卵泡液来源肽PDFF1在促卵丘扩张及改善IVM卵母细胞发育潜能中的作用机制研究

PDFF1 is an endogenous secretory peptide which is identified by peptidomic techniques in human mature follicular fluid. There are no function reports about it until now and its sequence is highly conserved. The preliminary study showed that PDFF1 could promote cumulus expansion of mouse cumulus-oocyte complexs, increase the rate of oocyte maturation and improve the developmental competence of the oocytes. The results of the pull-down experiment indicated that PDFF1 could combine with p38MAPK and increase phosphorylation level of p38MAPK in cumulus cells, which is associated with cumulus expansion and developmental competence of oocytes. However, PPM1A, which was the precursor protein of PDFF1, played the opposite function to PDFF1.Our study showed that PDFF1 might interact with p38MAPK and then suppress the dephosphorylation role of PPM1A, activate p38MAPK-induced signal pathway in cumulus cells. To explore the functions and mechanism of PDFF1 involved in promoting cumulus expansion and increasing the developmental competence of oocytes, we used the overexpression and silence strategy combined with rescue experiments. These studies may provide new candidate molecules for improving human IVM media and increasing the clinical IVM success rates.

PDFF1是我们借助多肽组学从人成熟卵泡液中鉴定的功能未知、序列高度保守的分泌型多肽。前期发现，PDFF1可促进小鼠GV-COCs卵丘细胞扩张，提高卵母细胞成熟率和改善卵母细胞发育潜能；Pull-down实验发现PDFF1可能与p38MAPK结合，能够提高卵丘细胞中p38MAPK的磷酸化水平。由于卵丘细胞中p38MAPK磷酸化水平与卵丘细胞扩张及卵母细胞发育潜能相关，而PDFF1的前体蛋白PPM1A能够导致p38MAPK去磷酸化，其功能与PDFF1相反，提示PDFF1可能与p38MAPK结合，抑制PPM1A对p38MAPK的去磷酸化作用，从而激活p38MAPK信号通路发挥其生物学功能。本研究拟应用过表达、沉默策略结合挽救实验及胚胎安全性评估，全面深入探讨PDFF1在促卵丘扩张、改善卵母细胞发育潜能中的作用机制。研究可为改进人IVM培养基提供新的候选分子，有助于提高临床IVM成功率。

从卵丘卵母细胞复合体（COCs）中获取的未成熟应通过体外成熟（IVM）获得成熟卵母细胞。然而IVM的效率并不令人满意。卵巢卵泡液（FF）在卵母细胞的发育和成熟中起着关键作用。我们用LC-MS/MS研究了人成熟和未成熟FF的肽谱。差异表达分析和卵母细胞培养证实，C3a肽通过与C3a受体C3aR协同作用，可以提高MII期卵母细胞的百分比，而不会增加染色体非整倍体比率，尤其是对于质量较差的卵母细胞。我们的研究结果首次表明C3aR定位于纺锤体，通过特异性结合MYO10，涉及F-actin向纺锤体和卵母细胞皮层下区域的募集。我们的结果为通过应用FF成分改善IVM培养系统打开了一个新的视角，并为C3a肽的生理功能、其与C3aR的相互作用及其在卵母细胞减数分裂中的作用提供了分子见解。