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

CircRNA-associated ceRNA networks (circCeNETs) in chronic obstructive pulmonary disease (COPD)

Chronic obstructive pulmonary disease (COPD), a chronic airway disorder, which is mostly brought on by cigarette smoke extract (CSE), is a leading cause of death which has a high frequency. In COPD patients, smoking cigarette could also trigger the epithelial-mesenchymal transition (EMT) of airway remodeling. One of the most significant elements of environmental contaminants that is linked to pulmonary damage is fine particulate matter (PM2.5). However, the basic processes of lung injury brought on by environmental contaminants and cigarette smoke are poorly understood, particularly the molecular pathways involved in inflammation. For the clinical management of COPD, investigating the molecular process and identifying workable biomarkers will be important. According to newly available research, circular RNAs (circRNAs) are aberrantly produced and serve as important regulators in the pathological processes of COPD. This class of non-coding RNAs (ncRNAs) functions as microRNA (miRNA) sponges to control the levels of gene expression, changing cellular phenotypes and advancing disease. These findings led us to concentrate our attention in this review on new studies about the regulatory mechanism and potential roles of circRNA-associated ceRNA networks (circCeNETs) in COPD.

Tanshinone IIA alleviates IL-1β-induced chondrocyte apoptosis and inflammation by regulating FBXO11 expression

OBJECTIVE

This study explored the pharmacological mechanism of Tanshinone IIA (TAN IIA) in the treatment of Osteoarthritis (OA), which provided a certain reference for further research and clinical application of Tan IIA in OA.

METHODS

CHON-001 cells were stimulated with 10 μg/mL IL-1β for 48 h and treated with 10 μM TAN IIA for 48 h. Cellular viability and apoptosis were evaluated by CCK-8 assay and flow cytometry, and Cleaved caspase-3 was measured by Immunoblot assay and RT-qPCR. TNF-α, IL-6, and iNOS in CHON-001 cells were determined by RT-qPCR and ELISA. To further verify the effect of TAN IIA on OA, a rat model of OA in vivo was established by right anterior cruciate ligament transection. TAN IIA was administered at 50 mg/kg or 150 mg/kg for 7 weeks. The degree of cartilage destruction in OA rats was observed by TUNEL and HE staining. Cleaved caspase-3 and FBXO11 were measured by immunohistochemical staining, RT-qPCR, and Immunoblot. TNF-α, IL-6, and iNOS in chondrocytes of OA rats were detected by ELISA.

RESULTS

IL-1β stimulated CHON-001 cell apoptosis and inflammation, and TAN IIA had anti-apoptosis and anti-inflammatory effects on IL-1β-regulated CHON-001 cells. TAN IIA down-regulated FBXO11 and inhibited PI3K/AKT and NF-κB pathways, thereby alleviating apoptotic and inflammatory reactions in CHON-001 cells under IL-1β treatment. Moreover, TAN IIA treatment improved chondrocyte apoptosis and inflammations in OA rats.

CONCLUSION

TAN IIA inhibits PI3K/Akt and NF-κB pathways by down-regulating FBXO11 expression, alleviates chondrocyte apoptosis and inflammation, and delays the progression of OA.

Antioxidants positively regulate obesity dependent circRNAs - sperm quality - functional axis

Obesity is a pathophysiological condition, dependent on body fat accumulation, that progressively induces systemic oxidative stress/inflammation leading to a set of associated clinical manifestations, including male infertility. CircRNAs, covalently closed RNA molecules, are key regulators of sperm quality. Recently, we have characterized a complete profile of high-fat diet (HFD) spermatic circRNA cargo, predicting paternal circRNA dependent networks (ceRNETs), potentially involved in sperm oxidative stress and motility anomalies. In the current work, using HFD C57BL6/J male mice, orally treated with a mix of bioactive molecules (vitamin C; vitamin B12; vitamin E; selenium-L-methionine; glutathione-GSH) for 4 weeks, a reversion of HFD phenotype was observed. In addition, the functional action of the proposed formulations on circRNA biogenesis was evaluated by assessing the endogenous spermatic FUS-dependent backsplicing machinery and related circRNA cargo. After that, spermatic viability and motility were also analyzed. Paternal ceRNETs, potentially involved in oxidative stress regulation and sperm motility defects, were identified and used to suggest that the beneficial action of the food supplements here conveniently formulated on sperm motility was likely due to the recovery of circRNA profile. Such a hypothesis was, then, verified by an in vitro assay.

