Regenerative Metaplastic Clones in COPD Lung Drive Inflammation and Fibrosis

Exportin XPO6 upregulation activates the TLR2/MyD88/NF-κB signaling by facilitating TLR2 mRNA nuclear export in COPD pulmonary monocytes

Chronic obstructive pulmonary disease (COPD) poses a significant health threat characterized by lung inflammation primarily triggered by pulmonary monocytes. Despite the centrality of inflammation in COPD, the regulatory mechanisms governing this response remain elusive, presenting a challenge for anti-inflammatory interventions. In this study, we assessed the expression of exportins in COPD mouse models, revealing a notable upregulation of XPO6 in the mouse lung (P = 0.0011). Intriguingly, we observed a consistent upregulation of XPO6 in pulmonary monocytes from both human and mouse COPD subjects (P < 0.0001). Furthermore, in human lung tissue, XPO6 expression exhibited a positive correlation with TLR2 expression (P = 0). In vitro investigations demonstrated that XPO6 enhances TLR2 expression, activating the MyD88/NF-κB inflammatory signaling pathway. This activation, in turn, promotes the secretion of pro-inflammatory cytokines such as TNFα, IL-6, and IL-1β in monocytes. Mechanistically, XPO6 facilitates the nuclear export of TLR2 mRNA, ensuring its stability and subsequent protein expression in monocytes. In conclusion, our findings unveil that the upregulation of XPO6 in COPD pulmonary monocytes activates the MyD88/NF-κB inflammatory signaling pathway by facilitating the nuclear export of TLR2 mRNA, thereby identifying XPO6 as a promising therapeutic target for anti-inflammatory interventions in COPD.

Metabolic pathways in immune senescence and inflammaging: Novel therapeutic strategy for chronic inflammatory lung diseases. An EAACI position paper from the Task Force for Immunopharmacology

The accumulation of senescent cells drives inflammaging and increases morbidity of chronic inflammatory lung diseases. Immune responses are built upon dynamic changes in cell metabolism that supply energy and substrates for cell proliferation, differentiation, and activation. Metabolic changes imposed by environmental stress and inflammation on immune cells and tissue microenvironment are thus chiefly involved in the pathophysiology of allergic and other immune-driven diseases. Altered cell metabolism is also a hallmark of cell senescence, a condition characterized by loss of proliferative activity in cells that remain metabolically active. Accelerated senescence can be triggered by acute or chronic stress and inflammatory responses. In contrast, replicative senescence occurs as part of the physiological aging process and has protective roles in cancer surveillance and wound healing. Importantly, cell senescence can also change or hamper response to diverse therapeutic treatments. Understanding the metabolic pathways of senescence in immune and structural cells is therefore critical to detect, prevent, or revert detrimental aspects of senescence-related immunopathology, by developing specific diagnostics and targeted therapies. In this paper, we review the main changes and metabolic alterations occurring in senescent immune cells (macrophages, B cells, T cells). Subsequently, we present the metabolic footprints described in translational studies in patients with chronic asthma and chronic obstructive pulmonary disease (COPD), and review the ongoing preclinical studies and clinical trials of therapeutic approaches aiming at targeting metabolic pathways to antagonize pathological senescence. Because this is a recently emerging field in allergy and clinical immunology, a better understanding of the metabolic profile of the complex landscape of cell senescence is needed. The progress achieved so far is already providing opportunities for new therapies, as well as for strategies aimed at disease prevention and supporting healthy aging.

Airway hillocks are injury-resistant reservoirs of unique plastic stem cells

Airway hillocks are stratified epithelial structures of unknown function1. Hillocks persist for months and have a unique population of basal stem cells that express genes associated with barrier function and cell adhesion. Hillock basal stem cells continually replenish overlying squamous barrier cells. They exhibit dramatically higher turnover than the abundant, largely quiescent classic pseudostratified airway epithelium. Hillocks resist a remarkably broad spectrum of injuries, including toxins, infection, acid and physical injury because hillock squamous cells shield underlying hillock basal stem cells from injury. Hillock basal stem cells are capable of massive clonal expansion that is sufficient to resurface denuded airway, and eventually regenerate normal airway epithelium with each of its six component cell types. Hillock basal stem cells preferentially stratify and keratinize in the setting of retinoic acid signalling inhibition, a known cause of squamous metaplasia2,3. Here we show that mouse hillock expansion is the cause of vitamin A deficiency-induced squamous metaplasia. Finally, we identify human hillocks whose basal stem cells generate functional squamous barrier structures in culture. The existence of hillocks reframes our understanding of airway epithelial regeneration. Furthermore, we show that hillocks are one origin of 'squamous metaplasia', which is long thought to be a precursor of lung cancer.

Promising Intestinal Microbiota Associated with Clinical Characteristics of COPD Through Integrated Bioinformatics Analysis

Introduction

Chronic obstructive pulmonary disease (COPD), an incurable chronic respiratory disease, has become a major public health problem. The relationship between the composition of intestinal microbiota and the important clinical factors affecting COPD remains unclear. This study aimed to identify specific intestinal microbiota with high clinical diagnostic value for COPD.

Methods

The fecal microbiota of patients with COPD and healthy individuals were analyzed by 16S rDNA sequencing. Random forest classification was performed to analyze the different intestinal microbiota. Spearman correlation was conducted to analyze the correlation between different intestinal microbiota and clinical characteristics. A microbiota-disease network diagram was constructed using the gut MDisorder database to identify the possible pathogenesis of intestinal microorganisms affecting COPD, screen for potential treatment, and guide future research.

Results

No significant difference in biodiversity was shown between the two groups but significant differences in microbial community structure. Fifteen genera of bacteria with large abundance differences were identified, including Bacteroides, Prevotella, Lachnospira, and Parabacteroides. Among them, the relative abundance of Lachnospira and Coprococcus was negatively related to the smoking index and positively related to lung function results. By contrast, the relative abundance of Parabacteroides was positively correlated with the smoking index and negatively correlated with lung function findings. Random forest classification showed that Lachnospira was the genus most capable of distinguishing between patients with COPD and healthy individuals suggesting it may be a potential biomarker of COPD. A Lachnospira disease network diagram suggested that Lachnospira decreased in some diseases, such as asthma, diabetes mellitus, and coronavirus disease 2019 (COVID-19), and increased in other diseases, such as irritable bowel syndrome, hypertension, and bovine lichen.

Conclusion

The dominant intestinal microbiota with significant differences is related to the clinical characteristics of COPD, and the Lachnospira has the potential value to identify COPD.

Loss of an extensive ciliary connectome induces proteostasis and cell fate switching in a severe motile ciliopathy

Motile cilia have essential cellular functions in development, reproduction, and homeostasis. Genetic causes for motile ciliopathies have been identified, but the consequences on cellular functions beyond impaired motility remain unknown. Variants in CCDC39 and CCDC40 cause severe disease not explained by loss of motility. Using human cells with pathological variants in these genes, Chlamydomonas genetics, cryo-electron microscopy, single cell RNA transcriptomics, and proteomics, we identified perturbations in multiple cilia-independent pathways. Absence of the axonemal CCDC39/CCDC40 heterodimer results in loss of a connectome of over 90 proteins. The undocked connectome activates cell quality control pathways, switches multiciliated cell fate, impairs microtubule architecture, and creates a defective periciliary barrier. Both cilia-dependent and independent defects are likely responsible for the disease severity. Our findings provide a foundation for reconsidering the broad cellular impact of pathologic variants in ciliopathies and suggest new directions for therapies.

Identification of a distal enhancer regulating hedgehog interacting protein gene in human lung epithelial cells

BACKGROUND

An intergenic region at chromosome 4q31 is one of the most significant regions associated with COPD susceptibility and lung function in GWAS. In this region, the implicated causal gene HHIP has a unique epithelial expression pattern in adult human lungs, in contrast to dominant expression in fibroblasts in murine lungs. However, the mechanism underlying the species-dependent cell type-specific regulation of HHIP remains largely unknown.

