Senescence: Pathogenic Driver in Chronic Obstructive Pulmonary Disease

α‑1 Antitrypsin is a potential target of inflammation and immunomodulation (Review)

α‑1 Antitrypsin (AAT) is an acute phase protein encoded by the serine protease inhibitor family A member 1 gene. This multifunctional protein serves several roles, including anti‑inflammatory, antibacterial, antiapoptotic and immune regulatory functions. The primary role of AAT is to protect tissues and organs from protease‑induced damage due to its function as a serine protease inhibitor. AAT is associated with the development of lung inflammation, liver inflammation and immune‑mediated inflammatory diseases, which are influenced by environmental and genetic factors. For instance, AAT acts as an anti‑inflammatory protein to prevent and reverse type I diabetes. The present study briefly reviewed the molecular properties and mechanisms of AAT, as well as advances in the study of lung, liver and inflammatory diseases associated with AAT. The potential of AAT as a diagnostic and therapeutic target for inflammatory and immune‑mediated inflammatory diseases was reviewed. In addition, the damaging and protective effects of AAT, and its effects on organ function were discussed.

Research advances in polyphenols from Chinese herbal medicine for the prevention and treatment of chronic obstructive pulmonary disease: a review

Chronic obstructive pulmonary disease (COPD) is a global health problem due to its high death and morbidity worldwide, which is characterized by an incompletely reversible limitation in airflow that is not fully reversible. Unfortunately, Western medical treatments are unable to reverse the progressive decline in lung function. Importantly, polyphenolic compounds isolated from Chinese herbal medicine exhibited therapeutic/interventional effects on COPD in preclinical studies. This review systematically analyzed the pathogenesis of COPD, such as inflammation, oxidative stress, protease/antiprotease imbalance, aging, cell death, and dysbiosis of gut microbiota. Moreover, this review summarized the regulatory mechanisms of natural polyphenolic compounds for the treatment of COPD. Several studies have demonstrated that natural polyphenolic compounds have therapeutic effects on COPD by regulating various biological processes, such as anti-inflammatory, reduction of oxidative damage, anti-cell death, and inhibition of airway hyperglycemia. Mechanistically, this review found that the promising effects of natural polyphenolic compounds on COPD were mainly achieved through modulating the NF-κB and MAPK inflammatory pathways, the Nrf2 oxidative stress pathway, and the SIRT1/PGC-1α lung injury pathway. Furthermore, this review analyzed the efficacy and safety of natural polyphenolic compounds for the treatment of COPD in clinical trials, and discussed their challenges and future development directions. In conclusion, this review combined the latest literature to illustrate the various pathogenesis and interrelationships of COPD in the form of graphs, texts, and tables, and sorted out the functional role and mechanisms of natural polyphenols in treating COPD, with a view to providing new ideas and plans for the in-depth research on COPD and the systemic treatment of COPD with Chinese herbal medicine.

Aging Lung: Molecular Drivers and Impact on Respiratory Diseases-A Narrative Clinical Review

The aging process significantly impacts lung physiology and is a major risk factor for chronic respiratory diseases, including chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), asthma, and non-IPF interstitial lung fibrosis. This narrative clinical review explores the molecular and biochemical hallmarks of aging, such as oxidative stress, telomere attrition, genomic instability, epigenetic modifications, proteostasis loss, and impaired macroautophagy, and their roles in lung senescence. Central to this process are senescent cells, which, through the senescence-associated secretory phenotype (SASP), contribute to chronic inflammation and tissue dysfunction. The review highlights parallels between lung aging and pathophysiological changes in respiratory diseases, emphasizing the role of cellular senescence in disease onset and progression. Despite promising research into modulating aging pathways with interventions like caloric restriction, mTOR inhibitors, and SIRT1 activators, clinical evidence for efficacy in reversing or preventing age-related lung diseases remains limited. Understanding the interplay between aging-related mechanisms and environmental factors, such as smoking and pollution, is critical for developing targeted therapies. This review underscores the need for future studies focusing on therapeutic strategies to mitigate aging's detrimental effects on lung health and improve outcomes for patients with chronic respiratory conditions.

Therapeutic potential of 18-β-glycyrrhetinic acid-loaded poly (lactic-co-glycolic acid) nanoparticles on cigarette smoke-induced in-vitro model of COPD

