Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China.
Urology. 2013 Feb;81(2):464.e11-6. doi: 10.1016/j.urology.2012.10.045.
To investigate the expression of insulin-like growth factor binding protein-3 (IGFBP-3) in penile cavernous of streptozotocin (STZ)-induced DM rats and whether downregulation of IGFBP-3 by intracavernosal injection of short hairpin ribonucleic acid (shRNA) targeting IGFBP-3 could improve the erectile function in DM rats.
Diabetes was induced in rats by intraperitoneal injection of STZ, and the expression of IGFBP-3 in the penile tissue of adult normal and DM male rats was assayed using reverse transcriptase-polymerase chain reaction and Western blot. Next, shRNA-targeting IGFBP-3 and a scramble sequence were injected into the penile corpora cavernosa of DM rats. At 12 weeks after shRNA-IGFBP-3 administration, the intracavernous pressure in response to electrical stimulation of the cavernous nerves was evaluated. The expression of IGFBP-3 was assayed by Western blot. The concentration of cyclic guanosine monophosphate in the corpus cavernosum was assayed by enzyme-linked immunosorbent assay.
At 12 week after intraperitoneal administration of STZ, IGFBP-3 expression had increased in the penis of the DM rat (P <.05) compared with that of the normal control rats. Among the DM rats, IGFBP-3 expression at the messenger RNA and protein level was significantly inhibited 12 weeks after intracavernous administration of IGFBP-3 shRNA (P <.01). At 12 weeks after shRNA-IGFBP-3 injection, intracavernosal pressure was significantly increased in response to cavernous nerve stimulation (P <.05), and an increase in the concentration of cyclic guanosine monophosphate in the corpus cavernous tissue (P <.01) was detected compared with the "randomer" shRNA treatment group.
Gene transfer of shRNA-IGFBP-3 could improve erectile function in STZ-induced DM rats by an increase in the cyclic guanosine monophosphate concentration in cavernous tissue.
研究胰岛素样生长因子结合蛋白-3（IGFBP-3）在链脲佐菌素（STZ）诱导的糖尿病（DM）大鼠阴茎海绵体中的表达，以及通过腔内注射靶向 IGFBP-3 的短发夹 RNA（shRNA）下调 IGFBP-3 是否可以改善 DM 大鼠的勃起功能。
通过腹腔内注射 STZ 诱导大鼠糖尿病，使用逆转录-聚合酶链反应和 Western blot 检测成年正常和 DM 雄性大鼠阴茎组织中 IGFBP-3 的表达。然后，将靶向 IGFBP-3 的 shRNA 和乱序序列注射到 DM 大鼠的阴茎海绵体中。在 shRNA-IGFBP-3 给药 12 周后，评估电刺激海绵体神经时的海绵体内压。通过 Western blot 检测 IGFBP-3 的表达。通过酶联免疫吸附试验检测海绵体组织中环鸟苷酸（cGMP）的浓度。
腹腔内给予 STZ 12 周后，DM 大鼠阴茎 IGFBP-3 的表达增加（P<.05）与正常对照组大鼠相比。在 DM 大鼠中，IGFBP-3 的信使 RNA 和蛋白水平的表达在腔内给予 IGFBP-3 shRNA 12 周后明显受到抑制（P<.01）。在 shRNA-IGFBP-3 注射 12 周后，海绵体神经刺激时海绵体内压显著增加（P<.05），并且海绵体组织中环鸟苷酸（cGMP）的浓度增加（P<.01）与“随机”shRNA 处理组相比。
shRNA-IGFBP-3 的基因转移可以通过增加海绵体组织中环鸟苷酸（cGMP）的浓度来改善 STZ 诱导的 DM 大鼠的勃起功能。