METHODS

We employed snATAC-seq analysis to identify open chromatin regions within the COPD GWAS region in various human lung cell types. ChIP-quantitative PCR, reporter assays, chromatin conformation capture assays and Hi-C assays were conducted to characterize the regulatory element in this region. CRISPR/Cas9-editing was performed in BEAS-2B cells to generate single colonies with stable knockout of the regulatory element. RT-PCR and Western blot assays were used to evaluate expression of HHIP and epithelial-mesenchymal transition (EMT)-related marker genes.

FINDINGS

We identified a distal enhancer within the COPD 4q31 GWAS locus that regulates HHIP transcription at baseline and after TGFβ treatment in a SMAD3-dependent, but Hedgehog-independent manner in human bronchial epithelial cells. The distal enhancer also maintains chromatin topological domains near 4q31 locus and HHIP gene. Reduced HHIP expression led to increased EMT induced by TGFβ in human bronchial epithelial cells.

INTERPRETATION

A distal enhancer regulates HHIP expression both under homeostatic condition and upon TGFβ treatment in human bronchial epithelial cells. The interaction between HHIP and TGFβ signalling possibly contributes to COPD pathogenesis.

FUNDING

Supported by NIH grants R01HL127200, R01HL148667 and R01HL162783 (to X. Z).

Autologous transplantation of P63+ lung progenitor cells for chronic obstructive pulmonary disease therapy

Adult lung resident stem/progenitor cells, including P63+ progenitor cells, have demonstrated the capacity for regeneration of lung epithelium in preclinical models. Here, we report a clinical trial of intrapulmonary P63+ progenitor cell transplantation in 28 participants with stage II to IV chronic obstructive pulmonary disease (COPD). Autologous P63+ progenitor cells were isolated from the airway basal layer of participants in the intervention group via bronchoscopic brushing, cultured for 3 to 5 weeks, and then transplanted back into the lungs via bronchoscopy at 0.7 × 106 to 5.2 × 106 cells per kilogram of body weight. Twenty patients were evaluable at the end of the study (intervention group, n = 17; control group, n = 3). No grade 3 to 5 adverse events (AEs) or serious AEs occurred. Although bronchoscopy-associated AEs were recorded in participants in the intervention group, other AEs were not substantial different between groups. Twenty-four weeks after transplantation, participants in the intervention group displayed improvement in gas transfer capacity [diffusing capacity of the lung for carbon monoxide (DLCO) change from baseline: +18.2%], whereas the control group experienced a decrease (DLCO change from baseline: -17.4%; P = 0.008). Furthermore, participants in the intervention group showed >30-meter increase in walking distance within 6 minutes. Transcriptomic analysis of progenitor cells isolated from responding and nonresponding individuals in the intervention group showed that higher expression of P63 was associated with treatment efficacy. In conclusion, transplantation of cultured P63+ lung progenitor cells was safe and might represent a potential therapeutic strategy for COPD.

Lung regeneration: diverse cell types and the therapeutic potential

Lung tissue has a certain regenerative ability and triggers repair procedures after injury. Under controllable conditions, lung tissue can restore normal structure and function. Disruptions in this process can lead to respiratory system failure and even death, causing substantial medical burden. The main types of respiratory diseases are chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), and acute respiratory distress syndrome (ARDS). Multiple cells, such as lung epithelial cells, endothelial cells, fibroblasts, and immune cells, are involved in regulating the repair process after lung injury. Although the mechanism that regulates the process of lung repair has not been fully elucidated, clinical trials targeting different cells and signaling pathways have achieved some therapeutic effects in different respiratory diseases. In this review, we provide an overview of the cell type involved in the process of lung regeneration and repair, research models, and summarize molecular mechanisms involved in the regulation of lung regeneration and fibrosis. Moreover, we discuss the current clinical trials of stem cell therapy and pharmacological strategies for COPD, IPF, and ARDS treatment. This review provides a reference for further research on the molecular and cellular mechanisms of lung regeneration, drug development, and clinical trials.

Human apical-out nasal organoids reveal an essential role of matrix metalloproteinases in airway epithelial differentiation

Extracellular matrix (ECM) assembly/disassembly is a critical regulator for airway epithelial development and remodeling. Airway organoid is widely used in respiratory research, yet there is limited study to indicate the roles and mechanisms of ECM organization in epithelial growth and differentiation by using in vitro organoid system. Moreover, most of current Matrigel-based airway organoids are in basal-out orientation where accessing the apical surface is challenging. We present a human apical-out airway organoid using a biochemically defined hybrid hydrogel system. During human nasal epithelial progenitor cells (hNEPCs) differentiation, the gel gradually degrade, leading to the organoid apical surfaces facing outward. The expression and activity of ECM-degrading enzymes, matrix metalloproteinases (MMP7, MMP9, MMP10 and MMP13) increases during organoid differentiation, where inhibition of MMPs significantly suppresses the normal ciliation, resulting in increased goblet cell proportion. Moreover, a decrease of MMPs is found in goblet cell hyperplastic epithelium in inflammatory mucosa. This system reveals essential roles of epithelial-derived MMPs on epithelial cell fate determination, and provides an applicable platform enabling further study for ECM in regulating airway development in health and diseases.

Airway Basal Stem Cells in COVID-19 Exhibit a Proinflammatory Signature and Impaired Mucocililary Differentiation

Airway basal stem cells (BSCs) play a critical role in epithelial regeneration. Whether coronavirus disease (COVID-19) affects BSC function is unknown. Here, we derived BSC lines from patients with COVID-19 using tracheal aspirates (TAs) to circumvent the biosafety concerns of live-cell derivation. We show that BSCs derived from the TAs of control patients are bona fide bronchial BSCs. TA BSCs from patients with COVID-19 tested negative for severe acute respiratory syndrome coronavirus 2 RNA; however, these so-termed COVID-19-exposed BSCs in vitro resemble a predominant BSC subpopulation uniquely present in patients with COVID-19, manifested by a proinflammatory gene signature and STAT3 hyperactivation. Furthermore, the sustained STAT3 hyperactivation drives goblet cell differentiation of COVID-19-exposed BSCs in an air-liquid interface. Last, these phenotypes of COVID-19-exposed BSCs can be induced in control BSCs by cytokine cocktail pretreatment. Taken together, acute inflammation in COVID-19 exerts a long-term impact on mucociliary differentiation of BSCs.

Advanced lung organoids and lung-on-a-chip for cancer research and drug evaluation: a review

Lung cancer has become the primary cause of cancer-related deaths because of its high recurrence rate, ability to metastasise easily, and propensity to develop drug resistance. The wide-ranging heterogeneity of lung cancer subtypes increases the complexity of developing effective therapeutic interventions. Therefore, personalised diagnostic and treatment strategies are required to guide clinical practice. The advent of innovative three-dimensional (3D) culture systems such as organoid and organ-on-a-chip models provides opportunities to address these challenges and revolutionise lung cancer research and drug evaluation. In this review, we introduce the advancements in lung-related 3D culture systems, with a particular focus on lung organoids and lung-on-a-chip, and their latest contributions to lung cancer research and drug evaluation. These developments include various aspects, from authentic simulations and mechanistic enquiries into lung cancer to assessing chemotherapeutic agents and targeted therapeutic interventions. The new 3D culture system can mimic the pathological and physiological microenvironment of the lung, enabling it to supplement or replace existing two-dimensional culture models and animal experimental models and realize the potential for personalised lung cancer treatment.

