Senotherapy

The Association Between Dietary Magnesium Intake and Frailty in Patients with Chronic Obstructive Pulmonary Disease: National Health and Nutrition Examination Survey

Background

Patients with chronic obstructive pulmonary disease (COPD) are at high risk of developing frailty and need to be prevented and managed. This study aims to investigate the relationship between dietary magnesium (Mg) intake and the risk of frailty in patients with COPD.

Methods

We conducted a cross-sectional study from the National Health and Nutrition Examination Survey (NHANES) in the United States, focusing on patients with COPD. We used logistic regression to determine the adjusted odds ratios (OR) and 95% confidence interval (CI). Curve fitting, subgroup analysis, and sensitivity analysis were performed to further assess the relationship between dietary Mg intake and frailty in patients with COPD.

Results

There were 1696 participants in this study, and the mean age was 60.4 ± 0.4 years. Weighted logistic regression and curve fitting showed a linear relationship between dietary Mg intake and frailty in patients with COPD. The risk of frailty decreased by 15% for each 100-unit increase in Mg intake (OR: 0.85, 95% CI: 0.76-0.96). Participants in the highest quartile Q4 of Mg intake had a lower risk of frailty than those in the lowest quartile Q1 (OR: 0.48, 95% CI: 0.32-0.72).

Conclusion

There is a linear relationship between dietary Mg intake and frailty in patients with COPD. Increasing dietary Mg intake is associated with a decreased risk of frailty 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.

PM2.5 exposure-induced senescence-associated secretory phenotype in airway smooth muscle cells contributes to airway remodeling

Fine particulate matter (PM2.5) has been linked to increased severity and incidence of airway diseases, especially chronic obstructive pulmonary disease (COPD) and asthma. Airway remodeling is an important event in both COPD and asthma, and airway smooth muscle cells (ASMCs) are key cells which directly involved in airway remodeling. However, it was unclear how PM2.5 affected ASMCs. This study investigates the effects of PM2.5 on airway smooth muscle and its mechanism. We first showed that inhaled particulate matter was distributed in the airway smooth muscle bundle, combined with increased airway smooth muscle bundle and collagen deposition in vivo. Then, we demonstrated that PM2.5 induced up-regulation of collagen-I and alpha-smooth muscle actin (α-SMA) expression in rat and human ASMCs in vitro. Next, we found PM2.5 led to rat and human ASMCs senescence and exhibited senescence-associated secretory phenotype (SASP) by autophagy-induced GATA4/TRAF6/NF-κB signaling, which contributed to collagen-I and α-SMA synthesis as well as airway smooth muscle remodeling. Together, our results provided evidence that SASP induced by PM2.5 in airway smooth muscle cells prompted airway remodeling.

DNA hypomethylation-mediated upregulation of GADD45B facilitates airway inflammation and epithelial cell senescence in COPD

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease typically characterized by chronic airway inflammation, with emerging evidence highlighting the driving role of cellular senescence-related lung aging. Accelerated lung aging and inflammation mutually reinforce each other, creating a detrimental cycle that contributes to disease progression. Growth arrest and DNA damage-inducible (GADD45) family has been reported to involve in multiple biological processes, including inflammation and senescence. However, the role of GADD45 family in COPD remains elusive.

OBJECTIVES

To investigate the role and mechanism of GADD45 family in COPD pathogenesis.

METHODS

Expressions of GADD45 family were evaluated by bioinformatic analysis combined with detections in clinical specimens. The effects of GADD45B on inflammation and senescence were investigated via constructing cell model with siRNA transfection or overexpression lentivirus infection and animal model with Gadd45b knockout. Targeted bisulfite sequencing was performed to probe the influence of DNA methylation in GADD45B expression in COPD.

RESULTS

GADD45B expression was significantly increased in COPD patients and strongly associated with lung function, whereas other family members presented no changes. GADD45B upregulation was confirmed in mice exposed by cigarette smoke (CS) and HBE cells treated by CS extract as well. Moreover, experiments involving bidirectional modulation of GADD45B expression in HBE cells further substantiated its positive regulatory role in inflammatory response and cellular senescence. Mechanically, GADD45B-facilitated inflammation was directly mediated by p38 phosphorylation, while GADD45B interacted with FOS to promote cellular senescence in a p38 phosphorylation-independent manner. Furthermore, Gadd45b deficiency remarkably alleviated inflammation and senescence of lungs in CS-exposed mice, as well as improved emphysema and lung function. Eventually, in vivo and vitro experiments demonstrated that GADD45B overexpression was partially mediated by CS-induced DNA hypomethylation.

CONCLUSION

Our findings have shed light on the impact of GADD45B in the pathogenesis of COPD, thereby offering a promising target for intervention in clinical settings.

Biochemical and transcriptomic evaluation of a 3D lung organoid platform for pre-clinical testing of active substances targeting senescence

Chronic lung diseases such as chronic obstructive pulmonary disease and cystic fibrosis are incurable. Epithelial senescence, a state of dysfunctional cell cycle arrest, contributes to the progression of such diseases. Therefore, lung epithelial cells are a valuable target for therapeutic intervention. Here, we present a 3D airway lung organoid platform for the preclinical testing of active substances with regard to senescence, toxicity, and inflammation under standardized conditions in a 96 well format. Senescence was induced with doxorubicin and measured by activity of senescence associated galactosidase. Pharmaceutical compounds such as quercetin antagonized doxorubicin-induced senescence without compromising organoid integrity. Using single cell sequencing, we identified a subset of cells expressing senescence markers which was decreased by quercetin. Doxorubicin induced the expression of detoxification factors specifically in goblet cells independent of quercetin. In conclusion, our platform enables for the analysis of senescence-related processes and will allow the pre-selection of a wide range of compounds (e.g. natural products) in preclinical studies, thus reducing the need for animal testing.

