Biochemistry Unit, Department of Physiology, Faculty of Veterinary Science, Chulalongkorn University, 39 Henri-Dunant Road, Wangmai, Pathumwan, Bangkok, 10330, Thailand.
Proteomics Research Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand.
BMC Vet Res. 2020 Oct 2;16(1):373. doi: 10.1186/s12917-020-02591-1.
Cryptorchidism is a condition that occurs when one or both testes fail to descend into the scrotum. It is a common congenital disorder, causing economic loss in pig production. However, there have been only limited studies of differential protein expression profiles in undescended testes (UDTs) in the abdomen and descended testes (DTs) in cryptorchid pigs, especially at the peptidome and proteome levels. The present study aimed to analyze the peptidome of UDTs and DTs in unilateral cryptorchid pigs aged 1-2, 6, 15 and 20 weeks and in normal testes of healthy pigs aged 1-2 and 12 weeks, using peptide mass fingerprinting and three-dimensional principal component analysis (3D-PCA) with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and to identify potential protein candidates, using in-gel digestion coupled with mass spectrometry (GeLC-MS/MS). Western blot analysis was used to verify protein expression. Protein sequence was affirmed by liquid chromatography-tandem mass spectrometry.
A PCA plot showed a discrete cluster for each sample group. Peptide mass fingerprints (PMFs) demonstrated unique peptide fragments in UDTs at different ages. A number of markedly expressed proteins from GeLC-MS/MS were identified, including the multifunctional tumor necrosis factor receptor superfamily member 18 (TNFRSF18), in DTs at 1-2 and 6 weeks and in UDTs at 15 and 20 weeks of age. Using western blot analysis, high expression of TNFRSF18 was observed in the UDTs at 15 weeks. Using the STITCH database, this protein was found to be related to apoptosis, corresponding to the previous report in the UDTs at the same age.
The present study revealed the specific PMFs and clusters for porcine cryptorchidism, and a novel protein, TNFRSF18, associated with the disease mechanism. These results could provide further insights into the pathogenesis of the disease.
隐睾症是一种睾丸未能下降到阴囊的疾病。它是一种常见的先天性疾病，会给猪的生产带来经济损失。然而，对于隐睾猪的未降睾丸（UDTs）和降睾丸（DTs）的差异蛋白质表达谱的研究非常有限，特别是在肽组学和蛋白质组学水平。本研究旨在通过肽质量指纹图谱和基质辅助激光解吸/电离飞行时间质谱的三维主成分分析（3D-PCA），分析 1-2 周、6 周、15 周和 20 周龄单侧隐睾猪的 UDTs 和 DTs，以及 1-2 周和 12 周龄健康猪的正常睾丸的肽组，并通过胶内消化与质谱（GeLC-MS/MS）相结合来鉴定潜在的蛋白质候选物。采用 Western blot 分析验证蛋白质表达，采用液相色谱-串联质谱（LC-MS/MS）对蛋白质序列进行确证。
PCA 图显示每个样本组都有一个离散的聚类。PMF 显示了不同年龄 UDTs 中独特的肽片段。通过 GeLC-MS/MS 鉴定了许多明显表达的蛋白质，包括多功能肿瘤坏死因子受体超家族成员 18（TNFRSF18），在 1-2 周和 6 周龄的 DTs 以及 15 周和 20 周龄的 UDTs 中表达。通过 Western blot 分析，在 15 周龄的 UDTs 中观察到 TNFRSF18 的高表达。通过 STITCH 数据库发现该蛋白与凋亡有关，与之前同一年龄 UDTs 的报道相符。
本研究揭示了猪隐睾症的特定 PMF 和聚类，以及一种与疾病机制相关的新型蛋白 TNFRSF18。这些结果可以为该疾病的发病机制提供进一步的见解。