Inflammatory Activity of Epithelial Stem Cell Variants from Cystic Fibrosis Lungs Is Not Resolved by CFTR Modulators

Rationale: CFTR (cystic fibrosis transmembrane conductance regulator) modulator drugs restore function to mutant channels in patients with cystic fibrosis (CF) and lead to improvements in body mass index and lung function. Although it is anticipated that early childhood treatment with CFTR modulators will significantly delay or even prevent the onset of advanced lung disease, lung neutrophils and inflammatory cytokines remain high in patients with CF with established lung disease despite modulator therapy, underscoring the need to identify and ultimately target the sources of this inflammation in CF lungs. Objectives: To determine whether CF lungs, like chronic obstructive pulmonary disease (COPD) lungs, harbor potentially pathogenic stem cell "variants" distinct from the normal p63/Krt5 lung stem cells devoted to alveolar fates, to identify specific variants that might contribute to the inflammatory state of CF lungs, and to assess the impact of CFTR genetic complementation or CFTR modulators on the inflammatory variants identified herein. Methods: Stem cell cloning technology developed to resolve pathogenic stem cell heterogeneity in COPD and idiopathic pulmonary fibrosis lungs was applied to end-stage lungs of patients with CF (three homozygous CFTR:F508D, one CFTR F508D/L1254X; FEV1, 14-30%) undergoing therapeutic lung transplantation. Single-cell-derived clones corresponding to the six stem cell clusters resolved by single-cell RNA sequencing of these libraries were assessed by RNA sequencing and xenografting to monitor inflammation, fibrosis, and mucin secretion. The impact of CFTR activity on these variants after CFTR gene complementation or exposure to CFTR modulators was assessed by molecular and functional studies. Measurements and Main Results: End-stage CF lungs display a stem cell heterogeneity marked by five predominant variants in addition to the normal lung stem cell, of which three are proinflammatory both at the level of gene expression and their ability to drive neutrophilic inflammation in xenografts in immunodeficient mice. The proinflammatory functions of these three variants were unallayed by genetic or pharmacological restoration of CFTR activity. Conclusions: The emergence of three proinflammatory stem cell variants in CF lungs may contribute to the persistence of lung inflammation in patients with CF with advanced disease undergoing CFTR modulator therapy.

Pulmonary embolism induces pneumonia-like lung injury beyond pulmonary infarction

Patients with pulmonary embolism (PE) commonly manifest concomitant "pneumonia," which is generally believed to be either a cause (infection) or a consequence (infarction) of PE. This study aimed to clarify the relationship between PE and "pneumonia-like" lesions beyond pulmonary infection and infarction. Chest computed tomography (CT) images of patients with PE and deep vein thrombosis (DVT) were retrospectively analyzed to compare the incidence of pneumonia lesions. The pathological damage and wet/dry ratio of lung tissues were observed in PE rats and PE plasma-injected rats. In total, 793 and 914 inpatients were enrolled in the PE and DVT groups, respectively. Pneumonia lesions were observed in 36.9% and 26.3% of patients in the PE and DVT groups, respectively (p < 0.0001). Among PE rats, 33.3% exhibited focal severe lung injury, which closely resembled the pathological damage of community-acquired pneumonia. The wet/dry ratio was significantly higher in the PE group than in the PE-control group (4.98 ± 0.08 vs. 4.39 ± 0.06, p < 0.0001). Among PE plasma-injected rats, individuals with focal proven lung injury were found at all experimental points, with an incidence of 27.6%. The lung wet/dry ratio was significantly higher in the PE plasma group than in the PE-control plasma group at 1 and 2 h postinjection (5.02 ± 0.12 vs. 4.61 ± 0.06 and 4.76 ± 0.16 vs. 4.34 ± 0.09, respectively; p < 0.05). In conclusion, the manifestation of pneumonia lesions in chest CT images was higher among PE patients than among DVT patients. Plasma of PE rats could induce focal pneumonia-like lung injury in healthy rats.

Understanding and addressing the needs of people with cystic fibrosis in the era of CFTR modulator therapy

Cystic fibrosis is a multiorgan disease caused by impaired function of the cystic fibrosis transmembrane conductance regulator (CFTR). Since the introduction of the CFTR modulator combination elexacaftor-tezacaftor-ivacaftor (ETI), which acts directly on mutant CFTR to enhance its activity, most people with cystic fibrosis (pwCF) have seen pronounced reductions in symptoms, and studies project marked increases in life expectancy for pwCF who are eligible for ETI. However, modulator therapy has not cured cystic fibrosis and the success of CFTR modulators has resulted in immediate questions about the new state of cystic fibrosis disease and clinical challenges in the care of pwCF. In this Series paper, we summarise key questions about cystic fibrosis disease in the era of modulator therapy, highlighting state-of-the-art research and clinical practices, knowledge gaps, new challenges faced by pwCF and the potential for future health-care challenges, and the pressing need for additional therapies to treat the underlying genetic or molecular causes of cystic fibrosis.

Mechanical stretch promotes apoptosis and impedes ciliogenesis of primary human airway basal stem cells

BACKGROUND

Airway basal stem cells (ABSCs) have self-renewal and differentiation abilities. Although an abnormal mechanical environment related to chronic airway disease (CAD) can cause ABSC dysfunction, it remains unclear how mechanical stretch regulates the behavior and structure of ABSCs. Here, we explored the effect of mechanical stretch on primary human ABSCs.

METHODS

Primary human ABSCs were isolated from healthy volunteers. A Flexcell FX-5000 Tension system was used to mimic the pathological airway mechanical stretch conditions of patients with CAD. ABSCs were stretched for 12, 24, or 48 h with 20% elongation. We first performed bulk RNA sequencing to identify the most predominantly changed genes and pathways. Next, apoptosis of stretched ABSCs was detected with Annexin V-FITC/PI staining and a caspase 3 activity assay. Proliferation of stretched ABSCs was assessed by measuring MKI67 mRNA expression and cell cycle dynamics. Immunofluorescence and hematoxylin-eosin staining were used to demonstrate the differentiation state of ABSCs at the air-liquid interface.

RESULTS

Compared with unstretched control cells, apoptosis and caspase 3 activation of ABSCs stretched for 48 h were significantly increased (p < 0.0001; p < 0.0001, respectively), and MKI67 mRNA levels were decreased (p < 0.0001). In addition, a significant increase in the G0/G1 population (20.2%, p < 0.001) and a significant decrease in S-phase cells (21.1%, p < 0.0001) were observed. The ratio of Krt5+ ABSCs was significantly higher (32.38% vs. 48.71%, p = 0.0037) following stretching, while the ratio of Ac-tub+ cells was significantly lower (37.64% vs. 21.29%, p < 0.001). Moreover, compared with the control, the expression of NKX2-1 was upregulated significantly after stretching (14.06% vs. 39.51%, p < 0.0001). RNA sequencing showed 285 differentially expressed genes, among which 140 were upregulated and 145 were downregulated, revealing that DDIAS, BIRC5, TGFBI, and NKX2-1 may be involved in the function of primary human ABSCs during mechanical stretch. There was no apparent difference between stretching ABSCs for 24 and 48 h compared with the control.

CONCLUSIONS

Pathological stretching induces apoptosis of ABSCs, inhibits their proliferation, and disrupts cilia cell differentiation. These features may be related to abnormal regeneration and repair observed after airway epithelium injury in patients with CAD.

Advanced models for respiratory disease and drug studies

The global burden of respiratory diseases is enormous, with many millions of people suffering and dying prematurely every year. The global COVID-19 pandemic witnessed recently, along with increased air pollution and wildfire events, increases the urgency of identifying the most effective therapeutic measures to combat these diseases even further. Despite increasing expenditure and extensive collaborative efforts to identify and develop the most effective and safe treatments, the failure rates of drugs evaluated in human clinical trials are high. To reverse these trends and minimize the cost of drug development, ineffective drug candidates must be eliminated as early as possible by employing new, efficient, and accurate preclinical screening approaches. Animal models have been the mainstay of pulmonary research as they recapitulate the complex physiological processes, Multiorgan interplay, disease phenotypes of disease, and the pharmacokinetic behavior of drugs. Recently, the use of advanced culture technologies such as organoids and lung-on-a-chip models has gained increasing attention because of their potential to reproduce human diseased states and physiology, with clinically relevant responses to drugs and toxins. This review provides an overview of different animal models for studying respiratory diseases and evaluating drugs. We also highlight recent progress in cell culture technologies to advance integrated models and discuss current challenges and present future perspectives.

