Accelerated ageing of the lung in COPD: new concepts

The Impact of Different Smoking Behavior on Pulmonary Function and Pulmonary Hypertension Among Chinese Male Patients with Chronic Obstructive Pulmonary Disease

Purpose

Cigarette smoking is the most recognized risk factor of chronic obstructive pulmonary disease (COPD) in China. However, there are no studies analyzing the impact of different smoking behaviors on pulmonary function and pulmonary hypertension (PH) among Chinese male patients with COPD.

Patients and Methods

Chinese male smokers with COPD performed pulmonary function tests. Clinical characteristics, smoking behavior features, spirometry and echocardiographic results were compared between the two groups stratified by initial smoking age (18 years old) or complicated PH.

Results

The early-smoking group had more respiratory symptoms, more severe smoking behavior, worse pulmonary function with lower FEV1%pre (38.5% vs 70.2%) and FEV1/FVC% (47.5% vs 63.8%), and higher systolic pulmonary artery pressure (sPAP: 38.6 vs 33.9 mmHg) than the late-smoking group. Initiating smoking before adulthood was an independently contributing factor of ventilatory dysfunction and Global Initiative for Obstructive Lung Disease (GOLD) stage escalation. It also had a significant interaction with long smoking duration (≥30 years), characterized by markedly decreased lung volumes (VC%pre: 64.0% vs 84.5%), impaired diffusing capacity (DLCO%pre: 58.0% vs 76.8%) and severe emphysema (RV/TLC%pre: 145.2% vs 130.2%). COPD patients complicated with PH exhibited worse ventilatory function (FEV1%pre: 43.2% vs 56.2%), impaired diffusion capacity (DLCO%pre: 56.7% vs 77.1%) and decreased lung volume (VC%pre: 67.67% vs 75.38%). Both severe smoking behaviors and impaired pulmonary function had close correlations with sPAP.

Conclusion

The early-smoking group exhibited predominantly ventilation dysfunction and had complex interactions with long smoking duration to further affect lung volume and diffusion capacity. Different smoking behaviors influenced variations of pulmonary dysfunction and comorbid PH in patients with COPD.

Pulmonary drug delivery devices and nanosystems as potential treatment strategies for acute respiratory distress syndrome (ARDS)

Despite advances in drug delivery technologies, treating acute respiratory distress syndrome (ARDS) is challenging due to pathophysiological barriers such as lung injury, oedema fluid build-up, and lung inflammation. Active pharmaceutical ingredients (API) can be delivered directly to the lung site of action with the use of aerosol-based drug delivery devices, and this circumvents the hepatic first-pass effect and improves the bioavailability of drugs. This review discusses the various challenges and barriers for pulmonary drug delivery, current interventions for delivery, considerations for effective drug delivery, and the use of nanoparticle drug delivery carriers as potential strategies for delivering therapeutics in ARDS. Nanosystems have the added benefit of entrapping drugs, increase pulmonary drug bioavailability, and using biocompatible and biodegradable excipients that can facilitate targeted and/or controlled delivery. These systems provide an alternative to existing conventional systems. An effective way to deliver drugs for the treatment of ARDS can be by using colloidal systems that are aerosolized or inhaled. Drug distribution to the deeper pulmonary tissues is necessary due to the significant endothelial cell destruction that is prevalent in ARDS. The particle size of nanoparticles (<0.5 μm) makes them ideal candidates for treating ARDS as they can reach the alveoli. A look into the various potential benefits and limitations of nanosystems used for other lung disorders is also considered to indicate how they may be useful for the potential treatment of ARDS.

Human Muse cells isolated from preterm- and term-umbilical cord delivered therapeutic effects in rat bleomycin-induced lung injury model without immunosuppressant

BACKGROUND

Bleomycin (BLM)-induced lung injury is characterized by mixed histopathologic changes with inflammation and fibrosis, such as observed in human patients with bronchopulmonary dysplasia, idiopathic pulmonary fibrosis, and chronic obstructive pulmonary disease. Although no curative therapies for these lung diseases exist, stem cell therapy has emerged as a potential therapeutic option. Multilineage-differentiating stress-enduring (Muse) cells are endogenous pluripotent- and macrophage-like stem cells distributed in various adult and fetal tissues as stage-specific embryonic antigen-3-positive cells. They selectively home to damaged tissue by sensing sphingosine-1-phosphate and replace the damaged/apoptotic cells by in vivo differentiation. Clinical trials for some human diseases suggest the safety and therapeutic efficacy of intravenously injected human leukocyte antigen-mismatched allogenic Muse cells from adult bone marrow (BM) without immunosuppressant. Here, we evaluated the therapeutic effects of human Muse cells from preterm and term umbilical cord (UC), and adult BM in a rat BLM-induced lung injury model.

METHODS

Rats were endotracheally administered BLM to induce lung injury on day 0. On day 3, human preterm UC-Muse, term UC-Muse, or adult BM-Muse cells were administered intravenously without immunosuppressants, and rats were subjected to histopathologic analysis on day 21. Body weight, serum surfactant protein D (SP-D) levels, and oxygen saturation (SpO2) were monitored. Histopathologic lung injury scoring by the Ashcroft and modified American Thoracic Society document scales, quantitative characterization of engrafted Muse cells, RNA sequencing analysis, and in vitro migration assay of infused Muse cells were performed.

RESULTS

Rats administered preterm- and term-UC-Muse cells exhibited a significantly better recovery based on weight loss, serum SP-D levels, SpO2, and histopathologic lung injury scores, and a significantly higher rate of both Muse cell homing to the lung and alveolar marker expression (podoplanin and prosurfactant protein-C) than rats administered BM-Muse cells. Rats receiving preterm-UC-Muse cells showed statistically superior results to those receiving term-UC-Muse cells in many of the measures. These findings are thought to be due to higher expression of genes related to cell migration, lung differentiation, and cell adhesion.

CONCLUSION

Preterm UC-Muse cells deliver more efficient therapeutic effects than term UC- and BM-Muse cells for treating BLM-induced lung injury in a rat model.

The aging lung: microenvironment, mechanisms, and diseases

With the development of global social economy and the deepening of the aging population, diseases related to aging have received increasing attention. The pathogenesis of many respiratory diseases remains unclear, and lung aging is an independent risk factor for respiratory diseases. The aging mechanism of the lung may be involved in the occurrence and development of respiratory diseases. Aging-induced immune, oxidative stress, inflammation, and telomere changes can directly induce and promote the occurrence and development of lung aging. Meanwhile, the occurrence of lung aging also further aggravates the immune stress and inflammatory response of respiratory diseases; the two mutually affect each other and promote the development of respiratory diseases. Explaining the mechanism and treatment direction of these respiratory diseases from the perspective of lung aging will be a new idea and research field. This review summarizes the changes in pulmonary microenvironment, metabolic mechanisms, and the progression of respiratory diseases associated with aging.

Olfactory decline develops in parallel with frailty in older US adults with obstructive lung diseases

BACKGROUND

Frailty is prevalent among older adults with asthma or chronic obstructive pulmonary disease (obstructive lung diseases [OLDs]). Frailty and OLD's co-occurrence is associated with increased hospitalization/mortality. Chemosensory dysfunction is closely connected to both OLD and frailty. We evaluated the utility of olfactory decline as a biomarker of frailty in the setting of OLD.

METHODS

We performed a prospective, longitudinal, nationally representative study of community-dwelling older US adults in the National Social Life, Health and Aging Project, an omnibus in-home survey. Respondents reported a physician's diagnosis of OLD. Decline in odor identification and sensitivity over 5 years and frailty (adapted fried frailty phenotype criteria) were measured using standard tools. Multivariate logistic regressions evaluated the association between OLD status, olfactory decline, and frailty.

RESULTS

We compared individuals with OLD (n = 98; mean age 71.2 years, 59.2% women) and those without OLD (n = 1036; mean age 69.5 years, 58.9% women). Olfactory identification decline was associated with developing frailty over the 5-year follow-up period in individuals with OLD (odds ratio [OR] = 9.1, 95% confidence interval [CI] = 2.1-38.6, p = 0.003). Olfactory decline predicted incidence of frailty in individuals with OLD (identification: OR = 4.8, 95% CI = 1.3-17.5, P = 0.018; sensitivity: OR = 6.1, 95%CI = 1.2-31.0, p = 0.030) but not in those without OLD adjusting for demographics, heavy alcohol use, current smoking, and comorbidity. Results were robust to different thresholds for olfactory decline and frailty development.

CONCLUSIONS

Older adults with OLD who experience olfactory decline face higher odds of developing frailty. Use of olfactory decline as a biomarker to identify frailty could allow earlier intervention and decrease adverse outcomes for high-risk older adults with OLD.

Zerumbone liquid crystalline nanoparticles protect against oxidative stress, inflammation and senescence induced by cigarette smoke extract in vitro

The purpose of this study was to evaluate the potential of zerumbone-loaded liquid crystalline nanoparticles (ZER-LCNs) in the protection of broncho-epithelial cells and alveolar macrophages against oxidative stress, inflammation and senescence induced by cigarette smoke extract in vitro. The effect of the treatment of ZER-LCNs on in vitro cell models of cigarette smoke extract (CSE)-treated mouse RAW264.7 and human BCi-NS1.1 basal epithelial cell lines was evaluated for their anti-inflammatory, antioxidant and anti-senescence activities using colorimetric and fluorescence-based assays, fluorescence imaging, RT-qPCR and proteome profiler kit. The ZER-LCNs successfully reduced the expression of pro-inflammatory markers including Il-6, Il-1β and Tnf-α, as well as the production of nitric oxide in RAW 264.7 cells. Additionally, ZER-LCNs successfully inhibited oxidative stress through reduction of reactive oxygen species (ROS) levels and regulation of genes, namely GPX2 and GCLC in BCi-NS1.1 cells. Anti-senescence activity of ZER-LCNs was also observed in BCi-NS1.1 cells, with significant reductions in the expression of SIRT1, CDKN1A and CDKN2A. This study demonstrates strong in vitro anti-inflammatory, antioxidative and anti-senescence activities of ZER-LCNs paving the path for this formulation to be translated into a promising therapeutic agent for chronic respiratory inflammatory conditions including COPD and asthma.

