The study of DNA methylation status of HTR1A in the peripheral blood lymphocytes and the level of HTR1A mRNA in systemic lupus erythematosus patients

Abstract

Objective To explore the DNA methylation status of the promoter region of HTR1A and the level of HTR1A mRNA in the peripheral blood lymphocytes of 117 systemic lupus erythematosus (SLE) patients and 117 matched healthy controls. Methods Bisulfite modification cloning sequencing was conducted to detect the DNA methylation status of the promoter region of HTR1A. reverse transcription polymerase chain reaction (RT-PCR) was used to test the level of HTR1A mRNA in the peripheral blood lymphocytes. Statistical analyses were performed using Chi-square test and Fisher's exact test. Results The results showed significant hypomethylation of the promoter region of HTR1A in SLE patients compared with the healthy controls (χ2=28.811, P<0.01 for total mC and χ2=16.897, P<0.01 for Person with mC) , especially at site -340 [1.7% (2/117) vs 9.4% (11/117) , χ2=6.597, P<0.05]. The patients also showed a significantly higher HTR1A mRNA level than the controls (43±16 vs 0, t=12.82, P<0.01). Conclusion Our results support the hypothesis that the hypomethylation of the promoter region of HTR1A and overexpression of HTR1A might contribute to SLE. These results also reveal that epigenetic regulation via the serotonin system may contribute to SLE, and reveal the link between the brain and the immune system. Key words: Lupus erythematosus, systemic; Lymphocytes; HTR1A; DNA methylation; RNA, messenger