Magnolol alleviates pulmonary fibrosis inchronic obstructive pulmonary disease by targeting transient receptor potential vanilloid 4-ankyrin repeat domain

Transient receptor potential vanilloid 4 (TRPV4) plays a role in regulating pulmonary fibrosis (PF). While several TRPV4 antagonists including magnolol (MAG), have been discovered, the mechanism of action is not fully understood. This study aimed to investigate the effect of MAG on alleviating fibrosis in chronic obstructive pulmonary disease (COPD) based on TRPV4, and to further analyze its mechanism of action on TRPV4. COPD was induced using cigarette smoke and LPS. The therapeutic effect of MAG on COPD-induced fibrosis was evaluated. TRPV4 was identified as the main target protein of MAG using target protein capture with MAG probe and drug affinity response target stability assay. The binding sites of MAG at TRPV4 were analyzed using molecular docking and small molecule interaction with TRPV4-ankyrin repeat domain (ARD). The effects of MAG on TRPV4 membrane distribution and channel activity were analyzed by co-immunoprecipitation, fluorescence co-localization, and living cell assay of calcium levels. By targeting TRPV4-ARD, MAG disrupted the binding between phosphatidylinositol 3 kinase γ and TRPV4, leading to hampered membrane distribution on fibroblasts. Additionally, MAG competitively impaired ATP binding to TRPV4-ARD, inhibiting TRPV4 channel opening activity. MAG effectively blocked the fibrotic process caused by mechanical or inflammatory signals, thus alleviating PF in COPD. Targeting TRPV4-ARD presents a novel treatment strategy for PF in COPD.

Glucocorticoid Alleviates Mechanical Stress-Induced Airway Inflammation and Remodeling in COPD via Transient Receptor Potential Canonical 1 Channel

Background

Increased airway resistance and hyperinflation in chronic obstructive pulmonary disease (COPD) are associated with increased mechanical stress that modulate many essential pathophysiological functions including airway remodeling and inflammation. Our present study aimed to investigate the role of transient receptor potential canonical 1 (TRPC1), a mechanosensitive cation channel in airway remodeling and inflammation in COPD and the effect of glucocorticoid on this process.

Methods

In patients, we investigated the effect of pathological high mechanical stress on the expression of airway remodeling-related cytokines transforming growth factor β1 (TGF-β1), matrix metalloproteinase-9 (MMP9) and the count of inflammatory cells in endotracheal aspirates (ETAs) by means of different levels of peak inspiratory pressure (PIP) under mechanical ventilation, and analyzed their correlation with TRPC1. Based on whether patients regularly used inhaled corticosteroid (ICS), COPD patients were further divided into ICS group (n = 12) and non-ICS group (n=15). The ICS effect on the expression of TRPC1 was detected by Western blot. In vitro, we imitated the mechanical stress using cyclic stretch and examined the levels of TGF-β1 and MMP-9. The role of TRPC1 was further explored by siRNA transfection and dexamethasone administration.

Results

Our results revealed that the TRPC1 level and the inflammatory cells counts were significantly higher in COPD group. After mechanical ventilation, the expression of TGF-β1 and MMP-9 in all COPD subgroups was significantly increased, while in the control group, only high PIP subgroup increased. Meanwhile, TRPC1 expression was positively correlated with the counts of inflammatory cells and the levels of TGF-β1 and MMP-9. In vitro, mechanical stretch significantly increased TGF-β1 and MMP-9 levels and such increase was greatly attenuated by TRPC1 siRNA transfection and dexamethasone administration.

Conclusion

Our results suggest that the increased TRPC1 may play a role in the airway inflammation and airway remodeling in COPD under high airway pressure. Glucocorticoid could in some degree alleviate airway remodeling via inhibition of TRPC1.

Airway epithelium regeneration by photoactivated basal cells

The airway epithelium is the footstone to maintain the structure and functions of lung, in which resident basal cells (BCs) maintain homeostasis and functional regeneration of epithelial barrier in response to injury. In recent clinical researches, transplanting BCs has shown great inspiring achievements in therapy of various lung diseases. In this study, we report a noninvasive optical method to activate BCs for airway epithelium regeneration in vivo by fast scanning of focused femtosecond laser on BCs of airway epithelium to active Ca2+ signaling and subsequent ERK and Wnt pathways. The photoactivated BCs present high proliferative capacity and maintain high pluripotency, which enables them to plant in the injured airway epithelium and differentiate to club cells for regeneration of epithelium. This optical method can also work in situ to activate localized BCs in airway tissue. Therefore, our results provide a powerful technology for noninvasive BC activation in stem-cell therapy of lung diseases.

Colonic stem cells from normal tissues adjacent to tumor drive inflammation and fibrosis in colorectal cancer

BACKGROUND

In colorectal cancer (CRC), the normal tissue adjacent to tumor (NAT) communicates actively with the tumor. Adult stem cells from the colon play a crucial role in the development of the colonic epithelium. In the tumor microenvironment, however, it is unclear what changes have occurred in colonic stem cells derived from NAT.

METHODS

Using an intestinal stem cell culture system, we cultured colonic cells from NAT and paired CRC tissue, as well as cells from healthy tissue (HLT). Clonogenicity and differentiation ability were used to compare the function of clones from NAT, HLT and CRC tissues. RNA high-throughput sequencing of these clones was used to identify the molecular characteristics of NAT-derived clones. Coculture of clones from HLT and CRC was used to assess molecular changes.

RESULTS

We found that the morphological characteristics, clonogenic ability, and differentiation ability of NAT-derived clones were consistent with those of HLT-derived clones. However, NAT-derived clones changed at the molecular level. A number of genes were specifically activated in NAT. NAT-derived clones enriched pathways related to inflammation and fibrosis, including epithelial mesenchymal transition (EMT) pathway and TGF-beta signaling pathway. Our results also confirmed that NAT-derived clones could recruit fibroblasts in mice. In addition, HLT-derived clones showed high expression of FOSB when cocultured with tumor cells.

CONCLUSIONS

Our results demonstrate that colonic stem cells from NAT in the tumor microenvironment undergo changes at the molecular level, and these molecular characteristics can be maintained in vitro, which can induce fibrosis and an inflammatory response. Video Abstract.

Effectiveness of Pulmonary Rehabilitation for Chronic Obstructive Pulmonary Disease Therapy: Focusing on Traditional Medical Practices

Chronic obstructive pulmonary disease (COPD) is a complex and serious disease that is characterized by dyspnea, fatigue, decreased exercise tolerance, peripheral muscle dysfunction, and mood disorders. These manifestations are successfully treated with pulmonary rehabilitation, a comprehensive intervention and holistic approach designed to improve the physical and psychological condition of people with COPD. Exercise is a big component of pulmonary rehabilitation programs, but the efficacy of non-traditional forms of exercise as used in alternative medicine is poorly understood. Here, we aim to address this gap in knowledge and summarize the clinical evidence for the use of traditional exercise regimens in the pulmonary rehabilitation of COPD patients.

Long non-coding RNA PFI inhibits apoptosis of alveolar epithelial cells to alleviate lung injury via miR-328-3p/Creb1 axis

Acute lung injury (ALI), a common clinical type of critical illness, is an acute hypoxic respiratory insufficiency caused by the damage of alveolar epithelial cells and capillary endothelial cells. In a previous study, we reported a novel lncRNA, lncRNA PFI, which could protect against pulmonary fibrosis in pulmonary fibroblasts. The present study demonstrated that lncRNA PFI was downregulated in alveolar epithelial cell of mice injury lung tissues, and further investigated the role of lncRNA PFI in regulating inflammation-induced alveolar epithelial cell apoptosis. Overexpression of lncRNA PFI could partially abrogated bleomycin induced type II AECs injured. Subsequently, bioinformatic prediction revealed that lncRNA PFI might directly bind to miR-328-3p, and further AGO-2 RNA binding protein immunoprecipitation (RIP) assay confirmed their binding relationship. Furthermore, miR-328-3p promoted apoptosis in MLE-12 cells by limiting the activation of the Creb1, a protein correlated with cell apoptosis, whereas AMO-328-3p ablated the pro-apoptosis effect of silencing lncRNA PFI in MLE-12 cells. While miR-328-3p could also ablate the function of lncRNA PFI in bleomycin treated human lung epithelial cells. Enhanced expression of lncRNA PFI reversed the LPS-induced lung injury in mice. Overall, these data reveal that lncRNA PFI mitigated acute lung injury through miR-328-3p/Creb1 pathway in alveolar epithelial cells.

