Multiple time-point assessment of lncRNA MEG3 shows potential to monitor treatment efficacy in rheumatoid arthritis patients

A possible role of lncRNA MEG3 and lncRNA MAFG-AS1 on miRNA 147-b in the pathogenesis of Behcet's disease

Behcet's disease (BD) is a multisystem disease with altered Toll-like receptors (TLRs) on macrophages. Long noncoding RNA Maternally expressed gene 3 (lncRNA MEG3) and lncRNA Musculoaponeurotic fibrosarcoma oncogene family, protein G antisense 1 (MAFG-AS1) are regulators of microRNA (miRNA) 147-b, which is induced upon TLR stimulation. We included fifty BD patients, and fifty age and sex-matched controls. Real-time polymerase chain reaction (PCR) was used to measure the expression levels of serum lncRNA MEG3, lncRNA MAFG-AS1, and miRNA 147-b. LncRNA MEG3 and lncRNA MAFG-AS1 were significantly downregulated while miRNA 147-b was significantly upregulated in the BD patients' serum compared to the controls with p-value <0.001. Receiver operation characteristics (ROC) curve analysis revealed that the three biomarkers can discriminate between BD and control subjects with 76%, 100%, and 70% sensitivity respectively, and 100% specificity for all of them. There was a lower expression level of lnc RNA MEG3 among patients who had new eye involvement in the last month in comparison to those without new eye involvement (p-value=0.017). So, LncRNA MEG3, lncRNA MAFG-AS1, and miRNA147-b are promising diagnostic markers and therapeutic targets for BD patients. LncRNA MEG3 can be used as a predictor for new BD ocular involvement.

Study of lncRNAs expression profile in the response to biological drugs in Psoriatic Arthritis: MEG3 could be a potential genomic biomarker of therapy efficacy

We aimed to identify an expression profile of lncRNAs potentially related to treatment response in Psoriatic arthritis (PsA) patients, to be used as potential genomic biomarkers predictors of drug treatment effectiveness. In addition, we evaluated a possible association between lncRNAs genetic variants and the response to therapy using the clinical parameter of Disease Activity Index. For the expression study, we collected 48 treated PsA patients, monitoring the treatment response for 12 months. We initially used PCR Array and, then, we validated the results with qRT-PCR. We also retrospectively genotyped 163 treated PsA patients. Firstly, we observed a significant difference in the expression level between Responder and non-Responder patients, of 4 lncRNAs in the group of PsA patients treated with TNFi and of 3 lncRNAs in the group of patients treated with IL17i. Then, we confirmed a significant decrease of MEG3 expression in non-Responder patients compared to Responders, also considering separately the single groups of patients treated with TNFi and IL17i. In addition, our results seem to highlight a potential dose-dependent effect of rs941576 (MEG3) variant allele on Disease Activity Index. Our study suggests a possible role of the lncRNA MEG3 in the treatment response to biological drugs.

Biomarkers (mRNAs and non-coding RNAs) for the diagnosis and prognosis of rheumatoid arthritis

In recent years, diagnostic and therapeutic approaches for rheumatoid arthritis (RA) have continued to improve. However, in the advanced stages of the disease, patients are unable to achieve long-term clinical remission and often suffer from systemic multi-organ damage and severe complications. Patients with RA usually have no overt clinical manifestations in the early stages, and by the time a definitive diagnosis is made, the disease is already at an advanced stage. RA is diagnosed clinically and with laboratory tests, including the blood markers C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) and the autoantibodies rheumatoid factor (RF) and anticitrullinated protein antibodies (ACPA). However, the presence of RF and ACPA autoantibodies is associated with aggravated disease, joint damage, and increased mortality, and these autoantibodies have low specificity and sensitivity. The etiology of RA is unknown, with the pathogenesis involving multiple factors and clinical heterogeneity. The early diagnosis, subtype classification, and prognosis of RA remain challenging, and studies to develop minimally invasive or non-invasive biomarkers in the form of biofluid biopsies are becoming more common. Non-coding RNA (ncRNA) molecules are composed of long non-coding RNAs, small nucleolar RNAs, microRNAs, and circular RNAs, which play an essential role in disease onset and progression and can be used in the early diagnosis and prognosis of RA. In this review of the diagnostic and prognostic approaches to RA disease, we provide an overview of the current knowledge on the subject, focusing on recent advances in mRNA-ncRNA as diagnostic and prognostic biomarkers from the biofluid to the tissue level.

LncRNA MEG3 regulates the interplay between Th17 and Treg cells in Behçet's disease and systemic lupus erythematosus

BACKGROUND

Behçet's disease (BD) and systemic lupus erythematosus (SLE) are two autoimmune inflammatory diseases of indefinite etiology. However, up till now, no study has explored the exact regulatory mechanisms of lncRNA maternally expressed gene-3 (MEG3) over the balance between regulatory T-cells (Treg) and T helper-17 (Th17) cells in BD and SLE.

AIM

The current study aimed to investigate the role of lncRNA MEG3 in the interplay between the anti-inflammatory Treg/transcription factor forkhead box P3 (FOXP3) axis versus the pro-inflammatory Th17/retinoic acid orphan receptor-γt (RORγt) axis.

MAIN METHODS

100 subjects, 35 with BD and 35 with SLE in addition to 30 healthy participants were included in the study. Gene expression analysis was performed and ShinyGO database was utilized for in-depth analysis and graphical visualization of the gene ontology (GO) and pathway enrichment analysis for lncRNA and the other target genes.

KEY FINDINGS

The current results demonstrate the upregulation of lncRNA MEG3 in BD but not SLE patients. Moreover, significant differences in RORγt and FOXP3 were found between BD and SLE patients. The present findings linked lncRNA MEG3 to BD activity scores as well as CRP levels. Finally, lncRNA MEG3 showed excellent diagnostic power for BD, in addition to adequate discriminative power that can be used to differentiate between BD and SLE.

SIGNIFICANCE

The current study objectively elucidated a framework for the involvement of Treg/Th17 through transcription factors RORγt and FOXP3, in addition to their links to the downstream cytokines network including TGF-ꞵ, IL-10, IL-17 and IL-23 in BD and SLE pathogenesis and activity.

Functional Interactions Between lncRNAs/circRNAs and miRNAs: Insights Into Rheumatoid Arthritis

Rheumatoid arthritis (RA) is one of the most common autoimmune diseases that affect synovitis, bone, cartilage, and joint. RA leads to bone and cartilage damage and extra-articular disorders. However, the pathogenesis of RA is still unclear, and the lack of effective early diagnosis and treatment causes severe disability, and ultimately, early death. Accumulating evidence revealed that the regulatory network that includes long non-coding RNAs (lncRNAs)/circular RNAs (circRNAs), micro RNAs (miRNAs), and messenger RNAs (mRNA) plays important roles in regulating the pathological and physiological processes in RA. lncRNAs/circRNAs act as the miRNA sponge and competitively bind to miRNA to regulate the expression mRNA in synovial tissue, FLS, and PBMC, participate in the regulation of proliferation, apoptosis, invasion, and inflammatory response. Thereby providing new strategies for its diagnosis and treatment. In this review, we comprehensively summarized the regulatory mechanisms of lncRNA/circRNA-miRNA-mRNA network and the potential roles of non-coding RNAs as biomarkers and therapeutic targets for the diagnosis and treatment of RA.