ABSTRACT
Objective To discuss DNA methylation's effect on pathogenesis of pediatric immune thrombocytopenia (ITP)through detecting the expression level of DNA methyltransferases (DNMTs)mRNA in peripheral blood lymphocytes of children with ITP.Methods Two mL peripheral blood was collected from each of 25 children with persistent and chronic ITP and 20 healthy children (the healthy control group)by using aseptic method in the pediatric ward of the First Affiliated Hospital of Xinxiang Medical University from January 2014 to January 2015.First ethylene diamine tetraacetic acid (EDTA) was used as the anticoagulant.Then separate the mononuclear cells,extract RNA and detect expression levels of DNMT1,DNMT3A and DNMT3B mRNA using reverse transcription-polymerase chain reaction (RT-PCR) method.Results (1) The blood platelet (PLT) of children with persistent and chronic ITP was (36.2 ± 19.6) × 109/L,which was obviously lower than the healthy control group(168.8 ±46.8) × 109/L(t =-11.85,P =0.000).(2)The DNMT1 mRNA expression level of children with persistent and chronic ITP was 0.17 ± 0.05,which was obviously lower than the healthy control group (0.27 ± 0.10) (t =-3.912,P =0.001).The DNMT3A mRNA expression level of children with persistent and chronic ITP was 0.20 ± 0.10,which was obviously lower than the healthy control group (0.32 ±0.11) (t =-3.779,P =0.000).The DNMT3B mRNA expression level of children with persistent and chronic ITP was 0.16 ± 0.1 1,which was obviously lower than the healthy control group (0.31 ±0.11) (t =-4.641,P =0.000).(3) There was positive correlation between the expression of DNMT1 and DNMT3B mRNA(r =0.433,P =0.031).There was positive correlation between the expression of DNMT3A and DNMT3B mRNA(r =0.721,P =0.000).Conclusions (1) Children with persistent and chronic ITP have lower expression levels of DNMT1,DNMT3A,DNMT3 B mRNA,which indicates that DNA methylation contributes to the pathogenesis of pediatric persistent and chronic ITP.(2) DNMTs have synergistic effect on DNA methylation of pediatric persistent and chronic ITP.
ABSTRACT
Objective To study the relationship between DNA methylation and pathogenesis of childhood immune thrombocytopenic purpura (ITP) by examining the expression of DNA methyltransferase 1(Dnmt1) and DNA methyltransferase 3a (Dnmt3a) mRNA in peripheral blood lymphocytes of the children with ITP. Methods Expression of Dnmt 1 and Dnmt3a mRNA in the peripheral blood lymphocytes in 36 children with newly diagnosed ITP and 26 healthy children were detected using RT-PCR. Results Dnmt1 mRNA expression in peripheral blood lymphocytes in children diagnosed with ITP was 3.02±0.49, significantly lower than 4.58±0.52 in the control group (t=11.95, P<0.001). Dnmt3a mRNA expression in peripheral blood lymphocytes in children diagnosed with ITP was 1.49±0.44, signiifcantly lower than 2.41±0.32 in the control group (t=9.12, P<0.001). Conclusions Children with newly diagnosed ITP have lower DNA methylation status in peripheral blood lymphocytes as compared to that in healthy children. The DNA methylation may play an important role in the etiology of acute ITP in children.