Center of Reproduction and Genetics, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Suzhou 215002, China.
Laboratory for Reproductive Immunology, Hospital of Obstetrics and Gynecology, Shanghai Medical School, Fudan University, Shanghai 200080, China.
Biomolecules. 2022 Jan 29;12(2):231. doi: 10.3390/biom12020231.
The follicular microenvironment, including intra-follicular granulosa cells (GCs), is responsible for oocyte maturation and subsequent ovulation. However, the functions of GCs and cellular components of the follicular microenvironment in preovulatory follicles have not been extensively explored. Here, we surveyed the single-cell transcriptome of the follicular microenvironment around MII oocytes in six human preovulatory follicles in in vitro fertilization. There were six different cell types in the preovulatory follicles, including GCs and various immune cells. In GCs, we identified nine different functional clusters with different functional transcriptomic profiles, including specific clusters involved in inflammatory responses and adhesive function. Follicular macrophages are involved in immune responses, extracellular matrix remoulding and assist GCs in promoting the oocyte meiotic resumption. Interestingly, we observed that the specific terminal state subcluster of GCs with high levels of adhesive-related molecules should result in macrophage recruitment and residence, further contributing to an obvious heterogeneity of the immune cell proportion in preovulatory follicles from different patients. Our results provide a comprehensive understanding of the transcriptomic landscape of the preovulatory follicular microenvironment at the single-cell level. It provides valuable insights into understanding the regulation of the oocyte maturation and ovulation process, offering potential clues for the diagnosis and treatment of oocyte-maturation-related and ovulation-related diseases.
卵泡微环境，包括卵泡内颗粒细胞（GCs），负责卵母细胞成熟和随后的排卵。然而，GCs 的功能和卵泡微环境的细胞成分在排卵前卵泡中的作用尚未得到广泛研究。在这里，我们调查了体外受精中六个人类排卵前卵泡中围绕 MII 卵母细胞的卵泡微环境的单细胞转录组。排卵前卵泡中有六种不同的细胞类型，包括 GCs 和各种免疫细胞。在 GCs 中，我们鉴定了九个不同的功能簇，具有不同的功能转录组谱，包括参与炎症反应和黏附功能的特定簇。卵泡巨噬细胞参与免疫反应、细胞外基质重塑，并协助 GCs 促进卵母细胞减数分裂恢复。有趣的是，我们观察到具有高水平黏附相关分子的 GCs 的特定终末状态亚簇应该导致巨噬细胞募集和居留，进一步导致来自不同患者的排卵前卵泡中免疫细胞比例的明显异质性。我们的研究结果提供了在单细胞水平上对排卵前卵泡微环境转录组景观的全面了解。它为理解卵母细胞成熟和排卵过程的调控提供了有价值的见解，并为卵母细胞成熟相关和排卵相关疾病的诊断和治疗提供了潜在线索。
