Circ-RBMS1 Knockdown Alleviates CSE-Induced Apoptosis, Inflammation and Oxidative Stress via Up-Regulating FBXO11 Through miR-197-3p in 16HBE Cells.

Emerging evidence has reported that circular RNAs (circRNAs) are aberrantly expressed and act as significant regulators in pathological processes of chronic obstructive pulmonary disease (COPD). Here, the purpose of this article was to evaluate and clarify the biological functions and mechanism of circRNA single stranded interacting protein 1 (circ-RBMS1) in cigarette smoke (CS)-induced COPD. Human bronchial epithelial cells 16HBE treated with or without cigarette smoke extract (CSE) were used in the experimental group in vitro. Levels of circ-RBMS1, microRNA (miR)-197-3p, and F-box only protein 11 (FBXO11) were detected using quantitative real-time polymerase chain reaction and Western blot. The present study used cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EDU), flow cytometry and Western blot assays to determine the survival of 16HBE cells. The activity of interleukin (IL)-1β, tumor necrosis factor (TNF-α), malondialdehyde (MDA) and superoxide dismutase (SOD) was evaluated using the relative commercial kits. Dual-luciferase activity and RIP assays were used to identify the target relationship between miR-197-3p and circ-RBMS1 or FBXO11. Circ-RBMS1 was highly expressed in COPD patients, and CSE induced an increased expression of circ-RBMS1 in a dose-dependent manner. Functionally, knockdown of circ-RBMS1 attenuated CSE-induced apoptosis, inflammation and oxidative stress in 16HBE cells. Circ-RBMS1 directly targeted miR-197-3p, and miR-197-3p inhibition reversed the effects of circ-RBMS1 knockdown on CSE-induced 16HBE cells. FBXO11 was a target of miR-197-3p. MiR-197-3p overexpression or FBXO11 silencing reduced the apoptosis, inflammation and oxidative stress in CSE-induced 16HBE cells. Moreover, miR-197-3p exerted its effects by targeting FBXO11. Additionally, circ-RBMS1 acted as a sponge for miR-197-3p to positively regulate FBXO11 expression in 16HBE cells. Circ-RBMS1 knockdown alleviated CSE-induced apoptosis, inflammation and oxidative stress in 16HBE cells via miR-197-3p/FBXO11 axis, suggesting a new insight into the pathogenesis of CS-induced COPD.

Qiao D ，Hu C ，Li Q ，Fan J ... -  《International Journal of Chronic Obstructive Pulmonary Disease》

Circ-HACE1 Aggravates Cigarette Smoke Extract-Induced Injury in Human Bronchial Epithelial Cells via Regulating Toll-Like Receptor 4 by Sponging miR-485-3p.

Smoking is the most common cause of chronic obstructive pulmonary disease (COPD), and the early diagnosis for COPD remains poor. Exploring the molecular mechanism and finding feasible biomarkers will be beneficial for clinical management of COPD. Circular RNAs (circRNAs) are noncoding RNAs that act as miRNA sponges to regulate the expression levels of genes, leading to the changes of cellular phenotypes and disease progression. CircRNA HECT domain and ankyrin repeat containing E3 ubiquitin protein ligase 1 (circ-HACE1) was abnormally expressed after the induction of cigarette smoke extract (CSE) in cell model. This study was performed to explore its function and mechanism in COPD. Circ-HACE1, microRNA-485-3p (miR-485-3p) and toll-like receptor 4 (TLR4) detection was performed by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability and apoptosis/cell cycle were respectively examined using cell counting kit-8 (CCK-8) and flow cytometry. Inflammatory cytokines were determined by enzyme-linked immunosorbent assay (ELISA). Oxidative stress was evaluated through the measurement of malondialdehyde (MDA) and superoxide dismutase (SOD). The target binding analysis was conducted via dual-luciferase reporter assay. Western blot was employed for protein expression detection of TLR4. Circ-HACE1 was overexpressed in smokers or smokers with COPD and CSE upregulated circ-HACE1 expression in 16HBE cells. Knockdown of circ-HACE1 attenuated CSE-stimulated cell viability and cell cycle repression, as well as the enhancement of cell apoptosis, inflammatory response and oxidative stress. MiR-485-3p was a target of circ-HACE1. Circ-HACE1 regulated CSE-induced cell injury via targeting miR-485-3p. TLR4 was a downstream target of miR-485-3p, and miR-485-3p inhibited the CSE-induced cell damages by directly downregulating the level of TLR4. Circ-HACE1/miR-485-3p regulated TLR4 expression in CSE-treated 16HBE cells, and TLR4 overexpression also reversed all effects of si-circ-HACE1 on CSE-treated 16HBE cells. These findings elucidated that circ-HACE1 contributed to the CSE-induced cell damages in COPD cell models via regulating TLR4 by acting as the sponge of miR-485-3p.

