| The clinical study of LncRNA TUG1/miR-145-5p in acute exacerbation of chronic obstructive pulmonary diseaseIntroduction Chronic Obstructive Pulmonary Disease(COPD)is preventable and treatable chronic airway inflammation disease,which is characterized by incomplete reversible airflow limitation and persistent respiratory symptoms.Acute exacerbation of COPD(AECOPD)is characterized by an increase in cough,expectoration and dyspnea which exceeds the usual variation rate and requires a change of medication regimen.Acute exacerbations affect the overall severity of the disease.COPD patients may experience 0.5-3.5 times acute exacerbations per yaaer,the average hospitalization cost was 12,000 yuan,which seriously increases the economic burden.Meanwhile,the lung function of AECOPD patients was significantly reduced,which seriously affects patients' quality of life and increases the risk of death.Respiratory infection is a common cause of AECOPD.About 80 percent of AECOPD patients have clear evidence of viral or bacterial infection,among them 40-60 percent were bacterial infection and about 30-50 percent were virus infection.AECOPD patients complicated with respiratory virus infection have certain regional and ethnic heterogeneity.Rhinovirus is the common pathogen of AECOPD in European countries,while influenza virus is the common pathogens causing AECOPD in Asian countries.Our previous studies have shown that influenza virus is the common pathogen causing AECOPD in China.The severity of AECOPD is mainly assessed according to the clinical symptoms and signs of patients,as well as whether patients complicated with respiratory failure,etc.Laboratory tests,such as blood routine,C-reactive protein,and procalcitonin,play a certain role in the formulation of treatment plans for AECOPD.It should be noted that no specific biomarker can be identified to predict AECOPD at present.Human genomics studies have identified that,there are a large number of non-coding RNAs(ncRNAs)in the gene pool,in addition to protein-coding genes.Long non-coding RNAs(lncRNAs)are a class of RNAs with a length of > 200 nt.These RNAs lack or have no open reading frame,so they do not participate in peptide production and only regulate protein coding at the transcriptional and post-transcriptional levels.The abnormal expression of lncRNAs may be involved in the occurrence and development of a variety of diseases.Due to their special biological characteristics,lncRNAs do not play a direct role in life activities.Existing studies have shown that most lncRNAs mainly play a role by inhibiting the expression of micro RNAs(miRNAs).miRNAs are a class of short noncoding RNAs with several to twenty nucleotides in length,which are widely found in a variety of organisms.Their mechanism of action is mainly to complement and bind to the mRNA of target protein coding genes,and then regulate the expression and function of target protein.There are a variety of abnormally expressed miRNAs in COPD patients,and these abnormally expressed miRNAs can specifically act on the corresponding target proteins and participate in mucus hypersecretion,alveolar wall destruction,lung tissue fibrosis,small airway remodeling and other pathological processes of COPD patients.Taurine upregulated gene 1(TUG1),a lnc RNA associated with chromatin modification complex,was first discovered in the optic nerve fibroblasts of murine animals with a length of 7.1 kb.LncRNATUG1 is not only involved in the proliferation of gastrointestinal and reproductive system tumors,but also closely related to the occurrence of inflammatory bowel disease and systemic lupus erythematosus.By detecting the expression of lncRNAs/miRNAs in COPD and normal lung tissues,it was found that lncRNATUG1 in COPD patients was significantly increased,accompanied by a significant decrease of miR-145-5p.However,there have been few reports on the expression of lncRNATUG1 and miR-145-5p in patients with acute exacerbation of COPD and their correlation with lung function parameters and cellular inflammatory factors in patients with AECOPD.In this study,the peripheral venous blood and lung function parameters of patients with acute exacerbation of COPD,stable COPD patients and normal control group were collected to separate and extract mononuclear lymphocytes from human peripheral venous blood,using ?