Circ-UQCRC2 aggravates lipopolysaccharide-induced injury in human bronchial epithelioid cells via targeting miR-495-3p/MYD88-mediated inflammatory response and oxidative stress

circUQCRC2 promotes asthma progression in children by activating the VEGFA/NF-κB pathway by targeting miR-381-3p

This study targeted to explore circUQCRC2's role and mechanism in childhood asthma. A mouse model of ovalbumin-induced asthma was established to evaluate the effects of circUQCRC2 on childhood asthma in terms of oxidative stress, inflammation, and collagen deposition. The effects of circUQCRC2 on platelet-derived growth factor-BB (PDGF-BB)-induced smooth muscle cells (SMCs) were evaluated, the downstream mRNA of miRNA and its associated pathways were predicted and validated, and their effects on asthmatic mice were evaluated. circUQCRC2 levels were upregulated in bronchoalveolar lavage fluid of asthmatic mice and PDGF-BB-treated SMCs. Depleting circUQCRC2 alleviated tissue damage in asthmatic mice, improved inflammatory levels and oxidative stress in asthmatic mice and PDGF-BB-treated SMC, inhibited malignant proliferation and migration of SMCs, and improved airway remodeling. Mechanistically, circUQCRC2 regulated VEGFA expression through miR-381-3p and activated the NF-κB cascade. circUQCRC2 knockdown inactivated the NF-κB cascade by modulating the miR-381-3p/VEGFA axis. Promoting circUQCRC2 stimulates asthma development by activating the miR-381-3p/VEGFA/NF-κB cascade. Therefore, knocking down circUQCRC2 or overexpressing miR-381-3p offers a new approach to treating childhood asthma.

Reduced Expression of miR-146a Potentiates Intestinal Inflammation following Alcohol and Burn Injury

MicroRNAs (miRNAs) are small noncoding RNA molecules that negatively regulate gene expression. Within the intestinal epithelium, miRNAs play a critical role in gut homeostasis, and aberrant miRNA expression has been implicated in various disorders associated with intestinal inflammation and barrier disruption. In this study, we sought to profile changes in intestinal epithelial cell miRNA expression after alcohol and burn injury and elucidate their impact on inflammation and barrier integrity. Using a mouse model of acute ethanol intoxication and burn injury, we found that small intestinal epithelial cell expression of miR-146a is significantly decreased 1 d following injury. Using in vitro studies, we show that reduced miR-146a promotes intestinal epithelial cell inflammation by promoting p38 MAPK signaling via increased levels of its target TRAF6 (TNFR-associated factor 6). Furthermore, we demonstrate that in vivo miR-146a overexpression significantly inhibits intestinal inflammation 1 d following combined injury and potentially supports intestinal barrier homeostasis. Overall, this study highlights the important impact that miRNA expression can have on intestinal homeostasis and the valuable potential of harnessing aberrant miRNA expression as a therapeutic target to control intestinal inflammation.

Circ_0035292 knockdown alleviates lipopolysaccharide (LPS)-induced WI-38 cell apoptosis and inflammatory injury

BACKGROUND

Circular RNAs have emerged as important regulators in the pathogenesis of human diseases, including infantile pneumonia (IP). In this study, we aimed to explore the effects of circ_0035292 on lipopolysaccharide (LPS)-treated Wistsar Institute (WI)-38 cells.

METHODS

Quantitative real-time polymerase chain reaction and western blot were executed to detect the levels of circ_0035292, microRNA-370-3p (miR-370-3p) and transducin β-like 1X related protein 1 (TBL1XR1). Cell counting kit-8, 5-ethynyl-2'-deoxyuridine, and flow cytometry assessed cell proliferation and apoptosis. Concentrations of inflammatory factors were examined with enzyme linked immunosorbent assay kits. Dual-luciferase reporter assay and RNA immunoprecipitation were adopted to analyze binding between miR-370-3p and circ_0035292 or TBL1XR1.

RESULTS

Circ_0035292 level was increased in IP patients and LPS-triggered WI-38 cells. Circ_0035292 knockdown rescued LPS-mediated WI-38 cell proliferation suppression and WI-38 cell apoptosis and inflammation promotion. Circ_0035292 interacted with miR-370-3p and miR-370-3p directly targeted TBL1XR1. Moreover, miR-370-3p overexpression alleviated LPS-induced WI-38 cell apoptosis and inflammatory injury, which was abrogated via TBL1XR1 upregulation. Circ_0035292 absence inhibited the NF-κB pathway.

CONCLUSION

Knockdown of circ_0035292 rescued LPS-triggered WI-38 cell injury via miR-370-3p/TBL1XR1 axis and NF-κB pathway.

