Fertility in the Klinefelter syndrome by testicular stem cell transplantation - an experimantal approach in the XXY mice

通过睾丸干细胞移植治疗 Klinefelter 综合征的生育力——一种在 XXY 小鼠中进行的实验方法

• 批准号: 5454151
• 负责人: Dr. Joachim Wistuba
• 金额: --
• 依托单位: Abteilung für Klinische und Operative Andrologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5454151?language=en
• 关键词: Fertility; Klinefelter; syndrome; testicular; stem

The most common genetic cause of human male infertility is the Klinefelter syndrome (KS, 47,XXY) resulting in testicular failure, loss of germ cells and variable degrees of androgen deficiency paralleled by changes in gonadotropins. Although the KS is well known, it is not clear whether the loss of germ cells resulting in a Sertoli-cell-only (SCO) syndrome is due to a defect of the germ cell line, a disturbance of the testicular environment, or a combination of both. Many Klinefelter patients attend our Institute for infertility. Any possible therapeutic approaches to overcome this infertility requires findings from experimental work. The proposed project seeks to elucidate those prerequisites for therapeutic approaches to gain fertility in Klinefelter patients, e.g. by making use of autologous stem cells. Since at this stage such work cannot be performed in the patients themselves, the generation and use of an appropriate animal model is indespensable. Mice bearing a supernumerary X-chromosome (karyotype 41, XXY) mimicking the conditions found in patients have been generated by breeding animals with a spontaneously mutated Y-chromosome. We established a mouse colony of the strain B6Ei.Lt-Y to obtain 41 (XXY) male mice and determined the distinct karyotype of the living animals individually by fluorescence in situ hybridisation (FISH). We will show whether the testicular environment and the pituitary-gonadal axis in males bearing a supernumerary X-chromosome are able to support development of normal, diploid spermatogonial stem cells using our well-established methods of germ cell transplantation and grafting of testicular tissue. We will characterize aspects essential for male endocrinology and testicular function as in particular the Leydig cell function and maturation. Since some Klinefelter patients produce a small amount of sperm deriving from apparently normal diploid spermatogonia, the testicular environment should be able to support spermatogenesis. However, whether this would be possible in every patient or depends on the degree of mosaicism has not been clarified. Testicular sperm with a high rate of chromosomal abnormalities increase the abortion rate. Thus questions of disturbed testicular environment and an increased risk of aneuploidy have to be solved before any clinical transplantation approach can be offered. This problem will be addressed in the mouse model by examining sperm produced after germ cell transplantation and by performing ICSI followed by chromosomal analysis of embryos.

人类不孕症的最常见遗传原因是KlineFelter综合征（KS，47，XXY），导致睾丸衰竭，生殖细胞丧失和可变程度的雄激素缺乏度与促性腺激素的变化并行。尽管KS是众所周知的，但尚不清楚导致仅Sertoli细胞（SCO）综合征的生殖细胞的丧失是由于生殖细胞系的缺陷，睾丸环境的干扰还是两者的组合造成的。许多KlineFelter患者就读我们的不孕研究所。克服这种不育的任何可能的治疗方法都需要从实验工作中发现。拟议的项目旨在阐明那些治疗方法的先决条件，以在Klinefelter患者中获得生育能力，例如通过使用自体干细胞。由于在此阶段无法在患者本身中进行此类工作，因此适当的动物模型的产生和使用是可忽视的。带有超生物X染色体的小鼠（Karyotype 41，XXY）模仿患者发现的疾病是通过自发突变的Y染色体繁殖的动物而产生的。我们建立了B6EI.LT-Y菌株的小鼠菌落，以获得41（XXY）雄性小鼠，并通过荧光原位杂交（FISH）分别确定活动物的独特核型。我们将展示带有X染色体的男性的睾丸环境和垂体轴是否能够使用我们建立的生殖细胞移植和睾丸组织的培养方法来支持正常的二倍体精子干细胞的发展。我们将表征对男性内分泌学和睾丸功能必不可少的方面，尤其是Leydig细胞功能和成熟。由于一些KlineFelter患者产生的少量精子来自明显正常的二倍体精子，因此睾丸环境应能够支持精子发生。但是，尚未阐明每个患者在每个患者中都可能发生的，还是取决于镶嵌性程度。染色体异常率高的睾丸精子会增加堕胎率。因此，在提供任何临床移植方法之前，必须解决睾丸环境干扰的问题和非整倍性的增加的问题。通过检查生殖细胞移植后产生的精子并进行ICSI，然后进行ICSI，然后进行胚胎的染色体分析，将在小鼠模型中解决此问题。