Cigarette Smoke-Induced Gastric Cancer Cell Exosomes Affected the Fate of Surrounding Normal Cells via the Circ0000670/Wnt/β-Catenin Axis

Cigarette smoke is a major risk factor for gastric cancer. Exosomes are an important part of intercellular and intra-organ communication systems and can carry circRNA and other components to play a regulatory role in the occurrence and development of gastric cancer. However, it is unclear whether cigarette smoke can affect exosomes and exosomal circRNA to promote the development of gastric cancer. Exosomes secreted by cancer cells promote cancer development by affecting surrounding normal cells. Herein, we aimed to clarify whether the exosomes secreted by cigarette smoke-induced gastric cancer cells can promote the development of gastric cancer by affecting the surrounding gastric mucosal epithelial cells (GES-1). In the present study, we treated gastric cancer cells with cigarette smoke extract for 4 days and demonstrated that cigarette smoke promotes the stemness and EMT of gastric cancer cells and cigarette smoke-induced exosomes promote stemness gene expression, EMT processes and the proliferation of GES-1 cells. We further found that circ0000670 was up-regulated in tissues of gastric cancer patients with smoking history, cigarette smoke-induced gastric cancer cells and their exosomes. Functional assays showed that circ0000670 knockdown inhibited the promoting effects of cigarette smoke-induced exosomes on the stemness and EMT characteristic of GES-1 cells, whereas its overexpression had the opposite effect. In addition, exosomal circ0000670 was found to promote the development of gastric cancer by regulating the Wnt/β-catenin pathway. Our findings indicated that exosomal circ0000670 promotes cigarette smoke-induced gastric cancer development, which might provide a new basis for the treatment of cigarette smoke-related gastric cancer.

RNF113A targeted by miR-197 promotes proliferation and inhibits autophagy via CXCR4/CXCL12/AKT/ERK/Beclin1 axis in cervical cancer

Ring Finger Protein 113 (RNF113A), an ubiquitin E3 ligase, is genetically associated with many biological processes, including proliferation, differentiation, cell death, and neurogenesis. Recently, RNF113A has been found to be an abnormal expression in many diseases, such as X-linked trichothiodystrophy syndrome and esophageal cancer. Here, we explore the potential mechanism of RNF113A in the progression of cervical cancer (CC). In this study, we evaluated the expression level and biological function of RNF113A in CC both in vitro and in vivo by bioinformatic prediction, DIA proteomic analysis, compensation experiment, Co-IP, dual-luciferase reporter assay and nude mouse xenograft to identify the RNF113A-associated autophagy pathways involved with tumorigenesis. Consistent with the prediction from biological information analysis, we found that RNF113A was highly expressed in human CC tissues and cells. In addition, this study illustrated that the high expression of RNF113A dramatically promoted proliferation and suppressed autophagy both in vitro and in vivo. In contrast, low expression of RNF113A enhanced autophagy activities and inhibited tumor growth in CC. We also found that miRNA-197, the level of which (negative correlation with RNF113A) declined in human CC, directly restrained the expression of RNF113A. Mechanistically, proteomic and mechanistic assays uncovered that RNF113A confirmed as the direct downstream target of miR-197, promoted proliferation and restrained autophagy in CC not through direct ubiquitination degradation of autophagy marker Beclin1 but via CXCR4/CXCL12/AKT/ERK/Beclin1 signal transduction axis. In summary, we found a new miR-197/RNF113 A/CXCR4/CXCL12/AKT/ERK/Beclin1 regulation pathway that plays an important part in the survival and progression of CC.

Circular RNA_0003800 exacerbates IL-1β-induced chondrocyte injury via miR-197-3p/SOX5 axis

BACKGROUND

Osteoarthritis (OA) is a serious degenerative disease of articular cartilage, which has a great impact on the quality of life of patients. Circular RNA (circRNA) plays an important role in OA progression. Our study aims to explore the role and mechanism of circ_0003800 in OA.