Association Between Serum Klotho and Chronic Obstructive Pulmonary Disease in US Middle-Aged and Older Individuals: A Cross-Sectional Study from NHANES 2013-2016

Purpose

This study sought to examine the potential association between serum Klotho levels and the prevalence of COPD in the United States.

Patients and Methods

This study was a cross-sectional analysis involving 4361 adults aged 40-79 years participating in the US National Health and Nutrition Examination Survey (NHANES) conducted between 2013 and 2016. Our investigation utilized multivariate logistic regression and restricted cubic spline (RCS) regression to explore the potential correlation between serum Klotho concentrations and the prevalence of COPD. Additionally, we conducted stratified and interaction analyses to evaluate the consistency and potential modifiers of this relationship.

Results

In this study encompassing 4631 patients (with an average age of 57.6 years, 47.5% of whom were male), 445 individuals (10.2%) were identified as having COPD. In the fully adjusted model, ln-transformed serum Klotho was negatively associated with COPD (OR = 0.71; 95% CI: 0.51-0.99; p = 0.043). Meanwhile, compared with quartile 1, serum Klotho levels in quartiles 2-4 yielded odds ratios (ORs) (95% CI) for COPD were 0.84 (0.63~1.11), 0.76 (0.56~1.02), 0.84 (0.62~1.13), respectively. A negative relationship was observed between the ln-transformed serum Klotho and occurrence of COPD (nonlinear: p = 0.140). the association between ln-transformed serum Klotho and COPD were stable in stratified analyses.

Conclusion

Serum Klotho was negatively associated with the incidence of COPD, when ln-transformed Klotho concentration increased by 1 unit, the risk of COPD was 29% lower.

Development and validation of a nomogram model for mortality prediction in stable chronic obstructive pulmonary disease patients: A prospective observational study in the RealDTC cohort

Background

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide. There is no nomogram model available for mortality prediction of stable COPD. We intended to develop and validate a nomogram model to predict mortality risk in stable COPD patients for personalised prognostic assessment.

Methods

A prospective observational study was made of COPD outpatients registered in the RealDTC study between December 2016 and December 2019. Patients were randomly assigned to the training cohort and validation cohort in a ratio of 7:3. We used Lasso regression to screen predicted variables. Further, we evaluated the prognostic performance using the area under the time-dependent receiver operating characteristic curve (AUC) and calibration curve. We used the AUC, concordance index, and decision curve analysis to evaluate the net benefits and utility of the nomogram compared with three earlier prediction models.

Results

Of 2499 patients, the median follow-up was 38 months. The characteristics of the patients between the training cohort (n = 1743) and the validation cohort (n = 756) were similar. ABEODS nomogram model, combining age, body mass index, educational level, airflow obstruction, dyspnoea, and severe exacerbation in the first year, was constructed to predict mortality in stable COPD patients. In the integrative analysis of training and validation cohorts of the nomogram model, the three-year mortality prediction achieved AUC = 0.84; 95% confidence interval (CI) = 0.81, 0.88 and AUC = 0.80; 95% CI = 0.74, 0.86, respectively. The ABEODS nomogram model preserved excellent calibration in both the training cohort and validation cohort. The time-dependent AUC, concordance index, and net benefit of the nomogram model were higher than those of BODEx, updated ADO, and DOSE, respectively.

Conclusions

We developed and validated a prognostic nomogram model that accurately predicts mortality across the COPD severity spectrum. The proposed ABEODS nomogram model performed better than earlier models, including BODEx, updated ADO, and DOSE in Chinese patients with COPD.

Registration

ChiCTR-POC-17010431.

PU.1 alleviates the inhibitory effects of cigarette smoke on endothelial progenitor cell function and lung-homing through Wnt/β-catenin and CXCL12/CXCR4 pathways

INTRODUCTION

Endothelial progenitor cells (EPCs) dysfunction is involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). The transcription factor PU.1 is essential for the maintenance of stem/progenitor cell homeostasis. However, the role of PU.1 in COPD and its effects on EPC function and lung-homing, remain unclear. This study aimed to explore the protective activity of PU.1 and the underlying mechanisms in a cigarette smoke extract (CSE)-induced emphysema mouse model.

METHODS

C57BL/6 mice were treated with CSE to establish a murine emphysema model and injected with overexpressed PU.1 or negative control adeno-associated virus. Morphometry of lung slides, lung function, and apoptosis of lung tissues were evaluated. Immunofluorescence co-localization was used to analyze EPCs homing into the lung. Flow cytometry was performed to detect EPC count in lung tissues and bone marrow (BM). The angiogenic ability of BM-derived EPCs cultured in vitro was examined by tube formation assay. We determined the expression levels of PU.1, β-catenin, C-X-C motif ligand 12 (CXCL12), C-X-C motif receptor 4 (CXCR4), stem cell antigen-1 (Sca-1), and stemness genes.

RESULTS

CSE exposure significantly reduced the expression of PU.1 in mouse lung tissues, BM, and BM-derived EPCs. PU.1 overexpression attenuated CSE-induced emphysematous changes, lung function decline, and apoptosis. In emphysematous mice, PU.1 overexpression markedly reversed the decreased proportion of EPCs in BM and promoted the lung-homing of EPCs. The impaired angiogenic ability of BM-derived EPCs induced by CSE could be restored by the overexpression of PU.1. In addition, PU.1 upregulation evidently reversed the decreased expression of β-catenin, CXCL12, CXCR4, Scal-1, and stemness genes in mouse lung tissues, BM, and BM-derived EPCs after CSE exposure.

CONCLUSIONS

PU.1 alleviates the inhibitory effects of CSE on EPC function and lung-homing via activating the canonical Wnt/β-catenin pathway and CXCL12/CXCR4 axis. While further research is needed, our research may indicate a potential therapeutic target for COPD patients.

Anti-CELA1 antibody KF4 prevents emphysema by inhibiting stretch-mediated remodeling

There are no therapies to prevent emphysema progression. Chymotrypsin-like elastase 1 (CELA1) is a serine protease that binds and cleaves lung elastin in a stretch-dependent manner and is required for emphysema in a murine antisense oligonucleotide model of α-1 antitrypsin (AAT) deficiency. This study tested whether CELA1 is important in strain-mediated lung matrix destruction in non-AAT-deficient emphysema and the efficacy of CELA1 neutralization. Airspace simplification was quantified after administration of tracheal porcine pancreatic elastase (PPE), after 8 months of cigarette smoke (CS) exposure, and in aging. In all 3 models, Cela1-/- mice had less emphysema and preserved lung elastin despite increased lung immune cells. A CELA1-neutralizing antibody was developed (KF4), and it inhibited stretch-inducible lung elastase in ex vivo mouse and human lung and immunoprecipitated CELA1 from human lung. In mice, systemically administered KF4 penetrated lung tissue in a dose-dependent manner and 5 mg/kg weekly prevented emphysema in the PPE model with both pre- and postinjury initiation and in the CS model. KF4 did not increase lung immune cells. CELA1-mediated lung matrix remodeling in response to strain is an important contributor to postnatal airspace simplification, and we believe that KF4 could be developed as a lung matrix-stabilizing therapy in emphysema.

Activation of mTOR signaling in adult lung microvascular progenitor cells accelerates lung aging

Reactivation and dysregulation of the mTOR signaling pathway are a hallmark of aging and chronic lung disease; however, the impact on microvascular progenitor cells (MVPCs), capillary angiostasis, and tissue homeostasis is unknown. While the existence of an adult lung vascular progenitor has long been hypothesized, these studies show that Abcg2 enriches for a population of angiogenic tissue-resident MVPCs present in both adult mouse and human lungs using functional, lineage, and transcriptomic analyses. These studies link human and mouse MVPC-specific mTORC1 activation to decreased stemness, angiogenic potential, and disruption of p53 and Wnt pathways, with consequent loss of alveolar-capillary structure and function. Following mTOR activation, these MVPCs adapt a unique transcriptome signature and emerge as a venous subpopulation in the angiodiverse microvascular endothelial subclusters. Thus, our findings support a significant role for mTOR in the maintenance of MVPC function and microvascular niche homeostasis as well as a cell-based mechanism driving loss of tissue structure underlying lung aging and the development of emphysema.

