Blocking SNHG14 Antagonizes Lipopolysaccharides-Induced Acute Lung Injury via SNHG14/miR-124-3p Axis

Identifying the Interaction Between Tuberculosis and SARS-CoV-2 Infections via Bioinformatics Analysis and Machine Learning

The number of patients with COVID-19 caused by severe acute respiratory syndrome coronavirus 2 is still increasing. In the case of COVID-19 and tuberculosis (TB), the presence of one disease affects the infectious status of the other. Meanwhile, coinfection may result in complications that make treatment more difficult. However, the molecular mechanisms underpinning the interaction between TB and COVID-19 are unclear. Accordingly, transcriptome analysis was used to detect the shared pathways and molecular biomarkers in TB and COVID-19, allowing us to determine the complex relationship between COVID-19 and TB. Two RNA-seq datasets (GSE114192 and GSE163151) from the Gene Expression Omnibus were used to find concerted differentially expressed genes (DEGs) between TB and COVID-19 to identify the common pathogenic mechanisms. A total of 124 common DEGs were detected and used to find shared pathways and drug targets. Several enterprising bioinformatics tools were applied to perform pathway analysis, enrichment analysis and networks analysis. Protein-protein interaction analysis and machine learning was used to identify hub genes (GAS6, OAS3 and PDCD1LG2) and datasets GSE171110, GSE54992 and GSE79362 were used for verification. The mechanism of protein-drug interactions may have reference value in the treatment of coinfection of COVID-19 and TB.

Highly expressed long non-coding RNA SNHG14 activated MSU-induced inflammatory response in acute gout arthritis through targeting miR-223-3p

AIM

According to reports, long non-coding RNAs (lncRNAs) are involved in the regulation of many inflammatory diseases. Here, our main purpose was to ascertain the expression data of lncRNA SNHG14 in acute gouty arthritis (AGA) and to explore its possible mechanism in the regulation of AGA.

METHOD

Reverse transcription quantitative polymerase chain reaction technology was supplied to detect the lncRNA SNHG14 expression. A receiver operating characteristics curve was drawn to estimate the accuracy of lncRNA SNHG14 in AGA diagnosis. An in vitro AGA cell model was constructed by inducing THP-1 cells with monosodium urate (MSU). The concentrations of inflammatory factors such as interleukin-1β, interleukin-6, and tumor necrosis factor-α were measured by enzyme-linked immunosorbent assay. The luciferase reporter gene was used to verify the relationship between lncRNA SNHG14 and miR-223-3p.

RESULTS

In clinical analysis, the levels of serum lncRNA SNHG14 in AGA patients were significantly higher than those in the control group. Abnormally elevated lncRNA SNHG14 has high sensitivity and specificity for AGA diagnosis. In in vitro cell experiments, silencing lncRNA SNHG14 inhibited the inflammatory response of THP-1 cells stimulated by MSU, and the luciferase reporter gene proved that lncRNA SNHG14 could bind to miR-223-3p. In addition, the level of miR-223-3p declined in AGA patients and the AGA cell model. Overexpression of miR-223-3p is helpful to alleviate an MSU-induced inflammatory response.

CONCLUSION

In the AGA cell model, lncRNA SNHG14, as an miR-223-3p sponge, induces a cellular inflammatory response by controlling the level of miR-223-3p, so aggravating the disease progress of AGA.

Molecular Mechanism of Long Noncoding RNA SNHG14 in Osteogenic Differentiation of Bone Marrow-Derived Mesenchymal Stem Cells through the NEDD4L/FOXA2/PCP4 Axis

Bone marrow-derived mesenchymal stem cells (BMSCs) have a superior potential of osteogenic differentiation (OD) and a promising stem cell type to treat bone defects. This study sought to investigate the molecular mechanism of long noncoding RNA small nucleolar RNA host gene 14 (SNHG14) in OD of BMSCs. Western blot analysis or RT-qPCR showed that SNHG14, neural precursor cell expressed developmentally downregulated 4-like (NEDD4L), and Purkinje cell protein 4 (PCP4) were upregulated whereas forkhead box A2 (FOXA2) was declined in OD of BMSCs. RT-qPCR and cell staining showed that SNHG14 downregulation repressed OD of BMSCs, as manifested by reductions in osteopontin and osteocalcin levels, the mineralization degree, and alkaline phosphatase activity. RNA/Co/chromatin immunoprecipitation and dual-luciferase assays and determination of mRNA stability and ubiquitination level showed that SNHG14 bound to human antigen R improves NEDD4L mRNA stability and expression, further promoted FOXA2 ubiquitination to inhibit FOXA2 expression, and then reduced FOXA2 enrichment on the PCP4 promoter to upregulate PCP4 transcription. Functional rescue experiments showed that the overexpression of NEDD4L or PCP4 and knockdown of FOXA2 both attenuated the inhibition of SNHG14 downregulation on OD of BMSCs. Overall, our findings suggested that SNHG14 promoted OD of BMSCs through the NEDD4L/FOXA2/PCP4 axis.