METHODS

Circ_0003800, microRNA-197-3p (miR-197-3p) and SRY-box transcription factor 5 (SOX5) contents were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Cell Counting Kit-8 (CCK8), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, western blot and enzyme-linked immunosorbent assay (ELISA) were deployed to evaluate cell proliferation, apoptosis, extracellular matrix (ECM) degradation, inflammatory response and oxidative stress. Interaction of miR-197-3p and circ_0003800 or SOX5 was evidenced by dual-luciferase reporter system, RNA immunoprecipitation (RIP) and RNA pull down assays.

RESULTS

OA tissues and model cells had higher abundance of circ_0003800 and SOX5, while miR-197-3p content was lower. Functionally, circ_0003800 knockdown alleviated IL-1β-mediated injury in C28/I2 cells. Mechanistically, circ_0003800 could sponge miR-197-3p, and miR-197-3p could target SOX5. Besides, in-miR-197-3p reversed the suppressive effect of circ_0003800 downregulation on IL-1β-induced C28/I2 cell injury, and SOX5 overexpression could also diminish the inhibitory effect of miR-197-3p on IL-1β-induced C28/I2 cell injury.

CONCLUSION

Circ_0003800 exacerbates IL-1β-induced chondrocyte injury via miR-197-3p/SOX5 axis.

Gastric cancer stem cell-derived exosomes promoted tobacco smoke-triggered development of gastric cancer by inducing the expression of circ670

As one of the most common malignant cancers in the world, gastric cancer is caused by mang factors among which tobacco smoke is an important risk factor. Gastric cancer stem cells (GCSCs) and the derived exosomes play a key role in the occurrence and development of gastric cancer, and exosomal circRNA is considered as a new regulatory factor in the development of gastric cancer. However, it is unclear whether tobacco smoke can affect exosomes and their transport circRNAs to promote the development of gastric cancer. Herein, we provided a new insight into tobacco smoke promoting the progression of gastric cancer. In the present study, we demonstrated that tobacco smoke-induced exosomes promoted the spheroidizing ability, stemness genes expression, and epithelial-mesenchymal transition (EMT) process of GCSCs. We further found that hsa-circRNA-000670 (circ670) was up-regulated in tissues of gastric cancer patients with smoking history, tobacco smoke-induced GCSCs, and their exosomes. Functional assays have shown that circ670 knockdown inhibited the stemness and EMT process of GCSCs, whereas circ670 overexpression appeared to have an opposite effect. Our findings indicated that exosomal circ670 promotes the development of tobacco smoke-induced gastric cancer, which may provide insight into the mechanism of tobacco smoke promoting the progression of gastric cancer.

Construction of a potentially functional lncRNA-miRNA-mRNA network in sepsis by bioinformatics analysis

Objective: Sepsis is a common disease in internal medicine, with a high incidence and dangerous condition. Due to the limited understanding of its pathogenesis, the prognosis is poor. The goal of this project is to screen potential biomarkers for the diagnosis of sepsis and to identify competitive endogenous RNA (ceRNA) networks associated with sepsis.

Methods: The expression profiles of long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and messenger RNAs (mRNAs) were derived from the Gene Expression Omnibus (GEO) dataset. The differentially expressed lncRNAs (DElncRNAs), miRNAs (DEmiRNAs) and mRNAs (DEmRNAs) were screened by bioinformatics analysis. DEmRNAs were analyzed by protein-protein interaction (PPI) network analysis, transcription factor enrichment analysis, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and Gene Set Enrichment Analysis (GSEA). After the prediction of the relevant database, the competitive ceRNA network is built in Cytoscape. The gene-drug interaction was predicted by DGIgb. Finally, quantitative real-time polymerase chain reaction (qRT-PCR) was used to confirm five lncRNAs from the ceRNA network.

