Morphologically and karyotypically atypical cells of 'normal' human bronchial epithelial cell line (Beas-2B)

Two- and Three-Dimensional Culture Systems: Respiratory In Vitro Tissue Models for Chemical Screening and Risk-Based Decision Making

Risk of lung damage from inhaled chemicals or substances has long been assessed using animal models. However, New Approach Methodologies (NAMs) that replace, reduce, and/or refine the use of animals in safety testing such as 2D and 3D cultures are increasingly being used to understand human-relevant toxicity responses and for the assessment of hazard identification. Here we review 2D and 3D lung models in terms of their application for inhalation toxicity assessment. We highlight a key case study for the Organization for Economic Cooperation and Development (OECD), in which a 3D model was used to assess human toxicity and replace the requirement for a 90-day inhalation toxicity study in rats. Finally, we consider the regulatory guidelines for the application of NAMs and potential use of different lung models for aerosol toxicity studies depending on the regulatory requirement/context of use.

Recent advances on transport and transformation mechanism of nanoplastics in lung cells

Microplastics (MPs) are solid plastic particles less than or equal to 5 mm in size that are insoluble in water, and when the diameter is further reduced to <1 micrometer (μm), we call them nanoplastics (NPs). MPs and NPs are widely present in the atmosphere, and plastic particles have also been detected in the sputum of patients with respiratory diseases. This warns us that these tiny plastic particles are a potential threat to human respiratory health. The lungs, as the main organs of the respiratory system, are more likely to be adversely affected by inhaled NPs. However, the mechanism of transport and transformation of NPs in the lung is not clear, so our review mainly focuses on a series of effects and mechanisms of NPs on lung cells through absorption, distribution, metabolism, excretion (ADME) after inhalation into the human body. The most commonly used models in these experimental studies we focus on are A549 and BEAS-2B cells, which are used to model the lung cell response to plastic particles. In addition, we also summarize some shortcomings of these experiments and prospects for future studies, hoping to provide further clues for future studies and contribute to the prevention of related hazards and diseases.

Biological effect of U(VI) exposure on lung epithelial BEAS-2B cells

In this study, the biological effects of U(VI) exposure on lung epithelial cells were investigated by MTT assay, immunofluorescence, flow cytometry, and Western blotting. U(VI)-induced stress triggers oxidative stress in cells, activates MAPK signaling pathways, and promotes inflammation. Additionally, U(VI) causes damage to the cell membrane structure and severe DNA injury, impacting the accuracy of transcription and translation. The results demonstrate that U(VI) exposure significantly inhibits cell proliferation and migration. This is attributed to the disruption of the PI3K/AKT/GSK-3β/β-catenin signaling pathway and the reduction in CyclinD1 expression, leading to a delayed cell cycle, decreased growth rate, mitochondrial damage, and reduced energy metabolism. This study provides a comprehensive understanding of the molecular mechanisms underlying uranium-induced cellular toxicity in lung epithelial cells.

Role of Lipopolysaccharides in the Inflammation and Pyroptosis of Alveolar Epithelial Cells in Acute Lung Injury and Acute Respiratory Distress Syndrome

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) represent a spectrum of common critical respiratory conditions characterized by damage and death of alveolar epithelial cells (AECs). Pyroptosis is a form of programmed cell death with inflammatory characteristics, and activation of pyroptosis markers has been observed in AECs of patients with ALI/ARDS. Lipopolysaccharides (LPS) possess strong pro-inflammatory effects and are a crucial pathological factor leading to ALI in patients and animals. In LPS-induced ALI models, AECs undergo pyroptosis. However, physiologically and pathologically relevant concentrations of LPS lead to minor effects on AEC cell viability and minimal induction of cytokine release in vitro and do not induce classical pyroptosis. Nevertheless, LPS can enter the cytoplasm directly and induce non-classical pyroptosis in AECs when assisted by extracellular vesicles from bacteria, HMGB1, and pathogens. In this review, we have explored the effects of LPS on AECs concerning inflammation, cell viability, and pyroptosis, analyzing key factors that influence LPS actions. Notably, we highlight the intricate response of AECs to LPS within the framework of ALI and ARDS, emphasizing the variable induction of pyroptosis. Despite the minimal effects of LPS on AEC viability and cytokine release in vitro, LPS can induce non-classical pyroptosis under specific conditions, presenting potential pathways for therapeutic intervention. Collectively, understanding these mechanisms is crucial for the development of targeted treatments that mitigate the inflammatory responses in ALI/ARDS, thereby enhancing patient outcomes in these severe respiratory conditions.

An anti-tumor protein PFAP specifically interacts with cholesterol-enriched membrane domains of A549 cells and induces paraptosis and endoplasmic reticulum stress

Nowadays, non-small cell lung cancer (NSCLC) is still one of the most life-threatening diseases in the world. In previous studies, a fungal protein PFAP with anti-NSCLC properties was isolated and identified from Pleurotus ferulae lanzi. In this study, the amino acid sequence of PFAP was analyzed and found to be highly homologous to the aegerolysin family. PFAP, like other members of the aegerolysin family, specifically recognizes lipid raft domains rich in cholesterol and sphingomyelin, which is probably its specific anti-tumor mechanism. Previous studies have shown that PFAP can induce AMPK-mediated autophagy and G1-phase cell cycle arrest in A549 lung cancer cells. This study further revealed that PFAP can also induce paraptosis and endoplasmic reticulum stress (ERS) in A549 cells in vitro by targeting AMPK. PFAP induces multi-pathway death of A549 cells, and thus demonstrates its potential value for developing new drugs for NSCLC.