Targeting accelerated pulmonary ageing to treat chronic obstructive pulmonary disease-induced neuropathological comorbidities

Chronic obstructive pulmonary disease (COPD) is a major incurable health burden, ranking as the third leading cause of death worldwide, mainly driven by cigarette smoking. COPD is characterised by persistent airway inflammation, lung function decline and premature ageing with the presence of pulmonary senescent cells. This review proposes that cellular senescence, a state of stable cell cycle arrest linked to ageing, induced by inflammation and oxidative stress in COPD, extends beyond the lungs and affects the systemic circulation. This pulmonary senescent profile will reach other organs via extracellular vesicles contributing to brain inflammation and damage, and increasing the risk of neurological comorbidities, such as stroke, cerebral small vessel disease and Alzheimer's disease. The review explores the role of cellular senescence in COPD-associated brain conditions and investigates the relationship between cellular senescence and circadian rhythm in COPD. Additionally, it discusses potential therapies, including senomorphic and senolytic treatments, as novel strategies to halt or improve the progression of COPD.

Evaluating Novel Protein Phosphatase 2A Activators as Therapeutics for Emphysema

The activity of PP2A (protein phosphatase 2A), a serine-threonine phosphatase, is reduced by chronic cigarette smoke (SM) exposure and α-1 antitrypsin (AAT) deficiency, and chemical activation of PP2A reduces the loss of lung function in SM-exposed mice. However, the previously studied PP2A-activator tricyclic sulfonamide compound DBK-1154 has low stability to oxidative metabolism, resulting in fast clearance and low systemic exposure. Here we compare the utility of a new more stable PP2A activator, ATUX-792, versus DBK-1154 for the treatment of SM-induced emphysema. ATUX-792 was also tested in human bronchial epithelial cells and a mouse model of AAT deficiency, Serpina1a-e-knockout mice. Human bronchial epithelial cells were treated with ATUX-792 or DBK-1154, and cell viability, PP2A activity, and MAP (mitogen-activated protein) kinase phosphorylation status were examined. Wild-type mice received vehicle, DBK-1154, or ATUX-792 orally in the last 2 months of 4 months of SM exposure, and 8-month-old Serpina1a-e-knockout mice received ATUX-792 daily for 4 months. Forced oscillation and expiratory measurements and histology analysis were performed. Treatment with ATUX-792 or DBK-1154 resulted in PP2A activation, reduced MAP kinase phosphorylation, immune cell infiltration, reduced airspace enlargements, and preserved lung function. Using protein arrays and multiplex assays, PP2A activation was observed to reduce AAT-deficient and SM-induced release of CXCL5, CCL17, and CXCL16 into the airways, which coincided with reduced neutrophil lung infiltration. Our study indicates that suppression of the PP2A activity in two models of emphysema could be restored by next-generation PP2A activators to impact lung function.

DNA nanoparticles targeting FOXO4 selectively eliminate cigarette smoke-induced senescent lung fibroblasts

The pathogenesis and development of chronic obstructive pulmonary disease (COPD) are significantly related to cellular senescence. Strategies to eliminate senescent cells have been confirmed to benefit several senescence-related diseases. However, there are few reports of senolytic drugs in COPD management. In this study, we demonstrated elevated FOXO4 expression in cigarette smoke-induced senescent lung fibroblasts both in vitro and in vivo. Additionally, self-assembled DNA nanotubes loaded with single-stranded FOXO4 siRNA (siFOXO4-NT) were designed and synthesized to knockdown FOXO4 in senescent fibroblasts. We found that siFOXO4-NT can concentration- and time-dependently enter human lung fibroblasts (HFL-1 cells), thereby reducing FOXO4 levels in vitro. Most importantly, siFOXO4-NT selectively cleared senescent HFL-1 cells by reducing BCLXL expression and the BCL2/BAX ratio, which were increased in CSE-induced senescent HFL-1 cells. The findings from our work present a novel strategy for senolytic drug development for COPD therapy.

Animal models and mechanisms of tobacco smoke-induced chronic obstructive pulmonary disease (COPD)

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide, and its global health burden is increasing. COPD is characterized by emphysema, mucus hypersecretion, and persistent lung inflammation, and clinically by chronic airflow obstruction and symptoms of dyspnea, cough, and fatigue in patients. A cluster of pathologies including chronic bronchitis, emphysema, asthma, and cardiovascular disease in the form of hypertension and atherosclerosis variably coexist in COPD patients. Underlying causes for COPD include primarily tobacco use but may also be driven by exposure to air pollutants, biomass burning, and workplace related fumes and chemicals. While no single animal model might mimic all features of human COPD, a wide variety of published models have collectively helped to improve our understanding of disease processes involved in the genesis and persistence of COPD. In this review, the pathogenesis and associated risk factors of COPD are examined in different mammalian models of the disease. Each animal model included in this review is exclusively created by tobacco smoke (TS) exposure. As animal models continue to aid in defining the pathobiological mechanisms of and possible novel therapeutic interventions for COPD, the advantages and disadvantages of each animal model are discussed.