Results: Through Venn diagram analysis, we found that 57 DElncRNAs, 6 DEmiRNAs and 317 DEmRNAs expressed abnormally in patients with sepsis. GO analysis and KEGG pathway analysis showed that 789 GO terms and 36 KEGG pathways were enriched. Through intersection analysis and data mining, 5 key KEGG pathways and related core genes were revealed by GSEA. The PPI network consists of 247 nodes and 1,163 edges, and 50 hub genes are screened by the MCODE plug-in. In addition, there are 5 DElncRNAs, 6 DEmiRNAs and 28 DEmRNAs in the ceRNA network. Drug action analysis showed that 7 genes were predicted to be molecular targets of drugs. Five lncRNAs in ceRNA network are verified by qRT-PCR, and the results showed that the relative expression of five lncRNAs was significantly different between sepsis patients and healthy control subjects.

Conclusion: A sepsis-specific ceRNA network has been effectively created, which is helpful to understand the interaction between lncRNAs, miRNAs and mRNAs. We discovered prospective sepsis peripheral blood indicators and proposed potential treatment medicines, providing new insights into the progression and development of sepsis.

Circ_0040929 Serves as Promising Biomarker and Potential Target for Chronic Obstructive Pulmonary Disease

Background

Circular RNAs (circRNAs) can act as essential regulators in many diseases, including chronic obstructive pulmonary disease (COPD). We aimed to explore the role and underlying mechanism of circ_0040929 in COPD.

Methods

A cellular model of COPD was constructed by treating human bronchial epithelial cells (16HBE) with cigarette smoke extract (CSE). The levels of circ_0040929, microRNA-515-5p (miR-515-5p) and insulin-like growth factor-binding protein 3 (IGFBP3) were measured by quantitative real-time PCR. Cell proliferation was assessed by Cell Counting Kit-8 and 5-ethynyl-2'-deoxyuridine assays. Cell apoptosis was evaluated by flow cytometry. Protein expression was measured using Western blot assay. The levels of inflammatory factors and airway remodeling were assayed via enzyme-linked immunosorbent assay. The interaction between miR-515-5p and circ_0040929/IGFBP3 was confirmed by dual-luciferase reporter, RNA pull-down and RNA immunoprecipitation assays. Exosomes were detected using transmission electron microscopy.

Results

Circ_0040929 expression and IGFBP3 expression were upregulated in the serum of smokers (n = 22) compared to non-smokers (n = 22) and more significantly upregulated in the serum of COPD patients (n = 22). However, miR-515-5p expression was decreased in the serum of smokers compared to non-smokers and further reduced in the serum of COPD. Circ_0040929 knockdown attenuated CSE-induced cell injury by increasing proliferation and reducing apoptosis, inflammation, and airway remodeling in 16HBE cells. MiR-515-5p was a direct target of circ_0040929, and miR-515-5p inhibition reversed the effect of circ_0040929 knockdown in CSE-treated 16HBE cells. IGFBP3 was a direct target of miR-515-5p, and miR-515-5p overexpression alleviated CSE-induced cell injury via targeting IGFBP3. Moreover, circ_0040929 regulated IGFBP3 expression by targeting miR-515-5p. Importantly, circ_0040929 was upregulated in serum exosomes from COPD patients.

Conclusion

Circ_0040929 played a promoting role in CSE-induced COPD by regulating miR-515-5p/IGFBP3 axis, suggesting that it might be a novel potential target for COPD treatment.

Knockout of circRNA single stranded interacting protein 1 (circRBMS1) played a protective role in myocardial ischemia-reperfusion injury though inhibition of miR-2355-3p/Mammalian Sterile20-like kinase 1 (MST1) axis

Evidence suggests circRBMS1 regulates mRNA to mediate cell apoptosis, inflammation, and oxidative stress in different diseases. MST1 is reported to be the target and activator of apoptosis-related molecules and signaling pathways. Hence, the present study aims to investigate the role of circ-RBMS1/miR-2355-3p/MST1 in the development of I/R injury. In vitro experiments showed increased circ-RBMS1 and decreased miR-2355-3p in H/R-induced HCMs. CircRBMS1 served as a sponge for miR-2355-3p and miR-2355-3p targeted MST1. Furthermore, knockout of circRBMS1 attenuated cell apoptosis, oxidized stress, and inflammation in H/R-induced HCMs. In vivo experiments indicated circRBMS1 knockdown attenuated cardiac function damage, cell apoptosis, oxidative stress injury and inflammatory response through miR-2355-3p/MST1 axis in mice. In summary, these results demonstrated circRBMS1 played a protective role in myocardial I/R injury though inhibition of miR-2355-3p/MST1 axis. It might provide a new therapeutic target for cardiac I/R injury.

