microRNA-101在梗阻性膀胱重塑中的作用及机制研究

Lower urinary tract symptoms (LUTS) still cannot complete relieve after removing the bladder outlet obstruction(BOO). The present studies begin to focus on the bladder dysfunction inducing by bladder remodeling. Tissue hypoxia inducing HIF-1α /LOX and TGF-β/Smads signaling play an important roles in organ remodeling and epithelial-mesenchymal transition (EMT) of a variety of tissues, however, little is known about their roles in urinary bladder remodeling inducing by BOO. We performed the bioinformatics analysis of the expression profiles of mRNA and miRNA in a rat model of BOO. It was found that miR-101b expression was downregulated and LOX, served as one of its target genes, was upregulated over different time of obstruction. In addition, we further confirm that miR-101 expression was down regulated in the bladder tissue of BOO rat model. So we put forward the hypothesis that miR-101 played an important role in moderating the bladder wall remodeling induced by BOO. We collect the vein blood of BOO patients and carry on testing the expression level of miR-101, and analyze the relationship among miR-101 expression level, degree of BOO. Additionally, we perform primary bladder cells culture and construct the BOO rat model. In order to explore the role of miR-101 in the bladder wall remodeling, we will perform situ hybridization, transfection of adenovirus vector and so on. In the molecular, cellular, tissue and whole animal levels, it is conformed that miR-101 regulated HIF-1/LOX and TGF-β/Smads signaling in bladder remodeling. This study will lay the foundation on the bladder remodeling induced by hypoxia. We provide new ideas for the treatment of bladder dysfunction secondary to BOO.

许多膀胱出口梗阻（BOO）患者在解除梗阻后下尿路症状依然严重。对此，目前研究开始集中于膀胱重塑后的功能紊乱。组织低氧激活的低氧诱导因子-1/赖氨酰氧化酶（HIF-1/LOX）及TGF-β/Smads信号通路在低氧介导的多种组织上皮间质转化（EMT）、器官重塑中发挥作用，但在BOO后EMT、膀胱重塑中的作用不清。我们的生物信息学分析及BOO模型证实miR-101b在BOO膀胱组织中下调，而其靶基因LOX表达上调，提示miR-101在膀胱重塑过程中发挥重要抑制作用。本研究拟通过检测BOO患者血浆miR-101水平与BOO程度作相关性分析，在原代细胞及BOO大鼠模型两个层面，采用原位杂交、重组腺病毒转染等方法，多层次探讨miR-101对HIF-1/LOX、TGF-β/Smads等纤维化信号通路的调控机制，明确其对膀胱壁重塑的抑制作用，为阐明膀胱重塑的发生机制奠定科学依据，为BOO治疗提供新思路。

膀胱出口梗阻（BOO,bladder outlet obstruction）是泌尿系统常见的一类疾病，最常见的原因是前列腺增生，随着我国老龄化人口日益增多，前列腺增生患者也越来越多，这给我国的卫生健康事业带来的负担也越来越重。此类患者往往伴有下尿路症状，即使梗阻解除，许多患者下尿路症状依然存在，严重影响生活质量。有研究发现这与BOO引起的膀胱结构和功能变化具有密切关系，但具体机制仍有待研究。. 本课题通过构建BOO动物模型及体外膀胱平滑肌细胞培养主要对以下几个方面进行了研究：1.MicroRNA101在BOO引起的膀胱重塑中的作用及机制研究，2.ALK4在BOO引起的膀胱重塑中的作用及机制研究，3.低氧在BOO引起的膀胱上皮EMT中的作用及机制研究。结果发现：1. 低氧可以促进膀胱平滑肌发生纤维化改变，在BOO引起的膀胱重塑中具有重要作用，MicroRNA101在BOO 6W后的膀胱中表达升高，通过作用于TGFβR1进而抑制低氧诱导的膀胱平滑肌细胞纤维化转变；2.ALK4在BOO6W后的膀胱中表达水平明显升高，与野生型小鼠相比，ALK4+/-小鼠在BOO6W时的纤维化程度明显下降，其主要通过smad2/3信号通路调节BOO引起的膀胱纤维化；3.BOO后的膀胱上皮发生明显的EMT改变，而低氧可能是引起其EMT改变的重要因素。本研究阐述了BOO引起膀胱重塑性改变的关键分子及新机制，为梗阻性膀胱疾病的治疗提供了潜在新靶点，也为临床诊治工作提供一个新思路。