, the survival rate of 16-HBE cells augmented remarkably, and the levels of TNF-ɑ, IL-6, and IL-1β in cell supernatant reduced substantially (all P<0.05). 16-HBE with overexpression and knockdown of P2X7 was constructed. After being treated with betulin, the relative expression levels of messenger RNA (mRNA) of ERK, JNK, rho-associated protein kinase (ROCK), nuclear factor-κB (NF-κB), and p38 in 16-HBE cells with P2X7 overexpression or knockdown were decreased significantly (all P<0.05), but the above indicators were largely unchanged (all P>0.05).

Conclusions

Betulin relieved lung pathological injury, ameliorated lung ventilation function, and diminished the level of inflammatory factors in COPD mice, playing a therapeutic role via the P2X7 signaling pathway.

Hydrogels and Hydrogel Nanocomposites: Enhancing Healthcare through Human and Environmental Treatment

Humans are constantly exposed to exogenous chemicals throughout their life, which can lead to a multitude of negative health impacts. Advanced materials can play a key role in preventing or mitigating these impacts through a wide variety of applications. The tunable properties of hydrogels and hydrogel nanocomposites (e.g., swelling behavior, biocompatibility, stimuli responsiveness, functionality, etc.) have deemed them ideal platforms for removal of environmental contaminants, detoxification, and reduction of body burden from exogenous chemical exposures for prevention of disease initiation, and advanced treatment of chronic diseases, including cancer, diabetes, and cardiovascular disease. In this review, three main junctures where the use of hydrogel and hydrogel nanocomposite materials can intervene to positively impact human health are highlighted: 1) preventing exposures to environmental contaminants, 2) prophylactic treatments to prevent chronic disease initiation, and 3) treating chronic diseases after they have developed.

Exosomes derived from adipose-derived stem cells alleviate cigarette smoke-induced lung inflammation and injury by inhibiting alveolar macrophages pyroptosis

Background

Chronic obstructive pulmonary disease (COPD) is a frequently encountered disease condition in clinical practice mainly caused by cigarette smoke (CS). The aim of this study was to investigate the protective roles of human adipose-derived stem cells-derived exosomes (ADSCs-Exo) in CS-induced lung inflammation and injury and explore the underlying mechanism by discovering the effects of ADSCs-Exo on alveolar macrophages (AMs) pyroptosis.

Methods

ADSCs were isolated from human adipose tissues harvested from three healthy donors, and then ADSCs-Exo were isolated. In vivo, 24 age-matched male C57BL/6 mice were exposed to CS for 4 weeks, followed by intratracheal administration of ADSCs-Exo or phosphate buffered saline. In vitro, MH-S cells, derived from mouse AMs, were stimulated by 2% CS extract (CSE) for 24 h, followed by the treatment of ADSCs-Exo or phosphate buffered saline. Pulmonary inflammation was analyzed by detecting pro-inflammatory cells and mediators in the bronchoalveolar lavage fluid. Lung histology was assessed by hematoxylin and eosin staining. Mucus production was determined by Alcian blue-periodic acid-Schiff staining. The profile of AMs pyroptosis was evaluated by detecting the levels of pyroptosis-indicated proteins. The inflammatory response in AMs and the phagocytic activity of AMs were also investigated.

Results

In mice exposed to CS, the levels of pro-inflammatory cells and mediators were significantly increased, mucus production was markedly increased and lung architecture was obviously disrupted. AMs pyroptosis was elevated and AMs phagocytosis was inhibited. However, the administration of ADSCs-Exo greatly reversed these alterations caused by CS exposure. Consistently, in MH-S cells with CSE-induced properties modelling those found in COPD, the cellular inflammatory response was elevated, the pyroptotic activity was upregulated while the phagocytosis was decreased. Nonetheless, these abnormalities were remarkably alleviated by the treatment of ADSCs-Exo.

Conclusions

ADSCs-Exo effectively attenuate CS-induced airway mucus overproduction, lung inflammation and injury by inhibiting AMs pyroptosis. Therefore, hADSCs-Exo may be a promising cell-free therapeutic candidate for CS-induced lung inflammation and injury.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-01926-w.