Department of Biomedical Sciences, Tuskegee University, Tuskegee, Alabama.
Department of Anatomy, Physiology and Pharmacology, Auburn University, Auburn, Alabama.
J Urol. 2014 Jul;192(1):267-73. doi: 10.1016/j.juro.2013.11.101. Epub 2013 Dec 6.
We determined the effects of low androgens in the neonatal period on biomarkers of smooth muscle cell differentiation, Myh11 and Acta2, and on Pde5A expression in the penis.
One-day-old pups were treated daily with the gonadotropin-releasing hormone antagonist antide with or without dihydrotestosterone for 1 to 6 days. Tissues were collected at age day 7 and at adulthood at age 120 days. Penes were examined by quantitative reverse transcriptase-polymerase chain reaction, Western blot and immunohistochemistry. Testes were assayed for the intratesticular testosterone and steroidogenic enzymes Cyp17α1 and StAR.
Gonadotropin-releasing hormone antagonist exposure suppressed the neonatal testicular testosterone surge 70% to 80%. Quantitative reverse transcriptase-polymerase chain reaction revealed 80% to 90% reductions in Cyp17α1 and StAR protein, and 40% to 60% reductions in Myh11 and ACTA2 as a result of gonadotropin-releasing hormone antagonist compared to controls. Dihydrotestosterone co-administration mitigated these decreases. Western blot confirmed the Myh11 decrease at the protein level. Immunohistochemistry of Acta2 confirmed cavernous smooth muscle cell loss at the tissue level. Also, gonadotropin-releasing hormone antagonist exposure decreased Pde5a expression and dihydrotestosterone co-administration mitigated the decrease. Comparison of data between 2 parts of the penis body (corpora cavernosa and corpus spongiosum) showed that antagonist induced decreases in Myh11, Acta2 and Pde5a expression occurred only in the corpora cavernosa, implying that the latter is the target site of low androgen action.
As evidenced by gonadotropin-releasing hormone antagonist induced suppression of the neonatal testosterone surge and reduced steroidogenesis, low androgens in the neonatal period altered gene expression of biomarkers of smooth muscle cell differentiation. This led to loss of cavernous smooth muscle cells and consequently to penile maldevelopment.
我们旨在研究新生儿期雄激素水平低下对平滑肌细胞分化标志物 Myh11 和 Acta2 以及阴茎内 Pde5A 表达的影响。
1 日龄幼鼠每天接受促性腺激素释放激素拮抗剂 antide 处理，同时或不接受二氢睾酮处理，持续 1-6 天。在 7 日龄和 120 日龄成年时收集组织。通过定量逆转录聚合酶链反应、Western blot 和免疫组织化学检测阴茎组织。检测睾丸内睾酮和类固醇生成酶 Cyp17α1 和 StAR 的含量。
促性腺激素释放激素拮抗剂暴露抑制了新生儿睾丸内睾酮激增 70%-80%。定量逆转录聚合酶链反应显示，与对照组相比，Cyp17α1 和 StAR 蛋白减少 80%-90%，Myh11 和 ACTA2 减少 40%-60%，这是促性腺激素释放激素拮抗剂作用的结果。二氢睾酮共处理减轻了这些减少。Western blot 证实了 Myh11 蛋白水平的降低。免疫组织化学检测 Acta2 证实了组织水平的海绵状平滑肌细胞丢失。此外，促性腺激素释放激素拮抗剂暴露降低了 Pde5a 的表达，二氢睾酮共处理减轻了这种降低。对阴茎体（海绵体和阴茎海绵体）两部分数据的比较表明，拮抗剂诱导的 Myh11、Acta2 和 Pde5a 表达降低仅发生在海绵体中，这表明后者是低雄激素作用的靶位。
正如促性腺激素释放激素拮抗剂诱导的新生儿睾酮激增抑制和类固醇生成减少所证明的那样，新生儿期的低雄激素改变了平滑肌细胞分化生物标志物的基因表达。这导致了海绵状平滑肌细胞的丢失，进而导致了阴茎发育不良。