-actin as internal reference,the relative expression levels of lncRNATUG1 and miR-145-5p in peripheral blood mononuclear cells were detected,and the correlation between them and lung function parameters and serum inflammatory cytokines in patients with AECOPD was analyzed.To provide a new laboratory biomarker for clinical prediction and evaluation of the severity of acute exacerbation of COPD.Objective To observe the expression of lncRNATUG1 and miR-145-5p in peripheral blood monocytes of patients with acute exacerbation of COPD at the clinical level,and the relationship between lncRNATUG1 and miR-145-5p and pulmonary function parameters and related serum inflammatory cytokines in patients with acute exacerbation of COPD.To explore the role of lncRNATUG1 and miR-145-5p in disease assessment in patients with acute exacerbation of COPD.Materials and Methods A total of 180 subjects(including 50 cases of normal control group,50 cases of stable COPD patients,and 80 cases of acute exacerbation of COPD)were collected from January 2018 to December 2019.Demographic characteristics,lung function,peripheral blood serum were collected,peripheral blood mononuclear cells were extracted,and lncRNATUG1 and miR-145-5p in peripheral blood mononuclear cells of the patients were detected.The expression of lncRNATUG1 and miR-145-5p in peripheral blood mononuclear cells of patients with COPD in stable stage,acute exacerbation stage and normal control group were compared,as well as the relationship between lncRNATUG1 and miR-145-5p and lung function parameters and serum inflammatory cytokines in AECOPD patients.Results 1.The relative expression of lncRNATUG1 in AECOPD patients was significantly higher than that of patients with stable COPD and normal control group.2.The relative expression of miR-145-5p in in AECOPD patients was significantly lower than that of patients with stable COPD and normal control group.The relative expression of miR-145-5p in peripheral blood mononuclear cells of patients with stable COPD was significantly lower than that of normal control group.There was a significant negative correlation between the expression of lncRNATUG1 and miR-145-5p in AECOPD patients.3.The relative expression of lncRNATUG1 in AECOPD patients was negatively correlated with FEV1% and FVC,while miR-145-5p was positively correlated with FEV1% and FVC.4.The relative expression of lncRNATUG1 in AECOPD patients was significantly positively correlated with IL-1? and TNF-? in peripheral blood,while miR-145-5p was significantly negatively correlated with IL-1? and TNF-? in peripheral blood.Conclusion The expression of lncRNATUG1 in AECOPD patients is significantly higher than that in stable phase and normal controls,accompanied by a significant decrease of miR-145-5p.There is a significant negative correlation between lncRNATUG1 and miR-145-5p expression in AECOPD patients.The relative expression l of lncRNATUG1 and miR-145-5p in AECOPD patients were significantly correlated with FEV1%,FVC,IL-1? and TNF-?.LncRNATUG1 and miR-145-5p may become novel laboratory biomarkers for predicting and evaluating the severity of AECOPD patients.The influenza A virus H3N2 triggers the hypersusceptibility of airway inflammatory response via activating the lncRNA TUG1/miR-145-5p/NF-?B pathway in COPDBackground Influenza virus is a common pathogen leading to upper respiratory tract infection and the causative factor of acute exacerbation of COPD.Clinical studies have shown that influenza virus is the trigger factor of airway inflammation in the early stage of COPD.Patients with COPD are more prone to influenza virus infection than normal people,and the inflammatory response after infection is significantly more severe than that of normal people.However,the mechanism of the airway inflammatory response of COPD patients to influenza virus and the high sensitivity of airway inflammatory response is still unclear.We aim to explore the molecular mechanism of the airway inflammatory in patients with AECOPD,to provide preventable and treatable strategies of AECOPD for clinicians.Taurine upregulated gene 1(TUG1)was firstly discovered in mouse retinal cells with a length of 7.1Kb.It is a lnc RNA associated with chromatin modification complex and plays an important role in gene regulation.Current clinical study has found that lnc RNA TUG1 play an important role in the development of various diseases,previous studies have compared the expression