A novel circRNA-SNP may increase susceptibility to silicosis

In this study, we aimed to reveal the association between circRNA-related single nucleotide polymorphisms (SNPs) with the susceptibility of silicosis. To achieve this goal, a silicosis-related GWAS was constructed to select the candidate SNPs, and circBase database was utilized to select the promising SNPs which may locate on circRNAs. In addition, the eQTL analysis between the SNPs and located genes was performed to select the candidate SNPs. Finally, the association between candidate SNPs with the susceptibility of silicosis was validated. As a result, we firstly selected 10,922 SNPs with P < 1 × 10^-3 through the silicosis-related GWAS. Among which, 1,752 SNPs were identified that may locate on 2,660 circRNAs. After the MAF evaluation and the sequences checking, we obtained 94 SNPs and related 105 circRNAs. EQTL analysis indicated that 7 circRNA-SNPs might regulate the expression of located genes. Subsequently, a strong association was found between variant A of rs17115143 and silicosis risk in the validation stage (OR= 1.68, P = 0.032). Combination of the GWAS data and Taqman genotyping data also revealed a strong association between rs17115143 and silicosis risk in both dominant and additive models (dom: OR= 1.96, P = 3.98 × 10^-4; add: OR= 1.40, P = 3.06 × 10^-4). In conclusion, the variant A allele of circRNA-SNP rs17115143 could be a risk factor in the progression of silicosis. And related 6 circRNAs may function as novel biomarkers for the diagnostic of silicosis. Further researches to explore the biological mechanisms of rs17115143 related 6 circRNAs in the regulation of silicosis are warranted.

Role of miR-584-5p in Lipopolysaccharide-Stimulated Human Bronchial Epithelial Cell Inflammation and Apoptosis

Acute lung injury (ALI)/acute respiratory distress syndrome is a common clinical syndrome characterized by respiratory failure. MicroRNAs (miRNAs) are closely related to ALI and acute respiratory distress syndrome. TargetScan software analysis showed that miR-584-5p can bind to the 3' noncoding region of TLR4, which is involved in the occurrence and development of ALI, thereby affecting the inflammatory pathway and inflammation development. Thus, we aimed to determine whether miR-584-5p affects ALI. Human bronchial epithelial (16-HBE) cells were transfected with miR-584-5p mimics or inhibitors and then stimulated with lipopolysaccharide (LPS).The cell viability, apoptosis, release of proinflammatory factors, mTOR, and NF-κB pathway protein expression were evaluated respectively. Mimic584 increased, whereas inhibitor584 decreased, LPS-stimulated inflammation. The protein expression of inflammatory factors was significantly increased in 16-HBE cells in the mimic584 + LPS group and decreased in the inhibitor584 + LPS group. Mimic584 activated mTOR and the NF-κB-related proteins P65 and p-p65, whereas inhibitor584 inactivated the proteins in 16-HBE cells. Overexpression of miR-584 significantly promoted apoptosis in LPS-stimulated 16-HBE cells. There were no differences in the proliferation and cell cycle of LPS-stimulated 16-HBE cells regardless of mimic584 or inhibitor584 transfection. Collectively, we demonstrated that inhibitor584 can alleviate ALI-induced expression of inflammatory factors via mTOR signaling and the NF-κB pathway. In conclusion, we found that inhibitor584 transfection could be a potential therapeutic strategy for ALI.

Knockdown of receptor interacting protein 140 (RIP140) alleviated lipopolysaccharide-induced inflammation, apoptosis and permeability in pulmonary microvascular endothelial cells by regulating C-terminal binding protein 2 (CTBP2)

The main pathological feature of acute lung injury (ALI) is pulmonary edema caused by increased permeability of pulmonary microvascular endothelial cells (PMVECs). LPS was has been confirmed to lead to cell damage and barrier dysfunction in PMVECs. Furthermore, receptor interacting protein 140 (RIP140) was discovered to be increased in LPS-induced human pulmonary microvascular endothelial cells (HPMECs), but the mechanism of RIP140 on LPS-induced HPMECs has not been investigated. In this study, an acute lung injury model was constructed in LPS-induced HPMECs. After RIP140 was downregulated, inflammation, apoptosis and cell permeability levels were detected by RT-qPCR, TUNEL staining and FITC-Dextran, respectively. Western blotting was used to detect the protein levels of related factors. The binding of RIP140 and C-terminal binding protein 2 (CTBP2) was predicted by database and verified by Co-IP. Subsequently, CTBP2 overexpression was transfected into cells and the above experiments were performed again. The results showed that inflammation, apoptosis and permeability levels of LPS-induced HPMECs were remarkably increased compared to the untreated control group. However, these levels were suppressed after RIP140 was silenced compared to the LPS-induced HPMECs group. Notably, the Co-IP study demonstrated that RIP140 and CTBP2 interacted with each other. Moreover, CTBP2 overexpression reversed the inhibitory effects of RIP140 silencing on LPS-induced inflammation, apoptosis and permeability levels in HPMECs. Together, the study found that interference of RIP140 could alleviate LPS-induced inflammation, apoptosis and permeability in HPMECs by regulating CTBP2.

