ABSTRACT
Objective:To analyse the whole DNA methylation status , expression of DNMT1 and DNA methylation status of DNMT1 promoter from patients with systemic lupus erythematosus ( SLE) .To assess the negative feedback effection of DNA methylation on the expression of DNMT1 in the patients with SLE.Methods:The whole DNA methylation status in T cells from 34 SLE patients and 23 healthy controls was assessed by the specific monoclonal antibodies to 5-methylcytosine (5-mc) and the DNA methylation status of DNMT1 promoter was assessed by the Bisulfite Conversion Kit and sequencing.Real time RT-PCR was applied to analyse DNMT 1 mRNA levels in T cells from the patients and controls.Results: SLE patients had siginificantly whole DNA hypomethylation than controls(P<0.05),and the whole DNA methylation was negative correlated with the SLE-DAI.There was no difference in levels of DNA methylation of DNMT1 promoter between patients and controls ,also no correlation between the levels of DNA methylation of DNMT 1 promoter and DNMT1 mRNA.Conclusion:There was no negative feedback effection of DNA methylation on the expression of DNMT 1 in the patients with SLE.The mechanism of lower expression of DNMT 1 in patients with SLE should be studied further.