Cigarette Smoke-Induced Oxidative Stress in Type I and Type II Lung Epithelial Cells

AbstractSevere acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is a major risk factor for mortality and morbidity in critical care hospitals around the world. Lung epithelial type II cells play a major role in several physiological processes, including recognition and clearance of respiratory viruses as well as repair of lung injury in response to environmental toxicants. Gene expression profiling of lung epithelial type II-specific genes led to the identification of lysosomal-associated membrane protein 3 (LAMP3). Intracellular locations of LAMP3 include plasma membrane, endosomes, and lysosomes. These intracellular organelles are involved in vesicular transport and facilitate viral entry and release of the viral RNA into the host cell cytoplasm. In this study, regulation of LAMP3 expression in human lung epithelial cells by several respiratory viruses and type I interferon signaling was investigated. Coronaviruses including SARS-CoV-1 and SARS-CoV-2 significantly induced LAMP3 expression in lung epithelial cells within 24 hours after infection that required the presence of ACE2 viral entry receptor. Time-course experiments revealed that the induced expression of LAMP3 by SARS-CoV-2 was correlated with the induced expression of interferon-beta1 (IFNB1) and signal transducers and activator of transcription 1 (STAT1) mRNA levels. LAMP3 was also induced by direct IFN-beta treatment or by infection with influenza virus lacking the non-structural protein1(NS1) in NHBE bronchial epithelial cells. LAMP3 expression was induced in human lung epithelial cells by several respiratory viruses, including respiratory syncytial virus (RSV) and the human parainfluenza virus 3 (HPIV3). Location in lysosomes and endosomes as well as induction by respiratory viruses and type I Interferon suggests that LAMP3 may have an important role in inter-organellar regulation of innate immunity and a potential target for therapeutic modulation in health and disease. Furthermore, bioinformatics revealed that a subset of lung type II cell genes were differentially regulated in the lungs of COVID-19 patients.

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Single-cell analysis of human lung epithelia reveals concomitant expression of the SARS-CoV-2 receptor ACE2 with multiple virus receptors and scavengers in alveolar type II cells

10.1101/2020.04.16.045617 ◽

2020 ◽

Author(s):

Guangchun Han ◽

Ansam Sinjab ◽

Warapen Treekitkarnmongkol ◽

Patrick Brennan ◽

Kieko Hara ◽

...

Keyword(s):

Epithelial Cells ◽

Single Cell ◽

Expression Patterns ◽

Severe Pneumonia ◽

Lung Epithelial Cells ◽

Chronic Obstructive ◽

Alveolar Type ◽

Type I ◽

Type Ii ◽

Lung Epithelial

ABSTRACTThe novel coronavirus SARS-CoV-2 was identified as the causative agent of the ongoing pandemic COVID 19. COVID-19-associated deaths are mainly attributed to severe pneumonia and respiratory failure. Recent work demonstrated that SARS-CoV-2 binds to angiotensin converting enzyme 2 (ACE2) in the lung. To better understand ACE2 abundance and expression patterns in the lung we interrogated our in-house single-cell RNA-sequencing dataset containing 70,085 EPCAM+ lung epithelial cells from paired normal and lung adenocarcinoma tissues. Transcriptomic analysis revealed a diverse repertoire of airway lineages that included alveolar type I and II, bronchioalveolar, club/secretory, quiescent and proliferating basal, ciliated and malignant cells as well as rare populations such as ionocytes. While the fraction of lung epithelial cells expressing ACE2 was low (1.7% overall), alveolar type II (AT2, 2.2% ACE2+) cells exhibited highest levels of ACE2 expression among all cell subsets. Further analysis of the AT2 compartment (n = 27,235 cells) revealed a number of genes co-expressed with ACE2 that are important for lung pathobiology including those associated with chronic obstructive pulmonary disease (COPD; HHIP), pneumonia and infection (FGG and C4BPA) as well as malarial/bacterial (CD36) and viral (DMBT1) scavenging which, for the most part, were increased in smoker versus light or non-smoker cells. Notably, DMBT1 was highly expressed in AT2 cells relative to other lung epithelial subsets and its expression positively correlated with ACE2. We describe a population of ACE2-positive AT2 cells that co-express pathogen (including viral) receptors (e.g. DMBT1) with crucial roles in host defense thus comprising plausible phenotypic targets for treatment of COVID-19.

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Difference on oxidative stress in lung epithelial cells and macrophages induced by ambient fine particulate matter (PM2.5)

Air Quality Atmosphere & Health ◽

10.1007/s11869-020-00835-5 ◽

2020 ◽

Vol 13 (7) ◽

pp. 789-796 ◽

Cited By ~ 1

Author(s):

Ran Li ◽

Yixuan Wang ◽

Xinghua Qiu ◽

Fanfan Xu ◽

Rucheng Chen ◽

...

Keyword(s):

Oxidative Stress ◽

Particulate Matter ◽

Epithelial Cells ◽

Fine Particulate Matter ◽

Lung Epithelial Cells ◽

Fine Particulate ◽

Lung Epithelial

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Senescence associated long non-coding RNA 1 regulates cigarette smoke-induced senescence of type II alveolar epithelial cells through sirtuin-1 signaling

Journal of International Medical Research ◽

10.1177/0300060520986049 ◽

2021 ◽

Vol 49 (2) ◽

pp. 030006052098604

Author(s):

Dong Yuan ◽

Yuanshun Liu ◽

Mengyu Li ◽

Hongbin Zhou ◽

Liming Cao ◽

...

Keyword(s):

Epithelial Cells ◽

Cigarette Smoke ◽

Alveolar Epithelial Cell ◽

Alveolar Epithelial Cells ◽

Lung Epithelial Cells ◽

Sirtuin 1 ◽

Type Ii ◽

Alveolar Epithelial ◽

Non Coding Rna ◽

Long Non Coding Rna

Objective The primary aim of our study was to explore the mechanisms through which long non-coding RNA (lncRNA)-mediated sirtuin-1 (SIRT1) signaling regulates type II alveolar epithelial cell (AECII) senescence induced by a cigarette smoke-media suspension (CSM). Methods Pharmacological SIRT1 activation was induced using SRT2104 and senescence-associated lncRNA 1 (SAL-RNA1) was overexpressed. The expression of SIRT1, FOXO3a, p53, p21, MMP-9, and TIMP-1 in different groups was detected by qRT-PCR and Western blotting; the activity of SA-β gal was detected by staining; the binding of SIRT1 to FOXO3a and p53 gene transcription promoters was detected by Chip. Results We found that CSM increased AECII senescence, while SAL-RNA1 overexpression and SIRT1 activation significantly decreased levels of AECII senescence induced by CSM. Using chromatin immunoprecipitation, we found that SIRT1 bound differentially to transcriptional complexes on the FOXO3a and p53 promoters. Conclusion Our results suggested that lncRNA-SAL1-mediated SIRT1 signaling reduces senescence of AECIIs induced by CSM. These findings suggest a new therapeutic target to limit the irreversible apoptosis of lung epithelial cells in COPD patients.

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