MicroRNA-497 functions as an inflammatory suppressor via targeting DDX3Y and modulating toll-like receptor 4/NF-κB in cigarette smoke extract-stimulated human bronchial epithelial cells

Knockdown of DDX3Y alleviates ovalbumin-induced allergic rhinitis in mice by regulating NF-κB pathway

Allergic rhinitis (AR), a type of chronic inflammatory disease that exists in the nasal mucosa, significantly impacts the quality of life. DDX3Y gene encodes an RNA helicase belonging to the DEAD-box protein family and is part of the DDX3 subfamily that affects the progression of multiple diseases. However, the specific role and mechanisms of DDX3Y in AR remain unclear. This study investigates the effects of DDX3Y knockdown on ovalbumin (OVA)-induced AR in mice. We found that DDX3Y is highly expressed in the nasal mucosa of AR mice. Knockdown of DDX3Y in OVA-induced AR mice significantly alleviated nasal manifestations, reduced immunoglobulin E and histamine levels, and improved nasal mucosal histopathology. Additionally, knockdown of DDX3Y suppressed secretion of inflammatory factor nuclear factor kappa B (NF-κB) phosphorylation, thereby mitigating local inflammatory responses. These findings suggested that targeting DDX3Y could offer a novel therapeutic strategy for managing AR by modulating the NF-κB pathway.

MicroRNA-497 inhibits inflammation in DSS-induced IBD model mice and lipopolysaccharide-induced RAW264.7 cells via Wnt/β-catenin pathway

BACKGROUND AND AIMS

MicroRNA (miR)-497 is downregulated in several inflammatory diseases, excluding inflammatory bowel disease (IBD). The aim of this study is to evaluate whether miR-497 inhibits gut inflammation both in vivo and in vitro.

METHODS

The 3% dextran sulphate sodium (DSS) was used to induce experimental colitis, while 1 μg/ml lipopolysaccharide (LPS) was for RAW264.7 cell damage.Colitis severity was evaluated by disease activity index (DAI), colon length, histopathologic injury, etc. The nuclear transcription factor NF-κB activity in colon tissues was also estimated by western blot. Then, the quantitative real-time polymerase chain reaction (qRT-PCR) was performed to evaluate the expression levels of miR-497, pro-inflammatory cytokines and chemokines in colon tissues and RAW264.7 cells. Furthermore, the activity of Wnt/β-catenin pathway was determined by western blot and TOP/FOP-flash reporter assays.

RESULTS

The level of miR-497 was reduced in inflamed mucosa from IBD patients, mice with colitis and LPS-treated RAW264.7 cells. miR-497 knockout (miR-497 KO) mice were more susceptible to DSS-induced colitis, with increased inflammatory response, compared with control mice. Furthermore, the overexpression of miR-497 reduced the release of pro-inflammatory cytokines and chemokines in LPS-treated RAW264.7 cells. Finally, we found that miR-497 inhibited inflammation through Wnt/β-catenin pathway both in vitro and in vivo.

CONCLUSION

Our data indicate that miR-497 inhibits inflammation in DSS-induced IBD model mice and LPS-induced RAW264.7 cells by inhibiting the activation of NF-κB pathway and the release of cytokines, indicating that miR-497 plays a key role in the progression of IBD. Thus, therapeutic regulation of miR-497 expression may be beneficial for the treatment of IBD.

Circular RNA_0037128 aggravates high glucose-induced damage in HK-2 cells via regulation of microRNA-497-5p/nuclear factor of activated T cells 5 axis

Circular RNAs (CircRNAs) were reported to play vital roles in the progression of DN. Herein, the action of circular RNA_0037128 (circ_0037128) was investigated in DN. The level of circ_0037128, microRNA-497-5p (miR-497-5p) and nuclear factor of activated T cells 5 (NFAT5) was determined using quantitative real-time polymerase chain reaction (qRT-PCR). The feature of circ_0037128 was tested by RNase R and Actinomycin D treatment assays. Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2ʹ-deoxyuridine (EdU) staining assays were conducted to evaluate the proliferation ability. The relative protein expression was determined via Western blot analysis. Levels of the inflammatory cytokines, like tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6), were assessed by enzyme-linked immunosorbent assay (ELISA). Reactive oxygen species (ROS) production, lactate dehydrogenase (LDH) and superoxide dismutase (SOD) activity were determined by the matched kits. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were conducted for evaluating the correlation between miR-497-5p and circ_0037128 or NFAT5. Circ_0037128 and NFAT5 were enhanced, while miR-497-5p was weakened in kidney tissues of DN patients and high glucose (HG)-cultured HK-2 cells. Circ_0037128 inhibition bated HG-caused inhibition effect on cell proliferation and promotion effects on oxidative stress, inflammation and fibrosis in HK-2 cells. Moreover, circ_0037128 knockdown alleviated HG-caused cell damage via regulating miR-497-5p. In addition, NFAT5 overexpression could reverse the influence of miR-497-5p on HG-induced injury in HK-2 cells. Mechanically, circ_0037128 sponged miR-497-5p to modulate NFAT5. Circ_0037128 downregulation could mitigate HG-stimulated cell damage via regulating the miR-497-5p/NFAT5 axis in HK-2 cells in vitro, providing a possible therapy target for DN.

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

Background

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.

Methods

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.

Results

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.

Conclusion

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.

miR-558 Reduces the Damage of HBE Cells Exposed to Cigarette Smoke Extract by Targeting TNFRSF1A and Inactivating TAK1/MAPK/NF-κB Pathway

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic smoking-related lung disease associated with higher mortality and morbidity. Herein, we attempted to investigate the function of miR-558/TNF Receptor Superfamily Member 1A (TNFRSF1A) in the progression of COPD.

