Analysis of Helios gene expression and Foxp3 TSDR methylation in the newly diagnosed Rheumatoid Arthritis patients

ABSTRACT

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.

KEYWORDS:

• Epigenetic
• Foxp3
• Helios
• methylation
• Rheumatoid arthritis
• TSDR

Acknowledgments

This work was performed in partial fulfillment of the requirements for MSc degree of Parisa Zafari, in the faculty of medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Additional information

Funding

This work was supported by the Kermanshah University of Medical Sciences grant number [94406].

Notes on contributors

Mahdi Taghadosi

Mahdi Taghadosi planned and supervised the study. Parisa Zafari performed the experiments. Kheirollah Yari helped supervise the project. Shayan Mostafaei performed the calculations. Nasrin Iranshahi and Adel Fekri participated in sample preparation and as a rheumatologist. Shirin Assar referred the RA patients for sampling. All authors provided critical feedback and helped shape the research, analysis, and manuscript.