Exposome and unhealthy aging: environmental drivers from air pollution to occupational exposures

The aging population worldwide is facing a significant increase in age-related non-communicable diseases, including cardiovascular and brain pathologies. This comprehensive review paper delves into the impact of the exposome, which encompasses the totality of environmental exposures, on unhealthy aging. It explores how environmental factors contribute to the acceleration of aging processes, increase biological age, and facilitate the development and progression of a wide range of age-associated diseases. The impact of environmental factors on cognitive health and the development of chronic age-related diseases affecting the cardiovascular system and central nervous system is discussed, with a specific focus on Alzheimer's disease, Parkinson's disease, stroke, small vessel disease, and vascular cognitive impairment (VCI). Aging is a major risk factor for these diseases. Their pathogenesis involves cellular and molecular mechanisms of aging such as increased oxidative stress, impaired mitochondrial function, DNA damage, and inflammation and is influenced by environmental factors. Environmental toxicants, including ambient particulate matter, pesticides, heavy metals, and organic solvents, have been identified as significant contributors to cardiovascular and brain aging disorders. These toxicants can inflict both macro- and microvascular damage and many of them can also cross the blood-brain barrier, inducing neurotoxic effects, neuroinflammation, and neuronal dysfunction. In conclusion, environmental factors play a critical role in modulating cardiovascular and brain aging. A deeper understanding of how environmental toxicants exacerbate aging processes and contribute to the pathogenesis of neurodegenerative diseases, VCI, and dementia is crucial for the development of preventive strategies and interventions to promote cardiovascular, cerebrovascular, and brain health. By mitigating exposure to harmful environmental factors and promoting healthy aging, we can strive to reduce the burden of age-related cardiovascular and brain pathologies in the aging population.

Keratin 15 protects against cigarette smoke-induced epithelial mesenchymal transformation by MMP-9

BACKGROUND

Chronic obstructive pulmonary disease (COPD), a chronic inflammatory lung disease, is a leading cause of morbidity and mortality worldwide. Prolonged cigarette smoking (CS) that causes irreversible airway remodeling and significantly reduces lung function is a major risk factor for COPD. Keratin15+ (Krt15+) cells with the potential of self-renewal and differentiation properties have been implicated in the maintenance, proliferation, and differentiation of airway basal cells; however, the role of Krt15 in COPD is not clear.

METHODS

Krt15 knockout (Krt15-/-) and wild-type (WT) mice of C57BL/6 background were exposed to CS for six months to establish COPD models. Krt15-CrePGR;Rosa26-LSL-tdTomato mice were used to trace the fate of the Krt15+ cells. Hematoxylin and eosin (H&E) and Masson stainings were performed to assess histopathology and fibrosis, respectively. Furthermore, lentivirus-delivered short hairpin RNA (shRNA) was used to knock down KRT15 in human bronchial epithelial (HBE) cells stimulated with cigarette smoke extract (CSE). The protein expression was assessed using western blot, immunohistochemistry, and enzyme-linked immunosorbent assay.

RESULTS

Krt15-/- CS mice developed severe inflammatory cell infiltration, airway remodeling, and emphysema. Moreover, Krt15 knockout aggravated CS-induced secretion of matrix metalloproteinase-9 (MMP-9) and epithelial-mesenchymal transformation (EMT), which was reversed by SB-3CT, an MMP-9 inhibitor. Consistent with this finding, KRT15 knockdown promoted MMP-9 expression and EMT progression in vitro. Furthermore, Krt15+ cells gradually increased in the bronchial epithelial cells and were transformed into alveolar type II (AT2) cells.

CONCLUSION

Krt15 regulates the EMT process by promoting MMP-9 expression and protects the lung tissue from CS-induced injury, inflammatory infiltration, and apoptosis. Furthermore, Krt15+ cells transformed into AT2 cells to protect alveoli. These results suggest Krt15 as a potential therapeutic target for COPD.

Literature review and development of pictorial action plan to promote self-management of chronic obstructive pulmonary disease

OBJECTIVE

This study aimed to review relevant literature and develop a pictorial action plan (PAP) to enhance self-management among older patients with chronic obstructive pulmonary disease (COPD).

METHODS

In Stage 1, an integrative review was conducted to identify key elements of respiratory self-management action plans. In Stage 2, cartoon pictograms with plain descriptions were designed. In Stage 3, the PAP was validated by 40 older patients with COPD and an expert panel.

RESULTS

While the eight included studies demonstrated positive effects on knowledge and quality of life, key elements identified included: traffic light motif, plain and explicit language, and several action plan topics. The final PAP comprises three traffic light-coloured zones and 24 pictograms that introduce self-management strategies for normal, decreasing, and severely decreased airflow. After revising the cartoon characters, all of the pictograms received guessability ratings above 70% and acceptable mean translucency ratings.

DISCUSSION

The integrative review provides evidence about the effectiveness and key elements of PAPs. The PAP developed was found to be valid and feasible for use among older patients with chronic respiratory conditions.

PRACTICE IMPLICATIONS

This study offered an example of translating evidence into patient education practice to enhance self-management in older patients with COPD.

FAM13A regulates cellular senescence marker p21 and mitochondrial reactive oxygen species production in airway epithelial cells

Inhalation of noxious gasses induces oxidative stress in airway epithelial cells (AECs), which may lead to cellular senescence and contribute to the development of chronic obstructive pulmonary disease (COPD). FAM13A, a well-known COPD susceptibility gene, is highly expressed in airway epithelium. We studied whether its expression is associated with aging and cellular senescence and affects airway epithelial responses to paraquat, a cellular senescence inducer. The association between age and FAM13A expression was investigated in two datasets of human lung tissue and bronchial brushings from current/ex-smokers with/without COPD. Protein levels of FAM13A and cellular senescence marker p21 were investigated using immunohistochemistry in lung tissue from patients with COPD. In vitro, FAM13A and P21 expression was assessed using qPCR in air-liquid-interface (ALI)-differentiated AECs in absence/presence of paraquat. In addition, FAM13A was overexpressed in human bronchial epithelial 16HBE cells and the effect on P21 expression (qPCR) and mitochondrial reactive oxygen species (ROS) production (MitoSOX staining) was assessed. Lower FAM13A expression was significantly associated with increasing age in lung tissue and bronchial epithelium. In airway epithelium of patients with COPD, we found a negative correlation between FAM13A and p21 protein levels. In ALI-differentiated AECs, the paraquat-induced decrease in FAM13A expression was accompanied by increased P21 expression. In 16HBE cells, the overexpression of FAM13A significantly reduced paraquat-induced P21 expression and mitochondrial ROS production. Our data suggest that FAM13A expression decreases with aging, resulting in higher P21 expression and mitochondrial ROS production in the airway epithelium, thus facilitating cellular senescence and as such potentially contributing to accelerated lung aging in COPD.NEW & NOTEWORTHY To our knowledge, this is the first study investigating the role of the COPD susceptibility gene FAM13A in aging and cellular senescence. We found that FAM13A negatively regulates the expression of the cellular senescence marker P21 and mitochondrial ROS production in the airway epithelium. In this way, the lower expression of FAM13A observed upon aging may facilitate cellular senescence and potentially contribute to accelerated lung aging in COPD.

Regenerative and translational medicine in COPD: hype and hope

COPD is a common, preventable and usually progressive disease associated with an enhanced chronic inflammatory response in the airways and lung, generally caused by exposure to noxious particles and gases. It is a treatable disease characterised by persistent respiratory symptoms and airflow limitation due to abnormalities in the airways and/or alveoli. COPD is currently the third leading cause of death worldwide, representing a serious public health problem and a high social and economic burden. Despite significant advances, effective clinical treatments have not yet been achieved. In this scenario, cell-based therapies have emerged as potentially promising therapeutic approaches. However, there are only a few published studies of cell-based therapies in human patients with COPD and a small number of ongoing clinical trials registered on clinicaltrials.gov Despite the advances and interesting results, numerous doubts and questions remain about efficacy, mechanisms of action, culture conditions, doses, timing, route of administration and conditions related to homing and engraftment of the infused cells. This article presents the state of the art of cell-based therapy in COPD. Clinical trials that have already been completed and with published results are discussed in detail. We also discuss the questions that remain unanswered about cell-based regenerative and translational medicine for COPD.

Recombinant Human HAPLN1 Mitigates Pulmonary Emphysema by Increasing TGF-β Receptor I and Sirtuins Levels in Human Alveolar Epithelial Cells

Chronic obstructive pulmonary disease (COPD) will be the third leading cause of death worldwide by 2030. One of its components, emphysema, has been defined as a lung disease that irreversibly damages the lungs' alveoli. Treatment is currently unavailable for emphysema symptoms and complete cure of the disease. Hyaluronan (HA) and proteoglycan link protein 1 (HAPLN1), an HA-binding protein linking HA in the extracellular matrix to stabilize the proteoglycan structure, forms a bulky hydrogel-like aggregate. Studies on the biological role of the full-length HAPLN1, a simple structure-stabilizing protein, are limited. Here, we demonstrated for the first time that treating human alveolar epithelial type 2 cells with recombinant human HAPLN1 (rhHAPLN1) increased TGF-β receptor 1 (TGF-β RI) protein levels, but not TGF-β RII, in a CD44-dependent manner with concurrent enhancement of the phosphorylated Smad3 (p-Smad3), but not p-Smad2, upon TGF-β1 stimulation. Furthermore, rhHAPLN1 significantly increased sirtuins levels (i.e., SIRT1/2/6) without TGF-β1 and inhibited acetylated p300 levels that were increased by TGF-β1. rhHAPLN1 is crucial in regulating cellular senescence, including p53, p21, and p16, and inflammation markers such as p-NF-κB and Nrf2. Both senile emphysema mouse model induced via intraperitoneal rhHAPLN1 injections and porcine pancreatic elastase (PPE)-induced COPD mouse model generated via rhHAPLN1-containing aerosols inhalations showed a significantly potent efficacy in reducing alveolar spaces enlargement. Preclinical trials are underway to investigate the effects of inhaled rhHAPLN1-containing aerosols on several COPD animal models.

