Background: The control of auto-reactive cells is defective in rheumatoid arthritis (RA). Regulatory T (Treg) cells which play a key role in the modulation of immune responses have an impaired function in RA. Foxp3 is a master regulator of Treg cells which its expression is under the tight control of epigenetic mechanisms. In the current study, we analyzed the epigenetic modulation of the Foxp3 Treg-specific demethylated region (TSDR) and Helios gene expression to determine Treg cells alteration in RA patients. Methods: We have recruited 20 newly diagnosed patients with RA and 41 healthy controls in our study. The measurement of Foxp3 and Helios gene expression was performed by the real-time PCR technique and the methylation level of TSDR was analyzed by bisulfite treatment and quantitative methylation-specific PCR (Q-MSP). Results: We found that RA patients had significantly lower level of Foxp3 gene expression and TSDR demethylation compared to healthy subjects (P < 0.001 and P = 0.006, respectively). Inversely, the Helios gene expression was elevated significantly in RA patients group (P = 0.048). We also observed a significant correlation between Foxp3 and Helios gene expression (P = 0.016) as well as a significant correlation between FoxP3 expression and demethylation rate of TSDR (P = 0.010). Conclusion: Our results suggested that both epigenetic modifications and Helios gene expression may have important roles in the pathogenesis of RA through their effects on Foxp3 gene expression.

Aging as an inevitable phenomenon is associated with pervasive changes in physiological functions. There is a relationship between aging and the increase of several chronic diseases. Most age-relat... Graphical abstract Plain language summary Aging as a natural process is associated with variation in physiological functions. One of the hallmarks of aging is epigenetic changes, which are directly involved in the ag...

Background: Interleukin-35 (IL-35) is a member of the IL-12 family of heterodimeric cytokines produced by regulatory T (Treg) cells. This immunosuppressive cytokine can prevent exaggerated inflammatory responses like those responsible for the development of rheumatoid arthritis (RA). This study aims to determine the correlation between the gene expression of Epstein–Barr virus-induced gene 3 (EBI-3) and IL-12A (p35) subunits of IL-35 in peripheral blood leukocytes with immunological and clinical parameters in RA patients. Methods: We recruited 47 patients with RA and 44 healthy subjects. The disease activity score-28 (DAS-28) was assessed by an expert rheumatologist and the plasma levels of neopterin and anti-cyclic citrullinated peptide (anti-CCP) was measured using ELISA method also Serum rheumatoid factor (RF) was assessed by the agglutination test. For the evaluation of IL-12A and EBI-3 gene expression, we used qPCR. Results: We did not find any significant correlation between the gene expression of IL-35 subunits and DAS-28. There was a negative correlation between the plasma levels of neopterin and the gene expression of EBI-3 (p = 0.004). Inversely, we found a positive correlation between plasma level of anti-CCP and neopterin (p < 0.001) also between RF and DAS-28 (p = 0.001). Conclusion: Regarding the significant negative correlation between EBI-3 gene expression and plasma levels of neopterin, it can be concluded that the altered gene expression of EBI-3 may play a role in the pathogenesis of RA.