Airway Epithelial Cultures of Children with Esophageal Atresia as a Model to Study Respiratory Tract Disorders

Esophageal atresia (EA) is a rare birth defect in which respiratory tract disorders are a major cause of morbidity. It remains unclear whether respiratory tract disorders are in part caused by alterations in airway epithelial cell functions such as the activity of motile cilia. This can be studied using airway epithelial cell culture models of patients with EA. Therefore, the aim of this study was to evaluate the feasibility to culture and functionally characterize motile cilia function in the differentiated air-liquid interface cultured airway epithelial cells and 3D organoids derived from nasal brushings and bronchoalveolar lavage (BAL) fluid from children with EA. We demonstrate the feasibility of culturing differentiated airway epithelia and organoids of nasal brushings and BAL fluid of children with EA, which display normal motile cilia function. EA patient-derived airway epithelial cultures can be further used to examine whether alterations in epithelial functions contribute to respiratory disorders in EA.

The role of Sirtuin 1 and its activators in age-related lung disease

Aging is a major driving factor in lung diseases. Age-related lung disease is associated with downregulated expression of SIRT1, an NAD⁺-dependent deacetylase that regulates inflammation and stress resistance. SIRT1 acts by inducing the deacetylation of various substrates and regulates several mechanisms that relate to lung aging, such as genomic instability, lung stem cell exhaustion, mitochondrial dysfunction, telomere shortening, and immune senescence. Chinese herbal medicines have many biological activities, exerting anti-inflammatory, anti-oxidation, anti-tumor, and immune regulatory effects. Recent studies have confirmed that many Chinese herbs have the effect of activating SIRT1. Therefore, we reviewed the mechanism of SIRT1 in age-related lung disease and explored the potential roles of Chinese herbs as SIRT1 activators in the treatment of age-related lung disease.

Human Airway Basal Cells Undergo Reversible Squamous Differentiation and Reshape Innate Immunity

Histological and lineage immunofluorescence examination revealed that healthy conducting airways of humans and animals harbor sporadic poorly differentiated epithelial patches mostly in the dorsal noncartilage regions that remarkably manifest squamous differentiation. In vitro analysis demonstrated that this squamous phenotype is not due to intrinsic functional change in underlying airway basal cells. Rather, it is a reversible physiological response to persistent Wnt signaling stimulation during de novo differentiation. Squamous epithelial cells have elevated gene signatures of glucose uptake and cellular glycolysis. Inhibition of glycolysis or a decrease in glucose availability suppresses Wnt-induced squamous epithelial differentiation. Compared with pseudostratified airway epithelial cells, a cascade of mucosal protective functions is impaired in squamous epithelial cells, featuring increased epithelial permeability, spontaneous epithelial unjamming, and enhanced inflammatory responses. Our study raises the possibility that the squamous differentiation naturally occurring in healthy airways identified herein may represent "vulnerable spots" within the airway mucosa that are sensitive to damage and inflammation when confronted by infection or injury. Squamous metaplasia and hyperplasia are hallmarks of many airway diseases, thereby expanding these areas of vulnerability with potential pathological consequences. Thus, investigation of physiological and reversible squamous differentiation from healthy airway basal cells may provide critical knowledge to understand pathogenic squamous remodeling, which is often nonreversible, progressive, and hyperinflammatory.

Butyrate inhibits iILC2-mediated lung inflammation via lung-gut axis in chronic obstructive pulmonary disease (COPD)

BACKGROUND

The study investigated the effects and underlying mechanisms of intestinal flora metabolite butyrate on inflammatory ILC2 cells (iILC2s)-mediated lung inflammation in chronic obstructive pulmonary disease (COPD).

METHODS

Mouse models of COPD and acute exacerbation of COPD (AECOPD) were established. Flow cytometry was used to detect natural ILC2 cells (nILC2s) and iILC2s in lung and colon tissues. The 16s rRNA and GC-MS were used to detect microbial flora and short chain fatty acids (SCFAs) in feces. ELISA was used to detect IL-13 and IL-4. Western blot and qRT-PCR were used to detect the relative protein and mRNA levels, respectively. In vitro experiments were performed with sorted ILC2s from colon tissues of control mice. Mice with AECOPD were treated with butyrate.

RESULTS

The nILC2s and iILC2s in lung and colon tissues of AECOPD mice were significantly higher than control groups. The abundance of the flora Clostridiaceae was significantly reduced, and the content of SCFAs, including acetate and butyrate, was significantly reduced. The in vitro experiments showed that butyrate inhibited iILC2 cell phenotype and cytokine secretion. Butyrate treatment reduced the proportion of iILC2 cells in the colon and lung tissues of mice with AECOPD.

CONCLUSIONS

The nILC2s and iILC2s in the colon tissues are involved in the course of COPD. Decreased Clostridiaceae and butyrate in AECOPD mice caused the accumulation of iILC2 cells in the intestines and lungs. Supplementation of butyrate can reduce iILC2 in the intestine and lung tissues. Our data may provide new ideas for prevention and treatment of COPD.

A Unique Cellular Organization of Human Distal Airways and Its Disarray in Chronic Obstructive Pulmonary Disease

Rationale: Remodeling and loss of distal conducting airways, including preterminal and terminal bronchioles (pre-TBs/TBs), underlie progressive airflow limitation in chronic obstructive pulmonary disease (COPD). The cellular basis of these structural changes remains unknown. Objectives: To identify biological changes in pre-TBs/TBs in COPD at single-cell resolution and determine their cellular origin. Methods: We established a novel method of distal airway dissection and performed single-cell transcriptomic profiling of 111,412 cells isolated from different airway regions of 12 healthy lung donors and pre-TBs of 5 patients with COPD. Imaging CyTOF and immunofluorescence analysis of pre-TBs/TBs from 24 healthy lung donors and 11 subjects with COPD were performed to characterize cellular phenotypes at a tissue level. Region-specific differentiation of basal cells isolated from proximal and distal airways was studied using an air-liquid interface model. Measurements and Main Results: The atlas of cellular heterogeneity along the proximal-distal axis of the human lung was assembled and identified region-specific cellular states, including SCGB3A2+ SFTPB+ terminal airway-enriched secretory cells (TASCs) unique to distal airways. TASCs were lost in COPD pre-TBs/TBs, paralleled by loss of region-specific endothelial capillary cells, increased frequency of CD8+ T cells normally enriched in proximal airways, and augmented IFN-γ signaling. Basal cells residing in pre-TBs/TBs were identified as a cellular origin of TASCs. Regeneration of TASCs by these progenitors was suppressed by IFN-γ. Conclusions: Altered maintenance of the unique cellular organization of pre-TBs/TBs, including loss of the region-specific epithelial differentiation in these bronchioles, represents the cellular manifestation and likely the cellular basis of distal airway remodeling in COPD.

An update in club cell biology and its potential relevance to chronic obstructive pulmonary disease

Club cells are found in human small airways where they play an important role in immune defense, xenobiotic metabolism, and repair after injury. Over the past few years, data from single-cell RNA sequencing (scRNA-seq) studies has generated new insights into club cell heterogeneity and function. In this review, we integrate findings from scRNA-seq experiments with earlier in vitro, in vivo, and microscopy studies and highlight the many ways club cells contribute to airway homeostasis. We then discuss evidence for loss of club cells or club cell products in the airways of patients with chronic obstructive pulmonary disease (COPD) and discuss potential mechanisms through which this might occur.