Pharmacotherapies in Older Adults with COPD: Challenges and Opportunities

Older adults have a higher prevalence of chronic obstructive pulmonary disease (COPD), which will likely increase substantially in the coming decades owing to aging populations and increased long-term exposure to risk factors for this disease. COPD in older adults is characterized by low-grade chronic systemic inflammation, known as inflamm-aging. It contributes substantially to age-associated pulmonary changes that are clinically expressed by reduced lung function, poor health status, and limitations in activities of daily living. In addition, inflamm-aging has been associated with the onset of many comorbidities commonly encountered in COPD. Furthermore, physiologic changes that are often seen with aging can influence the optimal treatment of older patients with COPD. Therefore, variables such as pharmacokinetics, pharmacodynamics, polypharmacy, comorbidities, adverse drug responses, drug interactions, method of administration, and social and economic issues that impact nutrition and adherence to therapy must be carefully evaluated when prescribing medication to these patients because each of them alone or together may affect the outcome of treatment. Current COPD medications focus mainly on alleviating COPD-related symptoms, so alternative treatment approaches that target the disease progression are being investigated. Considering the importance of inflamm-aging, new anti-inflammatory molecules are being evaluated, focusing on inhibiting the recruitment and activation of inflammatory cells, blocking mediators of inflammation thought to be important in the recruitment or activation of these inflammatory cells or released by these cells. Potential therapies that may slow the aging processes by acting on cellular senescence, blocking the processes that cause it (senostatics), eliminating senescent cells (senolytics), or targeting the ongoing oxidative stress seen with aging need to be evaluated.

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.

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.

Association between B-vitamins intake and frailty among patients with chronic obstructive pulmonary disease

PURPOSE

Gain insight into the impact of B vitamins, including vitamin B1, vitamin B2, niacin, vitamin B6, total folate, and vitamin B12 on the risk of frailty in patients with chronic obstructive pulmonary disease (COPD).

METHODS

This study was an American population-based cross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES). A total of 1201 COPD patients were included in the analysis. Of these, the intake of B vitamins was determined by the two 24-h recall interviews. We followed the method constructed by Hakeem et al. to calculate the frailty index (FI), which is used as a reliable tool to assess the debilitating status of patients with COPD. Missing data were imputed by the MissForest method based on random forests. Multivariate logistic regression model and inverse probability weighted based on propensity scores were used to correct for confoundings.

RESULTS

Logistic regression models showed that vitamin B6 intake was negatively correlated with frailty risk in COPD patients, while other B vitamins including B1, B2, niacin (vitamin B3), total folic acid and vitamin B12 were not. After adjusting for covariates, the association between vitamin B6 and frailty risk (adjusted OR = 0.80, 95%CI = 0.66-0.95, P = 0.013) remained significant. At the same time, sensitivity analysis proves the robustness of the results.

CONCLUSION

COPD patients with lower vitamin B6 intake have a higher risk of frailty. However, intake of vitamin B1, B2, niacin, total folic acid, and vitamin B12 was not associated with frailty risk in COPD patients.

p21 facilitates chronic lung inflammation via epithelial and endothelial cells

Cellular senescence is a stable state of cell cycle arrest that regulates tissue integrity and protects the organism from tumorigenesis. However, the accumulation of senescent cells during aging contributes to age-related pathologies. One such pathology is chronic lung inflammation. p21 (CDKN1A) regulates cellular senescence via inhibition of cyclin-dependent kinases (CDKs). However, its role in chronic lung inflammation and functional impact on chronic lung disease, where senescent cells accumulate, is less understood. To elucidate the role of p21 in chronic lung inflammation, we subjected p21 knockout (p21-/-) mice to repetitive inhalations of lipopolysaccharide (LPS), an exposure that leads to chronic bronchitis and accumulation of senescent cells. p21 knockout led to a reduced presence of senescent cells, alleviated the pathological manifestations of chronic lung inflammation, and improved the fitness of the mice. The expression profiling of the lung cells revealed that resident epithelial and endothelial cells, but not immune cells, play a significant role in mediating the p21-dependent inflammatory response following chronic LPS exposure. Our results implicate p21 as a critical regulator of chronic bronchitis and a driver of chronic airway inflammation and lung destruction.

Ageing and chronic obstructive pulmonary disease: interrelationships

PURPOSE OF REVIEW

As life expectancy increases, the ageing population accrues an increasing burden of chronic conditions and functional compromise. Some conditions that lead to compromise are deemed part of 'natural ageing,' whereas others are considered to represent disease processes. Ageing ('a natural process') and chronic obstructive pulmonary disease ('a disease') share many common features, both pulmonary and systemic. At times, the pathways of injury are the same, and at times they are concurrent. In some cases, age and disease are separated not by the presence but by the severity of a finding or condition. This brief review aims to compare some of the similarities between ageing and COPD and to compare/contrast mechanisms for each.

RECENT FINDINGS

At the cellular level, the natural process of ageing includes multiple systemic and molecular mechanisms. COPD, though defined by progressive pulmonary compromise, can also be a systemic disease/process. It has become evident that specific senescence pathways like p-16 and the sirtuin family of proteins are implicated both in ageing and in COPD. Also common to both ageing and COPD are increased inflammatory markers, leucocyte response abnormalities, and DNA-level abnormalities.