Autophagy/Mitophagy in Airway Diseases: Impact of Oxidative Stress on Epithelial Cells

Autophagy is the key process by which the cell degrades parts of itself within the lysosomes. It maintains cell survival and homeostasis by removing molecules (particularly proteins), subcellular organelles, damaged cytoplasmic macromolecules, and by recycling the degradation products. The selective removal or degradation of mitochondria is a particular type of autophagy called mitophagy. Various forms of cellular stress (oxidative stress (OS), hypoxia, pathogen infections) affect autophagy by inducing free radicals and reactive oxygen species (ROS) formation to promote the antioxidant response. Dysfunctional mechanisms of autophagy have been found in different respiratory diseases such as chronic obstructive lung disease (COPD) and asthma, involving epithelial cells. Several existing clinically approved drugs may modulate autophagy to varying extents. However, these drugs are nonspecific and not currently utilized to manipulate autophagy in airway diseases. In this review, we provide an overview of different autophagic pathways with particular attention on the dysfunctional mechanisms of autophagy in the epithelial cells during asthma and COPD. Our aim is to further deepen and disclose the research in this direction to stimulate the develop of new and selective drugs to regulate autophagy for asthma and COPD treatment.

Airway Epithelium Senescence as a Driving Mechanism in COPD Pathogenesis

Cellular senescence is a state of permanent cell cycle arrest triggered by various intrinsic and extrinsic stressors. Cellular senescence results in impaired tissue repair and remodeling, loss of physiological integrity, organ dysfunction, and changes in the secretome. The systemic accumulation of senescence cells has been observed in many age-related diseases. Likewise, cellular senescence has been implicated as a risk factor and driving mechanism in chronic obstructive pulmonary disease (COPD) pathogenesis. Airway epithelium exhibits hallmark features of senescence in COPD including activation of the p53/p21WAF1/CIP1 and p16INK4A/RB pathways, leading to cell cycle arrest. Airway epithelial senescent cells secrete an array of inflammatory mediators, the so-called senescence-associated secretory phenotype (SASP), leading to a persistent low-grade chronic inflammation in COPD. SASP further promotes senescence in an autocrine and paracrine manner, potentially contributing to the onset and progression of COPD. In addition, cellular senescence in COPD airway epithelium is associated with telomere dysfunction, DNA damage, and oxidative stress. This review discusses the potential mechanisms of airway epithelial cell senescence in COPD, the impact of cellular senescence on the development and severity of the disease, and highlights potential targets for modulating cellular senescence in airway epithelium as a potential therapeutic approach in COPD.

Cigarette Smoke-Induced Respiratory Response: Insights into Cellular Processes and Biomarkers

Cigarette smoke (CS) poses a significant risk factor for respiratory, vascular, and organ diseases owing to its high content of harmful chemicals and reactive oxygen species (ROS). These substances are known to induce oxidative stress, inflammation, apoptosis, and senescence due to their exposure to environmental pollutants and the presence of oxidative enzymes. The lung is particularly susceptible to oxidative stress. Persistent oxidative stress caused by chronic exposure to CS can lead to respiratory diseases such as chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), and lung cancer. Avoiding exposure to environmental pollutants, like cigarette smoke and air pollution, can help mitigate oxidative stress. A comprehensive understanding of oxidative stress and its impact on the lungs requires future research. This includes identifying strategies for preventing and treating lung diseases as well as investigating the underlying mechanisms behind oxidative stress. Thus, this review aims to investigate the cellular processes induced by CS, specifically inflammation, apoptosis, senescence, and their associated biomarkers. Furthermore, this review will delve into the alveolar response provoked by CS, emphasizing the roles of potential therapeutic target markers and strategies in inflammation and oxidative stress.

Impact of aging on immune function in the pathogenesis of pulmonary diseases: potential for therapeutic targets

INTRODUCTION

Several immunological alterations that occur during pulmonary diseases often mimic alterations observed in the aged lung. From the molecular perspective, pulmonary diseases and aging partake in familiar mechanisms associated with significant dysregulation of the immune systems. Here, we summarized the findings of how aging alters immunity to respiratory conditions to identify age-impacted pathways and mechanisms that contribute to the development of pulmonary diseases.

AREAS COVERED

The current review examines the impact of age-related molecular alterations in the aged immune system during various lung diseases, such as COPD, IPF, Asthma, and alongside many others that could possibly improve on current therapeutic interventions. Moreover, our increased understanding of this phenomenon may play a primary role in shaping immunomodulatory strategies to boost outcomes in the elderly. Here, the authors present new insights into the context of lung-related diseases and describe the alterations in the functioning of immune cells during various pulmonary conditions altered with age.

EXPERT OPINION

The expert opinion provided the concepts on how aging alters immunity during pulmonary conditions, and suggests the associated mechanisms during the development of lung diseases. As a result, it becomes important to comprehend the complex mechanism of aging in the immune lung system.

Senotherapy for lung diseases

Increasing evidence suggests that there is acceleration of lung ageing in chronic lung diseases, such as chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF), with the accumulation of senescent cells in the lung. Senescent cells fail to repair tissue damage and release an array of inflammatory proteins, known as the senescence-associated secretory phenotype, which drive further senescence and disease progression. This suggests that targeting cellular senescence with senotherapies may treat the underlying disease process in COPD and IPF and thus reduce disease progression and mortality. Several existing or future drugs may inhibit the development of cellular senescence which is driven by chronic oxidative stress (senostatics), including inhibitors of PI3K-mTOR signalling pathways, antagomirs of critical microRNAs and novel antioxidants. Other drugs (senolytics) selectively remove senescent cells by promoting apoptosis. Clinical studies with senotherapies are already underway in chronic lung diseases.

Recent Prevalence of and Factors Associated With Chronic Obstructive Pulmonary Disease in a Rapidly Aging Society: Korea National Health and Nutrition Examination Survey 2015-2019

BACKGROUND

The prevalence of chronic obstructive pulmonary disease (COPD) increases with age, and aging is an important risk factor for COPD development. In the era of global aging, demographic information about the prevalence of and factors associated with COPD are important to establish COPD care plans. However, limited information is available in rapidly aging societies, including Korea.

METHODS

We conducted a cross-sectional observational study using Korea National Health and Nutrition Examination Survey data from 2015-2019. We included 15,613 participants and analyzed trends of and factors associated with COPD.

RESULTS

During the study period, the overall prevalence of COPD was 12.9%. Over five years, the yearly prevalence of COPD was fairly constant, ranging from 11.5% to 13.6%. Among individuals aged ≥ 70 years, nearly one-third met COPD diagnostic criteria. In the multivariable analysis, age 70 years or older was the most strong factor associated with COPD (adjusted odds ratio [aOR], 17.86; 95% confidence interval [CI], 14.16-22.52; compared with age 40-49), followed by asthma (aOR, 3.39; 95% CI, 2.44-4.71), male sex (aOR, 2.64; 95% CI, 2.18-3.19), and current smokers (aOR, 2.60; 95% CI, 2.08-3.25). Additionally, ex-smokers, low income, decreased forced expiratory volume in 1 second %pred, and a history of pulmonary tuberculosis were associated with COPD. On the other hand, body mass index (BMI) ≥ 25 kg/m² (aOR, 0.62; 95% CI, 0.54-0.71; compared with BMI 18.5-24.9 kg/m²) had an inverse association with COPD.

CONCLUSION

Recent trends in the prevalence of COPD in South Korea are relatively stable. Approximately one-third of participants aged 70 years and older had COPD. Aging was the most important factor associated with COPD.

Review of the British Thoracic Society Winter Meeting 23 November 2022 23-25 November 2022

The British Thoracic Society Winter Meeting at the QEII Centre in London provided the first opportunity for the respiratory community to meet and disseminate research findings face to face since the start of the COVID-19 pandemic. World-leading researchers from the UK and abroad presented their latest findings across a range of respiratory diseases. This article aims to represent the range of the conference and as such is written from the perspective of a basic scientist, a physiotherapist and two doctors. The authors reviewed showcase sessions plus a selection of symposia based on their personal highlights. Content ranged from exciting new developments in basic science to new and unpublished results from clinical trials, delivered by leading scientists from their fields including former deputy chief medical officer Professor Sir Jonathan Van-Tam and former WHO chief scientist Dr Soumya Swaminathan.

Clinical-functional characteristics and risk of exacerbation and mortality among more symptomatic patients with chronic obstructive pulmonary disease: a retrospective cohort study

OBJECTIVES

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 classified chronic obstructive pulmonary disease (COPD) patients into more and less symptomatic groups. This study aimed to analyze the clinical characteristics, risk of future exacerbation and mortality among patients in more symptomatic group.

DESIGN

A retrospective cohort study.

SETTING

Data were obtained from patients enrolled in a database setup by Second Xiangya Hospital of Central South University.

PARTICIPANTS

1729 stable COPD patients listed from September 2017 to December 2019 in the database. The patients were classified into more and less symptomatic groups based on GOLD 2017 report.

OUTCOMES

All patients were followed up for 18 months. We collected baseline data and recorded the number of exacerbations and mortality during follow-up.

RESULTS

The more symptomatic patients were older, had higher Clinical COPD Questionnaire (CCQ) scores, more severe airflow limitation and higher number of exacerbations and hospitalizations in the past year (P < 0.05). Logistic regression showed that having more symptoms correlated with the CCQ scores and exacerbations in the past year (P < 0.05). After patients were followed up, there were higher numbers of exacerbations, hospitalizations and mortality rates in more symptomatic patients (P < 0.05). The multivariate model showed that age more than 65 years (OR = 2.047, 95% CI = 1.020-4.107) and COPD assessment test scores more than 30 (OR = 2.609, 95% CI = 1.339-5.085) were independent risk factors for mortality, whereas current smoker (OR = 1.565, 95% CI = 1.052-2.328), modified Medical Research Council scores (OR = 1.274, 95% CI = 1.073-1.512) and exacerbations in the past year (OR = 1.061, 95% CI = 1.013-1.112) were independent risk factors for exacerbation in more symptomatic patients (P < 0.05).

