Investigation On The Circular RNA Expression Pattern Of Peripheral Blood In Lupus Nephritis And Rheumatoid Arthritis

Part 1:Using plasma circRNA 002453 as a novel biomarker in the diagnosis of lupus nephritisBackground:Systemic lupus erythematosus（SLE）is a common but severe autoimmune disease characterized by thepresence of autoantibodies against several self-antigens,which causes serious injury to various organsor systems.Lupus nephritis（LN）is a common and serious complication that is often associated with a poor long-term prognosis;up to 70%of SLE patients are affected of LN and about 10-30%of which will progress to end-stage renal failure（ESRD）,therefore,early diagnosis and treatment can improve the prognosis of LN.Objective:To survey that whether plasma circular RNA could reflect renal damage and be a diagnostic biomarker.Methods:CircRNA microarray was performed to screen differential expressed circRNAs in the plasma of 5 LN,5 SLE without LN and 5 healthy control.qRT-PCR was used to validate the microarray results and to assess the differential expressed circRNAs in 59 SLE（30 LN,29 SLE without LN）,27 healthy control.We also test the expression of circRNA₀02453 in plasma of 26 RA.Spearman correlation analysis was used to evaluate the relationship between the differential expressed circRNA and the clinical variables of LN.Receiver operating characteristic（ROC）curve was calculated to evaluate the diagnostic value.Results:Compared with SLE without LN group,RA group and healthy control group,the expression of circRNA₀02453 was significantly increased in LN group,.We also found that the expression of circRNA₀02453 in SLE group was significantly higher than RA group and healthy control group.Among these LN patients,we detected the expression of circRNA₀02453 was related to both 24-hour proteinuria and rSLEDAI,but unrelated to C3 and C4 and SLEDAI.ROC analysis showed that plasma circRNA₀02453 had an AUC 0.906（95%CI 0.838-0.974,p=0.000）to discriminate individuals with LN from controls（SLE without LN,RA and healthy controls）with a sensitivity 0.900 and specificity 0.841.The biggest Youden index was 0.741,the corresponding cut off was 0.001.Conclusion:Up-regulated circRNA₀02453 in plasma is related to renal damage by lupus nephritis and reflects renal damage,and it may be a novel dianostic biomarker of LN.Part 2:Investigation on the circular RNA expression pattern of peripheral blood mononuclear cells from RA patientsBackground:Circular RNAs,a unique class of endogenous RNAs,are mainly composed of transcripts from the exons and are formed by non-colinear reverse splicing.Compared with traditional linear RNA,circRNAs do not have the free 3’or 5’ends,but form covalently closed continuous loops.This confers resistance to RNase R treatment,allowing circRNAs to maintain stable expression and making them more suitable biomarkers than other types of RNA and making them more suitable biomarkers than other types of RNA.Few reports indicate the correlation between circRNA and RA at present.Objective:To survey that whether the differential expression of circRNA has a diagnostic value for RA in PBMCs.Methods:CircRNA microarray was performed to screen differential expressed circRNAs from 5 RA patients and 5 healthy control.qRT-PCR was used to validate the microarray results and to assess the differential expressed circRNAs in RA synovioblast and knee osteoarthritis（KOA）synovioblast.Spearman correlation test was performed to assess the correlation of circRNAs and clinical variables.Receiver operating characteristic（ROC）curve was calculated to evaluate the diagnostic value.Results:We identified and verified five circRNAs（092516,003524,103047,104871,101873）that were significantly elevated in PBMCs from RA patients.Comparing to KOA synovioblast,the expression of circRNA₁04871 was higher in RA synovioblast.Among these RA patients,we detected no significant correlation between the five circRNAs and the disease severity,including disease activity score（DAS28）,erythrocyte sedimentation rate（ESR）,C-reactive protein（CRP）,and health assessment questionnaire（HAQ）.ROC curve analysis suggested that circRNA₁04871 has significant value of RA diagnosis（AUC=0.833,P<0.001）,followed by circRNA₀03524（AUC=0.683,P=0.020）,circRNA₁01873（AUC=0.676,P=0.026）,and circRNA₁03047（AUC=0.671,P=0.030）.Conclusion:Comparing to healthy controls,the higher expressions of circRNAs（circRNA₁04871,circRNA₀03 5 24,circRNA₁01873 and circRNA₁03047）in PBMCs may be a diagnostic value for RA.