SUMMARY

The prevalence of COPD increases with increasing age. COPD contributes to the accrued burden of chronic disease and is a significant contributor to morbidity and mortality in this population. This review attempts to summarize some of similarities between ageing and COPD and their underlying mechanisms.

The therapeutic potential of quercetin for cigarette smoking-induced chronic obstructive pulmonary disease: a narrative review

Quercetin is a flavonoid with antioxidant and anti-inflammatory properties. Quercetin has potentially beneficial therapeutic effects for several diseases, including cigarette smoking-induced chronic obstructive pulmonary disease (CS-COPD). Many studies have shown that quercetin's antioxidant and anti-inflammatory properties have positive therapeutic potential for CS-COPD. In addition, quercetin's immunomodulatory, anti-cellular senescence, mitochondrial autophagy-modulating, and gut microbiota-modulating effects may also have therapeutic value for CS-COPD. However, there appears to be no review of the possible mechanisms of quercetin for treating CS-COPD. Moreover, the combination of quercetin with common therapeutic drugs for CS-COPD needs further refinement. Therefore, in this article, after introducing the definition and metabolism of quercetin, and its safety, we comprehensively presented the pathogenesis of CS-COPD related to oxidative stress, inflammation, immunity, cellular senescence, mitochondrial autophagy, and gut microbiota. We then reviewed quercetin's anti-CS-COPD effects, performed by influencing these mechanisms. Finally, we explored the possibility of using quercetin with commonly used drugs for treating CS-COPD, providing a basis for future screening of excellent drug combinations for treating CS-COPD. This review has provided meaningful information on quercetin's mechanisms and clinical use in treating CS-COPD.

Aging and aging-related diseases: from molecular mechanisms to interventions and treatments

Aging is a gradual and irreversible pathophysiological process. It presents with declines in tissue and cell functions and significant increases in the risks of various aging-related diseases, including neurodegenerative diseases, cardiovascular diseases, metabolic diseases, musculoskeletal diseases, and immune system diseases. Although the development of modern medicine has promoted human health and greatly extended life expectancy, with the aging of society, a variety of chronic diseases have gradually become the most important causes of disability and death in elderly individuals. Current research on aging focuses on elucidating how various endogenous and exogenous stresses (such as genomic instability, telomere dysfunction, epigenetic alterations, loss of proteostasis, compromise of autophagy, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, deregulated nutrient sensing) participate in the regulation of aging. Furthermore, thorough research on the pathogenesis of aging to identify interventions that promote health and longevity (such as caloric restriction, microbiota transplantation, and nutritional intervention) and clinical treatment methods for aging-related diseases (depletion of senescent cells, stem cell therapy, antioxidative and anti-inflammatory treatments, and hormone replacement therapy) could decrease the incidence and development of aging-related diseases and in turn promote healthy aging and longevity.

Effective-component compatibility of Bufei Yishen formula III ameliorated COPD by improving airway epithelial cell senescence by promoting mitophagy via the NRF2/PINK1 pathway

Background

Effective-component compatibility of Bufei Yishen formula III (ECC-BYF III) demonstrates positive effects on stable chronic obstructive pulmonary disease (COPD).

Purpose

To investigate the mechanisms of ECC-BYF III on COPD rats from the aspect of airway epithelial cell senescence.

Methods

COPD model rats (Sprague-Dawley rat) were treated with ECC-BYF III for 8 weeks, and the efficacy was evaluated. Cigarette smoke extract (CSE)-induced senescence model of airway epithelial cells was treated with ECC-BYF III, and related enzymes and proteins involved in oxidative stress and mitophagy were detected.

Results

ECC-BYF III markedly rescued pulmonary function and histopathological changes, which might be associated with the amelioration of lung senescence, including the reduction of malondialdehyde (MDA) and tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and matrix metalloproteinase (MMP)-9 levels, increase of the level in total superoxide dismutase (T-SOD), and decease in the p21 level in the airways. Furthermore, ECC-BYF III suppressed p16 and p21 expressions and senescence-associated β-galactosidase (SA-β-Gal) in CSE-induced airway epithelial cells. Moreover, ECC-BYF III upregulated mitophagy-related proteins, including the co-localizations of TOM20 and LC3B, PINK1 and PARK2, and improved mitochondrial function by upregulating mitochondrial mitofusin (MFN)2 and reducing dynamin-related protein 1 (DRP1) expression. ECC-BYF III enhanced the activities of T-SOD and GSH-PX by up-regulating NRF2, thus inhibiting oxidative stress. After intervention with NRF2 inhibitor, the regulation effects of ECC-BYF III on oxidative stress, mitophagy and senescence in airway epithelial cells were significantly suppressed.

Conclusions

ECC-BYF III exerts beneficial effects on COPD rats by ameliorating airway epithelial cell senescence, which is mediated by inhibiting oxidative stress and subsequently enhancing mitophagy through the activation of NRF2 signaling.

