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Role of the hepatic plasma protein Fetuin-B in fertility

肝血浆蛋白胎球蛋白-B 在生育力中的作用

基本信息

批准号：
250118446
负责人：
Professor Dr. Wilhelm Jahnen-Dechent
金额：
--
依托单位：
Klinik für Gynäkologische Endokrinologie und Reproduktionsmedizin
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2014
资助国家：
德国
起止时间：
2013-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/250118446?language=en
关键词：
Role hepatic plasma protein Fetuin

项目摘要

The zona pellucida (ZP) is a glycoprotein matrix surrounding mammalian oocytes. Upon fertilization, ZP hardening prevents sperm from binding to and penetrating the ZP. We reported that targeted gene deletion of the liver-derived plasma protein fetuin-B causes premature ZP hardening and, consequently, female infertility. Transplanting fetuin-B- deficient ovaries into wild-type recipients restored fertility, indicating that plasma fetuin-B is necessary and sufficient for fertilization. In vitro fertilization of oocytes from fetuin-B-deficient mice only worked after rendering the ZP penetrable by laser perforation. Mechanistically, fetuin-B sustains fertility by inhibiting ovastacin, a cortical granula protease known to trigger ZP hardening. Thus, plasma fetuin-B is necessary to restrain protease activity and thereby maintain ZP permeability until after gamete fusion. These results also show that premature ZP hardening can cause infertility in mice. To better understand the sequence of events that lead to infertility in the absence of fetuin-B, we will determine the exact timing of protease activation, minimum amount and duration of fetuin-B action required. To rescue fertility in fetuin-B deficient mice we will restore hepatic fetuin-B expression by hydroponic plasmid, and adenoviral gene transfer. To prove that ovastacin inhibition is necessary and sufficient to maintain fertility in the absence of fetuin-B, we will generate fetuin-B/ovastacin double deficient mice that should be fertile despite fetuin-B deficiency. To test if fetuin-B deficiency may be a viable alternative to hormonal contraception, we will reduce fetuin-B plasma levels by immune depletion, and by antisense oligonucleotide mediated down-regulation of expression. Test matings of female mice thus treated will show if, and how long infertility can be induced by therapeutic fetuin-B downregulation.We will collect blood, follicular fluid and DNA samples from patients undergoing infertility treatment in preparation of an association study of fetuin-B polymorphisms and infertility.We will determine the glycosylation pattern of fetuin-B, and produce up to 50 mg of homogeneously glycosylated fetuin-B to determine a high resolution 3-D structure of the protein in collaboration with renownded protein crystallographers.

透明带（ZP）是围绕在哺乳动物卵母细胞周围的糖蛋白基质。受精后，ZP硬化阻止精子结合并穿透ZP。我们报道了肝源性血浆蛋白胎儿蛋白b的靶向基因缺失导致ZP过早硬化，从而导致女性不孕。将缺乏胎儿素b的卵巢移植到野生型受体中可以恢复生育能力，这表明血浆胎儿素b对于受精是必要和充分的。胚胎素b缺乏小鼠卵母细胞的体外受精只有在激光穿孔使ZP可穿透后才有效。从机制上讲，胎儿素b通过抑制ovastacin来维持生育能力，ovastacin是一种皮质颗粒蛋白酶，已知会引发ZP硬化。因此，血浆胎儿素b对于抑制蛋白酶活性，从而维持ZP的通透性直到配子融合后是必需的。这些结果还表明，ZP过早硬化可导致小鼠不孕。为了更好地了解在缺乏胎儿蛋白b的情况下导致不孕的事件序列，我们将确定蛋白酶激活的确切时间、胎儿蛋白b作用所需的最小量和持续时间。为了挽救胎儿蛋白b缺陷小鼠的生育能力，我们将通过水培质粒和腺病毒基因转移恢复胎儿蛋白b在肝脏的表达。为了证明在缺乏胎儿激素b的情况下卵形他星抑制是维持生育能力的必要和充分条件，我们将产生胎儿激素b /卵形他星双缺陷小鼠，尽管胎儿激素b缺乏，但它们仍能生育。为了测试胎儿蛋白b缺乏是否可能是激素避孕的可行替代方案，我们将通过免疫消耗和反义寡核苷酸介导的下调表达来降低胎儿蛋白b血浆水平。用这种方法治疗的雌性小鼠的交配试验将会显示出是否可以，以及治疗性的胎儿素- b下调能诱导不育多长时间。我们将收集接受不孕症治疗的患者的血液、卵泡液和DNA样本，为胎儿蛋白b多态性与不孕症的关联研究做准备。我们将确定胎儿蛋白b的糖基化模式，并与著名的蛋白质晶体学家合作，生产多达50毫克的均匀糖基化胎儿蛋白b，以确定蛋白质的高分辨率3d结构。