| Immune thrombocytopenia(ITP) is a clinically common autoimmune disease characterized by bleeding, which makes up about a third of hemorrhagic diseases. It is characterized by peripheral blood platelet reduction, bone marrow megakaryocyte number increased or normal accompanied by mature obstacles and detected antiplatelet autoantibodies in the body. In recent years, the study found that micro RNAs are widely involved in regulating differentiation and function of the innate immunity and adaptive immune cells, the micro RNAs as gene regulatory role in the pathogenesis of ITP are gradually taken seriously. mi R-155(micro RNA-155) is one of the most main micro RNAs in immune system, it expresses generally higher in the activated immune cells, and is the most important of micro RNAs of the natural immune response and specific immune response. Therefore, this study discusses the two parts, one part is to detect the expression of mi R-155 and the function of CD19+B cells in peripheral blood of the patients with immune thrombocytopenia(ITP), the other part is to investigate the target genes of mi R-155 in ITP.Part 1 The expression of mi R-155 and the function of B lymphocyte in patients with immune thrombocytopeniaObjective: To investigate the relevance between the expression of mi R-155 and the level of CD80?CD86?Ig G?Ig M of CD19+B cells in peripheral blood of the patients with immune thrombocytopenia(ITP), and to explore the role of mi R-155 in pathogenesis of ITP.Methods: A total of 55 ITP patients(30 patients were newly diagnosed, 25 patients were in remission) were collected from December 2014 to October 2015 in our hospital, and 25 healthy controls were enrolled in this study.Then extracted the CD19+B cells by immunomagnetic microbeads. The expression of mi R-155 in CD19+B cells were detected by quantitative real-time PCR. The level of CD19+CD5+B?CD19+CD80+B?CD19+CD86+B?Ig G?Ig M in CD19+B cellls were measured by flow cytometry(FCM). Correlation between mi R-155 and clinical parameters of ITP patients was analysed.Results: 1?The percentage of mi R-155 in CD19+B cells of newly diagnosed ITP patients(4.57±1.03) was significantly higher than that of remitted ITP patients(0.79± 0.13) and controls(1.74 ± 0.32), the remitted ITP patients was lower than controls(all P<0.05).And at the early treatment, the level of mi R-155 of the effective group(3.85±0.71) was lower than the refractory group(6.67±1.05)(P<0.05).2?The percentage of CD19+CD5+B of newly diagnosed ITP patients(8.48%±1.42%) was significantly higher than that of remitted ITP patients(2.33%±0.72%) and controls(1.86%±0.41%)(P<0.05).3?The level of CD19+CD80+B of newly diagnosed ITP patients(31.37%±2.34%) was significantly higher than that of remitted ITP patients(20.80%±2.67%) and controls(15.95%±2.89%)( P<0.05).4?The percentage of Ig G?Ig M in CD19+B cells of newly diagnosed ITP patients(35.20%±6.19%, 26.87%±5.01%) was significantly higher than that of remitted ITP patients(7.51%±1.91%,5.93%±2.23%) and controls(8.23%±0.68%, 8.21%±1.08%)(all P<0.05).5?The expression of mi R-155 in CD19+B cells of ITP patients had positive correlation with CD19+CD5+B cells(r=0.576, P=0.003); and had negative correlation with the PB platelet count(r=-0.402, P=0.002). The level of CD19+CD80+B ? CD19+Ig G+ ?CD19+Ig M+ of newly diagnosed ITP patients had negative correlation with PB platelet count(r=-0.424, r=-0.658, r=-0.526)(P<0.05).Conclusion: mi R-155 is abnormally high expression in peripheral blood B lymphocytes in patients with ITP, which makes the transfer function of CD80 and CD86 as the second signal molecules enhanced, that can lead to abnormal activation of B lymphocytes, and the number of CD19+CD5+B and intracellular antibodies increased, which lead to the immune system disorder, involved in the pathogenesis of ITP. Inhibiting the expression of mi R-155 is expected to become the ITP new therapeutic target.Part 2 the study of the target protein of micro RNA-155 in B lymphocyte in patients with immune thrombocytopeniaObjective: By detecting the expression of SHIP-1 which is the negative regulatory factors of B lymphocytes in patients with immune thrombocytopenia,correlation between SHIP-1 and mi R-155?clinical parameters of ITP patients was analysed. then explore the role of the SHIP-1 in the pathogenesis of ITP.Methods: A total of 55 ITP patients(30 patients were newly diagnosed, 25 patients were in remission) were collected from December 2014 to October 2015 in our hospital, and 25 healthy controls were enrolled in this study.Then extracted the CD19+B cells by immunomagnetic microbeads.The expression of SHIP-1 in CD19+B cells were detected by quantitative real-time PCR and western blot. Correlation between SHIP-1 and clinical parameters of ITP patients was analysed.Results:1?The percentage of SHIP-1 in CD19+B cells of newly diagnosed ITP patients(0.78±0.26) was significantly lower than that of remitted ITP patients(1.91±0.53) and controls(1.69±0.44)(P<0.05).2?Western blot test shows that the SHIP-1protein levels of newly diagnosed ITP patients was significantly lower than that remitted ITP patients and controls. 3?the expression level of SHIP-1 in CD19+B cells of ITP patients had negative correlation with the level of mi R-155(r=-0.445, P=0.014)(P<0.05).Conclusion: The mi R-155 of B lymphocytes in patients with ITP may through keep the SHIP-1 which is the negative regulatory factors of B lymphocytes silent to stimulate the activation of B lymphocyte receptor, and excessive B lymphocyte responses to activate itself, then promote the production of specific antibodies, and all of these processes eventually mediated platelet destruction. Therefore, the over expression of mi R-155 and the lower expression of SHIP-1 may together lead to the dysfunction of immune system. |
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