Cellular senescence is increased in airway smooth muscle cells of elderly persons with asthma

Senescent cells can drive age-related tissue dysfunction partially via a senescence-associated secretory phenotype (SASP) involving proinflammatory and profibrotic factors. Cellular senescence has been associated with a structural and functional decline during normal lung aging and age-related diseases such as chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). Asthma in the elderly (AIE) represents a major healthcare burden. AIE is associated with bronchial airway hyperresponsiveness and remodeling, which involves increased cell proliferation and higher rates of fibrosis, and resistant to standard therapy. Airway smooth muscle (ASM) cells play a major role in asthma such as remodeling via modulation of inflammation and the extracellular matrix (ECM) environment. Whether senescent ASM cells accumulate in AIE and contribute to airway structural or functional changes is unknown. Lung tissues from elderly persons with asthma showed greater airway fibrosis compared with age-matched elderly persons with nonasthma and young age controls. Lung tissue or isolated ASM cells from elderly persons with asthma showed increased expression of multiple senescent markers including phospho-p53, p21, telomere-associated foci (TAF), as well as multiple SASP components. Senescence and SASP components were also increased with aging per se. These data highlight the presence of cellular senescence in AIE that may contribute to airway remodeling.

Targeting the mitochondria in chronic respiratory diseases

Mitochondria are one of the basic essential components for eukaryotic life survival. It is also the source of respiratory ATP. Recently published studies have demonstrated that mitochondria may have more roles to play aside from energy production. There is an increasing body of evidence which suggest that mitochondrial activities involved in normal and pathological states contribute to significant impact to the lung airway morphology and epithelial function in respiratory diseases such as asthma, COPD, and lung cancer. This review summarizes the pathophysiological pathways involved in asthma, COPD, lung cancer and highlights potential treatment strategies that target the malfunctioning mitochondria in such ailments. Mitochondria are responsive to environmental stimuli such as infection, tobacco smoke, and inflammation, which are essential in the pathogenesis of respiratory diseases. They may affect mitochondrial shape, protein production and ultimately cause dysfunction. The impairment of mitochondrial function has downstream impact on the cytosolic components, calcium control, response towards oxidative stress, regulation of genes and proteins and metabolic activities. Several novel compounds and alternative medicines that target mitochondria in asthma and chronic lung diseases have been discussed here. Moreover, mitochondrial enzymes or proteins that may serve as excellent therapeutic targets in COPD are also covered. The role of mitochondria in respiratory diseases is gaining much attention and mitochondria-based treatment strategies and personalized medicine targeting the mitochondria may materialize in the near future. Nevertheless, more in-depth studies are urgently needed to validate the advantages and efficacy of drugs that affect mitochondria in pathological states.

Targeted delivery strategy: A beneficial partner for emerging senotherapy

Numerous cutting-edge studies have confirmed that the slow accumulation of cell cycle arrested and secretory cells, called senescent cells (SCs), in tissues is an important negative factor, or even the culprit, in age- associated diseases such as non-alcoholic fatty liver, Alzheimer's disease, type 2 diabetes, atherosclerosis, and malignant tumors. With further understanding of cellular senescence, SCs are important effective targets for the treatment of senescence-related diseases, called the Senotherapy. However, existing therapies, including Senolytics (which lyse SCs) and Senostatic (which regulate senescence-associated secretory phenotype), do not have the properties to target SCs, and side effects due to non-specific distribution are one of the hindrances to clinical use of Senotherapy. In the past few decades, targeted delivery has attracted much attention and been developed as a recognized diagnostic and therapeutic novel tool, due to the advantages of visualization of targets, more accurate drug/gene delivery, and ultimately "reduced toxicity and enhanced efficacy". Despite considerable advances in achieving targeted delivery, it has not yet been widely used in Senotherapy. In this review, we clarify the challenge for Senotherapy, then discuss how different targeted strategies contribute to imaging or therapy for SCs in terms of different biomarkers of SCs. Finally, the emerging nano-Senotherapy is prospected.

New Trends in Aging Drug Discovery

Aging is considered the main risk factor for many chronic diseases that frequently appear at advanced ages. However, the inevitability of this process is being questioned by recent research that suggests that senescent cells have specific features that differentiate them from younger cells and that removal of these cells ameliorates senescent phenotype and associated diseases. This opens the door to the design of tailored therapeutic interventions aimed at reducing and delaying the impact of senescence in life, that is, extending healthspan and treating aging as another chronic disease. Although these ideas are still far from reaching the bedside, it is conceivable that they will revolutionize the way we understand aging in the next decades. In this review, we analyze the main and well-validated cellular pathways and targets related to senescence as well as their implication in aging-associated diseases. In addition, the most relevant small molecules with senotherapeutic potential, with a special emphasis on their mechanism of action, ongoing clinical trials, and potential limitations, are discussed. Finally, a brief overview of alternative strategies that go beyond the small molecule field, together with our perspectives for the future of the field, is provided.

Senescence: Pathogenic Driver in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is recognized as a disease of accelerated lung aging. Over the past two decades, mounting evidence suggests an accumulation of senescent cells within the lungs of patients with COPD that contributes to dysregulated tissue repair and the secretion of multiple inflammatory proteins, termed the senescence-associated secretory phenotype (SASP). Cellular senescence in COPD is linked to telomere dysfunction, DNA damage, and oxidative stress. This review gives an overview of the mechanistic contributions and pathologic consequences of cellular senescence in COPD and discusses potential therapeutic approaches targeting senescence-associated signaling in COPD.

Cellular senescence in cancers: relationship between bone marrow cancer and cellular senescence

INTRODUCTION

There are many factors and conditions that lead to cellular senescence. Replicative senescence and Hayflick phenomenon are the most important causes of cellular senescence. Senescent cells also lead to wound healing conditions resulting from injury and toxic conditions.

