Department of Paediatrics, Centre for Liver, Digestive, and Metabolic Diseases, University of Groningen, University Medical Centre Groningen, 9713 GZ, Groningen, The Netherlands.
Department of Obstetrics and Gynaecology, Section Reproductive Medicine, University of Groningen, University Medical Centre Groningen, 9713 GZ, Groningen, The Netherlands.
Sci Rep. 2019 Sep 6;9(1):12817. doi: 10.1038/s41598-019-49091-3.
High density lipoproteins (HDL) are the main cholesterol carriers in follicular fluid (FF), the natural environment of oocyte development. Additionally, HDL have critical biological functions such as anti-oxidative capacity, which have not been studied in reproduction. Therefore, this study aimed to investigate whether the anti-oxidative function of FF-HDL is associated with fertility outcomes. From 253 women undergoing modified natural cycle (MNC)- IVF at a single academic centre FF and plasma were collected (n = 375 cycles). Anti-oxidative function of FF was mainly attributable to HDL (n = 8; 83%). FF-HDL had a higher anti-oxidative function than plasma HDL (n = 19, P < 0.001) coinciding with increased vitamin E and sphingosine 1 phosphate content (P = 0.028 each). Proteomic analysis indicated no significant differences in major anti-oxidative proteins such as paraoxonase 1, apolipoprotein (apo) A-I or apoA-IV between FF-HDL and matched plasma-HDL (n = 5), while apoC-III, apoE and apoC-II were relatively lower in FF-HDL. Finally, FF-HDL anti-oxidative function was related to a decrease in the odds of the oocyte undergoing normal fertilization, an association that persisted after adjustment for confounders (odds ratio 0.97 (0.93-1), P = 0.041). In conclusion, FF-HDL has considerable anti-oxidative properties that might be relevant for embryo quality.
高密度脂蛋白（HDL）是卵泡液（FF）中胆固醇的主要载体，FF 是卵母细胞发育的天然环境。此外，HDL 具有重要的生物学功能，如抗氧化能力，而这些在生殖领域尚未得到研究。因此，本研究旨在探讨 FF-HDL 的抗氧化功能是否与生育结局相关。
在一家学术中心，对 253 名接受改良自然周期（MNC）-IVF 的女性进行了研究，共收集了 375 个周期的 FF 和血浆。FF 的抗氧化功能主要归因于 HDL（n=8；83%）。FF-HDL 的抗氧化功能高于血浆 HDL（n=19，P<0.001），同时维生素 E 和神经鞘氨醇 1 磷酸的含量也增加（P=0.028）。
蛋白质组学分析表明，FF-HDL 与匹配的血浆-HDL 之间主要抗氧化蛋白如对氧磷酶 1、载脂蛋白（apo）A-I 或 apoA-IV 无显著差异（n=5），而 apoC-III、apoE 和 apoC-II 在 FF-HDL 中相对较低。最后，FF-HDL 的抗氧化功能与卵母细胞正常受精的几率降低相关，这种关联在调整混杂因素后仍然存在（比值比 0.97（0.93-1），P=0.041）。
总之，FF-HDL 具有相当大的抗氧化特性，这可能与胚胎质量有关。
