Oviductal regulation of gamete interaction and reproductive function

哺乳动物的输卵管在卵泡发育后期和发情期经历了生理和生化的改变。这些激素调节的变化优化了受精和早期胚胎发育的输卵管微环境。输卵管细胞分泌的一种主要糖蛋白，即输卵管蛋白，在许多哺乳动物物种中都是保守的。在我们实验室使用的仓鼠模型中，输卵管蛋白是一种O-糖基化蛋白，在发情周期中经历糖基化的周期性变化。我们已发表了大量关于仓鼠输卵管蛋白(HamOVGP1)的生物合成、分泌、定位和生化性质的文献。在我最后一次担任NSERC DG期间，我们首次展示了HamOVGP1通过增强精子蛋白子集的酪氨酸磷酸化来增强获能能力的能力，已知的精子蛋白子集在精子功能中发挥特定作用。我们的结果进一步支持了输卵管蛋白在受精早期输卵管环境中的重要作用。最近，我们成功地在HEK293细胞中获得了重组仓鼠输卵管蛋白(RHamOVGP1)。在NSERC的支持下，我们最近的工作重申了我们的实验室在哺乳动物输卵管蛋白领域处于领先地位和权威地位。根据我们以前的研究表明，输卵管蛋白定位于仓鼠子宫内膜上皮细胞亚群的细胞表面，我们推测在某些子宫细胞的细胞表面存在一种可能的输卵管蛋白受体，该受体可能在子宫容受性中发挥重要作用。我们计划1)检测rHamOVGP1的糖组分通过增强精子蛋白的酪氨酸磷酸化而增强精子获能的作用，并评估rHamOVGP1的糖链和糖肽衍生物在精子-卵子结合和受精中的作用；2)确定rHamOVGP1如何介导调节蛋白酪氨酸磷酸化的信号转导途径的机制；3)鉴定和鉴定仓鼠输卵管蛋白受体并生产重组受体，以测试其在子宫接受性中的可能作用。到目前为止，输卵管蛋白调节获能和精卵结合的机制仍然是个谜。使用我们在我最后一个NSERC DG任期内成功生产的rHamOVGP1，现在有可能解开输卵管蛋白的机制，它调节了导致成功受精的一些关键事件，以及输卵管蛋白在早期植入中的可能作用。预计从这项研究中获得的结果将导致开发一种适当的“药物鸡尾酒”疗法，利用输卵管蛋白及其葡聚糖衍生物来改进加拿大农业中的家畜授精程序以及研究实验室中的啮齿动物试管受精程序。

The mammalian oviduct undergoes physiological and biochemical modifications during late follicular development and estrus. These hormonally regulated changes optimize the oviductal microenvironment for fertilization and early embryonic development. A major glycoprotein secreted by oviductal cells, known as oviductin, is conserved across a number of mammalian species. In the hamster model used in our laboratory, oviductin is an O-glycosylated protein that undergoes cyclic variation of glycosylation during the estrous cycle. We have published extensively on the biosynthesis, secretion, localization and biochemical properties of hamster oviductin (HamOVGP1). During the tenure of my last NSERC DG, we demonstrated, for the first time, the ability of HamOVGP1 to enhance capacitation by potentiating tyrosine phosphorylation of a subset of sperm proteins known to play specific roles in sperm function. Our results further support an important role for oviductin in the oviductal milieu during the early events of fertilization. Recently, we have successfully produced recombinant hamster oviductin (rHamOVGP1) in HEK293 cells. Our recent work supported by NSERC reaffirms our laboratory in the forefront and as an authority in the field of mammalian oviductin. Based on our previous studies showing localization of oviductin to the cell surface of a subpopulation of epithelial cells of the hamster endometrium, we hypothesize that a putative oviductin receptor is present at the cell surface of certain uterine cells and that this receptor may play an important role in uterine receptivity. We plan 1) to examine the role of glycocomponents of rHamOVGP1 in enhancing sperm capacitation through enhancement of tyrosine phosphorylation of sperm proteins, and to assess the effect of glycan and glycopeptide derivatives of rHamOVGP1 in sperm-egg binding and fertilization; 2) to determine the mechanism of how rHamOVGP1 mediates signal transduction pathways that regulate protein tyrosine phosphorylation, and 3) to identify and characterize hamster oviductin receptor and to produce recombinant receptor for testing its possible role in uterine receptivity. To date, the mechanism of oviductin regulating the enhancement of capacitation and sperm-egg binding remains an enigma. Using the rHamOVGP1 that we successfully produced during the tenure of my last NSERC DG, it is now possible to unravel the mechanism of oviductin that regulates some of the key events that lead to successful fertilization and the possible role of oviductin in early implantation. It is anticipated that results obtained from this study will lead to the development of a suitable "drug cocktail" therapy utilizing oviductin and its glycan derivatives for improving the insemination procedures involving farm animals in the Canadian agriculture industry as well as IVF procedures involving rodents in research laboratories.