MATERIAL AND METHODS

When a cell becomes senescent, it stops replication and begins to leak inflammatory signals before growth. It also alters the extracellular matrix and behavior of neighbor cells and even motivates them. This review was conducted to determine the association between senescence and bone marrow cancer.

RESULTS

The results showed that senescent cells have a short life span due to their self-destructive nature or natural removal from the body by the immune system. These signals are effective to a certain extent in regenerating the damaged cells when present in a transient state. Cellular senescence can decrease the risk of all cancers, including bone marrow cancer, ensuring that cells with significant DNA injury are prevented from replication.

CONCLUSION

However, senescent cells increase in number as they age, which is very harmful over time. These cells extend into an older tissue for longer periods of time and form longer clusters in older tissues. Therefore, cellular senescence significantly contributes to aging.

Reduced decline of lung diffusing capacity in COPD patients with diabetes and metformin treatment

We studied whether in patients with COPD the use of metformin for diabetes treatment was linked to a pattern of lung function decline consistent with the hypothesis of anti-aging effects of metformin. Patients of GOLD grades 1–4 of the COSYCONET cohort with follow-up data of up to 4.5 y were included. The annual decline in lung function (FEV₁, FVC) and CO diffusing capacity (KCO, TLCO) in %predicted at baseline was evaluated for associations with age, sex, BMI, pack-years, smoking status, baseline lung function, exacerbation risk, respiratory symptoms, cardiac disease, as well as metformin-containing therapy compared to patients without diabetes and metformin. Among 2741 patients, 1541 (mean age 64.4 y, 601 female) fulfilled the inclusion criteria. In the group with metformin treatment vs. non-diabetes the mean annual decline in KCO and TLCO was significantly lower (0.2 vs 2.3, 0.8 vs. 2.8%predicted, respectively; p < 0.05 each), but not the decline of FEV₁ and FVC. These results were confirmed using multiple regression and propensity score analyses. Our findings demonstrate an association between the annual decline of lung diffusing capacity and the intake of metformin in patients with COPD consistent with the hypothesis of anti-aging effects of metformin as reflected in a surrogate marker of emphysema.

Dysregulated Cell Signaling in Pulmonary Emphysema

Pulmonary emphysema is characterized by the destruction of alveolar septa and irreversible airflow limitation. Cigarette smoking is the primary cause of this disease development. It induces oxidative stress and disturbs lung physiology and tissue homeostasis. Alveolar type II (ATII) cells have stem cell potential and can repair the denuded epithelium after injury; however, their dysfunction is evident in emphysema. There is no effective treatment available for this disease. Challenges in this field involve the large complexity of lung pathophysiological processes and gaps in our knowledge on the mechanisms of emphysema progression. It implicates dysregulation of various signaling pathways, including aberrant inflammatory and oxidative responses, defective antioxidant defense system, surfactant dysfunction, altered proteostasis, disrupted circadian rhythms, mitochondrial damage, increased cell senescence, apoptosis, and abnormal proliferation and differentiation. Also, genetic predispositions are involved in this disease development. Here, we comprehensively review studies regarding dysregulated cell signaling, especially in ATII cells, and their contribution to alveolar wall destruction in emphysema. Relevant preclinical and clinical interventions are also described.

Cellular senescence-an aging hallmark in chronic obstructive pulmonary disease pathogenesis

Chronic obstructive pulmonary disease (COPD),¹ a representative aging-related pulmonary disorder, is mainly caused by cigarette smoke (CS) exposure. Age is one of the most important risk factors for COPD development, and increased cellular senescence in tissues and organs is a component of aging. CS exposure can induce cellular senescence, as characterized by irreversible growth arrest and aberrant cytokine secretion of the senescence-associated secretory phenotype; thus, accumulation of senescent cells is widely implicated in COPD pathogenesis. CS-induced oxidative modifications to cellular components may be causally linked to accelerated cellular senescence, especially during accumulation of damaged macromolecules. Autophagy is a conserved mechanism whereby cytoplasmic components are sent for lysosomal degradation to maintain proteostasis. Autophagy diminishes with age, and loss of proteostasis is one of the hallmarks of aging. We have reported the involvement of insufficient autophagy in regulating CS-induced cellular senescence with respect to COPD pathogenesis. However, the role of autophagy in COPD pathogenesis can vary based on levels of cell stress and type of selective autophagy because excessive activation of autophagy can be responsible for inducing regulated cell death. Senotherapies targeting cellular senescence may be effective COPD treatments. Autophagy activation could be a promising sonotherapeutic approach, but the optimal modality of autophagy activation should be examined in future studies.

Repairing damaged lungs using regenerative therapy

There is an urgent need for better treatment of lung diseases that are a major cause of morbidity and mortality worldwide. This urgency is illustrated by the current COVID-19 health crisis. Moderate-to-extensive lung injury characterizes several lung diseases, and not only therapies that reduce such lung injury are needed but also those that regenerate lung tissue and repair existing lung injury. At present, such therapies are not available, but as a result of a rapid increase in our understanding of lung development and repair, lung regenerative therapies are on the horizon. Here, we discuss existing targets for treatment, as well as novel strategies for development of pharmacological and cell therapy-based regenerative treatment for a variety of lung diseases and clinical studies. We discuss how both patient-relevant in vitro disease models using innovative culture techniques and other advanced new technologies aid in the development of pulmonary regenerative medicine.

