Wen Yujiao, Ma Xixiang, Wang Xiaoli, Wang Fengli, Dong Juan, Wu Yanqing, Lv Chunyu, Liu Kuan, Zhang Yan, Zhang Zhibing, Yuan Shuiqiao
Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
Department of Obstetrics & Gynecology, Wayne State University, Detroit, MI 48201, USA.
Theranostics. 2021 Oct 25;11(20):10030-10046. doi: 10.7150/thno.66819. eCollection 2021.
Sertoli cells are essential regulators of testicular fate in the differentiating gonad; however, its role and underlying molecular mechanism of regulating testicular development in prepubertal testes are poorly understood. Although several critical regulatory factors of Sertoli cell development and function have been identified, identifying extrinsic factors that regulate gonocyte proliferation and migration processes during neonatal testis development remains largely unknown. We used the Sertoli cell-specific conditional knockout strategy (Cre/Loxp) in mice and molecular biological analyses (Luciferase assay, ChIP-qPCR, RNA-Seq, etc.) in vitro and in vivo to study the physiological roles of hnRNPU in Sertoli cells on regulating testicular development in prepubertal testes. We identified a co-transcription factor, hnRNPU, which is highly expressed in mouse and human Sertoli cells and required for neonatal Sertoli cell and pre-pubertal testicular development. Conditional knockout of hnRNPU in murine Sertoli cells leads to severe testicular atrophy and male sterility, characterized by rapid depletion of both Sertoli cells and germ cells and failure of spermatogonia proliferation and migration during pre-pubertal testicular development. At molecular levels, we found that hnRNPU interacts with two Sertoli cell markers WT1 and SOX9, and enhances the expression of two transcriptional factors, and in Sertoli cells by directly binding to their promoter regions. Further RNA-Seq and bioinformatics analyses revealed the transcriptome-wide of key genes essential for Sertoli cell and germ cell fate control, such as biological adhesion, proliferation and migration, were deregulated in Sertoli cell-specific hnRNPU mutant testes. Our findings demonstrate an essential role of hnRNPU in Sertoli cells for prepubertal testicular development and testis microenvironment maintenance and define a new insight for our understanding of male infertility therapy.
支持细胞是分化中的性腺中睾丸命运的关键调节因子；然而，其在青春期前睾丸中调节睾丸发育的作用及潜在分子机制仍知之甚少。尽管已经鉴定出支持细胞发育和功能的几个关键调节因子，但在新生儿睾丸发育过程中调节生殖母细胞增殖和迁移过程的外在因子仍基本未知。我们在小鼠中采用支持细胞特异性条件性敲除策略（Cre/Loxp），并在体外和体内进行分子生物学分析（荧光素酶测定、染色质免疫沉淀定量PCR、RNA测序等），以研究hnRNPU在支持细胞中对青春期前睾丸发育的调节生理作用。我们鉴定出一种共转录因子hnRNPU，其在小鼠和人类支持细胞中高度表达，是新生儿支持细胞和青春期前睾丸发育所必需的。在小鼠支持细胞中条件性敲除hnRNPU会导致严重的睾丸萎缩和雄性不育，其特征是在青春期前睾丸发育过程中支持细胞和生殖细胞迅速耗竭，以及精原细胞增殖和迁移失败。在分子水平上，我们发现hnRNPU与两种支持细胞标记物WT1和SOX9相互作用，并通过直接结合其启动子区域来增强支持细胞中两种转录因子的表达。进一步的RNA测序和生物信息学分析表明，在支持细胞特异性hnRNPU突变睾丸中，支持细胞和生殖细胞命运控制所必需的关键基因的全转录组，如生物黏附、增殖和迁移等，均失调。我们的研究结果证明了hnRNPU在支持细胞中对青春期前睾丸发育和睾丸微环境维持的重要作用，并为我们理解男性不育治疗提供了新的见解。
