Distinctive Changes in Histone H3K4 Modification Mediated via Kdm5a Expression in Spermatogonial Stem Cells of Cryptorchid Testes
Distinctive Changes in Histone H3K4 Modification Mediated via Kdm5a Expression in Spermatogonial Stem Cells of Cryptorchid Testes
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DOI：
10.1016/j.juro.2013.10.071
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发表时间：
2014-05-01
影响因子：
6.6
通讯作者：
Kohri, Kenjiro
中科院分区：
文献类型：
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作者：
Nishio, Hidenori;Hayashi, Yutaro;Kohri, Kenjiro
目的：性细胞分化为精原干细胞，使其终生持续维持精子发生成为可能。我们之前报道过隐睾症患者睾丸中精原干细胞活性减弱，导致精子发生改变并影响生育能力。然而，很少有研究小组研究从性腺细胞到精原干细胞的分化过程。为了更全面地阐明其可能的机制，我们利用基因芯片技术分析了幼年大鼠正常和隐睾腺组织中转录产物的差异表达。材料与方法：利用基因芯片技术比较了正常和隐睾腺组织的整体基因表达。随后，我们通过实时逆转录聚合酶链式反应验证候选基因的差异表达，并进行免疫组织化学。我们还检测了组蛋白H3K4在隐睾丸和GC-1精原细胞系中的甲基化状态。结果：我们检测到24个上调基因和39个下调基因。在这些基因中，KDM5A在隐睾腺中的表达显着升高。免疫组织化学显示KDM5A定位于性腺母细胞、精原细胞和精母细胞的胞核。H3K4me2/ME3的表达水平在产后第9天下降。此外，KDM5A在GC-1细胞中的过表达导致Esr2、Neurog3、Pou5f1、Ret和Thy1的表达增加。结论：最近的研究表明，不仅遗传调控参与了精子发生，表观遗传调控也参与了精子的发生。KDM5A可能通过H3K4组蛋白修饰对特定基因的转录调控参与了性腺细胞向精原干细胞的转化。据我们所知，这是对早期精子发生过程中生殖细胞分化的表观遗传学分析的第一份报告。
Purpose: Gonocytes differentiate into spermatogonial stem cells, which make it possible to maintain spermatogenesis continuously throughout life. We previously reported attenuated spermatogonial stem cell activity in cryptorchid testes, which resulted in altered spermatogenesis and affected fertility. However, few groups have examined the differentiation process from gonocytes to spermatogonial stem cells. To clarify the underlying mechanisms comprehensively we performed microarray analysis to assess differential expression of transcripts between normal and undescended testes in juvenile rats.Materials and Methods: Using microarray analysis we compared whole mRNA expression of normal and cryptorchid testes in a rat model. We subsequently validated differential expression of candidate genes by real-time reverse transcriptase-polymerase chain reaction and performed immunohistochemistry. We also investigated the methylation status of histone H3K4 in cryptorchid testes and the GC-1 spermatogonial cell line.Results: We detected 24 up-regulated and 39 down-regulated genes. Of these genes Kdm5a expression was significantly higher in undescended testes. Immunohistochemistry showed that Kdm5a was localized in the nuclei of gonocytes, spermatogonia and spermatocytes. H3K4me2/me3 expression levels were decreased in undescended testes at 9 days postpartum. Furthermore, Kdm5a over expression in GC-1 cells led to increased expression of Esr2, Neurog3, Pou5f1, Ret and Thy1.Conclusions: Recent investigations revealed that not only genetic but also epigenetic regulation has a role in spermatogenesis. Kdm5a is likely involved in the transformation of gonocytes into spermatogonial stem cells by transcriptional regulation of specific genes via H3K4 histone modification. To our knowledge this is the first report of epigenetic analysis of germ cell differentiation during early spermatogenesis.