Role of DNA methylation in transcription of human endogenous retrovirus in the pathogenesis of systemic lupus erythematosus.

OBJECTIVE: We recently reported that transcription of human endogenous retrovirus (HERV) clone 4-1-like sequences is increased in patients with systemic lupus erythematosus (SLE). We therefore investigated the role of DNA methylation in the transcription of this HERV. METHODS: The effect of a demethylating agent, 5-aza-deoxycytidine (5-aza C), on the transcription of HERV clone 4-1 in healthy individuals and patients with SLE was examined using reverse transcriptase-PCR and real-time quantitative PCR. RESULTS: 5-aza C increased clone 4-1-like messenger RNA in healthy controls, but not in patients with SLE. CONCLUSION: Defects of methylation may contribute to the transcription of HERV in patients with SLE and this may be related to the pathogenesis of SLE.