Expression Levels Of Serum LncRNA HOTAIR In Patients With Rheumatoid Arthritis And Its Clinical Application

Background:Long non-coding RNAs(lncRNAs)are closely related to the occurrence and development of various diseases,and have been found to be abnormally elevated in the serum of many cancer patients and have been demonstrated as a novel biomarker for diagnosisvalue.lncRNAs are present in the synovial tissues,osteoclasts and chondrocytes of patients with rheumatoid arthritis(RA)and are involved in the development of RA.However,no studies have been reported on the expression of IncRNAs in serum and serum exosomes of RA patients.Objective:To study the differential expression of three types of IncRNAs such as HOTAIR in serum and serum exosomes in patients with RA,systemic lupus erythematosus(SLE)and healthy controls,and to analyze the correlation between the expression of lncRNA HOTAIR and disease activity in patients with RA,and to explore serum IncRNA HOTAIR as a diagnostic maker of RA and to provides new laboratory indicators for the judgment of RA and activity monitoring of RA patients.Methords:110serum samples were selected from 50 patients with RA,50 patients with Systemic lupus erythematosus(SLE)and 60 healthy controls.The total RNAs from serum were extracted,and the expressions of IncRNA HOTAIR,XIST and H19 were detected by the method of RT-qPCR.Pearson correlation analysis was used to explore the correlation between disease activity index(DAS28)of RA and the Expression level of HOTAIR.The receiver-operating characteristic(ROC)is used to compare the clinical value of serum HOTAIR for RA prediction.The serum from the same patients and controls were selected,including 40 RA,50 SLE and 60 healthy control serums.The serum exosomes were isolated and purified,and the exosomes were characterized and analyzed by nanoparticle tracing analysis and transmission electron microscopy;The body membrane surface markers CD63 and CD81 quantitatively detect the number of exosomes.RT-qPCR was used to detect the expression levels of HOTAIR,XIST and H19 in exosomes.The correlations between serum IncRNA and exonuclear IncRNA were compared and the potential diagnostic value of exosome HOTAIR was evaluated by ROC curve.Results:Partl:Serum IncRNAs test results.Compared with control groups,the expression level of HOTAIR in RA group is obviously increased(P=0.0005),AUC=0.69 Sensitivity and Specificity are 58%and 78%respectively.Compared with SLE groups,the expression level of HOTAIR in RA group is obviously increased(P=0.004),AUC=0.67 Sensitivity and Specificity are56%and 78%respectivly.There were no any significant differences of XISTbetween RA and control groups and the expression of H19 is too low to deteced.Furthermore,the serum level of HOTAIR has a positive correlation with DAS28 score(P=0.005,r=0.4937)and the serum level of HOTAIR in the higher activity of RA group whose DAS28 score is greater than 5.1 is higher than the activity of RA group whose DAS28 score is greater than 3.2,No significant correlations were found between levels of HOTAIR and other laboratory parameters including rheumatoid factor(RF),anti-cyclic citrullinated peptide autoantibodiesand erythrocyte sedimentation rate(ESR),but the expression of HOTAIR is correlations with CRP(r=0.411,P=0.004).Part2:Serum exosomes lncRNAs detection results.Detection of CD81+ showed that the concentration of exosomes in RA decreased significantly than other groups(P<0.05),CD63 +was no statistical difference between three groups(P>0.05).The three IncRNAs,only lncRNA Hotair levels of serum exosomes in RA were significantly higher than SLE and healthy controls(P=0.0001),the areas under the ROC curve were 0.79 and 0.76,the sensitivity and specificity are 73%,80%and 66%,85%respectivly.In addition,levels of HOTAIR were related to the level of erythrocyte sedimentation rate(ESR)(P=0.008,r=0.481)and no correlations with the Simplified Disease Activity Index score.In addition,there is a correlation between the HOTAIR expression of serum and HOTAIR expression of exosome(P=0.003,r=0.482).Conclutions:Expression level of IncRNA HOTAIR in the serumand exosome of RA patients was significantly higher than healthy donors and SLE patients.HOTAIR is abnormally expressed in the serum of RA patients.Detecting the serum expression level of HOTAIR is helpful for the differential diagnosis of rheumatoid arthritis and the judgment of disease activity.HOTAIR in the serumand exosomeof serum may serve as a novel and valuable biomarker for the diagnosis of RA.