The James Buchanan Brady Urological Institute, Department of Urology, The Johns Hopkins School of Medicine, Baltimore, MD, USA.
J Sex Med. 2014 Feb;11(2):424-30. doi: 10.1111/jsm.12391. Epub 2013 Nov 20.
Sickle cell disease (SCD)-associated vasculopathy in the penis is characterized by aberrant nitric oxide and phosphodiesterase (PDE) 5 signaling, and by increased oxidative stress. Preliminary clinical trials show that continuous treatment with PDE5 inhibitor sildenafil unassociated with sexual activity decreases priapic activity in patients with SCD. However, the mechanism of its vasculoprotective effect in the penis remains unclear.
We evaluated whether continuous administration of PDE5 inhibitor sildenafil promotes eNOS function at posttranslational levels and decreases superoxide-producing enzyme NADPH oxidase activity in the sickle cell mouse penis.
SCD transgenic mice were used as an animal model of SCD. WT mice served as controls. Mice received treatment with the PDE5 inhibitor sildenafil (100 mg/kg/day) or vehicle for 3 weeks. eNOS phosphorylation on Ser-1177 (positive regulatory site), eNOS interactions with heat-shock protein 90 (HSP90) (positive regulator), phosphorylated AKT (upstream mediator of eNOS phosphorylation on Ser-1177), an NADPH oxidase catalytic subunit gp91(phox), and a marker of oxidative stress (4-hydroxy-2-nonenal [HNE]) were measured by Western blot.
Effect of continuous sildenafil treatment on eNOS posttranslational activation, NADPH oxidase catalytic subunit, and oxidative stress in the penis of the sickle cell mouse.
Continuous treatment with sildenafil reversed (P < 0.05) the abnormalities in protein expressions of P-eNOS (Ser-1177), eNOS/HSP90 interaction, P-AKT, protein expression of gp91(phox), and 4-HNE, in the sickle cell mouse penis. Sildenafil treatment of WT mice did not affect any of these parameters.
Our findings that sildenafil enhances eNOS activation and inhibits NADPH oxidase function in the sickle cell mouse penis offers a vasculoprotective molecular basis for the therapeutic effect of sildenafil in the penis in association with SCD.
镰状细胞病（SCD）相关的阴茎血管病变的特征是一氧化氮和磷酸二酯酶（PDE）5 信号异常，以及氧化应激增加。初步临床试验表明，与性行为无关的 PDE5 抑制剂西地那非的持续治疗会降低 SCD 患者的阴茎勃起活动。然而，其在阴茎中的血管保护作用的机制尚不清楚。
我们评估了 PDE5 抑制剂西地那非的持续给药是否会促进镰状细胞小鼠阴茎中的内皮型一氧化氮合酶（eNOS）在翻译后水平上的功能，并降低超氧化物产生酶 NADPH 氧化酶的活性。
使用 SCD 转基因小鼠作为 SCD 的动物模型。WT 小鼠作为对照。小鼠接受 PDE5 抑制剂西地那非（100mg/kg/天）或载体治疗 3 周。通过 Western blot 测量 eNOS 丝氨酸 1177 磷酸化（正调控位点）、eNOS 与热休克蛋白 90（HSP90）的相互作用（正调节物）、磷酸化 AKT（eNOS 丝氨酸 1177 磷酸化的上游介质）、NADPH 氧化酶催化亚基 gp91（phox）和氧化应激标志物（4-羟基-2-壬烯醛[HNE]）。
连续西地那非治疗对镰状细胞小鼠阴茎中 eNOS 翻译后激活、NADPH 氧化酶催化亚基和氧化应激的影响。
连续西地那非治疗逆转了（P<0.05）镰状细胞小鼠阴茎中 P-eNOS（Ser-1177）、eNOS/HSP90 相互作用、P-AKT、gp91（phox）蛋白表达和 4-HNE 的蛋白表达异常。西地那非治疗 WT 小鼠不会影响这些参数中的任何一个。
我们的发现表明，西地那非增强了 SCD 小鼠阴茎中的 eNOS 激活并抑制了 NADPH 氧化酶的功能，为西地那非在 SCD 相关阴茎中的治疗效果提供了一个血管保护的分子基础。
