Background: Systemic lupus erythematosus (SLE) is a chronic relapsing autoimmune disease characterized by production of autoantibodies against a series of nuclear antigens and by chronic inflammation. The etiology of SLE is the result of interactions between genetic, epigenetic, hormonal, and environmental factors. Changes in histone acetylation and methylation contribute to structural chromatin modifications.
Objective: We studied the histone demethylase JHDM1D and histone deacetylases HDAC1, HDAC2, and HDAC3 transcript levels in peripheral blood mononuclear cells (PBMCs) from patients diagnosed with systemic lupus erythematosus (SLE). Furthermore, the association of JHDM1D, HDAC1, HDAC2, and HDAC3 transcript levels with gender, age, and major clinical manifestations were analyzed.
Materials and methods: Real-time quantitative polymerase chain reaction (RQ-PCR) analysis was used to determine JHDM1D, HDAC1, HDAC2, and HDAC3 mRNA expression levels in peripheral blood mononuclear cells (PBMCs) from 30 patients with SLE and 36 healthy controls.
Results: Significantly lower HDAC2 transcript levels (p = 0.006785) and significantly higher JHDM1D (p = 0.0000002) and HDAC1 (p = 0.010581) transcript levels in SLE patients were observed compared with healthy controls. Higher JHDM1D mRNA expression was detected in active SLE patients when compared with inactive patients (p = 0.005). Furthermore, the JHDM1D transcript levels were positively correlated with disease activity (r(s) = 0.368, p = 0.045), while HDAC2 mRNA expression was positively correlated with disease duration (r(s) = 0.502, p = 0.0047).
Conclusion: Our analyses confirmed the importance of epigenetic alterations (histone demethylation and acetylation) in SLE etiology. Moreover, our results suggest that the presence of some clinical manifestations, like hematological disease and anti-Ro antibody, might be associated with the dysregulation of histone demethylase and deacetylases mRNA expression levels.
Keywords: Antigens, nuclear; Epigenesis, genetic; Histone deacetylases; Histone demethylases; Histone modifications.