Laboratory for Experimental Medicine and Endocrinology, Katholieke Universiteit Leuven, Leuven, Belgium.
PLoS One. 2010 Nov 30;5(11):e14168. doi: 10.1371/journal.pone.0014168.
The observation that mice with a selective ablation of the androgen receptor (AR) in Sertoli cells (SC) (SCARKO mice) display a complete block in meiosis supports the contention that SC play a pivotal role in the control of germ cell development by androgens. To delineate the physiological and molecular mechanism responsible for this control, we compared tubular development in pubertal SCARKO mice and littermate controls. Particular attention was paid to differences in SC maturation, SC barrier formation and cytoskeletal organization and to the molecular mediators potentially involved. Functional analysis of SC barrier development by hypertonic perfusion and lanthanum permeation techniques and immunohistochemical analysis of junction formation showed that SCARKO mice still attempt to produce a barrier separating basal and adluminal compartment but that barrier formation is delayed and defective. Defective barrier formation was accompanied by disturbances in SC nuclear maturation (immature shape, absence of prominent, tripartite nucleoli) and SC polarization (aberrant positioning of SC nuclei and cytoskeletal elements such as vimentin). Quantitative RT-PCR was used to study the transcript levels of genes potentially related to the described phenomena between day 8 and 35. Differences in the expression of SC genes known to play a role in junction formation could be shown from day 8 for Cldn11, from day 15 for Cldn3 and Espn, from day 20 for Cdh2 and Jam3 and from day 35 for ZO-1. Marked differences were also noted in the transcript levels of several genes that are also related to cell adhesion and cytoskeletal dynamics but that have not yet been studied in SC (Actn3, Ank3, Anxa9, Scin, Emb, Mpzl2). It is concluded that absence of a functional AR in SC impedes the remodeling of testicular tubules expected at the onset of spermatogenesis and interferes with the creation of the specific environment needed for germ cell development.
研究发现，生精细胞中雄激素受体（AR）选择性缺失的小鼠（SCARKO 小鼠）减数分裂完全受阻，这支持了生精细胞的发育受雄激素调控的观点。为了阐明雄激素调控的生理和分子机制，我们比较了青春期 SCARKO 小鼠和同窝对照小鼠的管状发育情况。特别关注了生精细胞成熟、生精细胞屏障形成和细胞骨架组织的差异，以及潜在的参与分子。通过高渗灌注和镧渗透技术对生精细胞屏障发育进行功能分析，并通过免疫组织化学分析连接形成进行分析，结果表明，SCARKO 小鼠仍试图形成一种将基底室和腔室隔开的屏障，但屏障形成延迟且有缺陷。屏障形成缺陷伴随着生精细胞核成熟的紊乱（不成熟的形态，缺乏明显的三部分核仁）和生精细胞极化的紊乱（生精细胞核和细胞骨架成分如波形蛋白的位置异常）。通过定量 RT-PCR 研究了在第 8 天至 35 天之间与描述的现象相关的潜在基因的转录水平。第 8 天可以观察到参与连接形成的已知与生精细胞功能相关的基因的表达存在差异，如 Cldn11；第 15 天可以观察到 Cldn3 和 Espn；第 20 天可以观察到 Cdh2 和 Jam3；第 35 天可以观察到 ZO-1。在几个与细胞黏附和细胞骨架动力学相关的基因的转录水平上也观察到了明显的差异，但这些基因在生精细胞中尚未进行研究（Actn3、Ank3、Anxa9、Scin、Emb、Mpzl2）。综上所述，生精细胞中 AR 的缺失会阻碍精子发生开始时睾丸小管的重塑，并干扰生精细胞发育所需的特定环境的形成。
