腺苷酸活化蛋白激酶对膀胱过度活动症逼尿肌细胞缝隙连接蛋白43调控机制的研究

Over active bladder (OAB) is a symptom complex that is characterized by urinary urgency with serious effects on the patients’ physical and mental health and quality of life. An increasing incidence of OAB has been reported in China in the past decades. Currently, there are limited therapeutic options available to eradicate the symptom. .The pathophysiological mechanism remains poorly understood. Gap junctions (GJs) have been extensively investigated and are recognized as one of the key factors influencing OAB. However, the available approaches for modulating Cx43 expression and function in the bladder are still limited. To identify targets that can down-regulate Cx43 expression in the bladder might be an effective treatment of OAB. Given that AMP-activated protein kinase (AMPK) has anti-inflammatory, anti-oxidative, channel-inhibiting properties and regulatory effects on metabolism, we speculate that AMPK might have the potential to regulate Cx43 expression in the bladder and likely bladder activity as well. .In this study, we will establish the OAB mice model through partially bladder outlet obstruction. In vitro, we will detect the effect of AMPK on Cx43 expression and function in primary cultured bladder smooth muscle cell (BSMC) of normal or OAB mice. Further more, we will investigate the possible mechanisms involved in the regulation of Cx43 by AMPK. In vivo study, we will confirm the role of Cx43 in controlling bladder function by comparing the voiding pattern in Cx43+/+ and Cx43+/- normal and OAB mice. Then, the urine biochemistry, bladder pathology, Cx43 expression and distribution, and voiding behavior will be evaluated to explore the potential effect of AMPK on OAB mice..Collectively, our results will indicate a novel mechanism that involved in regulation of BSMC Cx43 expression and function by AMPK. Strategies targeting AMPK might be developed as an effective therapeutic approach for treating OAB.

膀胱过度活动症(OAB)是一种因膀胱逼尿肌功能异常导致的以尿急症状为特征的症候群,严重影响患者生活质量，近年发病上升明显，但目前药物疗效不佳。缝隙连接蛋白43（Cx43）表达及功能的异常与OAB发生关系密切，故针对Cx43进行干预是治疗OAB的方向。鉴于腺苷酸活化蛋白激酶（AMPK）具有抗炎抗氧化、抑制通道活性和调节代谢等多种作用，并基于我们的前期研究基础，推测AMPK很可能参与了调控Cx43表达及功能，进而影响膀胱逼尿肌功能。本课题拟通过观察AMPK对膀胱逼尿肌细胞Cx43表达及功能的影响，并检测膀胱逼尿肌相关功能的变化，来探索AMPK对Cx43可能的调控机制以及对OAB的潜在治疗效果。本研究是我们既往研究上的深入，为针对AMPK及Cx43治疗OAB提供理论基础，有助于筛选特异性药物应用于临床。

膀胱过度活动症(OAB)是一种因膀胱逼尿肌功能异常导致的以尿急症状为特征的症候群,严重影响患者生活质量，近年发病上升明显，但目前药物疗效不佳。缝隙连接蛋白43（Cx43）表达及功能的异常与OAB发生关系密切，故针对Cx43进行干预是治疗OAB的方向。鉴于腺苷酸活化蛋白激酶（AMPK）具有抗炎抗氧化、抑制通道活性和调节代谢等多种作用，并基于我们的前期研究基础，推测AMPK很可能参与了调控Cx43表达及功能，进而影响膀胱逼尿肌功能。我们的研究结果显示AMPK活化后明显抑制了逼尿肌细胞中Cx43蛋白的表达及功能。进一步的机制研究提示AMPK对Cx43 的调节主要是通过抑制CX43转录因子CREB的磷酸化及其伴侣分子CRTC2的表达。此外，在PDGF或者TNFa/IL-b建立的细胞病理模型中，AMPK仍然有效抑制Cx43的表达和功能。通过建立OAB小鼠模型，结果显示AMPK活化后OAB小鼠膀胱中的Cx43表达明显下降，且明显改善小鼠的排尿行为，表现为：排尿次数减少，平均每次排尿量增加即膀胱容量增加。利用Cx43+/+和Cx43+/-小鼠分别建立OAB模型，可见Cx43+/-OAB小鼠排尿行为明显优于Cx43+/+OAB小鼠。我们的研究结果显示AMPK可以通过抑制转录因子CREB活性而下调Cx43表达，从而降低细胞间的兴奋传导，改善逼尿肌不稳定收缩而达到OAB的治疗效果。