Zhou F ，Cao C ，Chai H ，Hong J ，Zhu M ... -  《International Journal of Chronic Obstructive Pulmonary Disease》

CIRC_0026466 KNOCKDOWN PROTECTS HUMAN BRONCHIAL EPITHELIAL CELLS FROM CIGARETTE SMOKE EXTRACT-INDUCED INJURY BY PROMOTING THE MIR-153-3P/TRAF6/NF-ΚB PATHWAY.

Background: Considerable data have shown that circular RNAs (circRNAs) mediate the pathogenesis of chronic obstructive pulmonary disease (COPD). The study aims to analyze the function and mechanism of circ_0026466 in COPD. Methods: Human bronchial epithelial cells (16HBE) were treated with cigarette smoke extract (CSE) to establish a COPD cell model. Quantitative real-time polymerase chain reaction and Western blot were used to detect the expression of circ_0026466, microRNA-153-3p (miR-153-3p), TNF receptor associated factor 6 (TRAF6), cell apoptosis-related proteins, and NF-κB pathway-related proteins. Cell viability, proliferation, apoptosis, and inflammation were investigated by cell counting kit-8, EdU assay, flow cytometry, and enzyme-linked immunosorbent assay, respectively. Oxidative stress was evaluated by lipid peroxidation malondialdehyde assay kit and superoxide dismutase activity assay kit. The interaction between miR-153-3p and circ_0026466 or TRAF6 was confirmed by dual-luciferase reporter assay and RNA pull-down assay. Results: Circ_0026466 and TRAF6 expression were significantly increased, but miR-153-3p was decreased in the blood samples of smokers with COPD and CSE-induced 16HBE cells when compared with controls. CSE treatment inhibited the viability and proliferation of 16HBE cells but induced cell apoptosis, inflammation, and oxidative stress, but these effects were attenuated after circ_0026466 knockdown. Circ_0026466 interacted with miR-153-3p and regulated CSE-caused 16HBE cell damage by targeting miR-153-3p. Additionally, TRAF6, a target gene of miR-153-3p, regulated CSE-induced 16HBE cell injury by combining with miR-153-3p. Importantly, circ_0026466 activated NF-κB pathway by targeting the miR-153-3p/TRAF6 axis. Conclusion: Circ_0026466 absence protected against CSE-triggered 16HBE cell injury by activating the miR-153-3p/TRAF6/NF-κB pathway, providing a potential therapeutic target for COPD.

Wang C ，Tang Y ，Hou H ，Su C ，Gao Y ，Yang X ... -  《-》

Circular RNA 0000157 depletion protects human bronchial epithelioid cells from cigarette smoke extract-induced human bronchial epithelioid cell injury through the microRNA-149-5p/bromodomain containing 4 pathway.

Song B ，Wu S ，Ye L ，Jing Z ，Cao J ... -  《-》

CircRNA circ_0006892 regulates miR-24/PHLPP2 axis to mitigate cigarette smoke extract-induced bronchial epithelial cell injury.

Chronic obstructive pulmonary disease (COPD) is a chronic airway disorder mainly resulted from cigarette smoke exposure. The dysregulated circular RNAs (circRNAs) are relevant to the pathogenesis of COPD. This study aims to explore the function and mechanism of circRNA hsa_circ_0006892 (circ_0006892) in cigarette smoke extract (CSE)-induced bronchial epithelial injury. The lung tissues were collected from 17 nonsmokers and 23 smokers with COPD. The bronchial epithelial cells (BEAS-2B and 16HBE) were stimulated via CSE. Circ_0006892, microRNA-24 (miR-24), and PH domain and leucine-rich repeat protein phosphatase 2 (PHLPP2) abundances were examined via a quantitative reverse transcription polymerase chain reaction or Western blot. Cell viability, apoptosis, and inflammatory response were assessed via cell counting kit-8 (CCK-8), flow cytometry, and enzyme-linked immunosorbent assay (ELISA). The target relationship of miR-24 and circ_0006892 or PHLPP2 was tested via dual-luciferase reporter analysis, RNA immunoprecipitation, and RNA pull-down. Circ_0006892 expression was reduced in lung tissues of smokers with COPD and CSE-stimulated bronchial epithelial cells. Circ_0006892 overexpression alleviated CSE-induced viability reduction and promotion of apoptosis and inflammatory response. MiR-24 was bound via circ_0006892, and miR-24 overexpression reversed the effect of circ_0006892 on CSE-induced injury. PHLPP2 was targeted via miR-24, and miR-24 knockdown mitigated CSE-induced viability reduction and promotion of apoptosis and inflammatory response via regulating PHLPP2. Circ_0006892 could promote PHLPP2 expression via regulating miR-24. Circ_0006892 attenuated CSE-induced bronchial epithelial cell apoptosis and inflammatory response via regulating miR-24/PHLPP2 axis.

Zhang C ，Gu S ，Kang X 《-》