Research question

Granulosa cells (GCs) surrounding oocytes are crucial for follicular growth, oocyte development, ovulation, and luteinization under the dynamic co-stimulation of follicle stimulating hormone (FSH) and luteinizing hormone (LH). This study aimed to investigate the effect of LH levels on GCs in preovulatory follicles under gonadotropin releasing hormone antagonist-based ovarian stimulation. In vitro experiments were also conducted to study the direct effect of LH on GCs.

Methods

Twelve infertile women were divided into low (L), medium (M), and high (H) LH groups according to their serum LH levels during ovarian stimulation. RNA-sequencing (RNA-seq) was conducted to examine the transcriptome profiles of GCs obtained from the above patients during the oocyte retrieval. The activity of mitochondrial dehydrogenase was measured under the stimulation of recombinant LH (rLH) concentration gradient combined with recombinant FSH. The ultrastructures of subcellular organelles were observed.

Results

Bioinformatic analyses showed that compared with the M group, molecule and pathway changes in the L group and in the H group were similar. In cultured GCs, both insufficient and excessive rLH impaired the activity of mitochondrial dehydrogenase. With the medium rLH concentration, numerous cell connections and abundant mitochondria and liposomes were observed. Compared with the medium concentration, GCs showed smaller and rounder mitochondria, more autophagosomes, and massive organelles damages with excessive rLH, and swollen, circular, or forked mitochondria were observed with inadequate rLH.

Conclusions

RNA-seq provided a novel spectrum of transcriptome characteristics of GCs potentially affected by serum LH levels during ovarian stimulation. In vitro, rLH could directly affect GCs at the subcellular level.

中文翻译：

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促黄体激素浓度对卵巢颗粒细胞转录组和亚细胞器表型的影响

研究问题

在促卵泡激素 (FSH) 和促黄体生成素 (LH) 的动态共刺激下，卵母细胞周围的颗粒细胞 (GC) 对卵泡生长、卵母细胞发育、排卵和黄体化至关重要。本研究旨在探讨促性腺激素释放激素拮抗剂促排卵下 LH 水平对排卵前卵泡 GC 的影响。还进行了体外实验以研究 LH 对 GC 的直接影响。

方法

12 名不孕妇女根据促排卵期间血清 LH 水平分为低 (L)、中 (M) 和高 (H) LH 组。进行 RNA 测序 (RNA-seq) 以检查在取卵期间从上述患者获得的 GC 的转录组谱。在重组LH（rLH）浓度梯度联合重组FSH的刺激下测定线粒体脱氢酶的活性。观察亚细胞器的超微结构。

结果

生物信息学分析表明，与M组相比，L组和H组的分子和通路变化相似。在培养的 GCs 中，rLH 不足和过量都会损害线粒体脱氢酶的活性。在中等 rLH 浓度下，观察到大量细胞连接和丰富的线粒体和脂质体。与中等浓度相比，rLH过多时，GCs线粒体更小更圆，自噬体更多，细胞器损伤大，rLH不足时线粒体肿胀、圆形或叉形。

结论

RNA-seq 提供了一个新的 GCs 转录组特征谱，在卵巢刺激期间可能受血清 LH 水平的影响。在体外，rLH 可以直接影响亚细胞水平的 GC。