Waldkirch Eginhard S, Uckert Stefan, Langnäse Kristina, Richter Karin, Jonas Udo, Wolf Gerald, Andersson Karl-Erik, Stief Christian G, Hedlund Petter
Hannover Medical School, Department of Urology, 30625 Hannover, Germany.
Eur Urol. 2007 Aug;52(2):495-501. doi: 10.1016/j.eururo.2007.02.004. Epub 2007 Feb 12.
Phosphodiesterase 5 (PDE5) inhibitors improve smooth muscle relaxation and therefore are considered for pharmacotherapy of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). Cyclic guanosine monophosphate (cGMP)-dependent protein kinase-1 (cGKI) has been identified as one of the downstream targets for cGMP. The aim of the present study was to evaluate, by means of immunohistochemistry and Western blot analysis, the expression and localization of cGKI isoforms in relation to smooth muscle alpha-actin and cGMP in the human prostate.
Cryostat sections of tissue segments excised from the transition zone of human prostates from 11 patients (aged 54-68 yr) were incubated with primary antibodies directed against smooth muscle alpha-actin, cGMP, cGKI, cGKIalpha, and cGKIbeta. Visualization of double-labelled immunofluorescent staining was achieved by laser microscopy. Western blot analysis was performed to confirm the expression of cGKI isoforms.
Immunoreactivities specific for cGKI, cGKIalpha, and cGKIbeta were observed in the smooth musculature of the transition zone. Double-staining revealed the colocalization of smooth muscle alpha-actin, cGMP, and cGKI isoforms in smooth muscle cells of the fibromuscular stroma. The expression of cGKI isoforms was confirmed by Western blot analysis.
Our results confirm the presence of cGKI isoforms alpha and beta in the transition zone of human prostate tissue. In addition, the colocalization of alpha-actin, cGMP, and cGKI isoforms provides further evidence for a significant role of the nitric oxide/cGMP pathway in the regulation of smooth muscle contractility in human prostate tissue and therefore could provide additional targets for pharmacotherapy of BPH and LUTS.
磷酸二酯酶5（PDE5）抑制剂可改善平滑肌舒张，因此被考虑用于良性前列腺增生（BPH）和下尿路症状（LUTS）的药物治疗。环磷酸鸟苷（cGMP）依赖性蛋白激酶-1（cGKI）已被确定为cGMP的下游靶点之一。本研究的目的是通过免疫组织化学和蛋白质印迹分析，评估cGKI亚型在人前列腺中与平滑肌α-肌动蛋白和cGMP相关的表达和定位。
从11例患者（年龄54 - 68岁）的人前列腺移行区切除的组织切片在低温恒温器中用针对平滑肌α-肌动蛋白、cGMP、cGKI、cGKIα和cGKIβ的一抗孵育。通过激光显微镜实现双标记免疫荧光染色的可视化。进行蛋白质印迹分析以确认cGKI亚型的表达。
在移行区的平滑肌组织中观察到对cGKI、cGKIα和cGKIβ具有特异性的免疫反应性。双重染色显示平滑肌α-肌动蛋白、cGMP和cGKI亚型在纤维肌性基质的平滑肌细胞中共定位。蛋白质印迹分析证实了cGKI亚型的表达。
我们的结果证实了人前列腺组织移行区中存在cGKI亚型α和β。此外，α-肌动蛋白、cGMP和cGKI亚型的共定位为一氧化氮/cGMP途径在调节人前列腺组织平滑肌收缩性中的重要作用提供了进一步证据，因此可为BPH和LUTS的药物治疗提供额外靶点。