Cloning a profibrotic stem cell variant in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive, irreversible, and rapidly fatal interstitial lung disease marked by the replacement of lung alveoli with dense fibrotic matrices. Although the mechanisms initiating IPF remain unclear, rare and common alleles of genes expressed in lung epithelia, combined with aging, contribute to the risk for this condition. Consistently, single-cell RNA sequencing (scRNA-seq) studies have identified lung basal cell heterogeneity in IPF that might be pathogenic. We used single-cell cloning technologies to generate "libraries" of basal stem cells from the distal lungs of 16 patients with IPF and 10 controls. We identified a major stem cell variant that was distinguished from normal stem cells by its ability to transform normal lung fibroblasts into pathogenic myofibroblasts in vitro and to activate and recruit myofibroblasts in clonal xenografts. This profibrotic stem cell variant, which was shown to preexist in low quantities in normal and even fetal lungs, expressed a broad network of genes implicated in organ fibrosis and showed overlap in gene expression with abnormal epithelial signatures identified in previously published scRNA-seq studies of IPF. Drug screens highlighted specific vulnerabilities of this profibrotic variant to inhibitors of epidermal growth factor and mammalian target of rapamycin signaling as prospective therapeutic targets. This profibrotic stem cell variant in IPF was distinct from recently identified profibrotic stem cell variants in chronic obstructive pulmonary disease and may extend the notion that inappropriate accrual of minor and preexisting stem cell variants contributes to chronic lung conditions.

Epigenetics Approaches toward Precision Medicine for Idiopathic Pulmonary Fibrosis: Focus on DNA Methylation

Genetic information is not transmitted solely by DNA but by the epigenetics process. Epigenetics describes molecular missing link pathways that could bridge the gap between the genetic background and environmental risk factors that contribute to the pathogenesis of pulmonary fibrosis. Specific epigenetic patterns, especially DNA methylation, histone modifications, long non-coding, and microRNA (miRNAs), affect the endophenotypes underlying the development of idiopathic pulmonary fibrosis (IPF). Among all the epigenetic marks, DNA methylation modifications have been the most widely studied in IPF. This review summarizes the current knowledge concerning DNA methylation changes in pulmonary fibrosis and demonstrates a promising novel epigenetics-based precision medicine.

Pericytes: The lung-forgotten cell type

Pericytes are a heterogeneous population of mesenchymal cells located on the abluminal surface of microvessels, where they provide structural and biochemical support. Pericytes have been implicated in numerous lung diseases including pulmonary arterial hypertension (PAH) and allergic asthma due to their ability to differentiate into scar-forming myofibroblasts, leading to collagen deposition and matrix remodelling and thus driving tissue fibrosis. Pericyte-extracellular matrix interactions as well as other biochemical cues play crucial roles in these processes. In this review, we give an overview of lung pericytes, the key pro-fibrotic mediators they interact with, and detail recent advances in preclinical studies on how pericytes are disrupted and contribute to lung diseases including PAH, allergic asthma, and chronic obstructive pulmonary disease (COPD). Several recent studies using mouse models of PAH have demonstrated that pericytes contribute to these pathological events; efforts are currently underway to mitigate pericyte dysfunction in PAH by targeting the TGF-β, CXCR7, and CXCR4 signalling pathways. In allergic asthma, the dissociation of pericytes from the endothelium of blood vessels and their migration towards inflamed areas of the airway contribute to the characteristic airway remodelling observed in allergic asthma. Although several factors have been suggested to influence this migration such as TGF-β, IL-4, IL-13, and periostin, recent evidence points to the CXCL12/CXCR4 pathway as a potential therapeutic target. Pericytes might also play an essential role in lung dysfunction in response to ageing, as they are responsive to environmental risk factors such as cigarette smoke and air pollutants, which are the main drivers of COPD. However, there is currently no direct evidence delineating the contribution of pericytes to COPD pathology. Although there is a lack of human clinical data, the recent available evidence derived from in vitro and animal-based models shows that pericytes play important roles in the initiation and maintenance of chronic lung diseases and are amenable to pharmacological interventions. Therefore, further studies in this field are required to elucidate if targeting pericytes can treat lung diseases.

Lung Cell Atlases in Health and Disease

The human lung cellular portfolio, traditionally characterized by cellular morphology and individual markers, is highly diverse, with over 40 cell types and a complex branching structure highly adapted for agile airflow and gas exchange. While constant during adulthood, lung cellular content changes in response to exposure, injury, and infection. Some changes are temporary, but others are persistent, leading to structural changes and progressive lung disease. The recent advance of single-cell profiling technologies allows an unprecedented level of detail and scale to cellular measurements, leading to the rise of comprehensive cell atlas styles of reporting. In this review, we chronical the rise of cell atlases and explore their contributions to human lung biology in health and disease.

Cpt1a alleviates cigarette smoke‑induced chronic obstructive pulmonary disease

The current study aimed to determine the expression of carnitine palmitoyltransferase 1A (Cpt1a) in the lung tissue of chronic obstructive pulmonary disease (COPD) patients and its correlation with lung function. An increase in Cpt1a expression improved lung function in patients with COPD by inhibiting apoptosis and the inflammatory response of lung endothelial cells. Lung tissues of 20 patients with COPD and 10 control patients were collected, their Cpt1a expression was determined by western blotting and apoptosis and inflammation were assessed by haematoxylin-eosin staining, TUNEL assay and ELISA. Mice with knockout or overexpression of Cpt1a were constructed by lentivirus in vivo. A COPD model was induced by cigarette smoke and the role of Cpt1a in COPD was determined in vivo and in vitro. Cpt1a expression was positively correlated with lung function and negatively correlated with apoptosis and inflammation. Patients with COPD with higher expression of Cpt1a in lung tissues had improved lung function indices and lung tissue morphology with less apoptosis and decreased inflammatory response. Compared with the control group, COPD mice with Cpt1a knockdown had aggravated lung dysfunction and increased lung inflammation and apoptosis. Overexpression of Cpt1a alleviated lung dysfunction and reduced inflammatory response and apoptosis of lung tissues in COPD mice. Pulmonary microvascular endothelial cells of mice were isolated in vitro and the results were consistent with the findings obtained in vivo. In conclusion, the clinical, in vivo and in vitro data confirmed for the first time that Cpt1a alleviated lung dysfunction of patients with COPD by inhibiting apoptosis of endothelial cells and inflammatory responses.

Exploiting the potential of lung stem cells to develop pro-regenerative therapies

Acute and chronic lung diseases are a leading cause of morbidity and mortality globally. Unfortunately, these diseases are increasing in frequency and we have limited treatment options for severe lung diseases. New therapies are needed that not only treat symptoms or slow disease progression, but also enable the regeneration of functional lung tissue. Both airways and alveoli contain populations of epithelial stem cells with the potential to self-renew and produce differentiated progeny. Understanding the mechanisms that determine the behaviour of these cells, and their interactions with their niches, will allow future generations of respiratory therapies that protect the lungs from disease onset, promote regeneration from endogenous stem cells or enable regeneration through the delivery of exogenous cells. This review summarises progress towards each of these goals, highlighting the challenges and opportunities of developing pro-regenerative (bio)pharmaceutical, gene and cell therapies for respiratory diseases.

Nanocarrier-based approaches to combat chronic obstructive pulmonary disease

Abnormalities in airway mucus lead to chronic disorders in the pulmonary system such as asthma, fibrosis and chronic obstructive pulmonary disease (COPD). Among these, COPD is more prominent worldwide. Various conventional approaches are available in the market for the treatment of COPD, but the delivery of drugs to the target site remains a challenge with conventional approaches. Nanocarrier-based approaches are considered the best due to their sustained release properties to the target site, smaller size, high surface-to-volume ratio, patient compliance, overcoming airway defenses and improved pharmacotherapy. This article provides updated information about the treatment of COPD along with nanocarrier-based approaches as well as the potential of gene therapy and stem cell therapy to combat the COPD.