Context-Dependent Regulation of Gene Expression by Non-Canonical Small RNAs

In recent functional genomics studies, a large number of non-coding RNAs have been identified. It has become increasingly apparent that noncoding RNAs are crucial players in a wide range of cellular and physiological functions. They have been shown to modulate gene expression on different levels, including transcription, post-transcriptional processing, and translation. This review aims to highlight the diverse mechanisms of the regulation of gene expression by small noncoding RNAs in different conditions and different types of human cells. For this purpose, various cellular functions of microRNAs (miRNAs), circular RNAs (circRNAs), snoRNA-derived small RNAs (sdRNAs) and tRNA-derived fragments (tRFs) will be exemplified, with particular emphasis on the diversity of their occurrence and on the effects on gene expression in different stress conditions and diseased cell types. The synthesis and effect on gene expression of these noncoding RNAs varies in different cell types and may depend on environmental conditions such as different stresses. Moreover, noncoding RNAs play important roles in many diseases, including cancer, neurodegenerative disorders, and viral infections.

Emerging noncoding RNAs contained in extracellular vesicles: rising stars as biomarkers in lung cancer liquid biopsy

Lung cancer has a high morbidity and mortality rate, and affected patients have a poor prognosis and low survival. The therapeutic approaches for lung cancer treatment, including surgery, radiotherapy, and chemotherapy, are not completely effective, due to late diagnosis. Although the identification of genetic drivers has contributed to the improvement of lung cancer clinical management, the discovery of new diagnostic and prognostic tools remains a critical issue. Liquid biopsy (LB) represents a minimally invasive approach and practical alternative source to investigate tumor-derived alterations and to facilitate the selection of targeted therapies. LB allows for the testing of different analytes such as circulating tumor cells, extracellular vesicles (EVs), tumor-educated platelets, and cell-free nucleic acids including DNAs, RNAs, and noncoding RNAs (ncRNAs). Several regulatory factors control the key cellular oncogenic pathways involved in cancers. ncRNAs have a wide range of regulatory effects in lung cancers. This review focuses on emerging regulatory ncRNAs, freely circulating in body fluids or shuttled by EVs, such as circular-RNAs, small nucleolar-RNAs, small nuclear-RNAs, and piwi-RNAs, as new biomarkers for early detection, prognosis, and monitoring of therapeutic strategy of lung cancer treatment.

Knockdown of circFOXO3 ameliorates cigarette smoke-induced lung injury in mice

Background

Chronic obstructive pulmonary disease (COPD) remains a prevalent chronic airway inflammatory disease. Circular RNAs (circRNAs) are associated with inflammation regulation; therefore, we examined distinct effects of circRNA FOXO3 (circFOXO3) against pneumonic inflammatory processes in COPD.

Methods

We first quantified and localized circFOXO3 in mouse lung epithelial cell line MLE12 by quantitative reverse-transcription PCR and in situ hybridization. Next, circFOXO3 was suppressed by therapeutic administration of circFOXO3 knockdown lentivirus in mice exposed to air or cigarette smoke (CS) for 12 weeks, and several hallmarks of COPD were evaluated.

Results

We noticed that circFOXO3 is upregulated in CS-exposed lungs and cigarette smoke extract (CSE)-treated murine alveolar epithelial cells. Knockdown of circFOXO3 attenuated the release of CXCL1 and IL-6 as well as inflammatory processes in the lungs of CS-exposed mice. In addition, we identified miR-214-3p as a circFOXO3-targeted microRNA. MiR-214-3p overexpression exerted protective effects against pneumonic inflammation after CS exposure. Silencing of circFOXO3 downregulated IKK-β mRNA (miR-214-3p’s target), resulting in the dysfunction of the NF-κB signaling pathway and attenuation of CSE-induced inflammatory-cytokine expression.

Conclusions

Collectively, these findings reveal a crucial function of circFOXO3 in the pathological remodeling related to CS-induced inflammatory processes. Hence, circFOXO3 might be a good target for the treatment of inflammatory disorders similar to CS-induced lung inflammation.