MicroRNA Expression Analysis of Centenarians and Rheumatoid Arthritis Patients Reveals a Common Expression Pattern.

Micro-RNA (miRNA) are a family of small non-coding ribonucleic acids that inhibits post-transcriptionally the expression of their target messenger RNA (mRNA). We are interested in studying the involvement of miRNA in longevity and autoimmune diseases. In this study we compared the different expression of seven microRNAs between human plasma healthy controls, plasma samples of centenarians and samples from patients with rheumatoid arthritis. We used the Life Technologies' protocol to quantify seven miRNAs from 62 plasma samples: 20 healthy human controls, 14 centenarians, 28 patients with rheumatoid arthritis. TaqMan MicroRNA assays were used to analyze the expression profiles of miR-125b-5p, miR-425-5p, miR-200b5p, miR-200c-3p, miR-579-3p, miR-212-3p, miR-21-5p and miR-126-3p. The relative expression of mature miRNAs was analyzed using software REST. Our results show that miR-425-5p, miR-21 and miR-212 significantly decreased in centenarians and in patients with rheumatoid arthritis compared with controls. Furthermore in this work we highlight a connection between corticosteroid treatment and miRNAs expression.

Proteomic analysis of human plasma and peripheral blood mononuclear cells in Systemic Lupus Erythematosus patients.

Systemic Lupus Erythematosus (SLE) is a systemic autoimmune disease with a broad spectrum of clinical presentations and incompletely understood pathogenesis. This autoimmune disease is characterized by alterations in both the innate and adaptive immune system that lead to the loss of immunologic tolerance. In autoimmune diseases particularly in SLE, early diagnosis, flare or remission phases can be difficult to identify. Proteomics can help to find new therapeutic targets and it also could help to better understand the cellular mechanisms. The aim of this study was to observe the variations in plasma and Peripheral Blood Mononuclear Cells (PBMCs) proteome in order to increase our knowledge about pathogenesis and to find possible diagnostic markers and/or therapeutic targets for improving diagnosis and treatment. The comparative proteomic analyses showed that several proteins were differentially expressed in the PBMCs from SLE patients. Among these, PRDX2 may be used as candidate biomarker or target protein for further investigations. In plasma, we showed that plasma clusterin levels increased in SLE patients compared to healthy controls, but this increase is not statistically significant. These proteomic results provide suggestions for understanding the molecular mechanisms of SLE, as well as the physiological changes correlated with SLE disease.