Airway basal cells show regionally distinct potential to undergo metaplastic differentiation

Basal cells are multipotent stem cells of a variety of organs, including the respiratory tract, where they are major components of the airway epithelium. However, it remains unclear how diverse basal cells are and how distinct subpopulations respond to airway challenges. Using single cell RNA-sequencing and functional approaches, we report a significant and previously underappreciated degree of heterogeneity in the basal cell pool, leading to identification of six subpopulations in the adult murine trachea. Among these, we found two major subpopulations, collectively comprising the most uncommitted of all the pools, but with distinct gene expression signatures. Notably, these occupy distinct ventral and dorsal tracheal niches and differ in their ability to self-renew and initiate a program of differentiation in response to environmental perturbations in primary cultures and in mouse injury models in vivo. We found that such heterogeneity is acquired prenatally, when the basal cell pool and local niches are still being established, and depends on the integrity of these niches, as supported by the altered basal cell phenotype of tracheal cartilage-deficient mouse mutants. Finally, we show that features that distinguish these progenitor subpopulations in murine airways are conserved in humans. Together, the data provide novel insights into the origin and impact of basal cell heterogeneity on the establishment of regionally distinct responses of the airway epithelium during injury-repair and in disease conditions.

Telomeres and Telomerase in the Control of Stem Cells

Stem cells serve as a source of cellular material in embryogenesis and postnatal growth and regeneration. This requires significant proliferative potential ensured by sufficient telomere length. Telomere attrition in the stem cells and their niche cells can result in the exhaustion of the regenerative potential of high-turnover organs, causing or contributing to the onset of age-related diseases. In this review, stem cells are examined in the context of the current telomere-centric theory of cell aging, which assumes that telomere shortening depends not just on the number of cell doublings (mitotic clock) but also on the influence of various internal and external factors. The influence of the telomerase and telomere length on the functional activity of different stem cell types, as well as on their aging and prospects of use in cell therapy applications, is discussed.

Secretory Cells Are the Primary Source of pIgR in Small Airways

Loss of secretory IgA (SIgA) is common in chronic obstructive pulmonary disease (COPD) small airways and likely contributes to disease progression. We hypothesized that loss of SIgA results from reduced expression of pIgR (polymeric immunoglobulin receptor), a chaperone protein needed for SIgA transcytosis, in the COPD small airway epithelium. pIgR-expressing cells were defined and quantified at single-cell resolution in human airways using RNA in situ hybridization, immunostaining, and single-cell RNA sequencing. Complementary studies in mice used immunostaining, primary murine tracheal epithelial cell culture, and transgenic mice with secretory or ciliated cell-specific knockout of pIgR. SIgA degradation by human neutrophil elastase or secreted bacterial proteases from nontypeable Haemophilus influenzae was evaluated in vitro. We found that secretory cells are the predominant cell type responsible for pIgR expression in human and murine airways. Loss of SIgA in small airways was not associated with a reduction in secretory cells but rather a reduction in pIgR protein expression despite intact PIGR mRNA expression. Neutrophil elastase and nontypeable H. influenzae-secreted proteases are both capable of degrading SIgA in vitro and may also contribute to a deficient SIgA immunobarrier in COPD. Loss of the SIgA immunobarrier in small airways of patients with severe COPD is complex and likely results from both pIgR-dependent defects in IgA transcytosis and SIgA degradation.

Clinical Observation of General Anesthesia Combined with Spinal Anesthesia in Elderly Patients with Chronic Obstructive Pulmonary Disease

Objective

This work is aimed at evaluating the efficacy and safety of general anesthesia (GA) combined with spinal anesthesia (SA) (GA+SA) in elderly patients with chronic obstructive pulmonary disease (COPD). Methods and Material. 50 elderly COPD patients were rolled randomly into a control group (simple GA) and observation group (GA+SA). The differences in operation time, postoperative recovery time (PRT), language expression time (LET), anesthetic dosage (AD), catheter extubation time (CET), respiratory circulation indicators (mean arterial pressure (MAP), heart rate (HR), SaO2, and PaO2), postoperative VRS score, pulmonary function (forced vital capacity (FVC)), forced expiratory volume in 1 s (FEV1)/FVC and forced expiratory flow (FEF 25%~75%), serum inflammatory factors (IL-6, IL-8, and TNF-α), Short Portable Mental Status Questionnaire (SPMSQ) score, and the incidence of respiratory system events were analyzed.

Results

The results showed that the PRT, LET, AD, and CET of the observation group were all shorter (P < 0.05). The postoperative MAP, HR, SaO2, and PaO2 levels of patients who received GA+SA were much higher than those who received simple GA (P < 0.05). The postoperative VRS score of the observation group was better than that of the controls (P < 0.05). The postoperative pulmonary function of patients in the observation group was better compared with that in the control group (P < 0.05). The postoperative serum inflammatory factors in the observation group were lower in contrast to the patients who received simple GA (P < 0.05). The postoperative cognitive function SPMSQ score of patients who received GA+SA was lower compared with the score of patients who received simple GA (P < 0.05). However, the probability of respiratory system events in the observation group was lower (P < 0.05).

Conclusion

In conclusion, GA+SA could significantly shorten the PRT and improve the recovery quality of elderly COPD patients. It can also reduce the postoperative inflammatory response and strengthen the pulmonary function and cognitive function. It also enhances the analgesic which is beneficial to patients' postoperative recovery. Therefore, GA+SA was a highly effective and safe anesthesia method for elderly patients with COPD, and it was worthy of clinical application.

Pathological Mechanism and Targeted Drugs of COPD

Chronic obstructive pulmonary disease (COPD) includes chronic bronchitis, emphysema, and small airway obstruction. Incompletely reversible airflow limitation, inflammation, excessive mucus secretion and bronchial mucosal epithelial lesions are the main pathological basis of the disease. The prevalence of COPD is increasingly worldwide, which has caused the burden on individuals and society. This paper summarizes the pathogenesis of COPD and clarifies the effect and mechanism of the latest targeted drugs for COPD. Besides, we focus on NOD-like receptor thermal protein domain associated protein 3 inflammasome (NLRP3 inflammasome). NLRP3 can promote production of interleukin-1β (IL-1β) and interleukin-18 (IL-18). NLRP3 is an important factor in the migratory aggregation of macrophages and neutrophils and the generation of oxidative stress. Inhibition of NLRP3 inflammasome indirectly blocks the inflammatory effects of IL-1β and IL-18, which may be regarded as an ideal target for COPD treatment.

IL-17 Cytokines and Chronic Lung Diseases

IL-17 cytokines are expressed by numerous cells (e.g., gamma delta (γδ) T, innate lymphoid (ILC), Th17, epithelial cells). They contribute to the elimination of bacteria through the induction of cytokines and chemokines which mediate the recruitment of inflammatory cells to the site of infection. However, IL-17-driven inflammation also likely promotes the progression of chronic lung diseases, such as chronic obstructive pulmonary disease (COPD), lung cancer, cystic fibrosis, and asthma. In this review, we highlight the role of IL-17 cytokines in chronic lung diseases.

Distinct interactors define the p63 transcriptional signature in epithelial development or cancer

The TP63 is an indispensable transcription factor for development and homeostasis of epithelia and its derived glandular tissue. It is also involved in female germline cell quality control, muscle and thymus development. It is expressed as multiple isoforms transcribed by two independent promoters, in addition to alternative splicing occurring at the mRNA 3′-UTR. Expression of the TP63 gene, specifically the amino-deleted p63 isoform, ΔNp63, is required to regulate numerous biological activities, including lineage specification, self-renewal capacity of epithelial stem cells, proliferation/expansion of basal keratinocytes, differentiation of stratified epithelia. In cancer, ΔNp63 is implicated in squamous cancers pathogenesis of different origin including skin, head and neck and lung and in sustaining self-renewal of cancer stem cells. How this transcription factor can control such a diverse set of biological pathways is central to the understanding of the molecular mechanisms through which p63 acquires oncogenic activity, profoundly changing its down-stream transcriptional signature. Here, we highlight how different proteins interacting with p63 allow it to regulate the transcription of several central genes. The interacting proteins include transcription factors/regulators, epigenetic modifiers, and post-transcriptional modifiers. Moreover, as p63 depends on its interactome, we discuss the hypothesis to target the protein interactors to directly affect p63 oncogenic activities and p63-related diseases.