of lnc RNAs in the lung tissues of chronic obstructive pulmonary disease patients and normal subjects,and the results showed that the expression of lnc RNA TUG1 was significantly higher in the lung tissue of patients with COPD,and inhibition of lnc RNA TUG1 can significantly inhibit the airway remodeling of COPD by reducing the expression of MMP-9.LncRNAs can regulate the protein expressions through a variety of mechanisms.Bioinformatics showed that lnc RNA TUG1 could bind with miR-145-5p,and miR-145-5p could bind with the 3'UTR of NF-?Bp65,which is a classical signaling transcription factor in regulating the inflammatory response.Previous studies have confirmed the role of NF-?B signaling pathway in the inflammatory response of COPD.In combination with the expression of miR-145-5p in COPD and the related researches,we hypothesis that the lnc RNA TUG1 may regulate the airway inflammatory response in patients with AECOPD induced by influenza virus by sponging with miR-145-5p to regulate the NF-?B signaling pathway.Objective To explore the molecular mechanism of lnc RNA TUG1/miR-145-5p/NF-?B signaling pathway to regulate the airway inflammation in patients with AECOPD at the cellular level.Materials and Methods The primary airway epithelial cells of normal and COPD were isolated by enzyme digestion method,and the activation of NF-?B signaling pathway was compared between normal and COPD primary airway epithelial cells after infected with influenza virus H3N2 24 hours,and the relative expressions of lnc RNA TUG1 and miR-145-5p were compared in primary epithelial cells before and after infected with influenza virus H3N2.The expression of LncRNA TUG1 in primary airway epithelial cells of COPD was inhibited by sh RNA,and the effect of inhibition of LncRNA TUG1 on the inflammatory response of primary airway epithelial cells of COPD infected with H3N2 was observed.The primary airway epithelial cells of COPD were then transfected with miR-145-5p mimic to observe the role of miR-145-5p in the airway inflammatory response in AECOPD patients.Rescue assay was performed with miR-145-5p inhibitor and NF-?Bp65 plasmid.And the luciferase reporter gene assay was performed to investigate the molecular correlation of lnc RNA TUG1,miR-145-5p and NF-?Bp65.Results The primary airway epithelial cells of COPD expressed a significantly higher expression of lnc RNA TUG1 than that of normal primary airway epithelial cells,while the expression of miR-145-5p in COPD primary airway epithelial cells was significantly lower than that of normal primary airway epithelial cells.After 24 hours infection with influenza virus H3N2,the expression of lnc RNA TUG1 was significantly increased,accompanied by increased NF-?B signaling pathway and decreased miR-145-5p.The activation time of NF-?B signaling pathway in primary airway epithelial cells of COPD was significantly earlier than that in normal primary airway epithelial cells after infected with H3N2,and the expression levels of TNF-? and IL-1? in primary airway epithelial cells of COPD were also remarkablely increased than that in normal primary airway epithelial cells.Inhibition of lnc RNA TUG1 by sh RNA significantly reduced NF-?B signaling pathway activation after H3N2 infection.The transfection of primary airway epithelial cells with miR-145-5p mimic also significantly inhibited the activation of NF-?B signaling pathway after infected with H3N2.Rescue assay showed that miR-145-5p inhibitor or overexpression of NF-?Bp65 can effectively reverse the airway inflammatory response inhibited by sh RNA in COPD primary airway epithelial cells.Conclusions 1.The activation of NF-?B signaling pathway in primary airway epithelial cells of COPD infected with influenza virus H3N2 was significantly earlier than that in normal primary airway epithelial cells.2.Influenza virus H3N2 infection can significantly increase the expression of lnc RNA TUG1 in primary airway epithelial cells and decrease the expression of miR-145-5p,and inhibition of lnc RNA TUG1 can effectively reduce the inflammatory response of primary airway epithelial cells after H3N2 infection.3.LncRNA TUG1 may regulate the NF-?B signaling pathway by inhibiting miR-145-5p,thereby participating in the early airway inflammatory hypersensitivity response of acute exacerbation of COPD induced by influenza virus. |
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