Expression of DNA methyltransferase mRNA in children with persistent and chronic immune thrombocytopenia

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 ethylenediamine 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±0.11, 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, DNMT3B 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. Key words: Child; Immune thrombocytopenia, persistent, chronic; DNA methyltransferase