Chronic obstructive pulmonary disease (COPD) is strongly linked to cigarette smoke, which contains toxins that induce oxidative stress and airway inflammation, ultimately leading to premature airway epithelial cell senescence and exacerbating COPD progression. Current treatments for COPD are symptomatic and hampered by limited efficacy and severe side effects. This highlights the need to search for an optimal therapeutic candidate to address the root causes of these conditions. This study investigates the possible potential of poly (lactic-co-glycolic acid) (PLGA)-based nanoparticles encapsulating the plant-based bioactive compound 18-β-glycyrrhetinic acid (18βGA) as a strategy to intervene in cigarette smoke extract (CSE)-induced oxidative stress, inflammation, and senescence, in vitro. We prepared 18βGA-PLGA nanoparticles, and assessed their effects on cell viability, reactive oxygen species (ROS) production, anti-senescence properties (expression of senescence-associated β galactosidase and p21 mRNA), and expression of pro-inflammatory genes (CXCL-1, IL-6, TNF-α) and inflammation-related proteins (IL-8, IL-15, RANTES, MIF). The highest non-toxic concentration of 18βGA-PLGA nanoparticles to healthy human broncho epithelial cell line BCiNS1.1 was identified as 5 µM. These nanoparticles effectively mitigated cigarette smoke-induced inflammation, reduced ROS production, protected against cellular aging, and counteracted the effects of CSE on the expression of the inflammation-related genes and proteins. This study underscores the potential of 18βGA encapsulated in PLGA nanoparticles as a promising therapeutic approach to alleviate cigarette smoke-induced oxidative stress, inflammation, and senescence. Further research is needed to explore the translational potential of these findings in clinical and in vivo settings.

The cGAS-STING pathway in COPD: targeting its role and therapeutic potential

Chronic obstructive pulmonary disease(COPD) is a gradually worsening and fatal heterogeneous lung disease characterized by airflow limitation and increasingly decline in lung function. Currently, it is one of the leading causes of death worldwide. The consistent feature of COPD is airway inflammation. Several inflammatory factors are known to be involved in COPD pathogenesis; however, anti-inflammatory therapy is not the first-line treatment for COPD. Although bronchodilators, corticosteroids and roflumilast could improve airflow and control symptoms, they could not reverse the disease. The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) signaling pathway plays an important novel role in the immune system and has been confirmed to be a key mediator of inflammation during infection, cellular stress, and tissue damage. Recent studies have emphasized that abnormal activation of cGAS-STING contributes to COPD, providing a direction for new treatments that we urgently need to develop. Here, we focused on the cGAS-STING pathway, providing insight into its molecular mechanism and summarizing the current knowledge on the role of the cGAS-STING pathway in COPD. Moreover, we explored antagonists of cGAS and STING to identify potential therapeutic strategies for COPD that target the cGAS-STING pathway.

Unlocking the Future: Pluripotent Stem Cell-Based Lung Repair

The human respiratory system is susceptible to a variety of diseases, ranging from chronic obstructive pulmonary disease (COPD) and pulmonary fibrosis to acute respiratory distress syndrome (ARDS). Today, lung diseases represent one of the major challenges to the health care sector and represent one of the leading causes of death worldwide. Current treatment options often focus on managing symptoms rather than addressing the underlying cause of the disease. The limitations of conventional therapies highlight the urgent clinical need for innovative solutions capable of repairing damaged lung tissue at a fundamental level. Pluripotent stem cell technologies have now reached clinical maturity and hold immense potential to revolutionize the landscape of lung repair and regenerative medicine. Meanwhile, human embryonic (HESCs) and human-induced pluripotent stem cells (hiPSCs) can be coaxed to differentiate into lung-specific cell types such as bronchial and alveolar epithelial cells, or pulmonary endothelial cells. This holds the promise of regenerating damaged lung tissue and restoring normal respiratory function. While methods for targeted genetic engineering of hPSCs and lung cell differentiation have substantially advanced, the required GMP-grade clinical-scale production technologies as well as the development of suitable preclinical animal models and cell application strategies are less advanced. This review provides an overview of current perspectives on PSC-based therapies for lung repair, explores key advances, and envisions future directions in this dynamic field.

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

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

Alveolar repair following LPS-induced injury requires cell-ECM interactions

During alveolar repair, alveolar type 2 (AT2) epithelial cell progenitors rapidly proliferate and differentiate into flat AT1 epithelial cells. Failure of normal alveolar repair mechanisms can lead to loss of alveolar structure (emphysema) or development of fibrosis, depending on the type and severity of injury. To test if β1-containing integrins are required during repair following acute injury, we administered E. coli lipopolysaccharide (LPS) by intratracheal injection to mice with a postdevelopmental deletion of β1 integrin in AT2 cells. While control mice recovered from LPS injury without structural abnormalities, β1-deficient mice had more severe inflammation and developed emphysema. In addition, recovering alveoli were repopulated with an abundance of rounded epithelial cells coexpressing AT2 epithelial, AT1 epithelial, and mixed intermediate cell state markers, with few mature type 1 cells. AT2 cells deficient in β1 showed persistently increased proliferation after injury, which was blocked by inhibiting NF-κB activation in these cells. Lineage tracing experiments revealed that β1-deficient AT2 cells failed to differentiate into mature AT1 epithelial cells. Together, these findings demonstrate that functional alveolar repair after injury with terminal alveolar epithelial differentiation requires β1-containing integrins.

Airway Epithelium Senescence as a Driving Mechanism in COPD Pathogenesis

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

Respiratory Immune Responses during Infection and Pollution Inhalation

The COVID-19 pandemic highlighted the importance of lung immune responses to pathogens and environmental factors [...].