Yimpring Nathamon, Teankum Komkrich, Srisuwatanasagul Sayamon, Kunnasut Nanthida, Am-In Nutthee, Suriyaphol Gunnaporn
Biochemistry Unit, Department of Physiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand.
Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand.
Theriogenology. 2019 Mar 15;127:49-55. doi: 10.1016/j.theriogenology.2019.01.005. Epub 2019 Jan 11.
Cryptorchidism, a condition of one or two undescended testicles, is a common congenital disease in pigs, causing loss in the pig industry. One of the major factors affecting testicular descent is the androgen receptor (AR), which binds to androgen and then regulates the expression of androgen-responsive genes in the inguinoscrotal phase of testicular descent. AR expression has been reported to regulate apoptosis in testicular stem cells. The present study aimed to immunohistochemically examine AR and Ki-67 protein expression and apoptosis detection in unilateral undescended testicles (UDT) and descended testicles in cryptorchid pigs (DT) of suckling (aged 1-2 weeks), nursery (aged 6 weeks) and growing-finishing pigs (aged 12, 15 and 20 weeks) and in normal testicles (NT) at 1-2 and 12 weeks of age. At 1-2 weeks, decreased expression of AR was observed in UDT and DT compared with NT and was lower than that at 6-20 weeks. The expression of Ki-67, a marker of cell proliferation, in UDT and DT at 12 weeks was lower than that in NT at the same age. In addition, Ki-67 expression in UDT at 6 and 12 weeks was lower than that in UDT at 1-2 and 15-20 weeks. More testicular apoptosis was revealed in UDT at 1-2 weeks than in DT and NT at the same age. At 15-20 weeks, more apoptosis was detected in UDT than in DT. Positive correlation of AR expression in DT at 6 and 12 weeks was also noted, in addition to the association of the expression of AR and Ki-67 in NT at 12 weeks. Taken together, this study unveiled the low expression of AR and high apoptosis detection in UDT, whereas low expression of AR and low apoptosis detection were noted in DT in suckling piglets. Diminished cell proliferation was shown in UDT at 6-12 weeks, whereas high apoptosis was observed in UDT at 15-20 weeks. High expression of AR was shown only in nursery pigs. Distinct expression of AR in DT and NT at 1-2 and 12 weeks indicated that both conditions were not interchangeable.
隐睾症是指一侧或双侧睾丸未降入阴囊的一种病症，是猪常见的先天性疾病，给养猪业造成损失。影响睾丸下降的主要因素之一是雄激素受体（AR），它与雄激素结合，然后在睾丸下降的腹股沟阴囊期调节雄激素反应基因的表达。据报道，AR表达可调节睾丸干细胞的凋亡。本研究旨在通过免疫组织化学方法检测哺乳仔猪（1 - 2周龄）、保育仔猪（6周龄）和生长育肥猪（12、15和20周龄）的单侧隐睾（UDT）、下降睾丸（DT）以及1 - 2周龄和12周龄正常睾丸（NT）中AR和Ki - 67蛋白的表达及凋亡情况。在1 - 2周龄时，与NT相比，UDT和DT中AR的表达降低，且低于6 - 20周龄时的表达。12周龄时，UDT和DT中细胞增殖标志物Ki - 67的表达低于同年龄的NT。此外，6周龄和12周龄UDT中Ki - 67的表达低于1 - 2周龄和15 - 20周龄UDT中的表达。1 - 2周龄时，UDT中的睾丸凋亡比同年龄的DT和NT更多。在15 - 20周龄时，UDT中的凋亡比DT更多。还发现6周龄和12周龄DT中AR表达呈正相关，此外，12周龄NT中AR和Ki - 67的表达也有关联。综上所述，本研究揭示了UDT中AR表达低且凋亡检测率高，而哺乳仔猪的DT中AR表达低且凋亡检测率低。6 - 12周龄时UDT中细胞增殖减少，而15 - 20周龄时UDT中凋亡增加。仅在保育仔猪中观察到AR高表达。1 - 2周龄和12周龄时DT和NT中AR的不同表达表明这两种情况不可互换。
