Role of Glycolysis in the Metabolic Regulation of Sperm Motility and Male Fertili

基因靶向研究提供了令人信服的证据，表明精子中的糖酵解，而不是 线粒体ATP的产生对于维持小鼠的精子活力和雄性生育力是必需的。 虽然人类精子具有较高的糖酵解活性，但关于精子的相对糖酵解活性的报道相互矛盾。 糖酵解和线粒体氧化磷酸化对维持这些细胞中ATP水平的重要性 细胞此外，哺乳动物精子中存在数量惊人的糖酵解变体， 研究继续揭示糖酵解和其他代谢的新酶和调节特征， 内切酶该提案的具体目标将：i）确定小鼠精子中的能量产生是否是 由新的机制控制。我们将a）确定葡萄糖以外的底物是否维持精子 足以用于体外受精运动性和功能性，B）使用代谢组学和通量组学 确定精子如何代谢有效底物的方法，和c）确定PKA介导的 精子中的磷酸化对于维持糖酵解ATP的产生是必需的。2)识别底物 维持人类精子中ATP的产生和活力，并决定它们如何代谢。到 为了验证人类精子需要糖酵解才能受精的假设，我们将： 确定是否需要糖酵解和非糖酵解底物来维持精子功能， B）使用代谢组学方法来评估有效底物如何被人精子代谢，以及 c）确定是否有证据表明精子活力低的不育男性存在糖酵解缺陷。第三章 确定精子中新鉴定的糖酵解同工酶的功能特征。 这些研究将验证精子糖酵解精子的广泛修饰是必不可少的假设 对于替代的调节机制和/或途径成分与纤维鞘的结合， 沿着鞭毛的长度提供ATP的局部供应。我们将（a）确定 小鼠精子中存在的LDH同工酶，B）确定小鼠精子中是否存在醛缩酶A和新的LDH同工酶， 小鼠和人类精子具有独特的功能特性，以及c）使用基因组分析来评估 在精子糖酵解途径的其他步骤中使用的异构体的复杂性。获得的知识 这些研究将增加我们对精子糖酵解是如何调节的理解， 关于特定精子同工酶作为潜在避孕靶点的相对效用的见解。

Gene targeting studies provide compelling evidence that glycolysis in spermatozoa rather than mitochondrial ATP production is essential for maintaining sperm motility and male fertility in the mouse. Although human sperm exhibit high glycolytic activity, there are conflicting reports on the relative importance of glycolysis and mitochondrial oxidative phosphorylation for maintaining ATP levels in these cells. In addition, there are a surprising number of glycolytic variants in mammalian sperm, and recent studies continue to uncover new enzymes and regulatory features of both glycolytic and other metabolic enzymes. Specific aims of this proposal will: i) Determine if energy production in mouse sperm is regulated by novel mechanisms. We will a) determine if substrates other than glucose sustain sperm motility and functional properties sufficient for in vitro fertilization, b) use metabolomic and fluxomic approaches to determine how sperm metabolize effective substrates, and c) determine if PKA-mediated phosphorylation in sperm is essential for maintaining glycolytic ATP production. 2) Identify substrates that maintain ATP production and motility in human sperm and determine how they are metabolized. To test the hypothesis that human sperm require glycolysis for fertilization competence, we will a) determine if both glycolysable and non-glycolysable substrates are required to maintain sperm function, b) use metabolomic approaches to assess how effective substrates are metabolized by human sperm, and c) determine if there is evidence for glycolytic defects in infertile men with low sperm motility. 3) Determine functional characteristics of newly identified glycolytic isozymes that are present in sperm. These studies will test the hypothesis that extensive modifications of sperm glycolysis sperm are essential for alternative regulatory mechanisms and/or binding of pathway constituents to the fibrous sheath to provide a localized supply of ATP along the length of the flagellum. We will a) determine the diversity of LDH isozymes present in mouse sperm, b) determine if aldolase A and novel LDH isozymes present in mouse and human sperm have unique functional properties, and c) use genomic analyses to assess the complexity of isoforms that are used at other steps of the sperm glycolytic pathway. Knowledge gained from these studies will increase our understanding of how glycolysis is regulated in sperm and provide insights regarding the relative utility of specific sperm isozymes as potential contraceptive targets.