CONCLUSIONS

More symptomatic COPD patients have worse outcomes. In addition, several independent risk factors for exacerbation and mortality were identified. Therefore, clinicians should be aware of these risk factors and take them into account during interventions.

Effects of hypoxia on bronchial and alveolar epithelial cells linked to pathogenesis in chronic lung disorders

Introduction: Chronic lung disorders involve pathological alterations in the lung tissue with hypoxia as a consequence. Hypoxia may influence the release of inflammatory mediators and growth factors including vascular endothelial growth factor (VEGF) and prostaglandin (PG)E2. The aim of this work was to investigate how hypoxia affects human lung epithelial cells in combination with profibrotic stimuli and its correlation to pathogenesis.

Methods: Human bronchial (BEAS-2B) and alveolar (hAELVi) epithelial cells were exposed to either hypoxia (1% O2) or normoxia (21% O2) during 24 h, with or without transforming growth factor (TGF)-β1. mRNA expression of genes and proteins related to disease pathology were analysed with qPCR, ELISA or immunocytochemistry. Alterations in cell viability and metabolic activity were determined.

Results: In BEAS-2B and hAELVi, hypoxia significantly dowregulated genes related to fibrosis, mitochondrial stress, oxidative stress, apoptosis and inflammation whereas VEGF receptor 2 increased. Hypoxia increased the expression of Tenascin-C, whereas both hypoxia and TGF-β1 stimuli increased the release of VEGF, IL-6, IL-8 and MCP-1 in BEAS-2B. In hAELVi, hypoxia reduced the release of fibroblast growth factor, epidermal growth factor, PGE2, IL-6 and IL-8, whereas TGF-β1 stimulus significantly increased the release of PGE2 and IL-6. TGF-β1 stimulated BEAS-2B cells showed a decreased release of VEGF-A and IL-8, while TGF-β1 stimulated hAELVi cells showed a decreased release of PGE2 and IL-8 during hypoxia compared to normoxia. Metabolic activity was significantly increased by hypoxia in both epithelial cell types.

Discussion: In conclusion, our data indicate that bronchial and alveolar epithelial cells respond differently to hypoxia and profibrotic stimuli. The bronchial epithelium appears more responsive to changes in oxygen levels and remodelling processes compared to the alveoli, suggesting that hypoxia may be a driver of pathogenesis in chronic lung disorders.

Development and Internal Validation of Risk Assessment Models for Chronic Obstructive Pulmonary Disease in Coal Workers

Coal workers are more likely to develop chronic obstructive pulmonary disease due to exposure to occupational hazards such as dust. In this study, a risk scoring system is constructed according to the optimal model to provide feasible suggestions for the prevention of chronic obstructive pulmonary disease in coal workers. Using 3955 coal workers who participated in occupational health check-ups at Gequan mine and Dongpang mine of Hebei Jizhong Energy from July 2018 to August 2018 as the study subjects, random forest, logistic regression, and convolutional neural network models are established, and model performance is evaluated to select the optimal model, and finally a risk scoring system is constructed according to the optimal model to achieve model visualization. The training set results show that the logistic, random forest, and CNN models have sensitivities of 78.55%, 86.89%, and 77.18%; specificities of 85.23%, 92.32%, and 87.61%; accuracies of 81.21%, 85.40%, and 83.02%; Brier scores of 0.14, 0.10, and 0.14; and AUCs of 0.76, 0.88, and 0.78, respectively, and similar results are obtained for the test set and validation set, with the random forest model outperforming the other two models. The risk scoring system constructed according to the importance ranking of random forest predictor variables has an AUC of 0.842; the evaluation results of the risk scoring system shows that its accuracy rate is 83.7% and the AUC is 0.827, and the established risk scoring system has good discriminatory ability. The random forest model outperforms the CNN and logistic regression models. The chronic obstructive pulmonary disease risk scoring system constructed based on the random forest model has good discriminatory power.

Role of cellular senescence in inflammatory lung diseases

Cellular senescence, a characteristic sign of aging, classically refers to permanent cell proliferation arrest and is a vital contributor to the pathogenesis of cancer and age-related illnesses. A lot of imperative scientific research has shown that senescent cell aggregation and the release of senescence-associated secretory phenotype (SASP) components can cause lung inflammatory diseases as well. In this study, the most recent scientific progress on cellular senescence and phenotypes was reviewed, including their impact on lung inflammation and the contributions of these findings to understanding the underlying mechanisms and clinical relevance of cell and developmental biology. Within a dozen pro-senescent stimuli, the irreparable DNA damage, oxidative stress, and telomere erosion are all crucial in the long-term accumulation of senescent cells, resulting in sustained inflammatory stress activation in the respiratory system. An emerging role for cellular senescence in inflammatory lung diseases was proposed in this review, followed by the identification of the main ambiguities, thus further understanding this event and the potential to control cellular senescence and pro-inflammatory response activation. In addition, novel therapeutic strategies for the modulation of cellular senescence that might help to attenuate inflammatory lung conditions and improve disease outcomes were also presented in this research.

Protective Effects of Chestnut (Castanea crenata) Inner Shell Extract in Macrophage-Driven Emphysematous Lesion Induced by Cigarette Smoke Condensate

Chestnut (Castanea crenata) inner shell extract (CIE), a curative herb in Korea, has diverse pharmacological effects against various diseases including pulmonary fibrosis, asthma, and chronic obstructive pulmonary disease (COPD). However, its molecular mechanisms of anti-emphysematous effects are still not fully elucidated. In the present study, we elucidate the efficacy of CIE against emphysematous lesion progression in a cigarette smoke condensate (CSC)-instilled mice and CSC-stimulated H292 cell line. The mice are administered CSC via intranasal instillation at 7-day intervals for 1 month after 1 week of pretreatment with CIE. CIE (100 or 300 mg/kg) is administered by oral gavage for 1 month. CIE decreased the macrophage count in bronchoalveolar lavage fluid and the severity of emphysematous lesions in lung tissue. Additionally, CIE suppressed the phosphatidylinositol 3-kinase/protein kinase B/nuclear factor kappa B signal pathway and thereby downregulated matrix metalloprotease-9 expression, which was confirmed in CSC-stimulated H292 cells. Thus, CIE effectively inhibited CSC-induced macrophage-driven emphysema progression in airways; this inhibition was associated with the suppression of protease-antiprotease imbalance. Our results propose that CIE has the potential for the alleviation of COPD.

Genetic polymorphisms in MIR1208 and MIR5708 are associated with susceptibility to COPD in the Chinese population

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a complex disease characterized by limited airflow and is influenced by genetic and environmental factors. The purpose of this study was to investigate the effects of gene polymorphisms in MIR5708 and MIR1208 on COPD risk.

METHODS

Four single nucleotide polymorphisms (SNPs) in MIR5708 (rs6473227 and rs16907751) and MIR1208 (rs2608029 and rs13280095) were selected and genotyped among 315 COPD patients and 314 healthy controls using the Agena MassARRAY platform. SPSS 18.0 was used for statistical analysis and data processing. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the association between genetic variants of MIR1208 and MIR5708 and COPD risk.

RESULTS

The results suggested that rs16907751 variants in MIR5708 contributed to an increased susceptibility to COPD in the allelic (P = 0.001), co-dominant (homozygous) (P = 0.001), dominant (P = 0.017), recessive (P = 0.002), and additive (P = 0.002) models. The effects of MIR5708 and MIR1208 gene polymorphisms on the risk of COPD were age-, sex-, smoking status-, and BMI-related. Furthermore, the C-A and G-A haplotypes of rs2608029 and rs13280095 in MIR1208 were identified as risk factors for COPD in the population over 70 years (P = 0.029) and in women (P = 0.049), respectively. Finally, significant associations between rs16907751genotypes with pulse rate and forced expiratory volume in 1 s were found among COPD patients.

CONCLUSION

Genetic polymorphisms in MIR5708 and MIR1208 are associated with increased risk of COPD in China.

Sex-specific and age-specific incidence of ischaemic heart disease, atrial fibrillation and heart failure in community patients with chronic obstructive pulmonary disease

OBJECTIVE

To estimate the incidence of ischaemic heart disease, atrial fibrillation and heart failure in community patients with or without chronic obstructive pulmonary disease (COPD).

METHODS

For this population-based study, we used primary care data of the Julius General Practitioners' Network. Eligible participants were aged 40-80 years old and contributed data between January 2014 and February 2019. Participants were divided into groups according to COPD status and were followed up for new ischaemic heart disease, atrial fibrillation and/or heart failure. Age-specific and sex-specific incidence and incidence rate ratios were calculated for patients with and without COPD.

RESULTS

Mean follow-up was 3.9 years, 6223 patients were included in the COPD group, and 137 028 individuals in the background group without COPD. Incidence rates of all three heart diseases increased with age and were higher in males, independent of presence of COPD. Incidence rate ratios for patients with COPD, adjusted for age and sex, were 1.69 (95% CI 1.49 to 1.92) for ischaemic heart disease, 1.56 (95% CI 1.38 to 1.77) for atrial fibrillation and 2.96 (95% CI 2.58 to 3.40) for heart failure.

CONCLUSION

The incidence of all major cardiovascular diseases is higher in patients with COPD, with the highest incidence rate ratio observed for heart failure.

