Comprehensive analyses of long non-coding RNA expression profiles by RNA sequencing and exploration of their potency as biomarkers in psoriatic arthritis patients.

BACKGROUND: The aim of the current study was to investigate the long non-coding RNA (lncRNA) expression profiles in psoriatic arthritis (PSA) patients by RNA sequencing, and to further explore potential biomarkers that were able to predict PSA risk and activity. METHODS: LncRNA and mRNA expression profiles in peripheral blood mononuclear cells (PBMC) of 4 PSA patients and 4 normal controls (NCs) were detected by RNA sequencing, followed by comprehensive bioinformatic analyses. Subsequently, 3 top upregulated and 2 top downregulated lncRNAs were chosen for further validation in 93 PSA patients and 93 NCs by quantitative polymerase chain reaction (qPCR) assay. RESULTS: Totally 76 upregulated and 54 downregulated lncRNAs, as well as 231 upregulated and 102 downregulated mRNAs were discovered in PSA patients compared with NCs. Enrichment analyses revealed that they were mostly associated with nucleosome, extracellular exosome and extracellular matrix, and the top enriched pathways were systemic lupus erythematosus (SLE), alcoholism and viral carcinogenesis. qPCR assay showed that lnc-RP11-701H24.7 and lnc-RNU12 were upregulated in PSA patients compared with NCs, and they could predict PSA risk with high area under curves. Besides, lnc-RP11-701H24.7 was positively associated with ESR, SJC, TJC and pain VAS score while lnc-RNU12 was positively correlated with PASI score, CRP and PGA score, implying that both of them were positively correlated with disease activity. CONCLUSION: Our study facilitates comprehensive understanding of lncRNA expression profiles in PSA pathogenesis, and discovers that lnc-RP11-701H24.7 and lnc-RNU12 might be served as novel biomarkers for PSA risk and activity.

Circulating lnc-ITSN1-2 expression presents a high value in diagnosis of rheumatoid arthritis and correlates with disease activity.

This study was aimed to investigate the correlation of lnc-ITSN1-2, lnc-APOC3-2 and lnc-AL355149.1 expressions in plasma by qPCR with rheumatoid arthritis (RA) risk and disease activity. 30 RA patients and 30 health controls (HC) were enrolled in this study. Plasma sample were collected from RA patients before any treatment carried out and HCs. Top 3 RA related long non-coding RNAs (lncRNAs) (lnc-ITSN1-2, lnc-APOC3-2 and lnc-AL355149.1) were selected by a computational framework prediction. The expression of lnc-ITSN1-2, lnc-APOC3-2 and lnc-AL355149.1 were determined by qPCR method. Age (P=0.350) and gender (P=0.542) were similar between RA patients and HCs. lnc-ITSN1-2 level was extremely increased in RA patients compared with HCs (P<0.001), while both lnc-APOC3-2 and lnc-AL355149.1 expressions were numerically higher in RA patients but with no statistical significance (P=0.152 and P=0.139 respectively). Receiver Operating Characteristic (ROC) curves were performed and we found lnc-ITSN1-2 disclosed a great diagnostic value for RA with area under curve (AUC) 0.898, 95% CI 0.813-0.983, and sensitivity was 90.0% and specificity was 80.0% respectively at the best cut-off point. In addition, plasma lnc-ITSN1-2 level was illuminated to be positively associated with erythrocyte sedimentation rate (ESR) (P=0.049), C-reactive protein (CRP) (P<0.001) and disease activity score in 28 joints (DAS28) (P=0.007). Circulating lnc-ITSN1-2 expression was observed to be a novel and convincing biomarker for RA diagnosis as well as disease management.