PAX2持续异常表达在儿童原发性膀胱输尿管反流发生发展中的作用机制与早期诊断的意义

Vesicoureteral reflux is one of the Congenital anomalies of the kidney and urinary tract in children. The mechanism of VUR is complex，has certain genetic tendencies, but most of them cannot be explained by single gene pathogenesis. Some scholars believe that the development of VUR besides genes may be related to environmental factors and epigenetics changes. In the early stage of our study, the expression of PAX2 protein was increased in ureteral epithelial cells of VUR children, and it was associated with PAX2 gene hypomethylation. PAX2 gene plays an important role in the early stage of kidney development, and it shows trace expression in normal kidney after birth. Therefore, this study proposed the hypothesis that “PAX2 gene methylation is involved in the development of VUR and that PAX2 protein can be used as a biomarker for early diagnosis of VUR”. We would like use the PB transposon insertion of VUR mouse model of ROBO2 gene based luciferase reporter technology, detect the transcription factors associated with PAX2 gene methylation and observe the key factor downstream of PAX2 methylation in kidney development; application of Magnetic Nano-Sponges and polyacrylamide gel electrophoresis, to enrich and detect the VUR children with PAX2 protein in urine and evaluate it as a biomarker for early diagnosis of VUR with sensitivity and specificity.

原发性膀胱输尿管反流（VUR）是儿童常见的先天性肾脏和尿路畸形之一。VUR发生机制复杂，具有一定遗传倾向，但多数无法用单基因致病来解释，有学者认为VUR的发生除了基因，可能与环境、表观遗传学也有一定关联。本课题组前期在VUR患儿输尿管上皮细胞中发现PAX2蛋白表达增高，且其与PAX2基因低甲基化相关，而PAX2基因在肾脏早期发育阶段有重要作用，正常肾脏生后痕量表达。故本研究提出“PAX2基因甲基化修饰参与VUR的发生发展且PAX2蛋白可作为VUR早期诊断的生物标志物”的假设。基于PB 转座子插入ROBO2基因构建的VUR小鼠模型，通过荧光素酶报告技术，检测与PAX2基因甲基化修饰相关的转录因子，并观察PAX2甲基化所导致的下游肾脏发育关键因子的改变；应用聚合物磁性纳米凝胶微球与聚丙烯酰胺凝胶电泳技术，富集检测VUR患儿尿液中PAX2蛋白，评价其作为早期诊断VUR生物标记物的特异性与敏感性。

本研究针对PAX2持续异常表达在儿童原发性膀胱输尿管反流发生发展中的作为机制与早期诊断意义进行探索，主要研究成果包括：应用聚合物磁性纳米凝胶电泳技术，富集检测VUR患儿尿液中PAX2蛋白，评价其作为早期诊断VUR生物标志物的特异性和敏感性。明确了PAX2在儿童原发性膀胱输尿管反流中的异常升高可能与甲基化调控相关基因的异常表达有关，并初步探讨了关键作用分子。