Peptide location fingerprinting identifies species- and tissue-conserved structural remodelling of proteins as a consequence of ageing and disease

Extracellular matrices (ECMs) in the intervertebral disc (IVD), lung and artery are thought to undergo age-dependant accumulation of damage by chronic exposure to mechanisms such as reactive oxygen species, proteases and glycation. It is unknown whether this damage accumulation is species-dependant (via differing lifespans and hence cumulative exposures) or whether it can influence the progression of age-related diseases such as atherosclerosis. Peptide location fingerprinting (PLF) is a new proteomic analysis method, capable of the non-targeted identification of structure-associated changes within proteins. Here we applied PLF to publicly available ageing human IVD (outer annulus fibrosus), ageing mouse lung and human arterial atherosclerosis datasets and bioinformatically identified novel target proteins alongside common age-associated differences within protein structures which were conserved between three ECM-rich organs, two species, three IVD tissue regions, sexes and in an age-related disease. We identify peptide yield differences across protein structures which coincide with biological regions, potentially reflecting the functional consequences of ageing or atherosclerosis for macromolecular assemblies (collagen VI), enzyme/inhibitor activity (alpha-2 macroglobulin), activation states (complement C3) and interaction states (laminins, perlecan, fibronectin, filamin-A, collagen XIV and apolipoprotein-B). Furthermore, we show that alpha-2 macroglobulin and collagen XIV exhibit possible shared structural consequences in IVD ageing and arterial atherosclerosis, providing novel links between an age-related disease and intrinsic ageing. Crucially, we also demonstrate that fibronectin, laminin beta chains and filamin-A all exhibit conserved age-associated structural differences between mouse lung and human IVD, providing evidence that ECM, and their associating proteins, may be subjected to potentially similar mechanisms or consequences of ageing across both species, irrespective of differences in lifespan and tissue function.

White blood cell count and chronic obstructive pulmonary disease: A Mendelian Randomization study

Blood leukocyte counts (e.g., eosinophil count) are important biomarkers for the onset, classification, and exacerbation of chronic obstructive pulmonary disease (COPD). The causal relationships between them are necessary for the development of COPD treatment strategy, but remain unclear. Here, we implement two-sample bi-directional univariable Mendelian Randomization (MR) and multivariable MR to investigate the causal relationships. Univariable MR find that elevated blood eosinophil count significantly increases the risk of COPD (odds ratio (OR) = 1.22, 95% confidence interval (CI): 1.14-1.30, P = 1.54 × 10^-09) and COPD-related hospitalization (OR = 1.44, 95% CI: 1.15-1.80, P = 1.36 × 10^-03). Besides, it also significantly decreases the ratio of forced expiratory volume in the first second over forced vital capacity (FEV₁/FVC ratio) (OR = 0.942, 95% CI: 0.914-0.971, P = 1.02 × 10^-04). These findings are fully supported by multivariate MR results. Interestingly, univariable MR reveals a weak causal relationship between elevated blood eosinophil count and COPD risk in younger people (<65 years) (OR = 1.39, 95% CI: 1.10-1.75, P = 5.52 × 10^-03), but not older individuals (OR = 1.20, 95% CI: 0.926-1.55, P = 0.17). Finally, reverse univariable MR reveals the onset of COPD and the decreased FEV₁/FVC ratio both lead to increased blood neutrophil count (OR = 1.03, 95% CI: 1.01-1.05, P = 3.40 × 10^-03 and OR = 0.947, 95% CI: 0.91-0.986, P = 8.75 × 10^-03 respectively). In summary, this MR study demonstrates that high blood eosinophil count is an independent causal mediator of COPD risk, FEV₁/FVC decline, and COPD-related hospitalization. The increase in neutrophil count is induced by COPD onset or FEV₁/FVC decline. This suggests eosinophil, but not neutrophil, may be used as a therapeutic target for preventing the onset and exacerbation of COPD and FEV₁/FVC decline. Therefore, a non-neutrophil-targeted therapeutic strategy for neutrophilic COPD is required in the future.

Circadian clock gene Clock-Bmal1 regulates cellular senescence in Chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a progressive respiratory disease. COPD is associated with accelerated lung aging. Circadian clock is believed to play important roles in COPD. Although the circadian molecular clock regulates cellular senescence, there is no information available regarding the impact of COPD. The aim of this study is to investigate the role of the circadian clock protein BMAL1 and CLOCK in cellular senescence in order to understand the cellular mechanisms of accelerated aging of COPD. Bmal1 and Clock levels were assessed in the plasma samples of non-smokers, smokers, and patients with COPD. The regulation of ciracadian clock expression and cell senescence by cigarette smoke extract (CSE) was studied in vitro, and small interfering RNA (siRNA) and overexpression of Bmal1 or Clock were employed to investigate the role of circadian clock on cell senescence. Herein, patients with COPD showed lower Bmal1 and Clock expression in the plasma. Interestingly, CSE exposure contributed to the increased cell senescence, decreased Clock and Bmal1 in human bronchial epithelial cells (Beas-2B cells). We found that knockdown of Clock or Bmal1 lead to upregulation of cell senescence in Beas-2B cells, while overexpression of Clock or Bmal1 inhibited cell senescence in Beas-2B cells, which is through the MAPK pathways. Therefore, our findings indicated that Bmal1 or Clock deficiency may be a significant factor to increase cellular senescence of the lung to develop COPD.

Extracellular vesicles isolated from hyperuricemia patients might aggravate airway inflammation of COPD via senescence-associated pathway

BACKGROUNDS

Chronic obstructive pulmonary disease (COPD) is a major health issue resulting in significant mortality worldwide. Due to the high heterogeneity and unclear pathogenesis, the management and therapy of COPD are still challenging until now. Elevated serum uric acid(SUA) levels seem to be associated with the inflammatory level in patients with COPD. However, the underlying mechanism is not yet clearly established. In the current research, we aim to elucidate the effect of high SUA levels on airway inflammation among COPD patients.

METHODS

Through bioinformatic analysis, the common potential key genes were determined in both COPD and hyperuricemia (HUA) patients. A total of 68 COPD patients aged 50-75-year were included in the study, and their clinical parameters, including baseline characteristics, lung function test, as well as blood chemistry test were recorded. These parameters were then compared between the COPD patients with and without HUA. Hematoxylin & Eosin (HE), immunofluorescence (IF), and Masson trichrome staining were performed to demonstrate the pathological changes in the lung tissues. Furthermore, we isolated extracellular vesicles (EVs) from plasma, sputum, and bronchoalveolar lavage fluid (BALF) samples and detected the expression of inflammatory factor (Interleukin-6 (IL-6), IL-8 and COPD related proteases (antitrypsin and elastase) between two groups. Additionally, we treated the human bronchial epithelial (HBE) cells with cigarette smoke extract (CSE), and EVs were derived from the plasma in vitro experiments. The critical pathway involving the relationship between COPD and HUA was eventually validated based on the results of RNA sequencing (RNA-seq) and western blot (WB).

RESULTS

In the study, the COPD patients co-existing with HUA were found to have more loss of pulmonary function compared with those COPD patients without HUA. The lung tissue samples of patients who had co-existing COPD and HUA indicated greater inflammatory cell infiltration, more severe airway destruction and even fibrosis. Furthermore, the high SUA level could exacerbate the progress of airway inflammation in COPD through the transfer of EVs. In vitro experiments, we determined that EVs isolated from plasma, sputum, and BALF played pivotal roles in the CSE-induced inflammation of HBE. The EVs in HUA patients might exacerbate both systemic inflammation and airway inflammatory response via the senescence-related pathway.

CONCLUSION

The pulmonary function and clinical indicators of COPD patients with HUA were worse than those without HUA, which may be caused by the increased airway inflammatory response through the EVs in the patient's peripheral blood. Moreover, it might mediate the EVs via senescence-related pathways in COPD patients with HUA.

It is unlikely that oxygen supplementation in COPD patients with chronic respiratory failure reduce cardiac troponin level

Background

Cardiac troponin T (cTnT) is a biomarker of myocardial injury frequently elevated in COPD patients, potentially because of hypoxemia. This non-randomised observational study investigates whether long-term oxygen treatment (LTOT) reduces the cTnT level.

Methods

We compared cTnT between COPD patients who were candidates for LTOT (n = 20) with two reference groups. Patients from both reference groups were matched with the index group using propensity score.Reference groups consists of institutional pulmonary rehabilitation patients (short-term group) (n = 105 after matching n = 11) and outpatients at a pulmonary rehabilitation clinic (long-term group)(n = 62 after matching n = 10). Comparison was done within 24 h after LTOT initiation in first reference group and within 6 months after inclusion in the second group.

Results

The geometric mean of (standard deviation in parentheses) cTnT decreased from 17.8 (2.3) ng/L (between 8 and 9 a.m.) to 15.4 (2.5) ng/L between 1 and 2 p.m. in the LTOT group, and from 18.4 (4.8) ng/L to15.4 (2.5) ng/L in group (1) The corresponding long-term results were 17.0 (2.9) ng/L at inclusion (between 10 and 12 a.m.) to 18.4 (2.4) ng/L after 3 months in the LTOT-group, and from 14.0 (2.4) ng/L to 15.4 (2.5) ng/L after 6 months in group (2) None of the differences in cTnT during the follow-up between the LTOT-group and their matched references were significant.

Conclusion

Initiation of LTOT was not associated with an early or sustained reduction in cTnT after treatment with oxygen supplementation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02169-7.

Forthcoming complications in recovered COVID-19 patients with COPD and asthma; possible therapeutic opportunities

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been growing swiftly worldwide. Patients with background chronic pulmonary inflammations such as asthma or chronic obstructive pulmonary diseases (COPD) are likely to be infected with this virus. Of note, there is an argument that COVID-19 can remain with serious complications like fibrosis or other pathological changes in the pulmonary tissue of patients with chronic diseases. Along with conventional medications, regenerative medicine, and cell-based therapy could be alternative approaches to compensate for organ loss or restore injured sites using different stem cell types. Owing to unique differentiation capacity and paracrine activity, these cells can accelerate the healing procedure. In this review article, we have tried to scrutinize different reports related to the harmful effects of SARS-CoV-2 on patients with asthma and COPD, as well as the possible therapeutic effects of stem cells in the alleviation of post-COVID-19 complications. Video abstract.

