人尿源干细胞外泌体影响膀胱输尿管反流发生发展和关键因子ROBO2的探讨

Vesicoureteral reflux (VUR) and other congenital kidney and urinary tract malformation is the leading cause of end-stage renal disease in children..Robo2 influence the UB sprouting position via an effect on the Gdnf expression. Exosomes secreted by human urine-derived stem cells (USCs-Exo) have been shown to reduce smooth muscle and kidny injury in animal models, are immune tolerance. For the first time, we discovered the expression of ROBO2 and GDNF/RET on GDNF pathway in USCs from preterm neonates. Maternal exogenous hUSCs-Exo can be distributed to the urinary system of offspring mice and affect the length of CNDs and the function of ureteral smooth muscle in Robo2-deficient induced reflux mice. However, the molecular mechanism of USCs-Exo on VUR is not clear. Whether USCs-Exo can affect the development of VUR remains unclear. Therefore, in this project, preterm neonates hUSCs-Exo will be extracted and labeled with Dil dye. The pregnant mouse will be given a tail vein injection of hUSCs-Exo. We will trace its expression in the offsoring mouse urinary system and observe its impact on the occurence and prognosis of VUR. We plan to compare the expression level of the key regulatory molecules and speculate the key factor. Furthermore, we will use MicroRNAs and interfering RNAs-mediated reduction in the key factor's expression to confirm its role in the occurrence and prognosis of VUR, and to provide a solid foundation and a potential target for the prevention and treatment of clinical VUR.

膀胱输尿管反流(VUR)等先天性肾脏及尿路畸形是目前儿童终末期肾病的最主要原因。ROBO2介导泌尿发育重要的GDNF通路参与其中。尿源干细胞外泌体(USCs-Exo)可修复平滑肌和肾损伤，有免疫耐受等优势。我们首次发现hUSCs-Exo富集ROBO2和下游GDNF，母体外源性hUSCs-Exo可分布至子代小鼠泌尿系统，并影响Robo2缺陷致反流小鼠CND的长度，可能影响输尿管平滑肌结构功能。然而，USCs-Exo是否及如何影响VUR发生发展尚不清楚。因此，本课题主要通过收集提取早产新生儿hUSCs-Exo并运用Dil染料标记后尾静脉注射孕鼠，示踪并观察能否影响子鼠VUR发生发展。同时通过检测干预前后相关分子表达以探寻其分子机制。进一步调控(质粒转染/si-RNA干预)关键因子表达,确认其在VUR的发生发展中的作用，为临床VUR预防和及早治疗提供夯实的研究基础和全新的参考途径。

膀胱输尿管反流(VUR)等先天性肾脏及尿路畸形是目前儿童终末期肾病的最主要原因。ROBO2介导泌尿发育重要的GDNF通路参与其中。尿源干细胞外泌体(USCs-Exo)可修复平滑肌和肾损伤，有免疫耐受等优势。研究针对尿源干细胞外泌体对膀胱输尿管反流的发生发展的机制和治疗作用，主要研究成果包括：膀胱输尿管反流的发生可能与CND重塑相关，ROBO2PB/PB小鼠在肾脏发育早期的CND重塑过程中存在缺陷。尿源干细胞外泌体可以通过母-胎屏障到达子鼠输尿管芽，尿源干细胞外泌体可在Robo2PB/PB小鼠孕期改善子鼠的CND长度，使其更接近于健康小鼠。Robo2突变引起的VUR/CAKUT的潜在治疗策略应尽早实施以利用关键发育阶段改善患者泌尿系统表型，尿源干细胞外泌体为我们提供了早期干预VUR/CAKUT发生的新的可能。