Effect Analysis of Lung Rehabilitation Training in 5A Nursing Mode for Elderly Patients with COPD Based on X-Ray

This study was aimed at evaluating the application effect of pulmonary rehabilitation training under 5A nursing mode based on X-ray in elderly patients with chronic obstructive pulmonary disease (COPD). Then, 84 elderly patients with chronic obstructive emphysema were selected as the research subjects. COPD knowledge level questionnaire, caregiver self-efficacy scale (CSES), COPD assessment test (CAT), and 6-minute walking experiment (6MWD) were adopted, and the clinical application effect of pulmonary rehabilitation training and conventional nursing under 5A nursing mode was comprehensively compared. The results show that after two and four months of intervention, the average score of COPD knowledge level questionnaire in the test group was 27.43 points and 30.08 points, respectively, higher than that in the control group (P < 0.05). After two and four months of intervention, the number of patients with good compliance in the test group was remarkably improved, and the severity of airflow restriction in the test group was slower than that in the control group. In short, pulmonary rehabilitation training under 5A nursing mode based on X-ray can effectively improve the disease knowledge level, self-efficacy, and pulmonary rehabilitation training compliance of elderly COPD patients, which played an important role in improving the quality of life of patients and alleviating the degree of dyspnea of patients.

Increased Expression of LASI lncRNA Regulates the Cigarette Smoke and COPD Associated Airway Inflammation and Mucous Cell Hyperplasia

Research Impact

Cigarette smoke (CS) exposure is strongly associated with chronic obstructive pulmonary disease (COPD). In respiratory airways, CS exposure disrupts airway barrier functions, mucous/phlegm production, and basic immune responses of airway epithelial cells. Based on our recent identification of a specific immunomodulatory long noncoding RNA (lncRNA), we investigated its role in CS-induced responses in bronchial airways of cynomolgus macaque model of CS-induced COPD and in former smokers with and without COPD. The lncRNA was significantly upregulated in CS-induced macaque airways and in COPD airways that exhibited higher mucus expression and goblet cell hyperplasia. Experimental models of cells derived from COPD subjects recapitulated the augmented inflammation and mucus expression following the smoke challenge. Blocking of lncRNA expression in cell culture setting suppressed the smoke-induced and COPD-associated dysregulated mucoinflammatory response suggesting that this airway specific immunomodulatory lncRNA may represent a novel target to mitigate the smoke-mediated inflammation and mucus hyperexpression.

Rationale

In conducting airways, CS disrupts airway epithelial functions, mucociliary clearances, and innate immune responses that are primarily orchestrated by human bronchial epithelial cells (HBECs). Mucus hypersecretion and dysregulated immune response are the hallmarks of chronic bronchitis (CB) that is often exacerbated by CS. Notably, we recently identified a long noncoding RNA (lncRNA) antisense to ICAM-1 (LASI) that mediates airway epithelial responses.

Objective

To investigate the role of LASI lncRNA in CS-induced airway inflammation and mucin hyperexpression in an animal model of COPD, and in HBECs and lung tissues from former smokers with and without COPD. To interrogate LASI lncRNA role in CS-mediated airway mucoinflammatory responses by targeted gene editing.

Methods

Small airway tissue sections from cynomolgus macaques exposed to long-term mainstream CS, and those from former smokers with and without COPD were analyzed. The structured-illumination imaging, RNA fluorescence in-situ hybridization (FISH), and qRT-PCR were used to characterize lncRNA expression and the expression of inflammatory factors and airway mucins in a cell culture model of CS extract (CSE) exposure using HBECs from COPD (CHBEs) in comparison with cells from normal control (NHBEs) subjects. The protein levels of mucin MUC5AC, and inflammatory factors ICAM-1, and IL-6 were determined using specific ELISAs. RNA silencing was used to block LASI lncRNA expression and lentivirus encoding LASI lncRNA was used to achieve LASI overexpression (LASI-OE).

Results

Compared to controls, LASI lncRNA was upregulated in CS-exposed macaques and in COPD smoker airways, correlating with mucus hyperexpression and mucus cell hyperplasia in severe COPD airways. At baseline, the unstimulated CHBEs showed increased LASI lncRNA expression with higher expression of secretory mucin MUC5AC, and inflammatory factors, ICAM-1, and IL-6 compared to NHBEs. CSE exposure of CHBEs resulted in augmented inflammation and mucus expression compared to controls. While RNA silencing-mediated LASI knockdown suppressed the mucoinflammatory response, cells overexpressing LASI lncRNA showed elevated mRNA levels of inflammatory factors.

Conclusions

Altogether, LASI lncRNA may represent a novel target to control the smoke-mediated dysregulation in airway responses and COPD exacerbations.

Downregulation of microRNA‑423‑5p suppresses TGF‑β1‑induced EMT by targeting FOXP4 in airway fibrosis

Airway fibrosis (AF) is a common disease that can severely affect patient prognosis. Epithelial-mesenchymal transition (EMT) participates in the pathophysiological development of AF and several studies have demonstrated that some microRNAs (miRNAs) contribute to the development of EMT. The aim of this study was to investigate the function of miR-423-5p in the EMT process and its possible underlying mechanism in BEAS-2B cells. The present study utilized the BEAS-2B cell line to model EMT in AF. Online tools, fluorescence in situ hybridization analysis and an RNA pull-down assay were used to identify potential target genes of miR-423-5p. In addition, immunohistochemistry, wound healing assays, Transwell migration assays, flow cytometry, enzyme-linked immunosorbent assay, reverse transcription-quantitative PCR, western blot analysis and immunofluorescence staining were used to determine the function of miR-423-5p and its target gene in the EMT process in AF. The results indicated that the miR-423-5p expression in AF tissues and BEAS-2B cells stimulated with 10 ng/ml TGF-β1 for 24 h was significantly increased compared with that in the control group. Overexpression of miR-423-5p facilitated TGF-β1-induced EMT in BEAS-2B cells; by contrast, downregulation of miR-423-5p suppressed TGF-β1-induced EMT in BEAS-2B cells. Furthermore, forkhead box p4 (FOXP4) was identified as a potential target gene of miR-423-5p and changes in the miR-423-5p and FOXP4 expression were shown to significantly affect the expression of PI3K/AKT/mTOR pathway members. In summary, overexpression of miR-423-5P promoted the EMT process in AF by downregulating FOXP4 expression and the underlying mechanism may partly involve activation of the PI3K/AKT/mTOR pathway.

A Single-Cell Atlas of Large and Small Airways at Birth in a Porcine Model of Cystic Fibrosis

Lack of CFTR (cystic fibrosis transmembrane conductance regulator) affects the transcriptome, composition, and function of large and small airway epithelia in people with advanced cystic fibrosis (CF); however, whether lack of CFTR causes cell-intrinsic abnormalities present at birth versus inflammation-dependent abnormalities is unclear. We performed a single-cell RNA-sequencing census of microdissected small airways from newborn CF pigs, which recapitulate CF host defense defects and pathology over time. Lack of CFTR minimally affected the transcriptome of large and small airways at birth, suggesting that infection and inflammation drive transcriptomic abnormalities in advanced CF. Importantly, common small airway epithelial cell types expressed a markedly different transcriptome than corresponding large airway cell types. Quantitative immunohistochemistry and electrophysiology of small airway epithelia demonstrated basal cells that reach the apical surface and a water and ion transport advantage. This single cell atlas highlights the archetypal nature of airway epithelial cells with location-dependent gene expression and function.