METHODS

GEO database was applied to filtrate the differentially expressed mRNAs and miRNAs. KEGG enrichment was used to select the meaningful pathway related to the differentially expressed genes. TargetScan was used to predict the upstream regulator of TNFRSF1A, which was further affirmed by dual luciferase assay. HBE cells were stimulated by 20 μg/mL cigarette smoke extract (CSE) to mimic the COPD in vitro. The activity, apoptosis and inflammatory factors of HBE cells were evaluated by biological experiments. The levels of proteins related to TAK1/MAPK/NF-κB pathway were measured by Western blot.

RESULTS

TNFRSF1A is found to be highly expressed in COPD samples and enriched in TNF signaling pathway through bioinformatics analysis. miR-558 was verified as an upstream regulator of TNFRSF1A and negatively regulated TNFRSF1A expression. Up-regulation of miR-558 alleviated CSE-induced damage on HBE cells. The alleviative effect of miR-558 mimic on CSE-induced damage was suppressed by TNFRSF1A overexpression. The elevated expression of p-TAK1/p-p38 MAPK/p-NF-κB P65 in CSE condition was suppressed by miR-558 up-regulation. However, the results were reversed by TNFRSF1A overexpression. TAK1 inhibitor blocked the activation of TAK1/MAPK/NF-κB pathway, which was consistent with the results from miR-558 up-regulation.

CONCLUSIONS

Up-regulation of miR-558 relieved the damage of HBE cells-triggered by CSE via reducing TNFRSF1A and inactivating TAK1/MAPK/NF-κB pathway, affording novel molecules for COPD treatment.

Comprehensive Analysis of ceRNA Regulation Network Involved in the Development of Coronary Artery Disease

Background

Coronary artery disease (CAD) is one of the most common causes of sudden death with high morbidity in recent years. This paper is aimed at exploring the early peripheral blood biomarkers of sudden death and providing a new perspective for clinical diagnosis and forensic pathology identification by integrated bioinformatics analysis.

Methods

Two microarray expression profiling datasets (GSE113079 and GSE31568) were downloaded from the Gene Expression Omnibus (GEO) database, and we identified differentially expressed lncRNAs, miRNAs, and mRNAs in CAD. Gene Ontology (GO) and KEGG pathway analyses of DEmRNAs were executed. A protein-protein interaction (PPI) network was constructed, and hub genes were identified. Finally, we constructed a competitive endogenous RNA (ceRNA) regulation network among lncRNAs, miRNAs, and mRNAs. Also, the 5 miRNAs of the ceRNA network were verified by RT-PCR.

Results

In total, 86 DElncRNAs, 148 DEmiRNAs, and 294 DEmRNAs were dysregulated in CAD. We received 12 GO terms and 5 pathways of DEmRNAs. 31 nodes and 78 edges were revealed in the PPI network. The top 10 genes calculated by degree method were identified as hub genes. Moreover, there were a total of 26 DElncRNAs, 5 DEmiRNAs, and 13 DEmRNAs in the ceRNA regulation network. We validated the 5 miRNAs of the ceRNA network by RT-PCR, which were consistent with the results of the microarray.

Conclusions

In this paper, a CAD-specific ceRNA network was successfully constructed, contributing to the understanding of the relationship among lncRNAs, miRNAs, and mRNAs. We identified potential peripheral blood biomarkers in CAD and provided novel insights into the development and progress of CAD.

LncRNA-antisense non-coding RNA in the INK4 locus promotes pyroptosis via miR-497/thioredoxin-interacting protein axis in diabetic nephropathy

AIMS

Diabetic nephropathy (DN) is the most frequent complication of diabetes and causes millions of deaths each year. Finding novel therapy to DN is urgent, which requires a good understanding of the pathogenesis. Aims are to investigate the molecular mechanisms of DN by focusing on ANRIL/miR-497/TXNIP axis.

MAIN METHODS

Kidney tissues were collected from diagnosed DN patients. High glucose (HG) treatment of human renal tubular epithelial cell cells (HK-2) was used as the cell model of DN. qRT-PCR and Western blotting were performed to measure levels of ANRIL, miR-497, TXNIP, IL-1β, IL-18, caspase-1, and NLRP3. LDH leakage and cell viability were determined with commercial LDH activity kit and MTT assay. ELISA was employed to examine secreted IL-1β and IL-18 levels. Flow cytometry was used to examine caspase-1 activity. Dual luciferase assay was performed to validate interactions of ANRIL/miR-497 and miR-497/TXNIP.

KEY FINDINGS

ANRIL and TXNIP were elevated in DN kidney tissues and HG-treated HK-2 cells while miR-497 was reduced. ANRIL bound miR-497 while miR-497 directly targeted TXNIP. Knockdown of ANRIL suppressed HG-induced LDH leakage, TXNIP/NLRP3/caspase-1 activation, and increases of IL-1β and IL-18 secreted levels. miR-497 knockdown or TXNIP overexpression reversed the effects of ANRIL knockdown on LDH leakage and pyroptosis-related signaling. miR-497 mimics inhibited caspase-1-dependent pyroptosis while co-overexpression of TXNIP blocked its effects in HG-treated HK-2 cells.

SIGNIFICANCE

ANRIL promotes pyroptosis and kidney injury in DN via acting as miR-497 sponge to disinhibit TXNIP expression. These results shed light on the mechanisms of DN and provide targets for therapy development.