Expression of long non‐coding RNA LUCAT1 in patients with chronic obstructive pulmonary disease and its potential functions in regulating cigarette smoke extract‐induced 16HBE cell proliferation and apoptosis

Abstract

Background Chronic obstructive pulmonary disease (COPD), characterized by persistent airflow limitation, was a disease mediated by a combination of inflammatory factors, immune cells, and immune mediators. COPD was an inflammatory and autoimmune disease involving T‐lymphocytes triggered by cigarette smoke and other factors that progressively affected the bronchi, lung parenchyma, and pulmonary blood vessels. LncRNAs were reported to be implicated in COPD pathogenesis and development. Methods Non‐smokers, smokers (non‐COPD), and COPD patients were randomly selected in an established COPD surveillance cohort. Demographic and clinical information of all subjects were collected. Pulmonary function was measured by post‐bronchodilator testing. qRT‐PCR and ELISA assays were performed to detect the expression levels of lncRNA LUCAT1, miR‐181a‐5p, and inflammatory cytokines. An in vitro exposure model was constructed using cigarette smoke extract (CSE)‐induced human bronchial epithelial (16HBE) cells. The dual‐luciferase reporter and RNA pull‐down assays were used to detect the binding relationship between lncRNA LUCAT1 and miR‐181a‐5p; meanwhile, Spearman's correlation assay was used to verify the correlation between lncRNA LUCAT1 and miR‐181a‐5p. Afterward, the lncRNA LUCAT1 silencing plasmid was constructed and co‐transfected with a miR‐181a‐5p inhibitor to evaluate the effects on CSE‐induced 16HBE cell proliferation and apoptosis. Finally, a Western blot assay was utilized to determine the mechanism of lncRNA LUCAT1/miR‐181a‐5p/Wnt/β‐catenin axis in COPD. Results LncRNA LUCAT1 was upregulated in the serums of COPD patients. Correlation analysis further confirmed the strong correlation between LUCAT1 expression and inflammatory cytokines IL‐1β, IL‐6, and TNF‐α. Receiver operating characteristic (ROC) analysis verified the potential of LUCAT1 in COPD diagnosis. After treatment with CSE, LUCAT1 was significantly increased while its target miR‐181a‐5p was decreased in 16HBE cells. Cell proliferation and apoptosis assays showed that LUCAT1 silencing alleviated CSE’s effects on 16HBE cell proliferation and apoptosis. Mechanically, rescue assays demonstrated that miR‐181a‐5p inhibition could partially counteract the impact of LUCAT1 on COPD progression through the Wnt/β‐catenin pathway. Conclusions LncRNA LUCAT1 may be a valuable indicator for differentiating COPD. Moreover, LncRNA LUCAT1/miR‐181‐5p/Wnt/β‐catenin axis behaved as a critical role in COPD development, shedding new sights for clinical treatment.

Genome-wide differential expression profiling of lncRNAs and mRNAs in human induced pluripotent stem cell-derived endothelial cells exposed to e-cigarette extract

“…It has also been shown that the overexpression of LUCAT1 inhibits inducible nitric oxide synthase in lung cells under hyperglycemic conditions [ 46 ]. In line with our study, LUCAT1 was significantly increased in human bronchial epithelial cells following CSE treatment and the knockdown of LUCAT1 in conjunction with CSE treatment led to the alleviation of increased apoptosis and decreased cell proliferation caused by CSE [ 47 ]. Further, Zhao et al demonstrated that these effects are due in part to LUCAT1’s ability to sponge miR-181a, inhibiting miR-181a’s silencing effects on the Wnt/β-catenin pathway [ 47 ].…”

“…In line with our study, LUCAT1 was significantly increased in human bronchial epithelial cells following CSE treatment and the knockdown of LUCAT1 in conjunction with CSE treatment led to the alleviation of increased apoptosis and decreased cell proliferation caused by CSE [ 47 ]. Further, Zhao et al demonstrated that these effects are due in part to LUCAT1’s ability to sponge miR-181a, inhibiting miR-181a’s silencing effects on the Wnt/β-catenin pathway [ 47 ]. Altogether, these previous studies suggest an essential role of LUCAT1 in regulating endothelial function.…”

Role of Non-Coding RNAs in Post-Transcriptional Regulation of Lung Diseases

“…This implies that upregulation Notch1, which is implicated in various cellular processes such as cell proliferation, differentiation, and apoptosis, stimulates HOXA-AS2dependent cell proliferation and mitigates the cell viability injury. The lung cancer-associated transcript 1 (LUCAT1) is elevated in the serum of COPD patients (Zhao et al, 2021).…”

“…This implies that upregulation Notch1, which is implicated in various cellular processes such as cell proliferation, differentiation, and apoptosis, stimulates HOXA-AS2-dependent cell proliferation and mitigates the cell viability injury. The lung cancer-associated transcript 1 (LUCAT1) is elevated in the serum of COPD patients ( Zhao et al, 2021 ). Further studies in CSE-treated 16HBE cells show that LUCAT1 downregulates its target, miR-181a-5p, upregulates inflammatory cytokines (IL-1β, IL-6, and TNF-α), and regulates cell proliferation and apoptosis via the Wnt/β-catenin pathway ( Zhao et al, 2021 ).…”

“…The lung cancer-associated transcript 1 (LUCAT1) is elevated in the serum of COPD patients ( Zhao et al, 2021 ). Further studies in CSE-treated 16HBE cells show that LUCAT1 downregulates its target, miR-181a-5p, upregulates inflammatory cytokines (IL-1β, IL-6, and TNF-α), and regulates cell proliferation and apoptosis via the Wnt/β-catenin pathway ( Zhao et al, 2021 ). The role of activated Wnt/β-catenin pathway in induction of inflammatory cytokines (IL-1β, IL-6, and TNF-α) and cell proliferation and apoptosis are well characterized ( Masckauchan et al, 2005 ; Aumiller et al, 2013 ; Jang et al, 2017 ).…”