EVs-miRNA: The New Molecular Markers for Chronic Respiratory Diseases

Idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD), asthma and sleep disorders are chronic respiratory diseases that affect the airways, compromising lung function over time. These diseases affect hundreds of millions of people around the world and their frequency seems to be increasing every year. Extracellular vesicles (EVs) are small-sized vesicles released by every cell in the body. They are present in most body fluids and contain various biomolecules including proteins, lipids, mRNA and non-coding RNA (micro-RNA). The EVs can release their cargo, specifically micro-RNAs (miRNAs), to both neighboring and/or distal cells, playing a fundamental role in cell-cell communication. Recent studies have shown their possible role in the pathogenesis of various chronic respiratory diseases. The expression of miRNAs and, in particular, of miRNAs contained within the extracellular vesicles seems to be a good starting point in order to identify new potential biomarkers of disease, allowing a non-invasive clinical diagnosis. In this review we summarize some studies, present in the literature, about the functions of extracellular vesicles and miRNAs contained in extracellular vesicles in chronic respiratory diseases and we discuss the potential clinical applications of EVs and EVs-miRNAs for their possible use such as future biomarkers.

The interplay between oxidative stress and autophagy in chronic obstructive pulmonary disease

Autophagy is a highly conserved process that is indispensable for cell survival, embryonic development, and tissue homeostasis. Activation of autophagy protects cells against oxidative stress and is a major adaptive response to injury. When autophagy is dysregulated by factors such as smoking, environmental insults and aging, it can lead to enhanced formation of aggressors and production of reactive oxygen species (ROS), resulting in oxidative stress and oxidative damage to cells. ROS activates autophagy, which in turn promotes cell adaptation and reduces oxidative damage by degrading and circulating damaged macromolecules and dysfunctional cell organelles. The cellular response triggered by oxidative stress includes changes in signaling pathways that ultimately regulate autophagy. Chronic obstructive pulmonary disease (COPD) is the most common lung disease among the elderly worldwide, with a high mortality rate. As an induced response to oxidative stress, autophagy plays an important role in the pathogenesis of COPD. This review discusses the regulation of oxidative stress and autophagy in COPD, and aims to provide new avenues for future research on target-specific treatments for COPD.

Resveratrol Prevents Skeletal Muscle Atrophy and Senescence via Regulation of Histone Deacetylase 2 in Cigarette Smoke-Induced Mice with Emphysema

Objective

The aim of this study was to investigate the effects of resveratrol (RSV) on cigarette smoke (CS)-induced skeletal muscle atrophy and senescence in mice with emphysema and to explore the underlying mechanisms.

Methods

Gastrocnemius muscle weight and lung and muscular morphology were observed in CS-exposed mice with or without RSV treatment. The expression of atrophy-related markers (MURF1 and MAFbx), senescence-related markers (P53, P21 and SMP30) and NF-κB inflammatory pathways was detected by Western blotting and real-time PCR. The levels of IL-1β and TNF-α were also determined by ELISA, and the number of senescent cells was determined by SA-β gal staining. In addition, the expression of HDAC2 and the effect of HDAC2 on CSE-induced skeletal muscle atrophy and senescence by RSV treatment were investigated.

Results

RSV prevented emphysema and skeletal muscle atrophy in long-term CS-exposed mice. RSV decreased the expression of MURF1, MAFbx, P53, and P21 and inhibited the NF-κB pathway both in vivo and in vitro. Moreover, RSV reversed CS-induced downregulation of HDAC2 expression both in gastrocnemius and in C2C12 cells. Moreover, knockdown of HDAC2 significantly abolished the inhibitory effect of RSV on the expression of MURF1, MAFbx, P53, P21 and inflammatory factors (IL-1β and TNF-α) in C2C12 cells.

Conclusion

RSV prevents CS-induced skeletal muscle atrophy and senescence, and upregulation of HDAC2 expression and suppression of inflammation are involved.

Links of Cytoskeletal Integrity with Disease and Aging

Aging is a complex feature and involves loss of multiple functions and nonreversible phenotypes. However, several studies suggest it is possible to protect against aging and promote rejuvenation. Aging is associated with many factors, such as telomere shortening, DNA damage, mitochondrial dysfunction, and loss of homeostasis. The integrity of the cytoskeleton is associated with several cellular functions, such as migration, proliferation, degeneration, and mitochondrial bioenergy production, and chronic disorders, including neuronal degeneration and premature aging. Cytoskeletal integrity is closely related with several functional activities of cells, such as aging, proliferation, degeneration, and mitochondrial bioenergy production. Therefore, regulation of cytoskeletal integrity may be useful to elicit antiaging effects and to treat degenerative diseases, such as dementia. The actin cytoskeleton is dynamic because its assembly and disassembly change depending on the cellular status. Aged cells exhibit loss of cytoskeletal stability and decline in functional activities linked to longevity. Several studies reported that improvement of cytoskeletal stability can recover functional activities. In particular, microtubule stabilizers can be used to treat dementia. Furthermore, studies of the quality of aged oocytes and embryos revealed a relationship between cytoskeletal integrity and mitochondrial activity. This review summarizes the links of cytoskeletal properties with aging and degenerative diseases and how cytoskeletal integrity can be modulated to elicit antiaging and therapeutic effects.

P16INK4A—More Than a Senescence Marker

Aging is a biological feature that is characterized by gradual degeneration of function in cells, tissues, organs, or an intact organism due to the accumulation of environmental factors and stresses with time. Several factors have been attributed to aging such as oxidative stress and augmented production or exposure to reactive oxygen species, inflammatory cytokines production, telomere shortening, DNA damage, and, importantly, the deposit of senescent cells. These are irreversibly mitotically inactive, yet metabolically active cells. The reason underlying their senescence lies within the extrinsic and the intrinsic arms. The extrinsic arm is mainly characterized by the expression and the secretory profile known as the senescence-associated secretory phenotype (SASP). The intrinsic arm results from the impact of several genes meant to regulate the cell cycle, such as tumor suppressor genes. P16^INK4A is a tumor suppressor and cell cycle regulator that has been linked to aging and senescence. Extensive research has revealed that p16 expression is significantly increased in senescent cells, as well as during natural aging or age-related pathologies. Based on this fact, p16 is considered as a specific biomarker for detecting senescent cells and aging. Other studies have found that p16 is not only a senescence marker, but also a protein with many functions outside of senescence and aging. In this paper, we discuss and shed light on several studies that show the different functions of p16 and provide insights in its role in several biological processes besides senescence and aging.

Altered pharmacology and toxicology during ageing: implications for lung disease

PURPOSE OF REVIEW

Drug use in elderly people is high compared to younger people. Simultaneously, elderly are at greater risk when exposed to environmental substances. It is puzzling therefore, that ageing, as a variable in pharmacological and toxicological processes is not investigated in more depth. Moreover, recent data suggest that molecular manifestations of the ageing process also hallmark the pathogenesis of chronic lung diseases, which may impact pharmacology and toxicology.

RECENT FINDINGS

In particular, absorption, distribution, metabolism and excretion (ADME) processes of drugs and toxins alter because of ageing. Polypharmacy, which is quite usual with increasing age, increases the risk of drug-drug interactions. Individual differences in combination of drugs use in conjunction with individual variations in drug metabolizing enzymes can influence lung function.

SUMMARY

Exploring exposure throughout life (i.e. during ageing) to potential triggers, including polypharmacy, may avoid lung disease or unexplained cases of lung damage. Understanding of the ageing process further unravels critical features of chronic lung disease and helps to define new protective targets and therapies. Optimizing resilience can be key in pharmacology and toxicology and helps in maintaining healthy lungs for a longer period.

Identification and validation of aging-related genes in COPD based on bioinformatics analysis

Chronic obstructive pulmonary disease (COPD) is a serious chronic respiratory disorder. One of the major risk factors for COPD progression is aging. Therefore, we investigated aging-related genes in COPD using bioinformatic analyses. Firstly, the Aging Atlas database containing 500 aging-related genes and the Gene Expression Omnibus database (GSE38974) were utilized to screen candidates. A total of 24 candidate genes were identified related to both COPD and aging. Using gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses, we found that this list of 24 genes was enriched in genes associated with cytokine activity, cell apoptosis, NF-κB and IL-17 signaling. Four of these genes (CDKN1A, HIF1A, MXD1 and SOD2) were determined to be significantly upregulated in clinical COPD samples and in cigarette smoke extract-exposed Beas-2B cells in vitro, and their expression was negatively correlated with predicted forced expiratory volume and forced vital capacity. In addition, the combination of expression levels of these four genes had a good discriminative ability for COPD patients (AUC = 0.794, 95% CI 0.743-0.845). All four were identified as target genes of hsa-miR-519d-3p, which was significantly down-regulated in COPD patients. The results from this study proposed that regulatory network of hsa-miR-519d-3p/CDKN1A, HIF1A, MXD1, and SOD2 closely associated with the progression of COPD, which provides a theoretical basis to link aging effectors with COPD progression, and may suggest new diagnostic and therapeutic targets of this disease.

Immunosenescence, immune fitness and vaccination schedule in the adult respiratory patient

Immunosenescence is the gradual deterioration of the immune system caused by advancing age. It is associated with a reduced ability to respond to infections and develop long-term immune memory. It plays a key role in the development of respiratory diseases that are more common in older people, such as asthma, COPD, diffuse interstitial disease and respiratory infections in the elderly.

