c-kit/JAK-STAT信号通路对神经吻合前后大鼠膀胱Cajal细胞形态功能影响的实验研究

Neurogenic bladder (NB) is frequent and complex disease in the clinical urology practice. However, the pathophysiological mechanisms involved are not fully understood. Recently, the role of interstitial cells of Cajal (ICC) on NB has become an important research topic. It has been reported that ICC play a vital role in detrusor involuntary contractions and its function is influenced by the expression and function of c-kit. In preliminary experiments, we found that Cajal cells in the bladder tissue decreased significantly in Sprague-Dawley rats subjected to transection of the L6 spinal nerve. Conversely, Cajal cells partially increased after L6 end-to-side neurorrhaphy to L4. Therefore the pathogenesis of NB is closely related with the status of ICC. Therefore the aim of this research project is to study the influence of changes in c-kit/JAK-STAT signal pathway on the ICC function in NB. This research intends first to establish a rat model of NB by denervation of the L6 nerve and secondly re-establish the bladder innervation by anastomosing the transected L6 to L4. We will observe the variation of detrusor’s function in different rat models by urodynamics and muscle strips test. In addition, focus on the changes of ICC morphology, ultrastructure and JAK-STAT signal pathway before and after L6 transection and anastomosis. Finally, we will observe the influence of changing in c-kit/JAK-STAT signal pathway on the morphology and function of ICC in vitro among different models of NB. This may potentially provide a reference for delaying deterioration and promoting recovery of the bladder function in NB by changing the number of ICC.

神经源性膀胱（NB）临床多见，病变机制不清楚。近年，膀胱Cajal间质细胞（ICC）在NB中的作用研究受到重视。文献报道ICC在糖尿病性NB发病机制中起重要作用，其功能受到其特异性标志物c-kit的影响；c-kit和SCF结合能启动JAK-STAT信号通路。我们预实验发现支配大鼠膀胱的L6脊神经离断后ICC减少、吻合到L4后ICC部分恢复，JAK-STAT信号通路蛋白表达也发生了相应的变化。因此，我们假设NB的发病机制与ICC及c-kit/JAK-STAT信号通路的变化密切相关。本研究拟通过离断L6脊神经和吻合离断的L6到L4分别建立去神经NB模型和神经重建模型。通过尿动力等检查了解逼尿肌功能变化及神经离断前后和神经吻合后膀胱ICC形态和超微结构变化、观察c-kit/JAK-STAT信号通路变化对ICC形态和功能的影响，为临床干预ICC延缓NB膀胱功能恶化和促进膀胱功能恢复提供参考。

神经源性膀胱(NB)临床多见，病变机制不清楚，近年，膀胱Cajal间质细胞（ICC）在其中的作用受到重视。本研究通过离断左侧L6和S1脊神经成功建立神经源性膀胱大鼠模型，然后将L6脊神经远端的残端吻合到L4脊神经的侧面。我们发现，脊神经离断组大鼠术后出现排尿障碍，表现为下腹部饱满，可触及因尿潴留而增大的膀胱，影像尿动力学检查结果示脊神经离断组大鼠逼尿肌无明显收缩，最大膀胱测压容量和膀胱顺应性明显增加，逼尿肌漏尿点压下降；同步影像检查结果显示脊神经离断组大鼠膀胱呈“橄榄球”状，L6/L4脊神经端侧吻合（ECG）可以改善神经源性膀胱形态和功能，同时探讨了FK1706 促进 NB大鼠神经吻合后神经再生及膀胱形态功能的研究，HE染色发现FK1706+ECG大鼠水肿相对较轻。VG染色显示 FK1706+ECG大鼠膀胱纤维化程度较ECG大鼠轻。电刺激FK1706+ECG大鼠的膀胱内压升高大于ECG大鼠。在脊神经离断后，持续对大鼠进行Crede动作排尿长达24周以上发现大鼠膀胱最大容量的变化规律是先增大后缩小。原因是整个膀胱神经离断后变得无张力，逼尿肌先代偿肥大，后萎缩纤维化，我们对这一变化的机制又进行了深入的研究和探讨，发现随着离断时间，膀胱纤维化进行性加重，TGFβ1/Smads信号通路蛋白表达逐渐增加，由此可见神经源性膀胱发生发展的分子机制可能是通过激活纤维化TGFβ1/Smads信号通路。细胞实验部分对大鼠膀胱 ICC 细胞进行分离、鉴定和培养，在培养出的神经离断模型细胞中发现膀胱组织中ICC的超微结构变化，ICC数量减少，SCF / c-kit信号通路的抑制通过抑制JAK / STAT3通路来抑制ICC增殖。此外，抑制SCF / c-kit信号通路削弱了NB模型大鼠中SCF诱导的ICC损伤的减弱。总体而言，我们的数据表明SCF / c-kit信号通路参与了NB中的ICC损伤。在该基金的资助下，完成和在国际国内杂志发表相关论文和著作17篇，同时为了了解正常儿童的排尿规律，给神经源性膀胱的诊断和治疗提供依据 ，进行了婴幼儿把尿训练和尿不湿使用情况的流行病学调查。