Long Non-Coding RNA MEG8 Suppresses Hypoxia-Induced Excessive Proliferation, Migration and Inflammation of Vascular Smooth Muscle Cells by Regulation of the miR-195-5p/RECK Axis

It has been recognized that rebalancing the abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) helps relieve vascular injury. Presently, we aim to investigate whether long non-coding RNA (lncRNA) maternally expressed 8 (MEG8) plays a role in affecting the excessive proliferation and migration of VSMCs following hypoxia stimulation. A percutaneous transluminal angioplasty balloon dilatation catheter was adopted to establish vascular intimal injury, the levels of MEG8 and miR-195-5p in the carotid artery were tested by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Hypoxia was used to stimulate VSMCs, then the cell counting kit-8 (CCK-8) assay, Transnwell assay, and wound healing assay were conducted to evaluate the proliferation, and migration of VSMCs. The protein levels of RECK (reversion inducing cysteine rich protein with kazal motifs), MMP (matrix metalloproteinase) 3/9/13, COX2 (cytochrome c oxidase subunit II), macrophage inflammatory protein (MIP)-1beta, VCAM-1 (vascular cell adhesion molecule 1), ICAM-1 (intercellular adhesion molecule 1), and HIF-1α (hypoxia inducible factor 1 subunit alpha) were determined by western blot or cellular immunofluorescence. As the data showed, MEG8 was down-regulated in the carotid artery after balloon injury in rats and hypoxia-treated VSMCs, and miR-195-5p was overexpressed. Forced MEG8 overexpression or inhibiting miR-195-5p attenuated hypoxia-promoted cell proliferation and migration of VSMCs. In addition, miR-195-5p up-regulation reversed MEG8-mediated effects. Hypoxia hindered the RECK expression while boosted MMP3/9/13 levels, and the effect was markedly reversed with MEG8 up-regulation or miR-195-5p down-regulation. Mechanistically, MEG8 functioned as a competitive endogenous (ceRNA) by sponging miR-195-5p which targeted RECK. Moreover, the HIF-1α inhibitor PX478 prevented hypoxia-induced proliferation, and migration of VSMCs, upregulated MEG8, and restrained miR-195-5p expression. Overall, lncRNA MEG8 participated in hypoxia-induced excessive proliferation, inflammation and migration of VSMCs through the miR-195-5p/RECK axis.

Transforming Growth Factor-β1 Promotes M1 Alveolar Macrophage Polarization in Acute Lung Injury by Up-Regulating DNMT1 to Mediate the microRNA-124/PELI1/IRF5 Axis

Objective

Macrophages function as key orchestrators in the pathogenesis of acute lung injury (ALI). The current study sets out to investigate the molecular mechanism of transforming growth factor-β (TGFβ1) in the regulation of M1 alveolar macrophage polarization in ALI by modulating DNA methyltransferase 1 (DNMT1), along with the microRNA (miR)-124/Pellino 1 (PELI1)/interferon regulatory factor 5 (IRF5) axis.

Methods

First, ALI mouse models were established, and the proportion of M1 and M2 macrophages in mouse lung tissues was detected using flow cytometry. The targeting relationship between miR-124 and PELI1 was verified with the help of a dual luciferase gene reporter assay. Following TGFβ1 knockdown, RT-qPCR and Western blot assay were performed to analyze the expression patterns of TGFβ1, DNMT1, miR-124, and PELI1 and M1/M2 polarization markers in the lung tissues of ALI mice. Immunofluorescence was further employed to detect nuclear translocation of IRF5 in macrophages.

Results

The polarization of M1 macrophages was found to be positively correlated with the severity of lung injury. TGFβ1, DNMT1, PELI1 were highly expressed, while miR-124 was down-regulated in ALI mice, and IRF5 was primarily distributed in the nucleus. TGFβ1 promoted the polarization of M1 alveolar macrophages by up-regulating DNMT1. Furthermore, DNMT1 down-regulated the expression of miR-124, which led to enhancement of M1 alveolar macrophage polarization. Meanwhile, over-expression of miR-124 inhibited the nuclear translocation of IRF5 and suppressed M1 alveolar macrophage polarization. On the other hand, over-expression of PELI1 reversed the above trends.

Conclusion

Collectively, our findings indicated that TGFβ1 can promote the expression of DNMT1, which down-regulates miR-124 to activate PELI1 and nuclear translocation of IRF5, thereby aggravating ALI in mice.