G6PD deficiency, redox homeostasis, and viral infections: implications for SARS-CoV-2 (COVID-19)

The COVID-19 pandemic has so far affected more than 45 million people and has caused over 1 million deaths worldwide. Infection with SARS-CoV-2, the pathogenic agent, which is associated with an imbalanced redox status, causes hyperinflammation and a cytokine storm, leading to cell death. Glucose-6-phosphate dehydrogenase (G6PD) deficient individuals may experience a hemolytic crisis after being exposed to oxidants or infection. Individuals with G6PD deficiency are more susceptible to coronavirus infection than individuals with normally functioning G6PD. An altered immune response to viral infections is found in individuals with G6PD deficiency. Evidence indicates that G6PD deficiency is a predisposing factor of COVID-19.

Sex and Gender Omic Biomarkers in Men and Women With COPD: Considerations for Precision Medicine

Sex and gender differences in lung health and disease are imperative to consider and study if precision pulmonary medicine is to be achieved. The development of reliable COPD biomarkers has been elusive, and the translation of biomarkers to clinical care has been limited. Useful and effective biomarkers must be developed with attention to clinical heterogeneity of COPD; inherent heterogeneity exists related to grouping women and men together in the studies of COPD. Considering sex and gender differences and influences related to -omics may represent progress in susceptibility, diagnostic, prognostic, and therapeutic biomarker development and clinical innovation to improve the lung health of men and women.

Sialic acid-binding immunoglobulin-like lectin 9 as a potential therapeutic target for chronic obstructive pulmonary disease

ABSTRACT

Chronic obstructive pulmonary disease (COPD) has become the third-leading cause of death worldwide, which is a severe economic burden to the healthcare system. Chronic bronchitis is the most common condition that contributes to COPD, both locally and systemically. Neutrophilic inflammation predominates in the COPD airway wall and lumen. Logically, repression of neutrophilia is an essential fashion to COPD treatment. However, currently available anti-neutrophilic therapies provide little benefit in COPD patients and may have serious side effects. Thus, there is an urgent need to explore an effective and safe anti-neutrophilic approach that might delay progression of the disease. Sialic acid-binding immunoglobulin-like lectin (Siglec)-9 is a member of the Siglec cell surface immunoglobulin family. It is noteworthy that Siglec-9 is highly expressed on human neutrophils and monocytes. Ligation of Siglec-9 by chemical compounds or synthetic ligands induced apoptosis and autophagic-like cell death in human neutrophils. Furthermore, administration of antibody to Siglec-E, mouse functional ortholog of Siglec-9, restrained recruitment and activation of neutrophils in mouse models of airway inflammation in vivo. Given the critical role that neutrophils play in chronic bronchitis and emphysema, targeting Siglec-9 could be beneficial for the treatment of COPD, asthma, fibrosis, and related chronic inflammatory lung diseases.

Early Career Members at the ERS Lung Science Conference 2020: metabolic alterations in lung ageing and disease

Every year, the European Respiratory Society (ERS) organises the Lung Science Conference (LSC) in Estoril, Portugal, to discuss basic and translational science. The topic of the LSC 2020 was “Metabolic alterations in lung ageing and disease”. In addition to an outstanding scientific programme, the LSC provides excellent opportunities for career development and inclusion of Early Career Members (ECMs). All scientific and poster sessions are chaired by an ECM who is paired with a senior faculty member to allow ECMs to become acquainted with session chairing. In addition, 40 travel bursaries are made available to abstract authors and all bursary recipients are invited to take part in a mentorship lunch. Moreover, there is a session organised by the Early Career Members Committee (ECMC) dedicated to career development. Here, we describe the scientific highlights of LSC 2020 for those who could not attend.

The Lung Science Conference 2020 brought together leading experts in the field to discuss the latest cutting-edge science, as well as various career development opportunities for early career membershttps://bit.ly/2XZ5YGQ

Mitoquinone ameliorates cigarette smoke-induced airway inflammation and mucus hypersecretion in mice

BACKGROUND

Cigarette smoking, which induces airway inflammation and mucus hypersecretion, is a major risk factor for the development of cigarette smoke (CS)-induced airway disorders. In this study, we investigated the effects and mechanisms of mitoquinone (MitoQ), a mitochondria-targeted antioxidant, on CS-induced airway inflammation and mucus hypersecretion in mice.

METHODS

C57BL/6J mice were exposed to CS for 75 min twice daily, 5 days per week for 4 weeks. MitoQ (2.5, 5 mg/kg/day) was administered intraperitoneally 1 h before CS exposure. Bronchoalveolar lavage fluid (BALF) was obtained for cell counting and determination of pro-inflammatory cytokine levels. Lung tissue was collected for histological examination; Western blotting was used to measure levels of Mfn2, Drp1, cytochrome c, NF-κB p65, and IκBα.

