The Protein Expression Of DNA Methyltransferase In Children With Immune Thrombocytopenia

BackgroundIn Childhood,immune thrombocytopenia(ITP)is the most common hemorrhagic disease.The specific pathogenesis of ITP has not been fully elucidated.At present,it is mainly concerned with cellular immunity and humoral immunity.In recent years,epigenetics has been studied in many aspects,such as autoimmune diseases and tumors,especially in DNA methylation and DNA methyltransferase(DNMT).Studies have shown that abnormal expression of DNA methyltransferase and autoimmune diseases are closely related,but the research on the relationship between DNA methyltransferase and children’s reports are rare in the pathogenesis of ITP.ObjectiveIn this study,we aimed to explore the relationship between the protein levels of DNA methyltransferase(DNMTs)and the pathogenesis of ITP in children by detecting the protein expression levels of DNMTs in serum of newly diagnosed ITP.Methods1.Object of study The inclusion criteria were established by the hematology group of the Chinese Academy of Sciences and the ITP diagnostic and classification criteria established in 2013.We choose hundreds of newly diagnosed ITP children accepted inpatient or outpatient in pediatrics of First Affiliated Hospital of Xinxiang Medical University during the period of May 2015 to May 2016,a total of 60 children with newly diagnosed children were enrolled in the study group and 36 outpatients of the outpatient physical examination were enrolled in the control group.The two groups of children don’t take any folic acid,vitamin B6 and vitamin B12 preparation within 4 weeks.There were no significant difference in age and gender between the study group and control group.2.Detection of protein expression in DNMTs Two mL peripheral blood was collected from the newly diagnosed ITP(experimental group)and healthy children(the healthy control group)by using aseptic method and collect serum,Enzyme—linked immunosorbent assay(ELISA)method was used to measure the protein expressions of DNMTs in peripheral blood.3.Statistical analysis Conduct statistical analysis with SPSS19.0.Measurement data are represented by mean ± standard variation((?)±S);comparison of two sample’s mean is caculated using independent sample t-test method;gender analysis using chi-square test method;We used Pearson statistical software to analysis correlation of DNMTs protein expression,and it indicates significant difference of P<0.05.Results1.The protein expression levels of DNMTs in two groups The protein expression level of DNMT1 in study group was(1.43±0.96)ug/L,and the control group was(2.05±1.24)ug/L.The protein expression of DNMT1 in the study group was significantly lower than that in the control group.There was a significant difference in two groups(t =-2.547,P = 0.013).The protein expression level of DNMT3 a in experiment group was(0.67±0.39)ug/L,and the control group was(1.04±0.58)ug/L.The protein expression of DNMT3 a in the study group was significantly lower than that in the control group.There was a significant difference in two groups(t =-3.692,P = 0.000).The protein expression level of DNMT3 b in experiment group was(0.53±0.39)ug/L,and the control group was(0.73±0.45)ug/L.The experimental group was significantly lower than the control group.There was a significant difference in two groups.2.The protein expression of DNMTs in different ages The protein expression levels of DNMT1,DNMT3 a and DNMT3 b in the study group were no statistically significant difference between the 1 years old group,1 ~ 5 years old group and > 5 years old group(P> 0.05).3.The relationship between the protein expression of DNMTs and sex The protein expression of DNMT1,DNMT3 a and DNMT3 b levels in the male group were(1.62±0.93、0.67±0.39、0.55±0.39)ug/L,and in the femal were(1.19±0.97、0.68±0.38、0.49±0.39)ug/L.There were no significant differences in the expression levels of different genders(F=0.118、0.110、0.001;P = 0.085,0.877,0.576).4.The relationship between the protein expression of DNMTs and PLT Pearson correlation analysis showed that there were no significant correlation between DNMT1,DNMT3 a,DNMT3b levels and platelet levels in children with ITP(r =-0.062、0.161、0.079,P = 0.636、 0.220、 0.549).5.The relationship between the protein expression of DNMTs Pearson correlation analysis showed that there was no correlation between the protein expression of DNMT1 and DNMT3a(r=-0.025;P=0.851).The expression of DNMT1 and DNMT3 b was no correlation(r=-0.057;P=0.665).The protein expression of DNMT3 a and DNMT3 b has a positive correlation(r=0.259,P=0.046).ConclusionsThe protein expression levels of DNMT1,DNMT3 a and DNMT3 b in serum of newly diagnosed children with ITP were significantly decreased,suggesting that the abnormal expression of DNA methyltransferase may be related to the pathogenesis of ITP in children.DNMTs may play a synergistic role in the process of DNA methylation in children with ITP.