Post-transcriptional regulation of gene expression by microRNAs in antibody-mediated rejection

慢性抗体介导的排斥反应（AMR）是肾移植排斥反应的主要原因。然而 尽管它的临床重要性，一个完整的了解如何反应抗体， 补体介导的攻击是由移植肾调节尚未建立。 我们知识上的这种差距至少部分是由于对反应的不完全理解造成的 由肾脏产生，导致基因调节促进或防止损伤。微小RNA（miRNAs） 是一类在转录后调节基因表达的小的非编码RNA。 miRNAs在调节肾损伤中发挥重要作用。然而，对miRNAs在 排斥反应和肾损伤的研究主要基于对总细胞miRNAs的分析， 在疾病期间差异表达。这种方法是有问题的，因为它不提供 这些miRNAs靶向的mRNAs信息。为了解决这个问题，我们问， 有可能在RNA诱导的沉默中分离miRNA和它们靶向的mRNA， 通过分离与RNA结合蛋白（RBP）AGO 2交联的RNA，使用 该方法定义了移植相关肾损伤的第一个miRNA-mRNA相互作用图谱。 这些原理验证研究表明，在miRNA-mRNA靶组中， 定义的miRNAs和它们靶向的mRNA在细胞中经历独特的变化， 损伤途径富集分析表明，RISC复合物中存在的miRNA靶向 编码可能导致损伤的途径中的蛋白质的mRNA。根据这些研究，我们 假设miRNA-mRNA targetome可用于鉴定 有助于AMR。为了验证这一假设，我们将使用临床相关的小鼠模型， 确定AMR的miRNA-mRNA图谱，并使用靶向组阐明的信息， 研究由miRNAs调控的基因通路。我们检查我们的临床相关性， 通过研究人类肾脏移植中是否发生类似的变化来发现。这些研究 将提供独特的见解，推动与AMR相关的病理过程，信息， 可以用来区分AMR与其他类型的损伤，并提供了一个新的资源， 移植和更广泛的科学界。

Chronic antibody-mediated rejection (AMR) is a major cause of renal allograft rejection. Yet despite its clinical importance an integrated understanding of how responses to antibody and complement mediated attack are regulated by the transplanted kidney has not been established. This gap in our knowledge is due at least in part to an incomplete understanding of responses made by the kidney that result in gene regulation promote or prevent injury. MicroRNAs (miRNAs) are a class of small noncoding RNAs that regulate gene expression post-transcriptionally. miRNAs play an important role in regulating renal injury. However, the study of miRNAs in rejection and renal injury has largely been based on analysis of total cellular miRNAs that are differentially expressed during disease. This approach is problematic because it does not provide information on the mRNAs targeted by these miRNAs. To address this issue, we asked whether it is possible to isolate miRNAs and the mRNAs they are targeting in the RNA-Induced Silencing Complex (RISC) by isolating RNAs cross-linked to the RNA Binding Protein (RBP) AGO2. Using this approach we defined the first miRNA-mRNA interaction map for transplant related renal injury. These proof-of-principle studies revealed that within the miRNA-mRNA targetome it is possible to defined miRNAs and the mRNAs they target that undergo unique changes in cells undergoing injury. Pathway enrichment analysis indicated that miRNAs present in the RISC complex target mRNAs encoding proteins in pathways that may contribute to injury. Based on these studies, we hypothesize that the miRNA-mRNA targetome can be used to identify gene pathways that contribute to AMR. To test this hypothesis, we will use a clinically relevant murine model to determine the miRNA-mRNA map for AMR and use information elucidated by the targetome to examine gene pathways under regulation by miRNAs. We examine the clinical relevance of our findings by examining whether similar changes occur in human kidney transplants. These studies will provide unique insight into process that drive pathology associated with AMR, information that could be used to distinguish AMR from other types of injury, and provides a novel resource to the transplantation and wider scientific community.