MicroRNA Expression Profiling And Its Target Gene In Peripheral Blood Of Chronic Renal Allograft Rejection

Uremia is the end-stage outcome of various types of renal disease, kidney transplantation is the best treatment of uremia currently, due to the differences between individual HLA antigens, allograft rejection occurs inevitable.In recent years with the development of surgical techniques and the use of cyclosporine, acute renal allograft rejection were significantly decreased, but chronic rejection remains a serious threat to the survival of the transplanted kidney and by quality of life of persons. The reason for the clinical diagnosis of chronic rejection, there are some problems, biopsy is the the golden standard of chronic rejection, but biopsy is an invasive examination, there are so many complications. Hence, doctors need to find a non-invasive with high-sensitivity and specificity that can detect immune status, bring new ideas for the diagnosis and treatment of chronic rejection.MicroRNA (microRNA, miRNA) is a class of non-coding RNAs,about 20-25 nucleotides in length can regulate gene expression.miRNA play an important role in pathological, apoptosis physiological processes.There were 1/3 genes in our body regulated by miRNA which makes the changes of physiological and miRNA expression closely, different miRNA expression profiles can be found in different disease. It makes miRNA an excellent marker for the disease and can be used as diagnostic or prevention target of diseases.Objective:Filter miRNA that differently expressed in chronic rejection and control group,we hope to find a diagnostic biomarkers for chronic rejection.Methods:Three cases of renal biopsy diagnosis of chronic rejection in recipients of peripheral blood samples for the experimental group, three cases of renal biopsy diagnosis of renal allograft recipients of small lesions in peripheral blood samples for the control group. Total RNA Extraction Kit whole blood total RNA, Affymetrix-miRNA microarray experimental group and control group miRNA expression profiling, screening miRNAs differentially expressed between the two groups, the difference of miRNAs choice for real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) to verify the microarray results. Mirecords database using differentially expressed miRNA target genes predicted that a preliminary analysis of its features.Results:1. The concentration of total RNA in each group were more than 34.9ng/ml, the optical density of 260nm/280nm between 1.8-2.1, showed that RNA does not degradation or polluted.2. miRNA microarray results:there were 34 miRNA significant differently expressed in CR group compared with the NC group(p<0.05), of which 22 down-regulated and 12 up-regulated. miR-4423-3p were up-regulated 7.09 times, miR-3613-5p were down-regulated 0.08 times.3. Real-time PCR results:miR-133a-3p and miR-4423-3p validate the microarray results, quantitative PCR showed miR-133a-3p and miR-4423-3p differentially expressed in CR and NC group.4. About 9003 kinds of target genes were found, these target genes are more distributed in inflammation, angiogenesis,lymphocyte activation, cell proliferation.Conclusions:Chronic rejection has specific miRNA expression profile in peripheral blood and these specific miRNA target genes primarily associated with inflammation, lymphocyte activation, angiogenesis, renal fibrosis. The specific miRNA may become early, noninvasive diagnosis potential bio-marker for chronic rejection after renal transplantation.