High Density Lipoprotein (HDL) in Follicular Fluid and Fertility Outcomes

描述（由申请方提供）：有证据表明卵泡内的高密度脂蛋白颗粒在女性生殖潜力中发挥作用。卵泡液是揭示卵母细胞成熟过程中微环境代谢过程的生物学窗口。在FF中鉴定HDL生物标志物，预测早期胚胎发育结果参数，将使我们能够更好地了解体外受精（IVF）过程中调节卵母细胞能力的因素。这一知识的获得将允许进一步的研究发展，在人类卵泡内卵母细胞发育的遗传和环境调控的理解。高密度脂蛋白（HDL）是FF中存在的唯一脂蛋白。HDL的胆固醇转运、抗氧化和抗炎活性是动态HDL粒度分布和复杂HDL组成（包括脂质、载脂蛋白、微量营养素和酶）的函数。在初步研究中，我们已经确定，HDL胆固醇和载脂蛋白AI（Apo-AI）浓度，反映FF内的总HDL浓度，是IVF期间有害胚胎碎片的显著阴性预测因子。此外，我们已经确定，血清和FF HDL磷脂：胆固醇摩尔比（反映HDL颗粒大小和亚类分布）与胚胎碎裂呈正相关。我们还通过NMR光谱法和HDL亚类分离和分析直接证明了FF-HDL颗粒相对于血清具有改变的尺寸分布和脂质组成。最初还描述了FF中HDL相关的人血清对氧磷酶1（PON 1）活性的存在。 将招募180名接受IVF的女性的前瞻性队列。IVF治疗期间将采集卵泡液、颗粒细胞和外周血。将通过NMR光谱法测定血清和FF-HDL粒度，并分离HDL亚类（HDL 2和HDL 3），并评估其相关脂质、载脂蛋白、脂溶性微量营养素组成和PON 1活性。所有测量值将与胚胎形态学参数（卵母细胞完整性的替代标志物）相关。每个HDL 2或HDL 3颗粒的HDL亚类组分的标准化将用于表征FF-HDL相对于血清HDL的独特颗粒组成，并确定可能解释我们关于胚胎质量参数的初步观察的特定差异。我们还将研究脂蛋白信号和胆固醇代谢相关的基因表达的GC从胚胎与/无碎片，以确定胆固醇代谢基因的差异。除了其作为人类卵泡代谢状态的窗口的重要性之外，FF代表了用于研究HDL介导的胆固醇代谢和缺乏其他脂蛋白的生理系统中的转运机制的极好模型系统。了解FF中HDL的修饰如何使其功能失调，将更深入地了解HDL在人类卵母细胞和胚胎发育潜力中的作用。 公共卫生相关性：本研究提案中详细介绍的工作重点是更好地定义人类卵泡在HDL颗粒代谢方面的生理学，这可能会影响人类卵母细胞和胚胎的发育潜力。考虑到生育选择的社会困境与先进的产妇年龄导致不孕症的条件，以及越来越多的证据表明，环境暴露影响生殖生理学的各个方面，它是必要的，以发展一个更好的理解的作用，高密度脂蛋白在人类卵泡和卵母细胞的健康。

DESCRIPTION (provided by applicant): There is evidence that high density lipoprotein particles within the ovarian follicle play a role in female reproductive potential. Follicular fluid (FF) is a biological window which can reveal the metabolic processes occurring in the microenvironment of the maturing oocyte. Identification of HDL biomarkers in FF that predict early embryo development outcome parameters would enable a greater understanding of the factors that regulate oocyte competence during in vitro fertilization (IVF). This gain of knowledge would allow for further research development in the understanding of the genetic and environmental regulation of oocyte development within the human follicle. High density lipoprotein (HDL) is the sole lipoprotein present in FF. The cholesterol transport, anti-oxidant and anti-inflammatory activities of HDL are a function of the dynamic HDL particle size distributions and the complex HDL composition which includes lipids, apolipoproteins, micronutrients and enzymes. In pilot studies, we have established that HDL cholesterol and apolipoprotein AI (Apo-AI) concentrations, reflecting total HDL concentration within FF, are significant negative predictors of detrimental embryo fragmentation during IVF. Furthermore, we have established that serum and FF HDL phospholipid: cholesterol molar ratios (reflecting HDL particle size and subclass distribution) are positively correlated with embryo fragmentation. We have also directly demonstrated by NMR spectrometry and HDL subclass isolation and analysis that FF-HDL particles have an altered size distribution and lipid composition relative to serum. The presence of HDL-associated human serum paraoxonase 1 (PON1) activities in FF has also been originally described. A prospective cohort of 180 women undergoing IVF will be recruited. Follicular fluid, granulosa cells and peripheral blood will be collected during IVF treatment. Serum and FF-HDL particle size will be determined by NMR spectrometry and HDL subclass (HDL2 and HDL3) will be isolated and their associated lipid, apolipoprotein, fat-soluble micronutrient compositions, and PON1 activities will be assessed. All measurements will be correlated with embryo morphology parameters (surrogate markers of oocyte integrity). Normalization of HDL subclass components per HDL2 or HDL3 particle will be used to characterize the unique particle composition of FF-HDL relative to serum HDL and identify the specific differences which may account for our pilot observations with regard to embryo quality parameters. We will also examine the lipoprotein signaling and cholesterol metabolism-related gene expression from GCs obtained from embryos with/without fragmentation to identify differences in cholesterol metabolism genes. Aside from its importance as a window into the metabolic state of the human ovarian follicle, FF represents an excellent model system for studying HDL-mediated cholesterol metabolism and transport mechanisms in a physiologic system devoid of other lipoproteins. Understanding how modifications of HDL within FF render it dysfunctional would add greater depth of understanding to the role of HDL in the developmental potential of the human oocyte and embryo. PUBLIC HEALTH RELEVANCE: The work detailed in this study proposal focuses on better defining the physiology of the human ovarian follicle with respect to HDL particle metabolism that may influence the developmental potential of the human oocyte and embryo. Given the societal dilemma of reproductive choice with advanced maternal age resulting in the infertile condition together with the increasing evidence that environmental exposures influence various aspects of reproductive physiology, it is imperative to develop a greater understanding of the role that HDL plays in the health of the human ovarian follicle and the oocyte within.