RESULTS

Pretreatment with MitoQ significantly attenuated CS-induced thickening of the airway epithelium, peribronchial inflammatory cell infiltration, goblet cell hyperplasia and Muc5ac staining. The numbers of total cells, neutrophils and macrophages, as well as levels of TNF-α and IL-6 in BALF were remarkably decreased by MitoQ in a dose-dependent manner. MitoQ attenuated oxidative stress by preventing the CS-induced increase in malondialdehyde level and decrease in superoxide dismutase activity and GSH/GSSG ratio. MitoQ decreased the expression of mitochondrial fission protein Drp1 and increased that of mitochondrial fusion protein Mfn2, as well as reduced cytochrome c release into the cytosol. Furthermore, MitoQ suppressed IκBα degradation and NF-κB p65 nuclear translocation.

CONCLUSIONS

MitoQ attenuates inflammation, mucus hypersecretion, and oxidative stress induced by CS. It may exert these effects in part by modulating mitochondrial function and the NF-κB signal pathway.

Targeting cellular senescence as a new approach to chronic obstructive pulmonary disease therapy

Increasing evidence suggests that there is acceleration of normal lung ageing in chronic obstructive pulmonary disease (COPD), with the accumulation of senescent cells in the lung, which release an array of inflammatory proteins, which drive further senescence and disease progression. This suggests that drugs that target cellular senescence (senotherapies) may treat the underlying disease process in COPD and 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), whereas other drugs selectively remove senescent cells (senolytics). Clinical studies of senotherapies have commenced in several age-related diseases, and these approaches appear to be safe and feasible, although no clinical studies in COPD patients have yet been reported.

Mitochondrial dysfunction in lung ageing and disease

Mitochondrial biology has seen a surge in popularity in the past 5 years, with the emergence of numerous new avenues of exciting mitochondria-related research including immunometabolism, mitochondrial transplantation and mitochondria-microbe biology. Since the early 1960s mitochondrial dysfunction has been observed in cells of the lung in individuals and in experimental models of chronic and acute respiratory diseases. However, it is only in the past decade with the emergence of more sophisticated tools and methodologies that we are beginning to understand how this enigmatic organelle regulates cellular homeostasis and contributes to disease processes in the lung. In this review, we highlight the diverse role of mitochondria in individual lung cell populations and what happens when these essential organelles become dysfunctional with ageing and in acute and chronic lung disease. Although much remains to be uncovered, we also discuss potential targeted therapeutics for mitochondrial dysfunction in the ageing and diseased lung.

Targeting Aging Pathways in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) has become a global epidemic and is the third leading cause of death worldwide. COPD is characterized by chronic airway inflammation, loss of alveolar-capillary units, and progressive decline in lung function. Major risk factors for COPD are cigarette smoking and aging. COPD-associated pathomechanisms include multiple aging pathways such as telomere attrition, epigenetic alterations, altered nutrient sensing, mitochondrial dysfunction, cell senescence, stem cell exhaustion and chronic inflammation. In this review, we will highlight the current literature that focuses on the role of age and aging-associated signaling pathways as well as their impact on current treatment strategies in the pathogenesis of COPD. Furthermore, we will discuss established and experimental COPD treatments including senolytic and anti-aging therapies and their potential use as novel treatment strategies in COPD.

Virus-Induced Asthma Exacerbations: SIRT1 Targeted Approach

The prevalence of asthma has increased worldwide. Asthma exacerbations triggered by upper respiratory tract viral infections remain a major clinical problem and account for hospital admissions and time lost from work. Virus-induced asthma exacerbations cause airway inflammation, resulting in worsening asthma and deterioration in the patients’ quality of life, which may require systemic corticosteroid therapy. Despite recent advances in understanding the cellular and molecular mechanisms underlying asthma exacerbations, current therapeutic modalities are inadequate for complete prevention and treatment of these episodes. The pathological role of cellular senescence, especially that involving the silent information regulator 2 homolog sirtuin (SIRT) protein family, has recently been demonstrated in stable and exacerbated chronic respiratory disease states. This review discusses the role of SIRT1 in the pathogenesis of bronchial asthma. It also discusses the role of SIRT1 in inflammatory cells that play an important role in virus-induced asthma exacerbations. Recent studies have hypothesized that SIRT1 is one of major contributors to cellular senescence. SIRT1 levels decrease in Th2 and non-Th2-related airway inflammation, indicating the role of SIRT1 in several endotypes and phenotypes of asthma. Moreover, several models have demonstrated relationships between viral infection and SIRT1. Therefore, targeting SIRT1 is a novel strategy that may be effective for treating virus-induced asthma exacerbations in the future.

The ageing lung under stress

Healthy ageing of the lung involves structural changes but also numerous cell-intrinsic and cell-extrinsic alterations. Among them are the age-related decline in central cellular quality control mechanisms such as redox and protein homeostasis. In this review, we would like to provide a conceptual framework of how impaired stress responses in the ageing lung, as exemplified by dysfunctional redox and protein homeostasis, may contribute to onset and progression of COPD and idiopathic pulmonary fibrosis (IPF). We propose that age-related imbalanced redox and protein homeostasis acts, amongst others (e.g.cellular senescence), as a “first hit” that challenges the adaptive stress-response pathways of the cell, increases the level of oxidative stress and renders the lung susceptible to subsequent injury and disease. In both COPD and IPF, additional environmental insults such as smoking, air pollution and/or infections then serve as “second hits” which contribute to persistently elevated oxidative stress that overwhelms the already weakened adaptive defence and repair pathways in the elderly towards non-adaptive, irremediable stress thereby promoting development and progression of respiratory diseases. COPD and IPF are thus distinct horns of the same devil, “lung ageing”.