RNA Sequencing Analyses Reveal the Potential Mechanism of Pulmonary Injury Induced by Gallium Arsenide Particles in Human Bronchial Epithelioid Cells

Non-malignant respiratory illness associated with exposure to arsenic compounds in the environment

Arsenic (As), a toxic metalloid, primarily originates from both natural and anthropogenic activities. Reports suggested that millions of people globally exposed to high levels of naturally occurring As compounds via inhalation and ingestion. There is evidence that As is a well-known lung carcinogen. However, there has been relatively little evidence suggesting its non-malignant lung effects. This review comprehensively summarises current experimental and clinical studies implicating the association of As exposure and the development of several non-malignant lung diseases. Experimental studies provided evidence that As exposure induces redox imbalance, apoptosis, inflammatory response, epithelial-to-mesenchymal transition (EMT), and affected normal lung development through alteration of the components of intracellular signaling cascades. In addition, we also discuss the sources and possible mechanisms of As influx and efflux in the lung. Finally, current experimental studies on treatment strategies using phytochemicals and our perspective on future research with As are also discussed.

LncRNA CASC2 is involved in the development of chronic obstructive pulmonary disease via targeting miR-18a-5p/IGF1 axis

AIMS

Chronic obstructive pulmonary disease (COPD) is a systemic disease. Several long non-coding RNAs (lncRNAs) have been identified to be aberrantly expressed in COPD patients. This study investigated the role of lncRNA cancer susceptibility candidate 2 (CASC2) in COPD, as well as its potential mechanism.

METHODS

Fifty smokers with COPD and another 50 smokers without COPD were recruited. Receiver operating characteristic curve was constructed to assess the diagnostic value of CASC2 in COPD patients. 16HBE cells were treated with cigarette smoke extract (CSE) to establish a cell model. qRT-PCR was used for the measurement of mRNA levels. The cell viability and apoptosis were detected by using Cell Counting Kit-8 and flow cytometry assay. Enzyme-linked immunosorbent assay was performed to detect the levels of proinflammatory cytokines. Luciferase reporter assay was performed for the target gene analysis.

RESULTS

Serum CASC2 was dramatically decreased in COPD patients compared with smokers without COPD, and was positively associated with FEV1 (forced expiratory volume in one second). Serum CASC2 was overexpressed in severe COPD patients, and had the diagnostic accuracy to distinguish COPD patients from smokers. CASC2 overexpression alleviated CSE-induced apoptosis and inflammation in 16HBE cells. CASC2 functions as a ceRNA of miR-18a-5p. Upregulation of miR-18a-5p reversed the influence of CASC2 on cell apoptosis and inflammation in 16HBE cells. IGF1 was the target gene of miR-18a-5p.

CONCLUSION

CASC2 was downregulated in COPD patients and it might be a promising biomarker for the disease diagnosis. Overexpression of CASC2 might inhibit the bronchial epithelial cell apoptosis and inflammation via targeting miR-18a-5p/IGF1 axis.The reviews of this paper are available via the supplemental material section.