CIRC_0012535 CONTRIBUTES TO LIPOPOLYSACCHARIDE-INDUCED FETAL LUNG FIBROBLAST APOPTOSIS AND INFLAMMATION TO REGULATE INFANTILE PNEUMONIA DEVELOPMENT BY MODULATING THE MIR-338-3P/IL6R SIGNALING

ABSTRACT

Background: Infantile pneumonia is a respiratory infection disease, seriously threatening the life of neonatal patients. Circular RNA (circRNA) dysregulation is reported to be involved in pneumonia pathogenesis. Circ_0012535 was previously displayed to be upregulated in blood samples of patients with community-acquired pneumonia. However, circ_0012535's role in this disorder remains unclear. We thus aim to unveil the functions of circ_0012535 in infantile pneumonia. Methods: Fetal lung fibroblasts (WI38) treated with LPS were used as pneumonia cell models. Expression analysis for circ_0012535, miR-338-3p and IL6R was performed using quantitative real-time polymerase chain reaction. Cell counting kit 88), 5-ethynyl-2'-deoxyuridine, and flow cytometry assays were implemented for cell function detection. The release of inflammatory factors, and superoxide dismutase activity and malonaldehyde content were ascertained using commercial kits. The putative binding between miR-338-3p and circ_0012535 or IL6R was validated by dual-luciferase analysis, RIP analysis, and pull-down analysis. Results: Circ_0012535 was highly expressed in LPS-treated WI38 cells. Knockdown of circ_0012535 recovered LPS-inhibited cell viability and proliferation and attenuated LPS-induced cell apoptosis, cell cycle arrest, inflammation, and oxidative stress. Circ_0012535 bound to miR-338-3p and negatively regulated miR-338-3p expression. Inhibition of miR-338-3p reversed the role of circ_0012535 knockdown, thereby recovering LPS-induced WI38 cell apoptosis and inflammation. MiR-338-3p bound to IL6R 3'UTR, and circ_0012535 shared miR-338-3p binding site with IL6R. IL6R overexpression reversed the role of miR-338-3p, thereby recovering LPS-induced WI38 cell apoptosis and inflammation. Conclusion: Circ_0012535 supported LPS-induced WI38 cell apoptosis and inflammation to promote the progression of infantile pneumonia, and circ_0012535 functioned partly by targeting the miR-338-3p/IL6R signaling.

CIRCULAR RNA CIRC_0099188 CONTRIBUTES TO LPS-INDUCED HPAEpiC CELL INJURY BY TARGETING THE MIR-1236-3P/HMGB3 AXIS

ABSTRACT

Purpose: This study is designed to explore the role and mechanism of circ_0099188 in LPS-engendered HPAEpiC cells. Methods: Circ_0099188, microRNA-1236-3p (miR-1236-3p), and high mobility group box 3 (HMGB3) levels were measured using real-time quantitative polymerase chain reaction. Cell viability and apoptosis were assessed using cell counting kit-8 (CCK-8) and flow cytometry assays. Protein levels of B-cell lymphoma-2 (Bcl-2), Bcl-2 related X protein (Bax), cleaved-caspase 3, cleaved-caspase 9, and HMGB3 were determined using Western blot assay. IL-6, IL-8, IL-1β, and TNF-α levels were analyzed using enzyme-linked immunosorbent assays. After predicting using Circinteractome and Targetscan, the binding between miR-1236-3p and circ_0099188 or HMGB3 was verified using a dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays. Results: Circ_0099188 and HMGB3 were highly expressed, and miR-1236-3p was decreased in LPS-stimulated HPAEpiC cells. Also, the downregulation of circ_0099188 might overturn LPS-triggered HPAEpiC cell proliferation, apoptosis, and inflammatory response. Mechanically, circ_0099188 is able to affect HMGB3 expression by sponging miR-1236-3p. Conclusion: Circ_0099188 knockdown might mitigate LPS-induced HPAEpiC cell injury by targeting the miR-1236-3p/HMGB3 axis, providing an underlying therapeutic strategy for pneumonia treatment.

CircTRHDE knockdown protects WI-38 cells against LPS-induced inflammatory injury

BACKGROUND

Circular RNAs (circRNAs) have been reported to be involved in the progression of infantile pneumonia. Here, we investigated the function of circTRHDE in lipopolysaccharide (LPS)-induced cell inflammatory injury to evaluate its role in infantile pneumonia progression.

METHODS

The circTRHDE, microRNA (miR)-381-3p and TNF-receptor associated factor 3 (TRAF3) expression were detected by quantitative real-time PCR. LPS-induced WI-38 cells were used to construct an inflammatory injury model. Cell viability, inflammation and apoptosis were measured by cell counting kit assay, ELISA assay and flow cytometry. Caspase3 activity, MDA level and SOD activity were analysed to assess cell apoptosis and oxidative stress. Protein levels were determined using western blot analysis. The interaction between miR-381-3p and circTRHDE or TRAF3 was confirmed by dual-luciferase activity assay and RNA pull-down assay.

RESULTS

CircTRHDE had increased expression in infantile pneumonia patients and LPS-induced WI-38 cells. LPS treatment inhibited WI-38 cell viability while promoting inflammation, apoptosis and oxidative stress. However, knockdown of circTRHDE remitted LPS-triggered WI-38 cell injury. CircTRHDE could sponge miR-381-3p to positively regulate TRAF3 expression. MiR-381-3p suppressed LPS-induced WI-38 cell inflammatory injury, and this effect was revoked by TRAF3 overexpression. Also, LPS-induced WI-38 cell inflammatory injury restrained by circTRHDE knockdown also were reversed by miR-318-3p inhibitor or TRAF3 overexpression.

CONCLUSION

Our findings demonstrated that circTRHDE might be a target for infantile pneumonia treatment, which relieved LPS-induced cell inflammatory injury by the regulation of the miR-318-3p/TRAF3 axis.