Altered gene expression signature of early stages of the germ line supports the pre-meiotic origin of human spermatogenic failure
Altered gene expression signature of early stages of the germ line supports the pre-meiotic origin of human spermatogenic failure
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DOI：
10.1111/j.2047-2927.2014.00217.x
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发表时间：
2014-07-01
期刊：
影响因子：
4.5
通讯作者：
Larriba, S.
中科院分区：
文献类型：
--
作者：
Bonache, S.;Algaba, F.;Larriba, S.
生精失败（SpF）的分子基础在很大程度上仍然是未知的。越来越多的证据表明，一系列特定的事件，如减数分裂，是在精子发生的早期阶段决定的。本研究旨在评估不育睾丸活检中减数分裂前基因的表达谱，这可能有助于确定与人类精子产生不足相关的分子表型。在由于生殖细胞成熟缺陷、仅支持细胞综合征或保守精子发生而出现SpF的个体中，通过RT-qPCR对精原细胞中表达的基因mRNA水平进行了精确定量。此外，我们还比较了SpF与睾丸肿瘤的基因表达谱，睾丸肿瘤被认为是一种严重的生殖细胞分化发育疾病。通过免疫组织化学评价所选基因的蛋白表达。我们的研究结果表明，SpF伴随着与精原细胞相关的某些基因的表达差异，而在这种特定的细胞类型中没有任何明显的形态和/或数值变化。在SpF睾丸样本中，我们观察到参与细胞周期（CCNE1和POLD1）、转录和转录后调控（DAZL、RBM15和DICER1）、蛋白质降解（FBXO32和TM9SF2）和减数分裂同源重组（MRE11A和RAD50）的基因表达下调，这表明这些基因的表达对生殖细胞的正常发育至关重要。有趣的是，CCNE1、DAZL、RBM15和STRA8细胞转录水平的降低也被观察到，这表明在SpF中，精原细胞的基因表达能力发生了改变，导致精子产生失败。总之，这些数据表明，在生殖系的初始阶段就已经确定或产生了生精性紊乱。
The molecular basis of spermatogenic failure (SpF) is still largely unknown. Accumulating evidence suggests that a series of specific events such as meiosis, are determined at the early stage of spermatogenesis. This study aims to assess the expression profile of pre-meiotic genes of infertile testicular biopsies that might help to define the molecular phenotype associated with human deficiency of sperm production. An accurate quantification of testicular mRNA levels of genes expressed in spermatogonia was carried out by RT-qPCR in individuals showing SpF owing to germ cell maturation defects, Sertoli cell-only syndrome or conserved spermatogenesis. In addition, the gene expression profile of SpF was compared with that of testicular tumour, which is considered to be a severe developmental disease of germ cell differentiation. Protein expression from selected genes was evaluated by immunohistochemistry. Our results indicate that SpF is accompanied by differences in expression of certain genes associated with spermatogonia in the absence of any apparent morphological and/or numerical change in this specific cell type. In SpF testicular samples, we observed down-regulation of genes involved in cell cycle (CCNE1 and POLD1), transcription and post-transcription regulation (DAZL, RBM15 and DICER1), protein degradation (FBXO32 and TM9SF2) and homologous recombination in meiosis (MRE11A and RAD50) which suggests that the expression of these genes is critical for a proper germ cell development. Interestingly, a decrease in the CCNE1, DAZL, RBM15 and STRA8 cellular transcript levels was also observed, suggesting that the gene expression capacity of spermatogonia is altered in SpF contributing to an unsuccessful sperm production. Altogether, these data point to the spermatogenic derangement being already determined at, or arising in, the initial stages of the germ line.