Investigation of expression level and methylation pattern in promoter of protein gene survivin in peripheral blood mononuclear cells and relationship between that’s plasma concentration and disease activity in behcat’s patients

Abstract

Backgrounds and purpose: Behcet’s disease (BD) is an acute recurrent multisystem vasculitic disorder with unknown etiology. Immune-regulatory and autoimmunity mechanisms, environmental factors and genetic backgrounds are involved in the pathogenesis of BD. Survivin as a multifunctional protein is a member of inhibitor of apoptosis proteins (IAPs) encoded by BIRC5 gene and critical for proliferation, homeostasis and differentiation of effector and memory lymphocytes. The aim of this study is evaluation of BIRC5 mRNA expression, methylation status of promoter of this gene, and relationship between survivin and phosphorylated survivin in peripheral blood mononuclear cells and plasma of patients and disease activity in Behcet’s disease. Methods: In this study, 45 patients diagnosed with BD and 49 healthy controls were recruited. The expression level of survivin was measured by Quantitative Real-time-PCR. Promoter methylation status of BIRC5 gene was evaluated by methylation-specific PCR technique. Survivin plasma levels were measured using Enzyme-linked immunosorbent assays. Also, western blotting analysis was performed to measure phosphorylated-survivin and survivin levels in PBMCs and plasma of Behcet’s patients. P-value < 0.05 was considered as statistically significant. Results: BIRC5 gene expression significantly increased in BD patients compared with healthy controls (p= 0.001). There was none significant increase, in BIRC5 gene expression between patients within active and inactive BD (p=0.31). The difference between the disease activity and methylation of BIRC5 gene amongst the patients and healthy controls was none significant (p=0.33). No significant differences were observed between plasma survivin levels in the BD patients compared with control group (p=0.15). Plasma phosphorylated survivin levels in having BD patients were also downregulated compared to healthy individuals which was statistically insignificant (p=0.50). There was no association between survivin level and clinical characteristics including arthritis, skin and CNS involvements. Conclusion: Apoptosis has role in pathogenesis of BD. Survivin expression may not serve as a useful biomarker for diagnosis and/or monitoring disease activity in BD.