Wang Y, Kunit T, Ciotkowska A, Rutz B, Schreiber A, Strittmatter F, Waidelich R, Liu C, Stief C G, Gratzke C, Hennenberg M
Department of Urology, Ludwig Maximilian University, Munich, Germany.
Department of Urology, Zhujiang Hospital, Southern Medical University, Guangzhou, China.
Br J Pharmacol. 2015 Jun;172(11):2905-17. doi: 10.1111/bph.13099. Epub 2015 May 5.
Medical therapy of lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH) targets smooth muscle contraction in the prostate, or prostate growth. However, current therapeutic options are insufficient. Here, we investigated the role of Rac in the control of smooth muscle tone in human prostates and growth of prostate stromal cells.
Experiments were performed using human prostate tissues from radical prostatectomy and cultured stromal cells (WPMY-1). Expression of Rac was examined by Western blot and fluorescence staining. Effects of Rac inhibitors (NSC23766 and EHT1864) on contractility were assessed in the organ bath. The effects of Rac inhibitors were assessed by pull-down, cytotoxicity using a cell counting kit, cytoskeletal organization by phalloidin staining and cell growth using an 5-ethynyl-2'-deoxyuridine assay.
Expression of Rac1-3 was observed in prostate samples from each patient. Immunoreactivity for Rac1-3 was observed in the stroma, where it colocalized with the smooth muscle marker, calponin. NSC23766 and EHT1864 significantly reduced contractions of prostate strips induced by noradrenaline, phenylephrine or electrical field stimulation. NSC23766 and EHT1864 inhibited Rac activity in WPMY-1 cells. Survival of WPMY-1 cells ranged between 64 and 81% after incubation with NSC23766 (50 or 100 μM) or EHT1864 (25 μM) for 24 h. NSC23766 and EHT1864 induced cytoskeletal disorganization in WPMY-1 cells. Both inhibitors impaired the growth of WPMY-1 cells.
Rac may be a link connecting the control of prostate smooth muscle tone with proliferation of smooth muscle cells. Improvements in LUTS suggestive of BPH by Rac inhibitors appears possible.
提示良性前列腺增生（BPH）的下尿路症状（LUTS）的药物治疗靶点是前列腺平滑肌收缩或前列腺生长。然而，目前的治疗选择并不充分。在此，我们研究了Rac在控制人前列腺平滑肌张力和前列腺基质细胞生长中的作用。
使用前列腺癌根治术获取的人前列腺组织和培养的基质细胞（WPMY-1）进行实验。通过蛋白质免疫印迹法和荧光染色检测Rac的表达。在器官浴中评估Rac抑制剂（NSC23766和EHT1864）对收缩性的影响。通过下拉实验、使用细胞计数试剂盒检测细胞毒性、用鬼笔环肽染色检测细胞骨架组织以及使用5-乙炔基-2'-脱氧尿苷检测法评估Rac抑制剂的作用。
在每位患者的前列腺样本中均观察到Rac1-3的表达。在基质中观察到Rac1-3的免疫反应性，其与平滑肌标志物钙调蛋白共定位。NSC23766和EHT1864显著降低了去甲肾上腺素、苯肾上腺素或电场刺激诱导的前列腺条收缩。NSC23766和EHT1864抑制了WPMY-1细胞中的Rac活性。用NSC23766（50或100μM）或EHT1864（25μM）孵育24小时后，WPMY-1细胞的存活率在64%至81%之间。NSC23766和EHT1864诱导WPMY-1细胞中的细胞骨架紊乱。两种抑制剂均损害了WPMY-1细胞的生长。
Rac可能是连接前列腺平滑肌张力控制与平滑肌细胞增殖的一个环节。Rac抑制剂可能改善提示BPH的LUTS。