We call immune fitness the establishment of lifestyle habits that can improve our immune capacity. We now know that good eating habits, good social relationships, not smoking, limiting alcohol consumption, exercising, controlling stress levels and establishing a proper vaccination programme can slow down the process of immunosenescence.

Influenza and pneumococcal vaccines (PCV13 and PPSV23 conjugate) are well established in the adult vaccination schedule. The new pneumococcal vaccines PCV15 and PCV20 will help to extend protection against pneumococcal disease in adults. The vaccine against COVID-19 is currently the most useful tool to prevent the disease and reduce its pathogenicity. COPD patients and others with respiratory diseases may benefit from prevention of herpes zoster and Bordetella pertussis through vaccination. Respiratory syncytial virus (RSV) vaccine may be another vaccine to be added to the schedule, pending the results of its studies.

lnc-IL7R Expression Reflects Physiological Pulmonary Function and Its Aberration Is a Putative Indicator of COPD

Despite rapidly evolving pathobiological mechanistic demystification, coupled with advances in diagnostic and therapeutic modalities, chronic obstructive pulmonary disease (COPD) remains a major healthcare and clinical challenge, globally. Further compounded by the dearth of available curative anti-COPD therapy, it is posited that this challenge may not be dissociated from the current lack of actionable COPD pathognomonic molecular biomarkers. There is accruing evidence of the involvement of protracted ‘smoldering’ inflammation, repeated lung injury, and accelerated lung aging in enhanced predisposition to or progression of COPD. The relatively novel uncharacterized human long noncoding RNA lnc-IL7R (otherwise called LOC100506406) is increasingly designated a negative modulator of inflammation and regulator of cellular stress responses; however, its role in pulmonary physiology and COPD pathogenesis remains largely unclear and underexplored. Our previous work suggested that upregulated lnc-IL7R expression attenuates inflammation following the activation of the toll-like receptor (TLR)-dependent innate immune system, and that the upregulated lnc-IL7R is anti-correlated with concomitant high PM2.5, PM10, and SO2 levels, which is pathognomonic for exacerbated/aggravated COPD in Taiwan. In the present study, our quantitative analysis of lnc-IL7R expression in our COPD cohort (n = 125) showed that the lnc-IL7R level was significantly correlated with physiological pulmonary function and exhibited COPD-based stratification implications (area under the curve, AUC = 0.86, p < 0.001). We found that the lnc-IL7R level correctly identified patients with COPD (sensitivity = 0.83, specificity = 0.83), precisely discriminated those without emphysematous phenotype (sensitivity = 0.48, specificity = 0.89), and its differential expression reflected disease course based on its correlation with the COPD GOLD stage (r = −0.59, p < 0.001), %LAA-950insp (r = −0.30, p = 0.002), total LAA (r = −0.35, p < 0.001), FEV1(%) (r = 0.52, p < 0.001), FVC (%) (r = 0.45, p < 0.001), and post-bronchodilator FEV1/FVC (r = 0.41, p < 0.001). Consistent with other data, our bioinformatics-aided dose−response plot showed that the probability of COPD decreased as lnc-IL7R expression increased, thus, corroborating our posited anti-COPD therapeutic potential of lnc-IL7R. In conclusion, reduced lnc-IL7R expression not only is associated with inflammation in the airway epithelial cells but is indicative of impaired pulmonary function, pathognomonic of COPD, and predictive of an exacerbated/ aggravated COPD phenotype. These data provide new mechanistic insights into the ailing lung and COPD progression, as well as suggest a novel actionable molecular factor that may be exploited as an efficacious therapeutic strategy in patients with COPD.

Roles of sirtuin family members in chronic obstructive pulmonary disease

The globally increasing annual incidence of chronic obstructive pulmonary disease (COPD), a common chronic disease, poses a serious risk to public health. Although the exact mechanism underlying the pathogenesis of COPD remains unclear, a large number of studies have shown that its pathophysiology and disease course are closely related to oxidative stress, inflammation, apoptosis, autophagy, and aging. The key players involved in COPD include the sirtuin family of NAD-dependent deacetylases that comprise seven members (SIRT1-7) in mammals. Sirtuins play an important role in metabolic diseases, cell cycle control, proliferation, apoptosis, and senescence. Owing to differences in subcellular localization, sirtuins exhibit anisotropy. In this narrative review, we discuss the roles and molecular pathways of each member of the sirtuin family involved in COPD to provide novel insights into the prevention and treatment of COPD and how sirtuins may serve as adjuvants for COPD treatment.

The Protective Role of Hydrogen Sulfide and Its Impact on Gene Expression Profiling in Rat Model of COPD

Chronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide, which is usually caused by exposure to noxious particles or gases. Hydrogen sulfide (H₂S), as an endogenous gasotransmitter, is involved in the pathogenesis of COPD, but its role in COPD is little known. To investigate the role of H₂S in COPD, a rat model of COPD was established by cigarette smoking (CS) and intratracheal instillation of lipopolysaccharide (LPS). Rats were randomly divided into 4 groups: control, CS + LPS, CS + LPS + sodium hydrosulfide (NaHS, H₂S donor), and CS + LPS + propargylglycine (PPG, inhibitor of cystathionine-γ-lyase, and CTH). Lung function in vivo, histology analysis of lung sections, malondialdehyde (MDA) concentration, CTH protein, total superoxide dismutase (T-SOD), and catalase (CAT) activity in lung tissues were assessed. Gene expression profiling of lung was assessed by microarray analysis. The results showed that rats in the CS + LPS group had lower body weight and lung function but higher lung pathological scores, MDA concentration, CTH protein, T-SOD, and CAT activity compared with the control. Compared with CS + LPS group, NaHS treatment decreased lung pathological scores and MDA concentration, while PPG treatment decreased body weight of rats and T-SOD activity, and no significant differences were detected in pathological scores by PPG treatment. Microarray analysis identified multiple differentially expressed genes, and some genes regulated by H₂S were involved in oxidative stress, apoptosis, and inflammation pathways. It indicates that H₂S may play a protective role in COPD via antioxidative stress and antiapoptosis pathway.

Acrolein inhalation acutely affects the regulation of mitochondrial metabolism in rat lung

Exposure of the airways to cigarette smoke (CS) is the primary risk factor for developing several lung diseases such as Chronic Obstructive Pulmonary Disease (COPD). CS consists of a complex mixture of over 6000 chemicals including the highly reactive α,β-unsaturated aldehyde acrolein. Acrolein is thought to be responsible for a large proportion of the non-cancer disease risk associated with smoking. Emerging evidence suggest a key role for CS-induced abnormalities in mitochondrial morphology and function in airway epithelial cells in COPD pathogenesis. Although in vitro studies suggest acrolein-induced mitochondrial dysfunction in airway epithelial cells, it is unknown if in vivo inhalation of acrolein affects mitochondrial content or the pathways controlling this. In this study, rats were acutely exposed to acrolein by inhalation (nose-only; 0-4 ppm), 4 h/day for 1 or 2 consecutive days (n = 6/group). Subsequently, the activity and abundance of key constituents of mitochondrial metabolic pathways as well as expression of critical proteins and genes controlling mitochondrial biogenesis and mitophagy were investigated in lung homogenates. A transient decreasing response in protein and transcript abundance of subunits of the electron transport chain complexes was observed following acrolein inhalation. Moreover, acrolein inhalation caused a decreased abundance of key regulators associated with mitochondrial biogenesis, respectively a differential response on day 1 versus day 2. Abundance of components of the mitophagy machinery was in general unaltered in response to acrolein exposure in rat lung. Collectively, this study demonstrates that acrolein inhalation acutely and dose-dependently disrupts the molecular regulation of mitochondrial metabolism in rat lung. Hence, understanding the effect of acrolein on mitochondrial function will provide a scientifically supported reasoning to shortlist aldehydes regulation in tobacco smoke.

COPD is Associated with Epigenome-wide Differential Methylation in BAL Lung Cells

DNA methylation patterns in chronic pulmonary obstructive disease (COPD) might offer new insights into disease pathogenesis. To assess methylation profiles in the main COPD target organ, we performed an epigenome-wide association study on bronchoalveolar lavage (BAL) cells. Bronchoscopies were performed in 18 COPD subjects and 15 controls (ex- and current smokers). DNA methylation was measured with Illumina MethylationEPIC BeadChip covering >850,000 CpGs. Differentially methylated positions (DMPs) were examined for 1) enrichment in pathways and functional gene relationships using Kyoto Encyclopedia of Genes and Genomes and Gene Ontology; 2) accelerated aging using Horvath's epigenetic clock; 3) correlation with gene expression; and 4) co-localization with genetic variation. We found 1,155 Bonferroni significant (P < 6.74 × 10^-8) DMPs associated with COPD, many with large effect sizes. Functional analysis identified biologically plausible pathways and gene relationships, including enrichment for transcription factor activity. Strong correlation was found between COPD and chronological age, but not with accelerated epigenetic aging. For 79 unique DMPs, DNA methylation correlated significantly with gene expression in BAL cells. Thirty-nine percent of DMPs were co-localized with COPD-associated SNPs. To the best of our knowledge, this is the first EWAS of COPD on BAL cells, and our analyses revealed many differential methylation sites. Integration with mRNA data showed a strong functional readout for relevant genes, identifying sites where DNA methylation might directly impact expression. Almost half of DMPs were co-located with SNPs identified in previous GWAS of COPD, suggesting joint genetic and epigenetic pathways related to disease.