Department of Pediatrics and Developmental Biology, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, 113-8510, Japan.
Department of Systems BioMedicine, National Research Institute for Child Health and Development, Setagaya-ku, Tokyo, 157-8535, Japan.
Sci Rep. 2018 Sep 5;8(1):13263. doi: 10.1038/s41598-018-31376-8.
Peptidyl arginine deiminases (PADIs) are enzymes that change the charge of proteins through citrullination. We recently found Padi2 was expressed exclusively in fetal Sertoli cells. In this study, we analyzed the transcriptional regulation of Padi2 and the role of PADI2 in testicular development. We showed SOX9 positively regulated Padi2 transcription and FOXL2 antagonized it in TM3 cells, a model of Sertoli cells. The responsive region to SOX9 and FOXL2 was identified within the Padi2 sequence by reporter assay. In fetal testes from Sox9 knockout (AMH-Cre:Sox9) mice, Padi2 expression was greatly reduced, indicating SOX9 regulates Padi2 in vivo. In vitro analysis using siRNA suggested PADI2 modified transcriptional regulation by SOX9. However, Padi2 XY mice were fertile and showed no apparent reproductive anomalies. Although, PADI2 is known as an epigenetic transcriptional regulator through H3 citrullination, no significant difference in H3 citrullination between wildtype and Padi2 XY gonads was observed. These results suggest Padi2 is a novel gene involved in testis development that is specifically expressed in Sertoli cells through the regulation by SOX9 and FOXL2 and PADI2 supports regulation of target genes by SOX9. Analysis of the Padi2 XY phenotype suggested a redundant factor compensated for PADI2 function in testicular development.
肽基精氨酸脱亚氨酶（PADIs）是通过瓜氨酸化改变蛋白质电荷的酶。我们最近发现 Padi2 仅在胎儿支持细胞中表达。在这项研究中，我们分析了 Padi2 的转录调控以及 PADI2 在睾丸发育中的作用。我们表明 SOX9 正向调节 TM3 细胞（支持细胞模型）中的 Padi2 转录，而 FOXL2 则拮抗它。通过报告基因分析鉴定了 SOX9 和 FOXL2 的响应区域位于 Padi2 序列内。在 Sox9 敲除（AMH-Cre：Sox9）小鼠的胎儿睾丸中，Padi2 表达大大降低，表明 SOX9 在体内调节 Padi2。使用 siRNA 的体外分析表明 PADI2 通过 SOX9 修饰转录调控。然而，Padi2 XY 小鼠是可育的，没有明显的生殖异常。尽管 PADI2 是一种通过 H3 瓜氨酸化的表观遗传转录调节剂，但在野生型和 Padi2 XY 性腺中未观察到 H3 瓜氨酸化的显著差异。这些结果表明 Padi2 是一种参与睾丸发育的新型基因，通过 SOX9 和 FOXL2 的调节在支持细胞中特异性表达，并且 PADI2 支持 SOX9 对靶基因的调节。对 Padi2 XY 表型的分析表明，冗余因子补偿了 PADI2 在睾丸发育中的功能。
