肌球蛋白Ⅱ同工异构体在增生前列腺组织中的表达及体内外功能的研究

Benign prostatic hyperplasia (BPH) is a common disease in aging male, which is mainly caused by increased prostatic smooth muscle (SM) tone and volume, but the etiology and mechanism are not completely elucidated. Non-muscle myosin II (NMII) isoforms play important roles mediating cell proliferation. And the isoforms of SM myosin II (SMM II) are correlated to SM contractility. But both NM II and SMM II were less studied in BPH. Current study aims to investigate their roles in BPH. Prostate cell lines, animal BPH models and human BPH prostate tissues will be used. The expression of NM II isoforms in prostate will be detected by Western-blot and real-time quantitative RT-PCR, as well as florescence confocal microscope. The relative expression of prostate SMM II isoforms will be determined by competitive RT-PCR. The contractility of BPH SM will be investigated with in vitro organ bath study. It will also be studied whether silencing or overexpression of NMII can inhibit or induce proliferation of prostate cells and whether in vivo intraprostatic injection of ad-shNMMHC-A, B, C or blebbistatin, a selective myosin II inhibitor, can inhibit the development of BPH. Our study will try to explore the novel mechanism of dynamic and static components involving BPH. Meanwhile, current study will provide new targets for BPH therapy.

良性前列腺增生症(BPH)是老年男性常见病，由前列腺平滑肌(SM)张力及体积增加引起,但确切病因及病理机制未完全阐明。非肌肌球蛋白Ⅱ(NMII)参与细胞增殖，SM肌球蛋白Ⅱ(SMMII)同工异构体与SM收缩特性有关，但NMII及SMMII在BPH中的作用研究很少，本研究试图予以阐明。以细胞、BPH鼠模型及患者为研究对象；RT-PCR、Western-blot及Confocal检测NMII同工异构体的表达及定位；竞争性RT-PCR检测SMMII同工异构体的表达；离体组织舒缩实验探讨BPH平滑肌收缩特性；观察沉默或过表达NMII能否抑制或诱导前列腺细胞的增殖，活体注射ad-shNMMHC及肌球蛋白选择性抑制剂Blebbistatin能否抑制BPH的发生。其意义是阐明肌球蛋白II系统在BPH动力因素与静力因素中新的作用机制，为开发治疗BPH的新药物靶点提供理论依据。

良性前列腺增生症(BPH)是老年男性常见病，由前列腺平滑肌(SM)张力及体积增加引起,但确切病因及病理机制未完全阐明。非肌肌球蛋白Ⅱ(NMII)参与细胞增殖，SM肌球蛋白Ⅱ(SMMII)同工异构体与SM收缩特性有关，但NMII及SMMII在BPH中的作用研究很少，本研究试图予以阐明。本研究以前列腺BPH-1细胞、WPMY-1细胞、上皮增生为主的大鼠 BPH 模型、间质增生为主的大鼠 BPH 模型及 BPH 患者前列腺组织为研究对象。RT-PCR、Western-blot及Confocal检测NMII同工异构体的表达及定位；竞争性RT-PCR检测SMMII同工异构体的表达；离体组织舒缩实验探讨BPH平滑肌收缩特性。研究发现在人增生前列腺的间质组分中，SMMHC，NMMHC-A和NMMHC-B的表达比人正常前列腺都有上调，在增生前列腺的上皮组分中，NMMHC-A和NMMHC-B的表达对比人正常前列腺有上调。增生前列腺在PE刺激下的收缩张力较正常前列腺增强，收缩速度更慢，达到最大收缩力的时间更长。此外，Blebbistatin对于增生前列腺舒张作用更强。在BPH-1与WPMY-1细胞系中敲低NMMHC同工异构体后细胞凋亡增加，细胞增殖能力减弱。此外。同时活体实验中看到，Blebbistatin可使上皮增生为主的T-BPH大鼠模型以及间质增生为主的PE-BPH大鼠模型前列腺体积减小。对人体前列腺组织进行临床信息相关性分析，我们发现NMMHC-A的表达量与BPH患者的体积大小及IPSS评分呈正相关，与BPH患者最大尿流率呈负相关；NMMHC-B的表达量与BPH患者的IPSS评分呈负相关；NMMHC-C的表达量与BPH患者前列腺体积大小及残余尿呈正相关；SMMHC的表达量与BPH患者的IPSS评分呈负相关；SM1的相对表达量与BPH患者的IPSS评分呈正相关；SM-A的相对表达量与BPH患者前列腺体积大小，残余尿呈正相关，与患者最大尿流呈负相关；LC17b的相对表达量与BPH患者前列腺体积大小，tPSA，fPSA呈正相关，与患者最大尿流呈负相关。进一步揭示了肌球蛋白II系统在BPH动力因素与静力因素中新的作用机制，为开发治疗BPH的新药物靶点提供理论依据。